http://www.nasa.gov/centers/kennedy/news/releases/2004/59-04.html on August 3rd 2004, http://www.nasa.gov/mission_pages/messenger/main/index.html will become the first spacecraft to orbit http://en.wikipedia.org/wiki/Mercury_(planet).
News and updates are availbale via Johns Hopkins University MESSENGER http://messenger.jhuapl.edu/index.html and the Kennedy Space Center's MESSENGER http://www.ksc.nasa.gov/elvnew/messenger/index.htm.
There will be an earth flyby in August followed by a couple of swings by Venus and three velocity scrubbing passages past mecury before the craft enters orbit in March 2011.
April 18, 2005 http://messenger.jhuapl.edu/news_room/status_report_04_18_05.html from JHU. Extensive JHU FAQs page http://messenger.jhuapl.edu/faq/index.html.
Mariner 10 Photographed 45% of Mercury, or almost half. But only basically one illumination condition was covered - due to orbital mechanics, the same side was illuminated on all three flybys. And the views of many areas were very forshortened on the limb.
MESSENGER = strained acronym. It's even worse than Hipparcos.
Uh... doesn't Messenger have a laser altimiter?... that measures reflectance, as well as delay-time which equals range...
I'd have to check, but I thought it did...
I'm reminded of the darkside images taken of the Moon by Clementine - I wonder how well Venus will illuminate the shadowed parts of Mercury (obviously, at the right time of the Mercurian year it'll be *much* brighter).
Darn - I hadn't thought of that, and it's probably pretty obvious! Not only will libration effects be pretty minimal (unlike the Earth-Moon situation, where something interesting might be a goer), but as Venus and Mercury are probably in all sorts of orbital resonances there's likely to be only a few chances to view the same areas, badly illuminated at best. Oh, well, back to the drawing board.
OK, what about the Zodiacal Light...
Reflections from Comets...
Starlight...
Is Mercury atmosphere similar to Moon rather than Mars? What are the composition of Mercury's atmosphere (helllium, hydrogen, oxigen, potassium and sodium)? Wiill the Messengare space answer these questions?
Earth from MESSENGER at 29.6 million km
http://messenger.jhuapl.edu/news_room/press_release_5_31_05.html
"NASA’s Mercury-bound MESSENGER spacecraft – less than three months from an Earth flyby that will slingshot it toward the inner solar system – successfully tested its main camera by snapping distant approach shots of Earth and the Moon."
No focusing problems on this baby!
I always enjoy these far off shots of Earth. They really drive home how BIG space is and how SMALL our home is...
Anybody seen a higher rez version?
Bruce:
Can Messenger's instruments detect He on the surface of Mercury? I'm thinking of those old lunar He3 strip-mining plans...
Bob Shaw
Buck Galaxy said:
Huh? I thought the moon's regolith was full of He3?
No - it has minute amounts of He3. Major strip-mining would be needed to collect the amounts needed for the proposed power schemes.
Phil
Specifically, it's about one part He-3 per 100 million -- which gives you a better idea of the serious problems with mining the Moon for He-3 even if we finally do figure out how to fuse the stuff commercially (which we are absolutely nowhere near right now).
Mining the moon for He3 would, of course, give us access to all sorts of other things in the process - not least being meteorites from Earth, Mars, Venus and so on. Possibly even fossils from a certain nearby life-bearing planet (our own!).
So there will not be another image of Earth for how long?
Why don't they snap a picture at least once a week?
Because Messenger is usually too close to Earth to see it as more than a speck -- only during its close flybys of Earth will its camera be able to see Earth clearly. (I believe there is only one more Earth flyby planned before it moves on to using repeated flybys first of Venus and then of Mercury itself to finally put itself into an orbit almost parallel to Mercury, thus allowing it to use an acceptably small amount of fuel to finally brake into orbit around Mercury itself. The Europa Orbiter -- when they finally fly it -- will, after it enters orbit around Jupiter, use repeated flybys of Callisto, Ganymede, and finally Europa itself to match orbits in a similar way with Europa before braking into orbit around Europa.)
"Because Messenger is usually too close to Earth to see it as more than a speck..."
Gaaah. I'm going senile. Make that "too FAR FROM Earth to see it as more than a speck".
Yes indeedy. Quite a bit (even including using Messenger's laser altimeter to map Venusian cloud top altitudes). The question is whether it will do much of note that Venus Express won't (hopefully) already have done.
Galileo and NEAR both did it - producing movies of the flybys by the time they'd finished
Doug
They did it....BUT WHERE ARE THE IMAGES OR MOVIES???
There are only few images...here and there.
ERmmm..
NEAR - http://near.jhuapl.edu/Images/.Anim.html
specifically - http://near.jhuapl.edu/Voyage/img/earth_swby_lg.mpg
Galileo
http://galileo.jpl.nasa.gov/gallery/earthmoon-all.cfm
Took 60 seconds to find them
Doug
And if you want thousands of PDS-formatted Galileo images of the Earth there's always this:
http://pds-imaging.jpl.nasa.gov/cgi-bin/Nav/GLL_search.pl
http://messenger.jhuapl.edu/news_room/press_release_8_02_05.html
NASA’s MESSENGER spacecraft, headed toward the first study of Mercury from orbit, swung by its home planet today for a gravity assist that propelled it deeper into the inner solar system.
Mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md, say MESSENGER’s systems performed flawlessly as the spacecraft swooped around Earth, coming to a closest approach point of about 1,458 miles (2,347 kilometers) over central Mongolia at 3:13 p.m. EDT. The spacecraft used the tug of Earth’s gravity to change its trajectory significantly, bringing its average orbit distance nearly 18 million miles closer to the Sun and sending it toward Venus for another gravity-assist flyby next year.
waitng for the movie...
The picture reported in the Messenger site, taken with a telescope from Earth, show some darkening in the central part... look to this enhanced version:
Either reorientation or its in a constant slow rotation.
Just noticed this: http://planetary.org/news/2005/messenger_flyby_movie_0826.html
The movie of the rotating Earth receding in the distance is beautiful. It appears the dark, non-reflective area (i.e. dry land) going into darkness between 07:00-09:00UT is the north coast of Australia. Then near the end of the clip the deserts of the Arabian Peninsula and North Africa are visible through the clouds.
Oh that is just spec-freakin'-tacular! So smooth animation too! Wish there were a higer resolution version though.
We do have one hell of a beautiful planet.
Anyone know of rotation movies of other planets?
Hmmm...I wonder if they have done any ridiculously high resolution IMAX movies using full resolution shots of these rotations...
If and when the Messenger data is on the PDS - I'll work it into a WMVHD movie if appropriate. I've been playing with MER imagery at 720p25 format, and it looks fab
Doug
The MESSENGER team has posted a http://messenger.jhuapl.edu/the_mission/flyby_movie.html composed of 358 images they took during their craft's recent flyby showing the spinning Earth during one complete rotation disappearing into the void.
======
Stephen
That movie is one of the most spectacular things I've ever witness...I love the sun's reflection off the ocean and land masses.
To loosely quote "Pale Blue Dot"..."Everyone who has ever lived or died, been written about...was right there" One fragile planet spinning in dark emptiness.
Eric P / MizarKey
It is; it's a lovely piece of work.
That little movie captures the reality of what science fiction films have been speculatively presenting for more than a half a century.
Seeing the real thing at last, in such high definition realism, is immensely moving for me.
-the other Doug
Correct me if I'm wrong - but Messenger's imager is a 1024 x 1024 instrument isnt it? - I wonder/hope if they captured that data at full res, or downsampled it to 512 x 512. If they DID do it full res, I promise - hand on heart - to make a full resolution version when the data is released.
Doug
I was looking at the chart below. I noticed that beginning in October of next year, this mission should start getting interesting. Given the quality of the earth imagery, I am really excited about what we might see. I also wonder what if any science will be done at Venus.
Quite a bit -- they even intend to use the laser altimeter to measure Venusian cloud top altitudes.
Several years ago, Sean Solomon told me a fair amount about it -- but I'm not sure whether that's among the hundreds of stored E-mails that I later lost in an Outlook Express breakdown. I'll check when I get the chance. Suffice it to say that they plan to use virtually every Messenger instrument that CAN be used at Venus.
I know you can get them from Earth, I meant pictures taken by a spacecraft.
The only problem with the timeline is that at orbital insertion, I will be as old and onry as Bruce
From the http://messenger.jhuapl.edu/faq/faq_journey.html#4:
"The only problem with the timeline is that at orbital insertion, I will be as old and ornery as Bruce."
No you won't. By then, I will be significantly older and much more ornery.
You don't need to be old to be ornery (though it helps). I'd say the orneriest person I ever met was Harlan Ellison, back in the late '70s when he was a rather young man. He was ornerier then than most people get to be in their advanced years...
-the other Doug
Let me add to my reputation for orneriness: if you ever see him again, tell him to get off his damned duff and either publish "The Last Dangerous Visions" or at least release the stories he acquired for it from now-dead authors. The very last stories by Edgar Pangborn and Tom Reamy have now been moldering in a box in his office for three straight decades, and I wouldn't be surprised if there aren't a few more stories there by authors who have since gone to their reward.
Harlan Ellison: "The Mouth that Walks like a Man"
Being near Harlan is like the Ancient Chinese Curse: May You Live in Interesting Times.
Some of the LDV stories have been released and published, including a postumous collaboration between Cordwainer Smith and his wife, I believe.
As I noted in the "Future Venus Missions" thread below, we now have a very detailed description of the science measurements that Messenger will make during its second Venus flyby in June 2007. (It won't make any during its first one because it's near solar conjunction.)
http://www.lpi.usra.edu/vexag/Nov2005/MESSENGER_VEXAG.pdf
Projected arrival data at Mercury for Bepi Colombo, by the way, is now 2017.
Messenger Status Report :
MESSENGER Team Prepares for December Deep Space Maneuver (DSM-1), when the craft’s large bipropellant thruster will be fired for the first time.
http://messenger.jhuapl.edu/news_room/status_report_11_11_05.html
Rakhir
I saw that Messenger is currently closer to the Sun than Venus is. This is not unexpected, but I thought it was an interesting milestone.
This is the very last component of Messenger that hasn't already been tried out. (Andy Dantzler said at the COMPLEX meeting that the craft has had a few software hiccups, but no hardware problems whatsoever so far.)
Well, it *may* not happen in the lifetimes of the average members of this forum. But that all depends on the state of advancement of propulsion technology. I've seen some articles on plasma drive concepts that are being championed by, among others, Franklin Chang-Diaz, that could dramatically increase the amount of delta-V capacity a spaceship can drag along with it.
If we can develop bigger, better propulsion systems in the next 20 or 30 years, things that can give you constant acceleration for most of your flight (and not at measely 1/100th G levels, either), then you can tool around the Solar System in months when you used to need to spend years. Months or years when you used to need decades.
It's not like we will *always* be limited to push-real-hard-then-coast-for-years technologies. At least, I'm sincerely hoping not.
-the other Doug
I was hoping that since Messenger was launched on a mid size rocket, and that a large part of the delta vee is from the grav. assists at earth Venus, and Mercury, a big Titan IV (or whatever the big launcher is now) could send a useful vehicle on a two way trip. The 'smash and grab' idea for a sample return I saw here is just starting to seem a little more doable, perhaps . . . .
Amazing to be looking at these (formerly) exotic trajectories, from Mercury sample returns to Pluto landers, it just keeps getting better all the time.
Actually, it might be doable with a smaller booster. The question is how fast a flyby speed at Mercury you're willing to put up with during the sampling. Messenger will make multiple gravity-assist flybys of Mercury to slow itself down in order to minimize the fuel it has to burn at Mercury Orbit Insertion, but that problem doesn't apply to a nonstop smash-and-grab sampling flyby. The question is the speed at which the collected particles can plow through the aerogel before the frictional heat ruins them for scientific analysis.
But if you are willing to make that sampling run during your first flyby of Mercury, then making your way back to Earth via Venus gravity-asssist flybys becomes much easier and shorter.
http://www.space.com/astronotes/astronotes.html : Messenger fired its big engine successfully for almost 9 minutes on Dec. 12 -- the last component of the craft that hadn't been operated until then. So everything works (except for occasional software collywobbles). Now if everything will just continue working...
A thought from someone on another space list:
Will MESSENGER and Venus Express conduct any joint studies on Venus like Galileo and Cassini did with Jupiter in 2000? And if they can and do, what could they do together that they could not do alone?
It might be possible during the June 2007 flyby; however, MESSENGER won't be collecting science data during the October 2006 flyby (due to solar conjunction), so that opportunity is out.
MESSENGER Mission News
February 23, 2006
http://messenger.jhuapl.edu/
--------------------------------------------------------------------------------
MESSENGER Lines Up for Venus Flyby
MESSENGER trajectory correction maneuver 10 (TCM 10) lasted just over two minutes and adjusted its velocity by about 1.4 meters per second (4.6 feet per second). The short-duration maneuver yesterday placed the spacecraft on track for its next major mission event: the first Venus flyby on October 24, 2006.
Having completed six successful small TCMs that utilized all 17 of the spacecraft’s thrusters, this latest maneuver was the first to rely on the four B-side thrusters. During this maneuver, the thrusters on the opposite side of the spacecraft reduced a build-up of angular momentum due to an unseen force that causes the spacecraft to rotate if left uncorrected. This maneuver was only the seventh actual TCM for MESSENGER; the spacecraft’s trajectory was so close to optimal after TCM 3 and TCM 6 that planned TCMs 4, 7 and 8 weren't necessary.)
The maneuver started at 11 a.m. EST; mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, verified the start of the maneuver within 11 minutes and 48 seconds, when the first signals indicating spacecraft thruster activity reached NASA's Deep Space Network tracking station outside Goldstone, Calif.
At the start of the maneuver, the spacecraft was 132 million miles (212 million kilometers) from Earth and 83 million miles (133 million kilometers) from the Sun, speeding around the Sun at 68,163 miles (109,698 kilometers) per hour.
For graphics of MESSENGER's orientation during the maneuver, visit the “Trajectory Correction Maneuvers” section at http://messenger.jhuapl.edu/the_mission/mission_design.html.
--------------------------------------------------------------------------------
Earth Flyby Image Gallery Now Online
MESSENGER’s Mercury Dual Imaging System (MDIS) acquired spectacular images during the Earth flyby in August 2005, including a "film" of our home planet as it receded in the distance. Now, you can browse through the best of the MDIS flyby frames on the MESSENGER Web site!
Visit the MDIS Earth Flyby gallery at http://cps.earth.northwestern.edu/MESSENGER_20050802/.
Flyby images are beautiful, thanks Alex.
Starting from one eof these pictures and using also the famous MRO moon image, I made these mosaics... is only a "petit divertissment", first one should be geometrically more correct, while second one is a tribute...
http://messenger.jhuapl.edu/news_room/status_report_03_24_06.html
MESSENGER Status Report
March 24, 2006
Messenger is now further from the Sun than the Earth is. It will stay that way for several weeks, and then never again will it be that far from the Sun.
A new update news from Messenger status:
Mercury Messenger Probe Flips Sunshade Towards The Sun
http://www.spacedaily.com/reports/Mercury_Messenger_Probe_Flips_Sunshade_Towards_The_Sun.html
The Messenger spacecraft performed its final "flip" maneuver for the mission on June 21. Responding to commands sent from the Messenger Mission Operations Center at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., through NASA's Deep Space Network antenna station near Goldstone, Calif., the spacecraft rotated 180 degrees, pointing its sunshade toward the Sun.
Rodolfo
If this has been mentioned already, pardon the repeat, but for those who do not have access to some of those hard-to-obtain journals, I just noticed the http://messenger.jhuapl.edu/the_mission/publications.html now has links to several of the references.
MESSENGER Mission News
August 3, 2006
http://messenger.jhuapl.edu/
________________________________________________________
Happy Anniversary, MESSENGER!
Today marks the second anniversary of MESSENGER’s launch. “It’s still more than four and a half years to Mercury Orbit Insertion in March 2011, and there are many milestones between now and then,” says Dr. Sean C. Solomon, of the Carnegie Institution of Washington, who leads the mission as principal investigator. “But it’s worth pausing for a few moments today to appreciate how far we’ve come.”
And just how far has the spacecraft traveled since its Aug. 3, 2004, launch from Cape Canaveral Air Force Station, Fla.? Slightly more than 1.275 astronomical units (1 AU is Earth’s distance from the Sun). MESSENGER’s computers have executed 180,271 commands since liftoff, a time interval that includes seven major trajectory correction maneuvers.
“It’s been a busy two years,” says MESSENGER Mission Operations Manager Mark Holdridge, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. “We’ve been by Earth and now we are headed for Venus, another major milestone in this mission.”
MESSENGER team members have been running tests all summer to make sure the spacecraft will operate as intended during the Venus flyby – the first of two swings past the clouded planet –scheduled for Oct. 24, 2006. There will be a 57-minute solar eclipse during that operation. So on Aug. 11, engineers will turn the spacecraft solar panels edge-on to the Sun and discharge the battery, much in the same manner that the power system will function during the Venus flyby, to verify that the system will respond appropriately.
Two weeks later, on Aug. 21, engineers will conduct a “star-poor” region test, pointing the spacecraft’s star tracker in a region of the sky that might be utilized during the Venus operations Holdridge says a similar test was conducted on July 26, “and we got a positive result from that test; the preliminary results look good.”
All in all, Holdridge says, all systems are functioning very well. “The spacecraft is very healthy, and the team is working hard to make this first flyby of Venus a success!”
For encounter details and graphics associated with the October maneuver, go online to http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html
________________________________________________________
MESSENGER Engineer Named AIAA Engineer of the Year
APL’s T. Adrian Hill, the fault protection and autonomy lead for MESSENGER, was recently named Engineer of the Year by the Baltimore chapter of the American Institute of Aeronautics and Astronautics (AIAA). Each year, local AIAA chapters present this award to a member who has made significant contributions to the field of engineering. For more information, go online to http://www.jhuapl.edu/newscenter/pressreleases/2006/060623b.asp.
________________________________________________________
Where is Mercury?
Mercury's orbit is so close to the Sun that we can only see it from Earth either just before sunrise or just after sunset. For a diagram of the orbits of the inner planets, as they appear today, go online to http://btc.montana.edu/messenger/wheremerc/wheresmerc.php.
________________________________________________________
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.
MESSENGER Mission News
August 4, 2006
http://messenger.jhuapl.edu/
______________________________________________________________________________
CORRECTION
The August 3, 2006, MESSENGER Mission News incorrectly stated that the spacecraft had traveled “slightly more than 1.275 astronomical units” since its August 3, 2004, launch from Cape Canaveral Air Station, Fla. In fact, since lift off MESSENGER has traveled nearly 1.2 billion miles in its orbit around the Sun.
The spacecraft is currently 1.285 astronomical units (AU) distant from the Earth (1 AU equals 93 million miles). To track MESSENGER’s journey, go online to http://messenger.jhuapl.edu/whereis/index.php.
_______________________________________________________________________________
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.
http://messenger.jhuapl.edu/news_room/status_report_09_15_06.html
MESSENGER Mission News
September 15, 2006
A quick reminder : Messenger is only 13 days to Venus flyby.
http://messenger.jhuapl.edu/
Noteworthy. Too bad there will not be science observations on this flyby due to conjunction.
IIRC the trajectory of this flyby wasn't very interesting for science returns anyway. Though maybe they could try to image that http://www.unmannedspaceflight.com/index.php?s=&showtopic=3232&view=findpost&p=69368
This view hardly qualifies as uninteresting: http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=299&vbody=-236&month=10&day=24&year=2006&hour=07&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1
Hmmm. I'll have to find out where I read what I read...
From what I've seen playing around in the Simulator the past few minutes, it's a very low phase inbound and very high phase outbound encounter. Maybe not very photogenic for global imaging as you'd prefer moderate phase angles (at least I do), but in terms of cloud observation tracking and similar stuff it could have been pretty nice.
That rings a bell, but I haven't been able to Google up anything to support what I recalled. Chalk it up to my http://www.unmannedspaceflight.com/index.php?s=&showtopic=1705&view=findpost&p=46514 syndrome...
You have a typo in the URL there - it should be:
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html
Don't forget the animation for the third Mercury flyby on 30 Sep 2009.
The top right panel on the link for the first Venus flyby clearly states, when you enlarge it, that the spacecraft will be out of communication with earth due to the proximity of the sun in the line of sight.
Things will be better on the second flyby, and you'd think that they should be able to come up with some kind of coordinated activity with Venus Express. After all, two capable spacecraft observing the same object from different vantage points ...
Mercury and Venus are in inferior conjunction when they are more or less between the earth and sun. They are in superior conjuction (as Venus is now) when they are pretty much behind the sun as seen from earth. Mars is simply in "conjunction" in this situation, because its conjuctions can only be superior. Mars and other outer planets are in opposition when they transit near midnight, being more or less overhead then.
Tomorrow between 4-5 am, Messenger will be flying-by over Venus. I am still unclear about the Messenger path after seeing the flyby movies and pictures of Venus 1st Flyby. The pictures show that Messenger is coming from South Pole at about an angle of 60 degree to equotorial line. See the following picture:
The Meessenger approach to Venus side by side and it does not coincide with the above picture which shows that Messenger approach in about 85 degrees from the Sun to Venus.
http://messenger.jhuapl.edu/the_mission/movies.html
According to the picture which shows Earth, Venus and Mercury orbit around the Sun from the top view.
I am still puzzled that Messenger will approach to Venus from Sun and not by side by side toward with the same orbit direction as Venus.
Rodolfo
Well, the two diagrams do match up. The tick marks are a little more compressed looking in from the sun, but if you carefully trace by the intervals, you'll see in both cases that as viewed from Venus the spacecraft moves in from the sun moving westward and northward, before being flung back south. It still continues west on its departure.
It's necessary to pursue this path, flung backwards from the normal counterclockwise motion of the planets as viewed from north, in order to lose energy relative to the sun, and adjust the orbit inward toward Mercury. It is also necessary to go to high latitudes on Venus in order to adjust to the plane of Mercury's orbit.
2006-10-23 02:21:05 UTC — 1000000 km
2006-10-23 05:24:28 UTC — 900000 km
2006-10-23 08:27:49 UTC — 800000 km
2006-10-23 11:31:05 UTC — 700000 km
2006-10-23 14:34:15 UTC — 600000 km
2006-10-23 17:37:14 UTC — 500000 km
2006-10-23 20:39:59 UTC — 400000 km
2006-10-23 23:42:21 UTC — 300000 km
2006-10-24 02:44:00 UTC — 200000 km
2006-10-24 05:44:07 UTC — 100000 km
2006-10-24 06:01:58 UTC — 90000 km
2006-10-24 06:19:46 UTC — 80000 km
2006-10-24 06:37:31 UTC — 70000 km
2006-10-24 06:55:12 UTC — 60000 km
2006-10-24 07:12:50 UTC — 50000 km
2006-10-24 07:30:24 UTC — 40000 km
2006-10-24 07:47:58 UTC — 30000 km
2006-10-24 08:05:50 UTC — 20000 km
2006-10-24 08:27:26 UTC — 10000 km
2006-10-24 08:34:00 UTC — 9044 km (2992 km above surface)
Note: geometric range, not corrected for light-time
Yes, the emphasis on the second flyby would seem to be more toward reducing speed relative to the sun. The spacecraft will always be seen from the sun as moving eastward, giving a counterclockwise orbit as viewed from north to south. But Venus flinging it back will significantly reduce the spacecraft speed as seen from the sun (and microscopically increase the speed of Venus).
On the website space.jpl.nasa.gov you can see the approach (and departure) of Messenger in a broader scene up to a point. That point is 3:40 UTC on the 24th, with a sudden shift to a Venus centered approach line rather than sun centered for both planet and spacecraft. It will only show one snapshot at a given time at five minute intervals, but repeated entries will show the two closing in on each other.
Chose "MESSENGER" as seen from "above" with a selection of "60 degrees" field of view (make sure the field of view option is clicked) on this website and you'll see what I'm talking about.
Just about nine hours to go ...
By now, I haven't found any internet refresh news. Let suppose that the flyby have occured today at around 4:30 am at EDT time.
How was the Venus 1 fly-by?
Rodolfo
How could we possibly know? Venus, like Mars, is in conjunction. That is the reason there was no science planned for Messenger during this flyby - the spacecraft is totally out of touch.
Doug
Why no science?
Surely Messanger could be programmed for observations well in advance for the flyby - even if it was unable to transmit the results until sometime aftwards?
Would this not be at least an opportunity to test run some of the instruments ahead of the eventual rendezvous with Mercury?
There will be further chances to test the instruments out - but one could ask the same question of MGS, ODY and MRO at Mars during conjunction....why no science.
#1 reason - while you're out of touch you want the spacecraft to be as quiet as possible, so minimising the chance of anything going wrong and causing a safe event which may consume prop etc.
doug
Why no science?
The question has been asked many times. Simply put, if you can't communicate with the spacecraft and the encounter is not the main focus of the mission, you can't afford to conduct complex operations. If anything goes wrong and the spacecraft enters safe mode you can't go to work on it, and the potential for fatal errors is too high. And... there's a second chance to do some Venus science later.
Phil
But MRO IS making daily observations during the conjunction period.
Only a very limited ammount with two instruments in a steady orbit. To sequence fly-by observations is a much mroe involved and intensive operation. If Messenger does some Mag observations during this flyby, then that would be analogous to the MARCI/MCS obs of MRO during conjunction.
Doug
Bloody hell :
MESSENGER swung by Venus at 8:34 UTC (4:34 a.m. EDT), according to mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. About 18 minutes after the approach, an anticipated solar eclipse cut off communication between Earth and the spacecraft. Contact was reestablished at 14:15 UTC (10:15 a.m. EDT) through NASA's Deep Space Network, and the team is collecting data to assess MESSENGER's performance during the flyby.
...Doug, I assume "bloody hell" means "HELL yeah!" in American slang...I hope this is good news, although it seems a bit guarded...
I just saw something in the Florida Today "Flame Trench" blog that Messenger had an unexpected computer reset. I hope it's nothing serious.
Bloody hell! And that is NOT HELL yeah!
Update on the flyby: http://messenger.jhuapl.edu/news_room/status_report_10_24_06.html.
There's also an http://messenger.jhuapl.edu/the_mission/pictures/approach_venus.html of Venus taken by MDIS from 16.5 million km.
Rog on the "BH", Doug & Mchan...just didn't see any reference to the anomaly in Doug's post, so I got confused.
In fact, I can't find any mention of this on Google News or on the Messenger website, which is kind of worrisome. I hope this doesn't mean that anomaly recovery has been interrupted by superior conjunction. Anybody have an update?
There's something weird with the http://messenger.jhuapl.edu/whereis/index.php#view_earth page. Here are two screenshots of the same simulated time:
Seems OK to me. Looks just like parallax when you move towards mercury in the centre of your view.
How can you have parallax if your viewpoint (MESSENGER) is fixed?
hold a pencil in front of you and turn your head.
You do realize that by turning your head, you're shifting your eyes, do you? MESSENGER is a single, fixed point in the simulation. Only the look vector changes.
yes, but I think it's probably a very similar effect that comes out of the simulations. Not sure though, but it looks like it. Angles stay the same, but the projection doesn't, because you look in a different direction, so your plane of projection has a different angle. Will try to make a drawing.
Here's the drawing. green and red show two objects at different distances. lines show middle and edges of field-of-view. If you have a projection plane perpendicular to the middle line at a distance c, a will not equal b for the two cases. Not sure this is how exactly they made the plot though.
I'm not sure I get that plot, but I understand what you're saying about the distances. However, I'm talking about the angle between Earth-Sun-Mercury, see how it changes in the two instances. That does look like a bug. I have a fair amount of experience playing around in Celestia/Orbiter and never have I encountered such position shifts, even for large FOVs. To drive my point further, here are two plots from the Solar System Simulator:
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=399&vbody=-236&month=10&day=30&year=2006&hour=16&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=10&day=30&year=2006&hour=16&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1
If you disregard the rotation (the sim probably aligns to the target north axis), you can see how the angle stays the same and is consistent with the first screenshot I posted, viewing Earth. Earth stays on the same "side" of the Sun in both cases, as one would expect.
Having a fairly extensive experience playing around with 3D software and even writing a 3D renderer myself I cannot see how this could be anything but a bug. The views are supposed to show the Earth and Mercury as seen from Messenger at the same time and therefore the same location. The field of view is identical (or at least very nearly so), judging from Mercury's distance in pixels from the Sun. However, not only is the Earth's location relative to the Sun different in the two images, its 'distance' is also different and that difference is big. The field of view also isn't very wide (~30°) so distortion isn't significant.
Assuming the views generated by the http://space.jpl.nasa.gov/ are correct the view showing the Earth from Messenger is correct (or very nearly so) while the one showing Mercury is not.
ah, I think I know what you mean now. sorry, I misunderstood you - I looked at the sun and Mercury, not the angles between them all.
edit - what I think I was trying to say is that if you have a flat projection plane you might get things distorted, whereas you have a spherical projection plane the angles would always stay correct. I guess the same problems occur with e.g. a fisheye projection. angles of things relative to eachother may change depending on where you aim it. But if the fov is not very wide...
it has to be a bug.
There is no way that any projection can move objects around in respect to each other that way.
it looks to me as if these pictures are rendered with an equirectangular projection (ordinary 3d camera) and that the position of the camera has changed. Im 99.9% sure.
they probably have some strange offset. (like if you move out from an object in celestia and then turn the camera to look at something else)
The simulations look s bit substandard to me... not like something that you would expect from a project that cost millions and millions of dollars.
Had another think I see now I was just being plain stupid In my mind I had my projection plane some distance from the rotation point (Messenger), which would obviously give you a parallax. But maybe the programmer was similarly stupid Man, sometimes I wonder why i get up in the morning
On the date in question the spacecraft and Venus were some little distance apart. It looks to me like one simulation was viewed from Venus and one from Messenger, just a simple mistake in entering the viewpoint before doing the rendering.
Phil
Nope. Not even Venus as viewpoint brings Earth to the other side of the Sun. http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=399&vbody=299&month=10&day=30&year=2006&hour=16&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1.
MESSENGER Mission News
December 2, 2006
http://messenger.jhuapl.edu/news_room/status_report_12_02_06.html
IIRC, a similar change was made to the Voyager 1 (or was it 2?) flight plan post Jupiter.
It wound up saving some fuel as they were able to correct for some slight error sooner than had they waited for the error to have longer to operate.
I see Messenger has just started its fourth orbit. (Yes, I know it's a silly milsetone, but I like the graphs.)
http://messenger.jhuapl.edu/whereis/index.php#current_orbit
Given the shape of the orbit, that gravitational assist from Venus in June is going to be a whopper. I note also that we're within one year of the first Mercury flyby.
I was looking at the Messenger site, trying to figure out how many times Messenger will orbit Mercury before the first flyby, and I ended up constructing this table, which I thought I'd share:
Event SMA Period Orbits Date Total Orbits
Launch 1 365 1.00 8/3/2004
E1 0.809 266 1.69 8/2/2005 1.00
V1 0.724 225 1.00 10/24/2006 2.68
V2 0.539 145 1.55 6/5/2007 3.68
M1 0.507 132 2.01 1/14/2008 5.23
M2 0.466 116 3.09 10/5/2008 7.24
M3 0.435 105 5.10 9/29/2009 10.33
MOI 0.388 88 3/18/2011 15.43
(Hope that comes out looking right, given the tabs.)
First column is all the milestones in the mission. Second column is the semi-major axis of Messenger's orbit (in AU) AFTER each event. Third column is the period (in days) of that orbit. Fourth column is the number of orbits it makes before the next event. Fifth column is the date of each event. Last column is the total number of orbits before each event. (All these figures, except the orbit counts, come directly from the Messenger website.)
So, from this, I can see that Messenger will reach Mercury's orbit for the first time 145 days before the flyby -- on or around August 23 of this year.
That's a kind of cool milestone, I think. (Assuming I haven't messed up the figures somehow.)
--Greg
http://messenger.jhuapl.edu/news_room/status_report_02_05_07.html
MESSENGER Mission News
February 5, 2007
http://messenger.jhuapl.edu/news_room/status_report_02_20_07.html
MESSENGER Mission News
February 20, 2007
http://messenger.jhuapl.edu/news_room/status_report_03_19_07.html
MESSENGER Mission News
March 19, 2007
A new mission update. MESSENGER's Energetic Particle and Plasma Spectrometer (EPPS) has been fired back up, and both components are working nominally. Also, the team notes that yesterday (March 18) it was 4 years to the day for Mercury insertion.
http://messenger.jhuapl.edu/news_room/status_report_04_02_07.html
MESSENGER Mission News
April 2, 2007
Two-Fifths of the cruise duration is now behind us. A somewhat arbitrary landmark (spacemark?), but the MESSENGER team uses this as an opportunity to let us know what they are planning in June. Perhaps we'll get a nice combined NASA/ESA press release after the flyby? Time will tell.
"Planning is now underway to use the second Venus flyby on June 5 to complete final rehearsals for three Mercury flybys. Those flybys, assisted by four deep space maneuvers, will slow the spacecraft sufficiently for Mercury orbit injection on March 18, 2011.
The upcoming planetary encounter also offers a variety of opportunities for making new observations of Venus’ atmosphere and cloud structure, space environment, and, perhaps even the surface. All of the MESSENGER instruments will be trained on Venus during the encounter.
* The MDIS will image the night side in near-infrared bands, and color and higher-resolution monochrome mosaics will be made of both the approaching and departing hemispheres.
* The UltraViolet and Visible Spectrometer, part of the probe’s Mercury Atmospheric and Surface Composition Spectrometer (MASCS), will capture profiles of emissions from atmospheric species versus altitude on both the day and night sides as well as observations of the exospheric tail on departure.
* MASCS’s Visible and InfraRed Spectrograph will observe the planet near closest approach to assess the chemical composition of clouds. It may also detect near-infrared returns from the surface.
* The MESSENGER Laser Altimeter (MLA) will measure Venus’ brightness at 1064-nm by using its pulse return detector as a passive sensor. MLA will also pulse its laser in an attempt to measure the range to one or more cloud decks for several minutes near closest approach.
* The Magnetometer will characterize the magnetic structure of the Venus bow shock and draping of the interplanetary magnetic field over Venus’ ionosphere while the Energetic Particle and Plasma Spectrometer will observe charged particle acceleration and plasma flows associated with the bow shock.
The Venus Express mission of the European Space Agency is currently operating in an elliptical polar orbit about Venus, and MESSENGER’s June planetary encounter together with the ongoing observations by Venus Express will permit unique observations of the Venus-solar wind interaction. To understand fully how the solar wind plasma affects and controls the Venus ionosphere and nearby plasma dynamics, simultaneous measurements are needed of the interplanetary conditions and the particle-and-field environment at Venus. The combined MESSENGER and Venus Express observations will be the first opportunity to conduct such two-spacecraft measurements."
EDIT: Don Merritt over at VEX Science Operations states that http://www.unmannedspaceflight.com/index.php?showtopic=4011&st=15&p=87153&#entry87153 of the joint science will occur in mid-June. I'm looking forward to it.
http://messenger.jhuapl.edu/news_room/status_report_05_02_07.html
MESSENGER Mission News
May 2, 2007
MESSENGER completed a burn to set up the rapidly approaching second Venus flyby. Not everything is smooth sailing, however, as spacecraft "jitter" was detected during the burn, resulting in a slightly less than ideal trajectory. Scientists will analyze the attitude control system and tracking data to figure out the source of the problem, hopefully finding a solution before the May 25 trajectory correction maneuver that will put MESSENGER in the intended aim point of 337 kilometers above the surface of Venus.
Let's hope the engineers figure out the flutters in the spacecraft sooner than later.
http://messenger.jhuapl.edu/news_room/status_report_05_25_07.html
MESSENGER Mission News
May 25, 2007
The MESSENGER trajectory correction maneuver (TCM-16) completed on May 25 lasted 36 seconds and adjusted the spacecraft’s velocity by 0.212 meters per second (0.696 feet per second). The movement targeted the spacecraft close to the intended aim point 337 kilometers (209 miles) above the surface of Venus for the probe’s June 5 flyby of that planet.
The maneuver started at 12:00 p.m. EDT. Mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., verified the start of TCM-16 about 7 minutes later, when the first signals indicating thruster activity reached NASA’s Deep Space Network tracking station outside Madrid, Spain.
“Today’s operation completed just as planned,” says Mission Operations Manager Andy Calloway of APL. “All subsystems were nominal going into the maneuver, and the burn cutoff occurred right at the expected time. Now that TCM-16 is behind us, we are focused on loading the Venus flyby command load to the spacecraft next week.”
BTW, the Messenger site has a much improved interactive mission timeline well worth a look:
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/TimeLine_content.html
Looks like this coming January 14th we'll get to see unexplored territory not imaged by Mariner 10...go Messenger!
http://messenger.jhuapl.edu/news_room/status_report_05_30_07.html
MEDIA ADVISORY: M07-060
May 30, 2007
I note that they've updated the Messenger site to show Venus instead of Mercury.
http://messenger.jhuapl.edu/whereis/index.php#view_mercury
Even though the tag is still CALLED "view_mercury," of course. :-)
--Greg
The quote above suggests that the spacecraft would actually be visible to observers..
Would be nice, but I don't think you can see the spacecraft passing Venus
Looking forward to "Mercury Flyby 1" on the web site countdown clocks in the next couple of days.
Here's wishing a successful Venus flyby with good science.
I am not sure if this is planned, but I would love to see a flyby movie like the MESSENGER team created for the August 02, 2005 Earth flyby. I cannot stop playing that movie over and over again...
I was surprised during a recent search for Venus global views by how few there seemed to be. Maybe I am just missing the good ones. I am so excited to see Venus fill a MESSENGER camera view.
I can confirm that the MDIS team does have an outbound movie planned to about 30 hours after closest approach. They'll be using 3 filters: one at 415 nm that should show the clouds pretty well, and two near-infrared wavelengths that they hope might get through to the surface (I have my doubts, but I can't fault them for trying; I'm keeping my fingers crossed.)
I have more details...later...after I get my story on the flyby posted tomorrow.
--Emily
Thanks for the info, Emily. Looking forward to reading your report, and to the first images.
"... was surprised during a recent search for Venus global views by how few there seemed to be. Maybe I am just missing the good ones..."
Few missions to Venus have done imaging. Mariner 10 was the first, Soviet Venera 9 and 10 orbiters took limited data, not full disk. Pioneer Venus Orbiter took extensive "Imaging Cloud Polarimeter" camera data including a lot of whole disk coverage but that's increasingly forgotten and may not be available, even from the NSSDC.. worth investigating. Galileo got some nice full disc images but a very limited amount. That's it, so far, besides Venus Express.
I have been told that they are slowly working to put the PVO clould photopolarimeter on CD-ROM, but that right now it is only available in extremely arcane formats.
Louise wasn't that specific about the imaging strategy but she did say that they were using two NIR filters at, she thought, about 1 micron and about 1020 nm; and doing ratios seems to be a good reason to try two filters. The reason I'm doubtful that this will succeed is that I would have thought that if it turned out to be possible to see the surface this way, VIRTIS would already have done it. And it doesn't seem that Venus Express has managed to produce surface images. They have a less sharp imager but it has much higher spectral resolution -- it just seems that if this process works, it should already have been tried and found to succeed for VIRTIS.
--Emily
"...I think one issue is that we "experientialists" like to see true color images, but they have little scientific value at Venus. ..."
Eye candy, maybe, but don't knock the possibility. Messenger should periodically take a few sets of images using ALL spectral filters to map out the contrast of features in the clouds as a function of wavelength and look for wavelength varying features.
Mariner 10 took a very few sets of full disc UV, Blue and Orange filtered images. In the best set, the orange image showed a distinct dark band near the south polar collar, and a relatively bright collar. That dark band was NOT distinct in the UV image, just another dark band. It was darker in the blue image than other markings which were much weaker than in the UV.
There are more than one absorber in the clouds, and weak though the contrasts may be, seeing features change with wavelength is scientifically important. The near IR features Galileo saw were deeper and almost entirely uncorrelated with the UV/Blue features in the matching shortwave image.
She's made it
See: http://tinyurl.com/27m2uj
Still no pictures though...
Littlebit, you are thinking kilometers. Granted, this is still within Venus' rarified exosphere, but that shouldn't be much of a factor.
It looks like the Messenger Fly-By went just most extremely wonderfully nicely. Here's the press release.
For Immediate Release
June 5, 2007
Media Contact:
Paulette W. Campbell
(240) 228-6792 or (443) 778-6792
paulette.campbell@jhuapl.edu
MESSENGER Completes Second Venus Flyby,
Makes Its Way toward First Flyby of Mercury in 33 Years
NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft swung by Venus for the second time early this evening for a gravity assist that shrank the radius of its orbit around the Sun, pulling it closer to Mercury. At nearly 15,000 miles per hour, this change in MESSENGER’s velocity is the largest of the mission.
Mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., say MESSENGER’s systems performed flawlessly as the spacecraft sped over the cloud tops of Venus at a relative velocity of more than 30,000 miles per hour, passing within 200 miles of the surface of the planet at 23:08 UTC (7:08 p.m. EDT).
For 20 minutes during this closest approach, MESSENGER was within the shadow of Venus, and in the absence of solar power the probe relied solely on its internal battery. By 01:32 UTC (9:32 p.m. EDT) the battery had fully recharged, and the spacecraft was operating as planned.
“This second Venus flyby was a critical mission milestone on our craft’s circuitous journey toward Mercury orbit insertion,” declared MESSENGER principal investigator Sean Solomon, from the Carnegie Institution of Washington. “Not only did the maneuver sharpen the spacecraft’s aim toward the first encounter with Mercury in more than three decades, it presented a special opportunity to calibrate several of our science instruments and learn something new about Earth’s nearest neighbor.”
“The approach geometry is similar to that for the first Mercury flyby, allowing the seven instrumentation packages to be turned on and to operate collectively in science observing mode, just as they will be for Mercury,” noted MESSENGER Systems Engineer Eric Finnegan. “This event also marks the first time in flight that the entire instrumentation package will be operational simultaneously. Gathering approximately six gigabits of data, the spacecraft will take more than 630 images as well as make other scientific observations over the next few days.”
The team plans to image the upper cloud layers at visible and near-infrared wavelengths for comparison with earlier spacecraft observations. Magnetic field and charged particle observations will be made to characterize solar wind interaction and search for solar wind pick-up ions. Ultraviolet (UV)-visible and X-ray spectrometry will permit detailed observations of the composition of the upper atmosphere, and MESSENGER will search for lightning on the Venus night side.
“We are very excited with this next step in reaching our ultimate destination, Mercury,” says APL's Ralph McNutt, MESSENGER project scientist. “The data acquired with all of the instruments should begin arriving back at the Deep Space Network tracking stations just after 12 p.m. EST on June 7, with more data coming down during the next few days. By Friday we should have our color mosaic, as well as our laser altimeter observations, and these will be key in beginning several of the collaborative studies with our scientific colleagues on the Venus Express team.”
During this Venus encounter, MESSENGER joined forces with the European Space Agency’s Venus Express spacecraft, currently orbiting Venus, to make joint observations of the Venus environment. McNutt continued,” Although Venus’s atmospheric interaction with the solar wind was studied extensively by Pioneer Venus Orbiter in the 1980s, there has never before been an opportunity to measure simultaneously both interplanetary conditions and the particle-and-field characteristics at Venus. The combined MESSENGER and Venus Express observations will be the first opportunity to conduct such two-spacecraft measurements and should enable advances in our overall understanding of this interaction.”
Next up for MESSENGER is a trio of swings past Mercury in January and October 2008 and September 2009. During these flybys, MESSENGER will map most of the planet and determine surface and atmospheric composition; these data will be used to help plan priorities for the yearlong orbital mission, which begins in March 2011.
“The spacecraft and its operations team are poised to embark on the most intensive period of trajectory activities of the mission,” says Finnegan. “Over the next 18 months, the spacecraft will travel on a veritable inner-planetary roller coaster. Three passive gravity assists will be conducted, one by Venus and two by Mercury. Three Deep Space maneuvers will also be executed, using the large main engine of the spacecraft. In addition, 13 maneuvers utilizing smaller thrusters are possible in the event that periodic corrections to the trajectory are necessary along the way. All told, this adds up to a very high tempo of operations.”
MESSENGER Project Manager Dave Grant, of APL, says the work of the MESSENGER team of engineers and scientists in completing this second Venus flyby has been outstanding. “Our adherence to the designed mission trajectory and demonstrated performance of the science payload lends confidence to the ultimate success of the MESSENGER mission, and critical experience has been gained for managing future flybys and eventual orbit insertion at Mercury,” Grant says.
The MESSENGER project is the seventh in NASA’s Discovery Program of lower-cost, scientifically focused space missions. APL built and operates the MESSENGER spacecraft and manages the mission for NASA’s Science Mission Directorate, Washington.
For the latest news and images about the MESSENGER mission, visit: http://www.nasa.gov/messenger.
The Applied Physics Laboratory, a division of The Johns Hopkins University, meets critical national challenges through the innovative application of science and technology. For information, visit www.jhuapl.edu.
I've been forwarded a status report on MESSENGER that indicates that they've received telemetry indicating that there are hundreds of images now stored on the SSR, so it looks like they got lots of science done. Yay!
--Emily
Venus... yeah...... thats was the signpost just ahead for........your next stop..... Mercury.
My children were not even a gleam in my eye the last time we visited Mercury... but I remember the Mariner 10 saga......
Planets in front of us, planets behind us, planets above and below us... What a wonderful time to be alive.....
Craig
Do you mean DAWN?
The MESSENGER website appears to be down, I've made several attempts at access and all I get is:
Well... no images yet... not even one. We are all spoiled by Cassini, MER and New Horizons... but I was expecting at least one or 2 images after a few days. I just hope everything is OK with the data!
I don't have any problem in waiting for the images. I'm just worried with the general trend that seems to show that when raw images aren't available soon... you never get to see any finished products. I understand that on most cases at least pre-processing (Flat fielding, bias subtraction, etc) must be done, and it takes time. What I fear is getting the data and doing nothing with it, as happened on Roseta and VEX, for example. Let's hope this is not the case
Perhaps the MESSENGER team is waiting until they get enough results processed to present in a news conference. If it is a joint news conference with Venus Express (which would be considered more newsworthy), it would take additional time to coordinate and prepare.
VEX and Messenger are both waiting for the data to even get to the ground. Both have low data rates at the moment. So no one is hiding data (at least not yet). In worst case, the VEX data for Virtis won't even get all downlinked until 21 June. I think all Messenger data may be down now; I heard something about it. But they also took a while to get it. And if it is all down, it was only in the last couple days.
Thanks for the info, it makes sense. Downloading data off two spacecraft, with limited tracking infrastructure (don't know what is used for VEX, perhaps just ESA's antennas) does take a lot of time. Raw data are not JPGs, each just KB in size. We are talking several MB so the "delay" is justifiable. Perhaps a good way to make this facts more understandable to the public hould be to put a download bar on the site, next to the countdowns.
Anyway, lets wait then and hope for spectacular results from both missions and wish a very productive work for the teams involved!
I was going to show a plot of our VEX data downlink, which would show how much was stored in the on-board buffers and when it is dumped. But I can't figure out how to post an image.
But the VEX Virtis instrument data (the imaging spectrometer) won't be totally down (worst case) until 19 June (but may be down a couple days before that); all the other instruments should be down now.
I hear that all the Messenger data is down now. Reports are that the closest approach was within 5 Km of the target, which is great.
For VEX, we've been regularly analyzing data for a while now. Even so, it may not be trivial to process what the instrument teams have, because it was taken in a segment of the orbit where we've never taken data before. For Messenger, they are going to have to figure out what they have, and it may take a while for them to figure out what it is they are seeing. Some of the instruments are designed to work with rocks, not clouds. Shining a laser altimeter at clouds might make for messy data if you haven't seen it before.
ESA is planning a web site update on the fly-by within two or three weeks. I think the hope is that it will include a couple Messenger images. Keep in mind that the Messenger team will want to publish papers on the fly-by. If they release something now, it may be considered 'published' and journals won't accept papers on it. So they can't put out very much, or they risk running into trouble with editors.
Hope that helps.
I will continue to wait patiently and only check the MESSENGER website every hour instead of several times an hour. I do not envy the MESSENGER team their task, and whenever they are ready to release data is fine with me.
Even if they have a lot of image processing ahead of them, I would have thought that at least one or two, distant color images could have been released to at least show that they have data, it looks cool, and that there is more to come. Such an image wouldn't require that much processing, compared to the surface data they are trying to get, which from my own experience with Titan data, I know to be very patient for, or the mosaics they designed, which from my own experience, I know can't be done overnight.
Spacecraft operations and public releases are processes that are changing, and I think we should continue to be patient. It is true that teams use to hold onto data until they could get all the science out of them that they could. This philosophy is slowly changing, thanks to the MER team and others.
I know we are taxpayers (and I guess part of my income also comes from other taxpayers) but taxpayers also do not always know the ins and outs of the process. Sometimes their expectations are greater than reality. While it can be frustrating, change does come.
From experience, I know that sometimes the reasons why there are delays has nothing to do with philosophy, but everything to do with technical or logistical matters. Sometimes there are unexpected processing hardware and software failures, deaths in the family, unexpected DSN coverage issues, etc. Often there is not time to give the public the full reckoning to which they may feel entitled.
The desire to release data as quickly as possible is spreading through the community (and may even hit Europe someday!) The public, the taxpayer, should be careful with their sense of entitlement and let the process unfold, unless, of course, they choose to enter the field and help introduce new ideas.
The entire scientific world was fascinated by the almost real-time release of Voyager imagery. The audience is smaller, but the same is true for both Cassini and the MERs. NHs has been wonderful.
Nobody is fascinated with that Venus probe that has only released a handful of images...i forgot the name.
Messenger? Live up to yor name.
Littlebit, real-time release of Voyager imagery was only possible because most data was coming down, well, real-time. As for RAW image pages, that's a very nice practice, but it's only the mission folks' free will that enables such sorts of goodies for us amateurs.
I have to add that while I'm also looking forward to that departure movie of Venus, I'm expecting it to be pretty underwhelming (I'd like to see something other than a heavily processed sequence, a natural-ish color view instead), mainly a shrinking crescent with very little cloud structure discernible in the visible wavelengths. Certainly a lot less inspiring than that cool Earth departure sequence. Out of all 4 inner rocky planets, only Earth and Mars are photogenic enough (and rotate fast enough) for those kinds of movies to have a "wow" factor.
I'll be glad to be proven wrong, though!
Can we calm down the witch hunt please. We know they're going to release it all at some point ( look at the data of the Earth flyby - stunningly published in ful ) - give them time.
Doug
Well spoken! Don't shoot the MESSENG.... uh, never mind.
Hey, http://www.nasa.gov/mission_pages/messenger/multimedia/venus_flyby.html are up...
Awe-inspiring, aren't they?
BTW, full-res images http://messenger.jhuapl.edu/the_mission/flyby_movies.html.
Very... white...
Looking forward to more detailed images.
Seriously tho, I think it's very cool that on the next clear night I'll be able to stare up at the sky and when I look at Venus blazing like a lantern in the NW I can say "probe just passed there..." When I look at Mercury glittering above the trees I can say "probe heading there..." When I look at Saturn to venus' upper left I can say "probe orbiting that..." When I look at Jupiter hanging above the southern horizon I can say "probe just passed there" and then, before dawn, if I can spot Mars shining in the dusk glow I can also say "probes BESEIGING that planet..."
Give them a week or two more - and Messenger will outstrip VEX very easily.
Doug
I might have missed it but did anyone else see this http://solar-heliospheric.engin.umich.edu/shrgpub/news_images/FIPS_V2_release_08Jun2007.jpg?
Bland as it may seem, there's actually some cloud details visible in the global view. I monkeyed around a bit with high-pass filtering and such in Photoshop and came up with this version, which displays a little more detail. Can anyone do better than this? (If you can, I'd love an explanation of what you do.)
--Emily
Hey! What did you do to Planet Cue Ball!?!?!?
Seriously, nice to see the spigot opening up a bit....
Here's my version:
Nice work, Bjorn.
OK, after initial negative comments about a the lack of image releases, I all involved give my congratulations for the images. They have surpassed my expectations. I think that these images where taken with a violet-blue filter, so they show some cloud details while remaining within visible wavelengths. Very very interesting and comparable to earth based amateur observations (there are some very nice ones).
It is the hint of cloud structure that really makes this view of Venus so interesting to me. Awesome job to those who pulled out even more structure.
FYI, I'm told that the Messenger images have almost no contrast because they are taken at 480 nm.
VMC and VIRTIS on Venus Express are imaging at 365 nm, which gives far better contrasts.
480 nm means deep blue, so it's inside the visual spectrum. Therefore, the contrast is low, but the cloud details revealed would be visible to the naked eye.
True. Do you suppose that the unaided eye at C/A would see at least some of the details that Emily http://planetary.org/image/venus_messenger_globe_filtered.jpg with this degree of clarity? (Probably have to be wearing shades as well; my eyes hurt at the thought of staring at an object a third closer to the Sun than Earth with such a high albedo...)
Remember, "shades" are just another form of filter. What spectral range will you be getting through your preferred shades? That will make some difference in terms of the details that will be visible to you. Also, polarization will make a difference, too.
Back during Apollo, the most common sunglasses were green-tinted. The Apollo 12 crew really needed the sunglasses at times, but Pete Conrad decided not to use them at times because he didn't have nearly the visual acuity on the lunar surface through the green-tinted lenses that he had without them. So, the wavelengths passed through your shades, and those blocked, do make a noticeable difference.
-the other Doug
It may be visible to the naked eye, but it would appear much more as a color variation than a brightness variation.
Here's a paper that one should download now while it's free:
MESSENGER Mission Design and Navigation
James V. McAdams, Robert W. Farquhar, Anthony H. Taylor and Bobby G. Williams
Space Sci. Rev., In Press (2007)
DOI 10.1007/s11214-007-9162-x
http://www.springerlink.com/content/g62rru8048220547/fulltext.pdf
Though that's within the visual band, the detail in that image is still extremely subtle; I find it hard to believe it would be detectable through Earth's atmosphere with the naked eye. To be sure, MESSENGER's imagery covers only a single day on a planet with (presumably) significant atmospheric variations, but...
In Patrick Moore's Venus (recommended, if you haven't read it), he talks about an old experiment in which people looked through a telescope at a featureless ping-pong ball (IIRC, the same size as Venus would appear through a telescope from Earth), and who drew what they saw. Many of the volunteers drew subtle shadings and variations that simply weren't there--in other words, like many terrestrial observations of Venus. While UV detail is undeniable, I'm thus increasingly skeptical of earthbound visible observations.
For my part, only the prominent cusps Venus sometimes exhibits from Earth are possible visible features; if real features, they roughly correspond to the polar vortexes. As advanced as CCD imagery is today, I have yet to see a visible image that shows any hint of terminator irregularities, and even the cusps are absent.
Just my two bits--though for the record, I have a long-time interest in Venus. It's just that the amateur astronomer in me hoped that there would be more visual detail than that, and the lack thereof makes such skeptical studies as those cited by Moore increasingly relevant, IMO.
Almost daily amateur Venus images can be seen http://alpo-j.asahikawa-med.ac.jp/Latest/Venus.htm.
A nice visual image from that page is http://alpo-j.asahikawa-med.ac.jp/kk07/v070612z.htm. One of the polar areas is noticeable brighter, and that would be visible in a good telescope. As for more subtle details, one must be cautious in interpreting drawings and visual impressions. But in general, some brighter areas around the poles can be see from Earth.
Almost daily amateur Venus images can be seen http://alpo-j.asahikawa-med.ac.jp/Latest/Venus.htm.
Here is a nice visual image from that page:
.
One of the polar areas is noticeable brighter, and that would be visible in a good telescope. As for more subtle details, one must be cautious in interpreting drawings and visual impressions. But in general, some brighter areas around the poles can be see from Earth.
I took a crack at the full-disk messenger pic of Venus with my band-pass filtering and here's what I got. I think it preserves some larger scale features than the previous high-pass filtered version. The real solution is to calculate a global photometric function to match the image and divide the image by the function. Not trivial, and it can still go crazy at the limb and terminator.
Another freebie from Space Science Reviews:
MESSENGER: Exploring Mercury’s Magnetosphere
James A. Slavin et al.
Space Sci. Rev., In Press (2007)
DOI 10.1007/s11214-007-9154-x
http://www.springerlink.com/content/90q1l830752115l0/fulltext.pdf
It's been almost a month now since the Venus flyby, still no new images on the website
Do you hear that sound? It's the sound of me resisting the temptation to bag on the PR efforts from ESA
(as in comparing the lack of return to the pace of return from Mars Express/Venus Express)
I'm at a Venus Express science working team meeting right now, and the Messenger team is here to show us some early results of their second Venus flyby. The joint press release with ESA is moving forward, but there are a lot of cooks working on the soup so things are moving slower than anyone would like. And it isn't just the ESA end slowing it down. It sounds likely that some results will start getting posted next week. And then will trickle out after that. It doesn't look like there will be a big dump of data onto the web site.
One issue is that the Messenger team is hoping to publish some of their results in Science, and Science has an embargo on already-published material. So Messenger needs to be careful that they don't release something, and then not be able to publish it in the special issue of Science.
I wouldn't get too excited about the images they'll be posting from the Messenger flyby. The Messenger guys showed some of their early data at our meeting, in Rome on Monday. It is important to understand that their instruments are not well suited for Venus. For Messenger, this was mostly just a dry run of the flybys they will perform of Mercury itself; they do two Mercury flybys before going into Mercury orbit. This was the first time they turned on all their instruments and performed with them all together in a flyby mode. The first time they went past Venus, they couldn't do it because of various thermal constraints.
The camera images are at bad wavelength windows, so you get a white cue ball. The lidar doesn't work well with the clouds. There's useful science, but the images are not the most exciting pictures you'll ever see.
As a dry run of a flyby, though, it was very successful. Everything worked great. So in 2008, we can expect some great images of Mercury.
hi cndwrld
Thanks much for the update. I'm very glad to hear everything went well. Venus is a tough planet to image, indeed!
Additional Venus flyby images are up:
http://messenger.jhuapl.edu/the_mission/flyby_movies.html
I'm not seeing anything new there.
I was referring to the video link for the Venus departure sequence. Not really new images, but a repackaging of released ones. Sorry about the misrepresentation.
The departure sequence will be vastly more interesting when a photometric function of the shading across the disk is applied to the images, and then the images are displayed at full resolution, even better, at constant scale, matching the first in the sequence.
Messenger Fly-By of Venus
The ESA web page for the Messenger fly-by is on-line, on the ESA Space Science page, at
http://www.esa.int/esaSC/index.html
If you click on the third story, labeled, "Venusian rendezvous results: chapter one", you go to the dedicated fly-by page at:
http://www.esa.int/esaSC/SEMVN4HYX3F_index_0.html
The fly-by page can also be reached from the dedicated Venus Express page at:
http://www.esa.int/SPECIALS/Venus_Express/index.html
While counting down to the Phoenix launch to Mars, this http://messenger.jhuapl.edu/news_room/status_report_08_03_07.html recalls that 3 years ago yesterday, Messenger launched to Mercury. It is approaching perihelion within a month and the report mentions it will be the closest any 3-axis stabilized spacecraft has ever approached the Sun. Only the two Helios probes required more sun block.
I'm sure everyone has already seen these, but I've been taking a closer look at the details of the three flybys with an eye towards how much new information we should expect from each. Right off the bat, I realized all the flybys have to come from the night side, so the coverage may be more limited than I'd hoped. Still, anything new will be nice.
Looks like the first one -- this coming January -- will catch pics of maybe 2/5 of the surface that Mariner 10 couldn't see -- maybe less.
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby1Files/Mercury1AboveNorthPoleFull.jpg
Then the one a year from September fills in that annoying empty stripe plus a bit of the terrain that the first flyby missed.
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby3Files/Mercury3AboveNorthPoleFull.jpg
Sadly, the third flyby -- TWO years from next month -- doesn't appear to pick up anything the second one didn't see.
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby3Files/Mercury3AboveNorthPoleFull.jpg
However the very first orbit -- in March 2011 -- looks likely to fill in most of the remaining gaps.
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryOrbitInsertionFiles/MercuryOrbitInsertionAboveNorthPoleFull.jpg
Of course I realize a lot depends on the field of view of the cameras and exactly how they use them during each encounter. (And from how far away they can get useful shots.)
Does anyone know if they have specific imaging plans? And if they'd like to post them? :-)
--Greg
Greg, you seem to have the 3rd flyby linked twice, missing the second (although they are very similar).
If you have the bandwidth the animations of the flybys from MESSENGERS p.o.v are VERY illuminating.
http://messenger.jhuapl.edu/the_mission/ani.html - scroll down.
James
Are these figures still accurate? The publication seems to imply a July 2007 and Aprill 2008 flyby. It may have been written before the launch slipped.
An added note, regarding the putative Skinakas basin, the first flyby might show the eastern rim of the basin on the terminator, if the basin is truly huge. But the second and third flybys will show most of the putative basin area conveniently on the limb in the approach images. Since these images will represent well over an order of magnitude improvement in resolution over adaptive optics imaging, the second flyby should definitively settle the question of whether or not the basin exists.
The slipped flyby dates are Jan. 14, 2008, Oct. 7, 2008 and Oct. 1, 2009. Orbit insertion will be March 18, 2011. However, the exact dates after the first flyby may change slightly. On the 3 flybys most of the surface not seen by Mariner 10 will be imaged. Imaging sequences remain as described a few messages back.
There have been NO adaptive optics observations of Mercury. The sky is too bright even in twilight for the natural & laser guide stars required. Only short-exposures selected to minimize wavefront corrugation, which have attained ~100-150 km resolution.
Can you tell us at what resolution ranges Messenger will be able to image the previously-unobserved terrain during the flybys?
--Greg
It's also worth realizing that like with the lunar highlands, but perhaps even more so, high resolution imagery tends to be less than impressive in what it reveals. The impact cratering of the highlands and much of mercury is "making the rubble bounce" cratering. The Mariner 10 high resolution images, with resolution down to some 150 <flyout> and 250 <approach> meters/pixel <somebody see what the real numbers are, I don't remember> are less than impressive.
With much more coverage, there will be scattered images with impressive features showing up at high rez. but.... and it's a big but.
Indeed... we need global coverage at decently high resolution. In some ways, I'm more interested in the hints of primordial crust composition variations and later (but heavily battered) volcanic overprints, and still later visible volcanism that the multi-spectral data may reveal.
Mercury is not "pretty" but it's important. We have only 6 large rocky planetary objects in this solar system (in the geologic sense... including Moon and Io), plus small numbers of rocky sub-dwarf planets like Vesta that had active volcanism erupting onto the surface. It's a small sample and every one is important.
Meanwhile, I just noticed that Messenger has started on "Orbit #5" and looks like it'll reach Mercury's orbit for the first time in a week or so. (August 24 is still my best guess.)
http://messenger.jhuapl.edu/whereis/index.php#current_orbit
Of course, Mercury itself won't be there yet, but that means we're just one more orbit away from the first Mercury encounter in thirty years!
--Greg
2nd paragraph in http://messenger.jhuapl.edu/news_room/status_report_08_03_07.html alludes to Messenger orbit perihelion on Sep 1.
Thanks! I should read these things more carefully. :-)
--Greg
All..
Emily has posted a nice update about the MESSENGER January 14th 2008 Mercury flyby on her TPS blog.
http://www.planetary.org/blog/article/00001086/
Craig
Very nice!
Emily: (If you're reading this.) What would be extra nice, if it's not too hard, would be to add an indication to your composite Mercury map (the one that combines Mariner 10 and Arecibo data) outlining the portion that will be imaged on the first Messenger flyby. From the looks of it, your map is centered rougly opposite the midpoint of what Messenger will be able to image, so I"m thinking it'll cover the largest blank in the Arecibo data and just about reach that flag-shaped blank in the middle of the Mariner 10 data.
Unless I have it backwords or something. :-)
--Greg
Easiest way to visualize what will be Sunlit and thus visible to MDIS is to ask the Solar System Simulator what Mercury looks like as seen from the Sun at closest approach:
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=10&month=1&day=14&year=2008&hour=18&minute=17&rfov=2&fovmul=-1&bfov=30&porbs=1&showsc=1
Looks like roughly 40 degrees of the non-Mariner-10 hemisphere will be Sunlit, which is actually less than I had imagined. MESSENGER's outbound view will be almost entirely of the non-Mariner-10 hemisphere, but not so much of it will be Sunlit.
--Emily
Yeah...
if you look at the flyby plot you can see that a lot of the unseen hemisphere will be in darkness. Seeing that I have waited 32 years to see this much more, I can handle waiting for the orbital mission in 2011.
Following planetary science takes great patience but the payoff is out of this world.
Craig
New Messenger update, marking the first perihelion at Mercury-distance.
http://messenger.jhuapl.edu/news_room/status_report_08_31_07.html
--Greg
The more I look at the data, the more I think the January flyby will show us about 1/3 of the "missing" hemisphere of Mercury, then the October one will show another 1/3. The third flyby won't show us anything new, but (of course) once in orbit, we'll finally see the remaining piece.
Assuming I've got the links right this time :-) here's the trajectory of the first flyby:
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby1Files/Mercury1AboveNorthPoleFull.jpg
Sweeping across the unexplored terrain -- in the dark. Half a day later, here's the view from Messenger:
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=1&day=15&year=2008&hour=6&minute=00&fovmul=1&rfov=2&bfov=30
Just eyeballing it, then, that's roughly 1/3 of the "blank" space.
For the October flyby, Mercury has rotated 180 degrees, so the night flight is over known terrain, but, unfortunately, so is much of the day flight.
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby2Files/Mercury2AboveNorthPoleFull.jpg
About half a day past the encounter, about 1/3 of the blank space has peeked into view, but that's about it.
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=10&day=6&year=2008&hour=23&minute=00&fovmul=1&rfov=2&bfov=30
The third flyby, in September 2009, has about the same geometry as the second one:
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby3Files/Mercury3AboveNorthPoleFull.jpg
But it's not identical. Looking at Mercury from Messenger about half a day later, we actually see a bit LESS of the blank area than we did on flyby #2.
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=9&day=30&year=2009&hour=17&minute=00&fovmul=1&rfov=2&bfov=30
So it looks like the first two flybys will be pretty cool, but then we'll have a 2-1/2-year wait before there's much more new info.
Still not as bad as the 34-year wait BEFORE flyby #1!
--Greg
it looks like flyby's 2 and 3 will provide excellent quality stereo data, as the illumination (except pretty near the terminator) looks like it should be pretty similar. Baseline between the views isn't large, but probably decent.
http://messenger.jhuapl.edu/news_room/status_report_09_12_07.html
MESSENGER Mission News
September 12, 2007
I saw one of the principle scientists from Messenger the other day. Knowing the desires of people here, I noted the level of interest and asked how soon after the January 14 flyby some images might be released. He said that they are planning on getting the data down in two days, and should have images out shortly after that on the web site. So, expect the first public data on 16 or 17 January.
They have a big conference planned in Spring 2008. After that, more data should get released to the public.
Nice! Thanks, CND; definitely something to look forward to!
One step closer. MESSENGER sets itself up for the January flyby (in 88 days).
http://messenger.jhuapl.edu/news_room/status_report_10_17_07.html
MESSENGER Mission News
October 17, 2007
Great news.
I still find myself forgetting how long MESSENGER must travel in order to get to orbit insertion, especially given that the first flyby is only 53 days away. (That's less than two months for those of you keeping track.) Closest approach should be within 200 km. For comparison, Mariner 10 had three flybys with closest approaches of 703 km, 48069 km, and 327 km. Fortunately, MESSENGER's three planned flybys should keep us satiated, especially given how long we have waited to get to this point.
http://messenger.jhuapl.edu/news_room/status_report_11_19_07.html
MESSENGER Mission News
November 19, 2007
Contact made to Messenger after solar conjunction:
http://messenger.jhuapl.edu/news_room/status_report_12_03_07.html
The countdown clock to first flyby is now 40 days (and nights).
There's already enought recent posts in this thread to start a separate first flyby thread. (Hint, hint.)
Not related to this month's flyby (not to say completely arbitrary) but according to the website, Messenger completed orbit #5 last night.
http://messenger.jhuapl.edu/whereis/index.php
In particular, we can see that the new aphelion is inside Venus' orbit. After the big changes we saw from the Earth and Venus flybys, it's surprising just how much smaller the changes from the Mercury flybys are. Even knowing how small Mercury is.
--Greg
Noticed something else new on the "Where is MESSENGER?" page:
"Beginning in January 2008 additional Mercury surface features are displayed. These radar images, which came from the 1000-foot-diameter radar antenna at Arecibo, Puerto Rico, were provided by Professor Phillip Stooke of the University of Western Ontario."
If you look at the Mercury closeup view, you can see the mosaics (which, unfortunately, are dark right now since MESSENGER's approaching almost directly on the night side). Way to go, Phil!!!!!!
Pleiades star cluster.
.. and more
You saw it here first, nprev!
Phil
...<clink>...LAND HO!!!
Look at those beautiful albedo features already, esp. at the North Pole....wowowow!!!
I knew this was gonna be a good year...
April fool! That was the moon. Here it is modified a bit. (oh wait, it's not April)
Phil
unnecessary quoting removed
I fear that is ye olde Moone
You guys sure? I was thinking that too (farside view), but when I looked it over it didn't seem right...that dark polar hood didn't look right at all.
Oh, well; if it is the Moon, then I'm Ye Olde Foole...(yeah, that's unusual for me...)
That's no dark polar hood, that's Oceanus Procellarum. Besides, the approach view of Mercury is a narrow crescent.
Phil
It IS the Moon - hence why I cited the PDS where the early MDIS stuff is.
Sigh...too much anticipation...
I don't have time to search at the moment - is this the best moon view from this set?
Phil
I think images EN0031264914M.IMG and EN0031264925M.IMG are the best Moon images, the latter was taken almost at the same time as the first but is slightly blurrier for some reason.
Here's EN0031264914M.IMG cropped and sharpened:
Yep, Mare Orientale is near center, Procellarum is at top, the dark-but-not-maria patch at bottom is the Aiken-South Pole basin, and the south pole is near the middle of the terminator.
Mercury is much less contrasty than the Moon. Although it's a little more segregated than Mariner 10 images suggest simply because the border between the inbound view and the outbound view happened to fall roughly on the border between an area with smooth plains and an area of cratered highlands. Either Mariner 10 image individually shows less diversity than other hemispheric views of Mercury are likely to.
Here is my take on the image.
Wow, it really is a good camera. Here is the distant view taken before the first Venus flyby.
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