Posted on: Oct 7 2008, 12:40 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
|
Forum: Messenger · Post Preview: #128056 · Replies: 164 · Views: 273850 |
Posted on: Oct 5 2008, 10:29 AM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
|
Forum: Messenger · Post Preview: #127770 · Replies: 164 · Views: 273850 |
Posted on: Oct 4 2008, 11:49 PM | |||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Hi Phil, Certainly Skinakas Does Not exist. I really hope that the fifth image will be available soon. That southern basin is impressive. Certainly is reminicent of a mini Caloris. I've had a go at enlargening & sharpening each hemisphere from the original. Northern Hemisphere enlarged. Southern Hemisphere enlarged. Andrew Brown. |
||
Forum: Messenger · Post Preview: #127746 · Replies: 164 · Views: 273850 |
Posted on: Oct 3 2008, 09:30 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
I think Pluto will be ancient & cratered with little else. Triton was most likely a captured Dwarf Planet by Neptune. During capture the orbit was very elliptical, thus raising huge tides that heated up the interior (much like Jupiter with Io), initiating massive cryovolcanism that resurfaced Triton. When the orbit settled down, tidal flexing reduced & a new surface froze. Pluto, as far as is inferred, has never undergone such heating. I think a Triton, Europa, Enceladus, Dione, Ganymede, etc type surface is just wishful thinking. Sure there are ices present & these ices may migrate dependent on the season & the point of the elliptical solar orbit, but Pluto & for that matter the larger & more massive Eris do not appear to have been subjected to violent heating that Triton had. I think Pluto will look more like Callisto, Rhea or Iapetus. Mostly craters, with perhaps a few fractures. I may be wrong, but that's exploration. Andrew Brown. |
Forum: New Horizons · Post Preview: #127635 · Replies: 26 · Views: 48526 |
Posted on: Oct 3 2008, 06:01 PM | |||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Enlargement & enhancement of Crescent Mercury. It looks like the Skinakas Basin exists after all, despite being written off, though it is still a bit too soon to jump to that conclusion. The crop & blow up I have just done shows a large feature foreshortened in the northern hemisphere. We will definitely know more tomorrow, as this afternoon's image will be approx 25% closer to Mercury than this one. There also appears to be another large impact feature in the southern hemisphere. There is clearly a smattering of much smaller craters with bright ejecta blankets in the equatorial region. Northern horn of crescent Mercury. Looks like there IS a large circular feature foreshortened. I think it is the suspected Skinakas Basin. Obviously we will know much more tomorrow as the second Navigation image will be down, from much closer in. Every feature here is new to human eyes, very interesting & exciting. Andrew Brown. |
||
Forum: Messenger · Post Preview: #127583 · Replies: 164 · Views: 273850 |
Posted on: Sep 24 2008, 07:32 PM | ||||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
I suspect Thebe is a rubble pile held together by gravity. The 'pointy' end could be a 'shattercone' where at that end of the original larger object the impact that broke it occurred. With Thebe I have problems with that, i.e the giant crater suggests a rubble pile, not a shattered but hard body. 2867 Šteins, could be a shattercone, possibly once a part of the original larger Asteroid 434 Hungaria (which is now approx 20 KM in diameter). Enormous deep craters are not that unusual. Here is a montage I made of the Type C main belt Asteroid 253 Mathilde. It is known that 253 Mathilde is of very low density, a 'rubble pile' held together, so the porous nature of the asteroid absorbs impacts like punching in polystyrene. 2867 Šteins, I'm not sire. I have not seen any gravity data from Rosetta. The volume of 2867 Šteins is known through the images, so using those together with pertubation data will yield the density. Or was Rosetta passing by too quickly to feel the tug from 2867 Šteins? Perhaps if the NAC had worked, then greater detail of that 'large' crater on 2867 Šteins, may have helped determine if it's a hole in a rubble pile or was blasted out of more solid, but brittle material. I assume 2867 Šteins is still thought of being composed of iron poor silicate rich basalt? 243 Ida also has a large crater, but the Galileo data suggested that 243 Ida was too dense to be a rubble pile, but perhaps some parts of the asteroid are not so coherent? Also Mammoth Crater on main belt Asteroid 243 Ida. Some large boulders are visible. Andrew Brown. |
|||
Forum: Rosetta · Post Preview: #126744 · Replies: 309 · Views: 264210 |
Posted on: Sep 24 2008, 07:16 PM | |||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Temps are @ 1 metre IIRC. Also Oven 2 appears to have partially opened. Sol 118. SSI as imaged by the RAC Sol 117. The originals were very dark, so I have cropped, enlarged, brightened & contrast enhanced them. Andrew Brown. |
||
Forum: Phoenix · Post Preview: #126742 · Replies: 416 · Views: 271352 |
Posted on: Sep 13 2008, 10:04 PM | ||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Hi Emily, Did New Horizons image 2 Pallas from afar during the passage of the asteroid belt? Would have been a great test of the LORRI. Or have I misunderstood what you were saying? Most likely. Hi all, Had a go at bringing out more detail from the 2 Pallas HST image that Ted posted on the right. There are definitely some features visible, no doubt. I hope some image panels of a 2 Pallas rotation will be made up, like those already done for 1 Ceres & 4 Vesta. Also 2 Pallas has some weird seasons, owing to its almost tipped over rotation like Uranus & Asteroid 433 Eros. The best time to observe the whole of 2 Pallas obviously through a complete rotation would be around the Palladian Equinoxes, though other times would be better for the higher latitudes & polar regions. Andrew Brown. |
|
Forum: Cometary and Asteroid Missions · Post Preview: #125883 · Replies: 6 · Views: 10209 |
Posted on: Sep 13 2008, 01:45 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Wouldn't that be interesting? We've been seeing that apparently frayed bit of thread in thousands of telltale images for a long time. Still, it would be quite a coincidence. ![]() I wonder if it is a fibre that somehow come off the WindTeller? I think it is. What are the odds of that being a fibre from Mars Pathfinder airbag? Billions to one against, Trillions to one against? Just a thought. Andrew Brown. |
Forum: Phoenix · Post Preview: #125856 · Replies: 416 · Views: 271352 |
Posted on: Sep 13 2008, 01:34 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Thanks Ted, I tried downloading them but it didn't work. Are there JPEG, Gif or preferably BMP of the 2 Pallas images? I assume no moons have been found orbiting the giant asteroid (if so it would be mentioned in the general astronomical press / sites)? 2 Pallas has in my opinion been a bit of a Cinderella regarding the real big asteroids, the largest in the Main Belt if you do not consider 1 Ceres to be an asteroid, rather Dwarf Planet. I hope the option with DAWN has not been abandoned in December 2018, when 2 Pallas may be reachable during the descending node (assuming primary mission at 4 Vesta & 1 Ceres is successful). I looks like that there may be two large craters or basins on the right hand image. 2 Pallas will not be boring for sure. Hopefully 2 Pallas is high on the list of the new WF/PC 3 & repaired ACS? Once again, thank you very much Ted for the tip off. It is very much appreciated. ![]() Andrew Brown. |
Forum: Cometary and Asteroid Missions · Post Preview: #125854 · Replies: 6 · Views: 10209 |
Posted on: Sep 12 2008, 11:38 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
|
Forum: Rosetta · Post Preview: #125812 · Replies: 309 · Views: 264210 |
Posted on: Sep 9 2008, 01:08 PM | ||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
It will be interesting to see the results of the gravity data (slight deflection of Rosetta), the NAC images prior to safing & the multispectral data. An encounter montage I've made of the Asteroid 2867 Šteins. I know, not as good as many if not all of the contributions on this thread, but I do try. ![]() Using screen dumps from the ESA animation. Not raw screen dumps as I have enlarged each one by 350% & have enhanced the contrast slightly, all equally. Andrew Brown. |
|
Forum: Rosetta · Post Preview: #125576 · Replies: 309 · Views: 264210 |
Posted on: Sep 7 2008, 10:44 PM | ||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
I like that VP, perhaps best not to ask ANY questions that require an intelligent answer on a Sunday. ![]() I have been during quite a bit of gemming up on 2867 Šteins today, but not from Wikipedia. 2867 Šteins although not originally a part of 4 Vesta as per my first theory, does appear to be a chunk knocked off Asteroid 434 Hungaria, so my theory that 2867 Šteins is part of a mantle from a larger body, still stands. Apparently some Hungaria asteroids do come close to the orbit of Mars, though 2867 Šteins, does not & remains a core member that stays well within the main Asteroid Belt, though E Type main Belt asteroids are incredibly rare, so Rosetta by some very remote & lucky chance encountered one, on only the eigth close asteroid pass (ninth including 243 Ida's moon Dactyl). I wonder if someone knows. Does 2867 Šteins rotate prograde or retrograde? The Press Conference stated that 2867 Šteins has virtually no axial tilt, but did not mention direction of axial rotation. If anyones interested, view of Sun & Earth from 2867 Šteins @ time of Rosetta Closest Approch. Andrew Brown. |
|
Forum: Rosetta · Post Preview: #125442 · Replies: 309 · Views: 264210 |
Posted on: Sep 7 2008, 11:35 AM | ||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Hi imipak, My guess is that the sublimation has ceased from Holy Cow & Snow Queen. I think that you are correct linking the cessation of the growth of the globules on the leg with the lowering Sun. 'Night time' temperatures have lowered on average 5 C / 9 F since the Solstice & that is maybe enough to make the difference. Either way, the end game for Phoenix is drawing closer now but hopefully, she will survive to mid - late November when solar conjunction is nearing & power levels will be desperate. We are already seeing daily morning H2O frosts now, maybe in the shadows persisting into the afternoons. Below I've cropped & enlarged the Sun just beneath the horizon on Sol 101 @ 01:23 HRS LMST. Andrew Brown. |
|
Forum: Phoenix · Post Preview: #125414 · Replies: 60 · Views: 77930 |
Posted on: Sep 6 2008, 07:27 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
|
Forum: Phoenix · Post Preview: #125346 · Replies: 60 · Views: 77930 |
Posted on: Sep 6 2008, 07:20 PM | ||||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Well, we still have the 2009 Earth Flyby to look forward to, and, more importantly, the July 2010 Lutetia flyby. With a 100 km diameter, it should be quite spectacular. Yes indeed Ted, & also will be the first ever Type M seen up in close quarters. If Rosetta repeats at 21 Lutetia, what happened last night, with the NAC not going into safing @ 2867 Steins then yes, it will be a major spectacle. Also a few images I have been working on. 2867 Steins, just before CA. 2867 Steins, just after CA. 2867 Steins crater chain. Andrew Brown. |
|||
Forum: Rosetta · Post Preview: #125345 · Replies: 309 · Views: 264210 |
Posted on: Aug 27 2008, 07:36 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
AFAIK, the sunlight DID make the regolith clumpiness worse. The idea is that the ice softend in the sun & caused it to stick together. Aslo the scoop is dark, absorbing solar energy, warming it up slightly, thus making the ice rich regolith contained within to clump, as the ice rehardened. The idea f perhaps scooping some samples in the half light of the polar midnight twilight (as the sun will be setting 'properly' from this Saturday onwards) sounds much better. Delivering ice rich samples to TEGA should be easier as it should be more of a fine granular mix, rather than the stodgy stuff that has proven so difficult to load. The minus side of course, with proper night time arriving, well deep twilight (even on Sol 124 the final sol of the current extension, the Sun will only dip to just over four degrees below the horizon at midnight), power will become a big issue. Will each active period every Sol have to be reduced in duration to allow more time for recharging batteries? Andrew Brown. |
Forum: Phoenix · Post Preview: #124550 · Replies: 416 · Views: 271352 |
Posted on: Aug 27 2008, 07:25 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Also as Doug before you said, it is about changing inclination & also speed. The Mars encounter IIRC also prevents DAWN from coming much closer to the Sun again. Andrew Brown. |
Forum: Dawn · Post Preview: #124548 · Replies: 285 · Views: 271934 |
Posted on: Aug 17 2008, 10:14 AM | ||
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Hi everyone, Nice observation. Sol 80 @ 00:08 HRS LMST looking North. I have cropped & enlarged the central due north position of said image. 1,303 Km / 809 miles to the North Pole on mars. Andrew Brown. |
|
Forum: Phoenix · Post Preview: #123926 · Replies: 60 · Views: 77930 |
Posted on: Aug 17 2008, 10:03 AM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Remember everyone, the solar arrays are dark, so therefore will be warmer than the surface as they absorb more solar energy. Certainly the first frost IS the beginning of the end, averyage Sol temperatures will only get lower now, but I do not think it's signalling the imminent end of the Phoenix Mission & certainly IMO, Sol 124 for the extention mission end is not unreasonable. What I expect instead, is that surface operations will reduce, as more time will be required to charge the batteries & leep the internal heaters operating. Perhaps the RA & TEGA will have to be mothballed in the relatively near future, as they do use a lot of power, but the SSI, Meterology suite etc use relatively little & they should operate right to the bitter end. Interesting observation & certainly now early morning obs should be made compulsory every sol now, to monitor the build up & sublimation of frost. When does it form? Before Midnight? After midnight? Does anyone know what the temperature was when the frost was imaged? Andrew Brown. |
Forum: Phoenix · Post Preview: #123925 · Replies: 169 · Views: 148391 |
Posted on: Jul 30 2008, 03:38 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
|
Forum: Mars Express & Beagle 2 · Post Preview: #121782 · Replies: 243 · Views: 427434 |
Posted on: Jul 29 2008, 07:55 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
unnecessary quoting removed Thanks Stu, I was beginning to wonder also. Does anyone know what the resolution of the images at closest approach will be, 1 metre per pixel, better, worse? Hopefully we'll get some more insight as to where Phobos camefrom. Captured type D asteroid? Formed around Mars? Formed from impact ejecta from Mars? My bet is still option 1, despite the difficulties with explaining orbital mechanics, but I still think, Phobos is as alien to Mars as the spacecraft we have sent. It will be interesting to compare the new Phobos imagery with the NEAR / Shoemaker spacecraft imagery of similar resolution of asteroid 433 Eros. Perhaps Mars Express could do similar with Deimos? Comparisons with the MARSIS & multispectral imagers / spectrometers of the two would be most fascinating. Andrew Brown. |
Forum: Mars Express & Beagle 2 · Post Preview: #121705 · Replies: 243 · Views: 427434 |
Posted on: Jul 25 2008, 07:30 AM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
That's correct. The 10:00 PM / 22:00 position is on the left, the 2:00 AM / 02:00 Hrs position on the right. Midnight dead ahead. That montage covers a 4 hour sweep, though spread out over 11 sols. Andrew Brown. |
Forum: Phoenix · Post Preview: #121382 · Replies: 60 · Views: 77930 |
Posted on: Jul 23 2008, 09:35 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Awwwwwwwwww, sooooooooooooooooooo cool!!!! I have waited a long, long time to see that! ![]() Same here, in fact it was something I requested prior to Phoenix's arrival. Thank you so very much guys for bringing that here & for continuing the discussion. I thought that this would make for an interesting subject & pleased by the response at UMSF, that I was not deluded or wrong. Thank you all for welcoming me back, I was a little nervous at first, but I am amongst friends here & it shows. ![]() Andrew Brown. |
Forum: Phoenix · Post Preview: #121303 · Replies: 60 · Views: 77930 |
Posted on: Jul 23 2008, 09:22 PM | |
![]() Junior Member ![]() ![]() Group: Members Posts: 47 Joined: 27-June 08 From: Ashford, Kent, United Kingdom. Member No.: 4244 ![]() |
Thanks VP for setting me straight. I was aware of the Janus eclipse, & thought as the original image was so dark, that was taken during said eclipse, not just before. I see your enhancement, considerably better than mine. I assume the G Ring is responsible for the trapped radiation? I'm not as familiar with the Saturn system as I am of the Jupiter system. Once again, thanks VP & its great talking to you again. Hi jasedm, I'm aware of the Enceladus eclipse imagery a while back, faintly lit by Rhea, Dione & Tethys, with Cassini taking a longer exposure, but being further away with a much larger target, it seems to work. Janus is small & close in to Saturn, so yes that would probably not work thinking about it more logically. Andrew Brown. |
Forum: Cassini's ongoing mission and raw images · Post Preview: #121298 · Replies: 24 · Views: 28986 |
![]() ![]() ![]() ![]() |
![]() ![]() ![]() ![]() |
![]() |
Lo-Fi Version | Time is now: 24th April 2024 - 08:21 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |
![]() |