There have been noticeable advances in computer systems on spacecraft, particularly in both on-board data storage/processing and in architecture. For example, remember how Phoenix's image handling, running on basically the same system as that used for MPF and MPL, seemed so clunky and kludgey after we'd had the pleasure of the more advanced architectures of the MERs for several years? And while not quite as big of an increase in capabilities, MSL has an even more advanced system than the MERs, doing more on-board imaging caching and processing.

Also, Mars landing systems have been innovative for the past 20 years. The airbag landing concept was quite innovative in comparison to what had been used successfully before, and we used it to land three probes on Mars successfully. And while it's just a reworking of existing technology, the descent stage/skycrane maneuver used by MSL was definitely innovative. I'd call it anything but conservative.

Also, while not using any really new technologies, Cassini has an innovative combination of sensors -- for example, flying a radar imager solely for the Titan encounters was not a conservative choice, though it was driven by the science needs of the mission.

So, I guess it all depends on what you consider conservative vs. innovative...

-the other Doug (with my shield, not yet upon it)

Okay, so ESA will spend a lot of money on an EDL demonstrator, and has no plans to have a camera aboard the lander which can document the post-landing state of the lander???

So, if it lands and they get, say, 30 minutes of telemetry and then the thing goes dead, with no immediate check-out imaging they may not have a clue as to what caused a post-landing failure?

To me, if you want to verify a landing system, you need more than just basic survival to the surface to evaluate whether or not the landing system will be able to support landing the rover. You need to make sure that your actual landing systems have worked, that you didn't, say, bend the gear or provide too little clearance or overestimated your system's ability to deal with landing with one paw on a big rock, etc. There is no better way, IMHO, to answer those questions than to take a quick deck pan to see exactly what kind of shape your lander is in after it sets down.

Spending lots of millions of Euros to verify a landing system and then not providing a basic means of actually verifying that the landing worked as planned is, IMHO, being very penny-wise and pound-foolish.

-the other Doug (with my shield, not yet upon it)

Has anyone else noticed the pronounced visual similarity between the bases of these mounds at Kimberley and the base of Home Plate in Gusev?

I know that there is a great danger in coming to conclusions based on visual similarities. But it will be interesting to see if the mineralogy here and at Home Plate are similar, as well.

-the other Doug (with my shield, not yet upon it)

Odd -- not only will the link not load, the main JPL website won't load, either. I'm getting good page loads pretty much everywhere else on the 'net, so I don't think it's my connection, here.

-the other Doug (with my shield, not yet upon it)

Excellent. Hopefully more to come out of the dataset,

As something of an aside, I'm thinking that we may need to re-think the final naming convention formula for extrasolar planets. There are now hundreds (eventually thousands?) of planets, around a whole slew of stars, all named Keplernnna, where (from what I can tell) "nnn" is the numerical designation based on order of discovery and "a" is an alphabetic sub-class indicator.

I've got to think that there is a naming convention out there that will eventually be emplaced where the name of the planet somehow references its home star, not just the device used to discover it. I mean, right now if I came up and said that I have exciting new information about Kepler 367b (to pull a number out of the hat), you would more than likely have to look up a table of Kepler planets to figure out which one I was talking about and where in the Galaxy it was located...

I'm also not a huge fan of the naming convention used for non-probe discoveries. It's better than the Kepler planets in that the planets are named for their stars, but the designators for individual planets in a system are in order of discovery, not in order out from the star. Granted, we can't see how many planets some stars have with current sensitivities, but I figure that if we need to amend our planet designations as time goes on and renumber planets as we find new ones within solar systems, well, we've done sillier things. (Hey, I also think that the rings of Saturn ought to be redesignated based on distance from the planet, not on order of discovery, but that's certainly another discussion... )

-the other Doug (with my shield, not yet upon it)

Honestly, I was looking at the mosaic and thinking that the solar disc was not imaged, was behind the cut-outs on the upper left side of the mosaic. Looking more closely, it does indeed look like the solar disc is imaged (and completely saturates the pixels around it), rather farther down towards the horizon than I was thinking it should be.

Also, isn't Oppy on a slope? I thought perhaps that what looks like horizontal in the image really isn't because the horizon may not be horizontal where she's sitting. With an undulating horizon from a tilted rover, I wasn't very positive that a different distance above the horizon equated to a different elevation.

Again, though, thanks for the comments, guys. It looked like a sundog to me more because of the way the little arc sort of glowed in mid-arc, which does indeed resemble the sundog phenomenon. Dunno if that's an artifact of the mosaicing process or, as Doug suggested, an internal camera reflection, but it did fool me.

-the other Doug (with my shield, not yet upon it)

OK, kewl. I didn't have a really good way to measure the angular distance from the solar disc. Thanks for that.



-the other Doug (with my shield, not yet upon it)

Sure. Here's a piece of the cloud mosaic; the black arrows point to the top and bottom of the arc that I'm seeing. I put a green bracket to the left of the arc I'm seeing, as well.

Now, the thing that makes it look like a sundog to me is that in the middle of the arc, it looks like the cloud structure is unchanged but that it glows more brightly than to the right or left, or even up and down the ring arc a bit. That would be the center of the sundog on the right side of the sun.

I've seen the same kind of thing here on Earth thousands of times, and this looks like the same thing to me...

-the other Doug (with my shield, not yet upon it)

Yep -- and I believe that the brighter cloud arc to the right of the (not imaged) solar disc may well be a sundog. Looks like a subtle arc forming a portion of a halo around the sun, not directly associated with the cloud structures.

Cool!

-the other Doug (with my shield, not yet upon it)

Don't be modest. Yes, there is some minor streakiness inherent in how the cameras respond to being pointed at such a lighting situation. But this is one of the best, moody shots I can recall for the entire mission.

Incredible job!

-the other Doug (with my shield, not yet upon it)

These images of the Kimberly formation make me feel like, 17 years later, we've finally reached the Twin Peaks....

-the other Doug (with my shield, not yet upon it)

Just as sort of a summary...

Olympus Mons is both a difficult landing area (nearly sticks completely out of the sensible atmosphere, meaning you get a lot less braking from heat shield and parachutes) and represents in landforms just the final volcanic period of Mars' history. Water doesn't ever appear to have run down its slopes, nor of any of the other Great Volcanos of the Tharsis Plateau. We can investigate this mineralogy nearly as well from orbit as we can from the surface.

Hellas would let you land a larger vehicle, as it is well below the Martian mean surface altitude and parachutes would be very effective, moreso than at other places on Mars. However, it appears from orbital data to be deficient in hydrated minerals as compared to the southern highlands within which it resides. My best guess is that Hellas was formed after the time of a mostly warm, wet Mars and the enormous basin was likely dried out by the impact event. On the other hand, you do see some odd, unusual landforms in Hellas, but most people seem to think this is due to higher air pressure causing greater and different forms of wind erosion.

Finally, Valles Marineris is a rift valley, the bottom of which seems to have been primarily covered by large-bock talus and after that a thick layer of dust. And it primarily cuts through the great volcanic pile of the Tharsis Plateau, which again all seems to have been emplaced after Mars' warm, wet period. So, while interesting from a perspective of detailing the volcanic history of Mars, it's not a great place to land safely, and it doesn't preserve much signature from the warm, wet days. It's also nearly impossible to exactly locate a block in a talus field to the strata from which it fell...

-the other Doug

However, if the original moon had been mostly pulverized but had remnant (or re-accreted) one larger piece that was left about midway in the resulting ring, then that one decent-sized chunk would gradually clear the gap in the ring, resulting on the two separate rings.

-the other Doug

If the dip in these rockbeds is actually concentric into this crater, perhaps the beds were laid on top of something that has since been deflated from underneath it. For example, if these beds were deposited by, say, a series of pyroclastic or ejecta flows, the beds below these may have been removed later by subsurface aqueous processes, or perhaps the crater was full of ice, the beds were deposited onto the ice, and then much later the ice drained or sublimated away.

To me, it looks like these rockbeds just sort of tilt from the outer rim of this crater into the central depression. Since most depositional processes would fill a bowl rather than laying down a uniformly-thick coating along the bowl's interior, I'd have to at least entertain the notion that something that once supported these layers of rock has gone away...

-the other Doug

edit -- I see CR posted something of the same observation while I was typing this. Yeah -- I can imagine a number of ways the beds could have slumped into the bowl.

For those of us in the U.S., BRT (Brazillian time) is one hour ahead of EDT. The presser is supposed to be at 2:30pm BRT, so it will be at 1:30pm EDT, 12:30pm CDT, 11:30am MDT and 10:30am PDT. That works out to 5:30pm UTC, for those of you across the pond.

-the other Doug

I'm good with the AM-PM format. And yes, when you are logged in with your username, it does show the times in your local selected timezone. If you don't log in, I believe it just shows post times in UTC.

It has been in this format for as long as I can recall. Again, I'd just as soon have it stay the way it is. I use the board's function of showing me which threads have new posts since I last looked to avoid pulling up old posts I have already read.

-the other Doug

How to say this correctly, here...

One of the things that really fascinates me about cosmology is how we have a somewhat self-consistent mathematical model for the Big Bang which postulates "the fabric of spacetime" inflating at speeds far faster than C, and how it can be flat or curved, locally bent, even completely ingested into gravitational point sources. And yet we have no description or model, really, of exactly what the "fabric of spacetime" actually is, the mechanisms by which it can inflate, be distorted by mass, etc. We have macro- and micro-models of "reality" that don't mesh, either conceptually or mathematically, and the abyss that lies between must be where these mechanisms are hiding from our view.

Physics, as far as it has progressed in the past century or so, is now to the point where it can ask basic, cogent questions. But it's not yet to the point where they can be answered.

An exciting time to be alive, eh?

-the other Doug

Actually, the concept of a self-navigating Earth-return planetary probe goes back to the late 1950s, when Charles "Doc" Draper (of the MIT Instrumentation Lab) was approached to design an auto-navigation system for a Mars flyby-and-return probe. The concept was a probe that would autonomously navigate itself to a Mars flyby, expose several rolls of film using automated cameras, and come back for an Earth return.

The probe never made it out of an early study stage, but Draper's early work on it evolved into numerous applications of inertial guidance systems.

-the other Doug

Yes, materials right on the surface of Europa would be fried by radiation, but such "frying" leaves a number of remnants which can tell you a lot about the original materials. Also, ice is an excellent radiation shield, so digging down into the ice less than a meter can give you examples of materials that haven't been fried. This also goes for hitchhiking terrestrial materials on a probe that happens to crash into Europa and are buried deeply enough in the ice to provide substantial radiation shielding.

-the other Doug

I also believe that while Europa may recycle crust from the surface back into the interior, its surface coloration shows that material does come up to the surface from the interior. And (trying to phrase this acceptably), if a Europa probe finds anything interesting on the surface that could have come from within the putative deep ocean, you would want to be certain that it couldn't have hitched a ride on a terrestrial spacecraft.

-the other Doug

I don't think it's just a matter of tilt. It's more effective for dust cleaning to tilt into a prevailing wind, I think -- it increases the force of the wind for the surface to be more perpendicular to the airflow. Obviously, the edge of Home Plate wasn't an area where there was much prevailing wind. I'd guess there is more wind where Oppy sits now than there is down on the plains. I think the two -- a windy location plus a tilt into the wind -- worked together to create a gradual cleaning effect.

-the other Doug

Both mythologies are referenced in scientific jargon. For example, you'll see discussions of aeolian erosion forming ventifact rocks...

-the other Doug

Tonight on Ethel the Frog, we look at Opportunity's obsession that she is being followed by an enormous indurated breccia named Spiny Norman...



-the other Doug

Emily explains this in the cutline for a few images down. She says:

"This kind of polygonally patterned ground often forms in permafrost environments on Earth, where thermal contraction breaks the surface into polygonal shapes and then ice wedges form in between them. Thanks to Phoenix, we know that at least some of these polygonal terrains on Mars actually contain quite pure ice in the polygons themselves, quite close to the surface."

She also shows a Phoenix image that illustrates what polygonally patterned ground looks like from the surface.

-the other Doug

No, since this is an issue of perception, one person's individual perception is not a large enough sample to be meaningful.

We *all* need to go. (Just to settle the point, you know...)



-the other Doug