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Tom Ames
2004-May-11, 02:11 AM
Has anyone heard any elaboration of this "etched terrain" (distance to it, likelihood of visiting it, what it might be) in Meridiani?

NASA says:


During an extended mission following its three-month prime mission, Opportunity may finish examining Endurance, then head for a type of landscape to the southeast called "etched terrain." There, additional deposits of layered bedrock may lie exposed.

http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040408a/03-FN-03-oppmap-B074R1.jpg

ToSeek
2004-May-11, 02:56 AM
If Endurance doesn't mark the end for Opportunity, the rover may press on to other regions of interest. Squyres described "etched terrain" to the south where surface coloration suggests changing rock types.

“There are two ways to get deeper down,” he explained. “You can find a hole, or you can find rock layers where the surface is tilted slightly to form a very gently sloping surface.” On such structures -– and the "etched terrain" could be one -- the rover could reach lower and lower layers simply by moving downhill across the surface.

- http://www.msnbc.msn.com/id/4790474/

Example. (http://www.spaceref.com/news/viewsr.html?pid=7934)

My recollection is that it was a long but marginally manageable distance for Opportunity, on the order of 5 kilometers. But I can't verify that now, so I'm really not positive.

Edit: This page (http://www.msss.com/mars_images/moc/2004/02/09/) shows a wide view of Opportunity's landing site within the target oval, which is about 11.5 km wide. If we're talking about that whitish filiamentary stuff to the southeast, it appears to be about 7-8 kilometers away. Kind of a long haul, but on this terrain, Opportunity might be able to get there in 40 sols or so (less time than it's taking Spirit to get to the Columbia Hills).

Nirgal
2004-May-11, 04:18 PM
I too think it would be a good idea to take advantage of the Rovers increased mobility and lifetime (and the relatively easy terrain at Meridiani)
and try to reach as much geologically distinct terrain as possible
(instead of staying at one site too long)

In flat "Meridiani-style" terrain we could probably make 5 kilometers
within about a month which would also leave plenty of time
(extended mission lasts until September!) to do all the science
and even drive back to (and finally descent) Endurance again,
if nothing more interesting is found elsewhere.

On the other hand, if we now prematurely decide to do the "final descent"
into Endurance and be stuck there for many months of the Rover's lifetime
it would be a wast of the great advantage a mobile Rover offers over a
"fixed site" probe....

(with a single Rover it is alostmost as if we had multiple probes landed on multiple sites of the planet (provided we do take advantage of the mobility and do not just park the rover on on site for too long))

Irishman
2004-May-12, 09:54 PM
To voice an alternate opinion, the rover is beyond it's original expected mission life. There is no guarantee it will continue to operate and not break down. We have already taken advantage of the mobility of the rover to check out multiple sites, and Endurance Crater is definitely an important one to check out. It would really be disappointing to go crawling after the etched terrain and have something break and not get to check out Endurance.

That is part of the trade off that the science team is trying to evaluate right now.

TrAI
2004-May-12, 10:30 PM
I think it is important to remember that the rover isn't there just to take panoramas :wink:. While most people are satiated by a few images of each area, the scientists probably want more detailed information on it, so that the rover must take a lot of images and measurements of each area. This takes time, just think about all the little area of the opportunity landing site crater had to tell. The mobility was used for what it was worth, though in a small area.

Of course it's good to get to as many diverse features as possible, but if one doesn't take the time to see what they can tell us, one would loose a bit of the point with the project... I think that several of the instruments need some time to gather reliable data, and that limits the number of measurements that can be done in a sol... If it was a pure (non-microscopic)photographic mapping it might not need to spend so much time at each area...

ToSeek
2004-May-12, 11:42 PM
There's also the question of how much of the interesting stuff in Endurance Opportunity can get to - most of the worthwhile formations seem to be stuck in the edge of the crater at a very steep angle. I don't know if Opportunity could get its arm close to them even if it went inside the crater.

jumpjack
2004-May-13, 07:39 PM
If Endurance doesn't mark the end for Opportunity, the rover may press on to other regions of interest. Squyres described "etched terrain" to the south where surface coloration suggests changing rock types.

?There are two ways to get deeper down,? he explained. ?You can find a hole, or you can find rock layers where the surface is tilted slightly to form a very gently sloping surface.? On such structures -? and the "etched terrain" could be one -- the rover could reach lower and lower layers simply by moving downhill across the surface.

- http://www.msnbc.msn.com/id/4790474/

Example. (http://www.spaceref.com/news/viewsr.html?pid=7934)

My recollection is that it was a long but marginally manageable distance for Opportunity, on the order of 5 kilometers. .
5 Kilometers?!?
Look at the "200 m" text! The etched terrain is just 250 m far from Endurance! (Around 1 kilometers from landing site).
The dark spot above the etched terrain is the heatshield, already visible in Opportunity latest images.

Tom Ames
2004-May-13, 07:43 PM
I think the arrow is pointing in the direction of the "etched terrain".

Kullat Nunu
2004-May-13, 07:44 PM
5 Kilometers?!?
Look at the "200 m" text! The etched terrain is just 250 m far from Endurance! (Around 1 kilometers from landing site).
The dark spot above the etched terrain is the heatshield, already visible in Opportunity latest images.

I've understood that the arrow points towards the etched terrain, which lies beyond the edge of the photo.

jumpjack
2004-May-13, 07:57 PM
5 Kilometers?!?
Look at the "200 m" text! The etched terrain is just 250 m far from Endurance! (Around 1 kilometers from landing site).
The dark spot above the etched terrain is the heatshield, already visible in Opportunity latest images.

I've understood that the arrow points towards the etched terrain, which lies beyond the edge of the photo.

I thought you meant the terrain "etched" by lander landing-rockets. #-o

ToSeek
2004-May-13, 08:02 PM
Sounds as if Opportunity will be visiting the area of the heat shield, to see if anything interesting was excavated in the process, but that's nothing to do with the "etched terrain," which is well to the southeast.