Rover Exiting Crater To Continue Martian Marathon

Riding with Robots writes "The robotic geologist Opportunity has nearly reached the rim of Victoria Crater, which it is leaving after a year of exploration inside. Rover handlers decided to abandon attempts to approach the crater's cliff walls when they saw a power spike similar to the one that preceded a broken wheel on its twin, Spirit. Opportunity is already making do with a stuck robotic arm. The mission's manager said, 'Both rovers show signs of aging, but they are both still capable of exciting exploration and scientific discovery.' Opportunity is set to continue trekking across the Meridiani Plains of Mars, even though its wheels have already seen 10 times the use they were designed for. Meanwhile, Spirit has survived yet another harsh Martian winter to produce another striking panorama." Adam Korbitz notes other Mars-related news that funding has been approved for the Search for Extra-Terrestrial Genomes (SETG) Project. The project was one of 15 selected to receive funds through a NASA research opportunity program. The stated goal of the proposal is to "develop a PCR detector for in situ analysis on other planets, most immediately, Mars. This instrument is so sensitive it should allow the detection very low levels of microbial life on Mars, and will determine its phylogenetic position by analysis of the DNA sequence of the genes detected in situ."

zzz

[apodyopsis]

so.. we all know what would happen if Microsoft designed a motor car, but what would happen if the Rover Team designed one?

(I don't know about you, but I think still working after 4 years is damn impressive)

secrets to rovers' success?

[jschen]

Are there any key lessons to be learned from these rovers' success? Or is it simply that they have no critical consumables (being solar powered and all) and they evidently were overengineered? I guess for starters, having redundancy and the ability to turn off failing components is good, seeing as they're six wheel drive and one of the rovers is now dragging a bad wheel around. What else has been learned from these rovers about engineering long-lasting probes?

Re:PCR? With what primers?

[MightyMartian]

I think that's a ludicrous assumption. A reasonably safe assumption is that most life in the Universe is carbon-based, simply because carbon is capable of making the largest and most complex molecules. There's no reason I can think of to think that the end result of any abiogenesis process has to be DNA as the replicating molecule. Carbon can probably be used to produce all sorts of replicating molecules.

Re:Gene expressions?

[clonan]

Actually, there are fairly good odds that alien life uses DNA in a similar way that we do.

Primarily because proteins/amino acids are the only chemical family that has the variation needed for life to function. Sugars don't have the variety necessary and lipids have difficulty interacting with aqueous environments. the 20 amino acids we use cover the full range of conditions, acid/base/hydrophobic/hydrophilic/big/small/odd (proline). It is unlikley that other lifeforms will use significantly more or less amino acids even if the specific chemistry is slightly different.

The biggest problem with proteins is that they can't store information. They can't form complements and unfolding a protein to directly read off the amino acid sequence typically destroys the original protein. Life needs a repository of information that is self correcting and is non-destructive to existing proteins.

Since sugars and amino acids are common (sugar forms easily and amino acids are necessary for efficient life) it is not unlikley that DNA/RNA (which is based off of these two molecular families) would form and it DOES fit the bill for data storage. Since simplicity provides stability, it is unlikley that a huge number of different base pairs would be used so either 2 or 4 bases are likley. Due to space limitations it is very unlikley that a DNA/RNA system would use more than 3 hydrogen bonds and 1 hydrogen bond is too weak. Therefore the list of usefull base pairs drops to either 2 or 3 bonds and we call them adenine, thymine, guanine and cytosine.

I freely admit that this is based off of an N of 1. But even with that said it is important to remember that life is hard and the simpiler/more efficient a system is the better able a life form is to survive. While the system we use isn't mandatory, it is very likley that it is representative of other similarly effective systems.

A PCR system would be able to detect the residue of a lifeform that looks even remotly like us on a molecular level. Since we know our system works and we have no knowledge of a different life system it is only reasonable to look for a system we know works. PCR is our best bet for identifying life.

Re:Kind of a waste

[MightyMartian]

I tend to agree as far as finding life on Mars. Even if there is, it's either far under the surface (and it's highly unlikely that any robotic mission is going to get complex enough to wield great big drills), or they're looking the wrong places. I would think a more profitable region to look would be something like Valles Marineris, which at its deepest would have quite a bit denser atmosphere (maybe dense enough for liquid water).

Re:PCR? With what primers?

[exp(pi*sqrt(163))]

> This seems like a pretty dubious assumption to me.

We don't know how life arose on Earth but the assembly of complex self-reproducers from simpler compounds doesn't seem like any everyday occurrence. We do know that material can be transferred from Mars to Earth and possibly vice versa. So if we find life on Mars we have three scenarios:

1. Life arises spontaneously on Mars by unknown mechanism. Life arises spontaneously on Earth by unknown mechanism.
2. Life arises spontaneously on Mars by unknown mechanism. Life is transported to Earth by known mechanism.
3. Life arises spontaneously on Earth by unknown mechanism. Life is transported to Mars by known mechanism.

A simple application of Bayes' theorem tells us that the first is the least likely.

Re:PCR? With what primers?

[drolli]

Well.

a) Working point for life is liquid-solid

b) To form structures, valence bonds are suitable

c) Combinatorics requires more than two valence bonds to make different molecules

d) bonds should be strong in comparison to temperature, yet not forever

All this make carbon a pretty likely candidate to be involved. Hydrogen is painly so abundant that it *will* be involved and oxygen is also not seldom. So it is not unlikely that life somewhere else may be based on a cemistry similar to ours.

Re:zzz

[captainClassLoader]

And a tire life of ~400K miles (~644K km).

Martian Trash?

[trongey]

Did anybody else who's dowloaded the high res pic notice the white plastic pill bottle just right of center, about 1/3 of the way up from the bottom?

More Mars color BS

[Teilo]

Once again, another BS color image from Mars.

Anyone who cares to, do this: Open the image in Gimp or Photoshop.

Look at the per-channel histograms. You will see that someone compressed the Blue and Green channels before posting the image.

To fix:

Normalize each channel individually so that 0-255 spans the full channel range.

The result? Mars as Opportunity actually photographed it.

Does NASA really think that we are so simple-minded that we would be too confused and disoriented to see a Mars without red sky?