This is awesome! I love that Mars continues to baffle, astound, and fascinate us. Sometimes our 21st century hubris makes us think we are reaching some kind of peak knowledge, but moments like this prove that we yet know so little.
In particular, the geology of Mars in an incredibly fascinating topic. If you're looking for a good primer on the subject, I highly recommend Mapping Mars by Oliver Morton.
Mapping Mars contains a history of the science, highlighting the major contributors to the field and augmented with interviews from such notable science fiction authors as Kim Stanley Robinson. A good discussion is, for example, how much water exists on the planet. Consensus is now that there is water somewhere, but exactly how much water, where it sits, how it flows: great questions that are attacked with lucid explanations.
Hats off to NASA and human curiosity for this grand adventure.
In the Mars trilogy (Red Mars/Green Mars/Blue Mars) by Kim Stanley Robinson, the term "areology" was coined for describing geology-on-Mars. I always thought that was a great word.
Your point is a good one. However just to interject tangentially, hubris is demonstrably not a 21st century phenomenon, nor imho will it cease to be a phenomenon in any future period of human existence.
"Peaks of knowledge" have existed throughout our collective history and the single uniting feature of each is that they are never peaks. Local maxima perhaps, but the upslope of discovery always reasserts itself eventually. Afaik, nothing indicates that the future will differ in this regard.
Pardon my idiotic question, but why don't they just drive over there and check them out? Or are they just in a totally different place than the rover (like asking why someone in North America can't just hop over and check out Uluru)?
Apparently there are two active rovers on Mars right now [1], both of which have an average speed of about 0.02mph [2,3]. I haven't checked out the geography of the situation but it's not looking promising.
That is not an idiotic question at all, it's a very good question. The reason is that (as you surmised) the rovers are very far away. Which begs the obvious question: why didn't they land a rover closer? That's a much harder question to answer. Landing site selection is a complex and somewhat political process. But there have been two polar missions, one successful, one not:
It's a combination of a scientific and engineering limitation. The Curiosity rover's power source generates an average of about 1/6th of a horsepower of electrical power. In practice this is used to trickle charge the batteries of the rover over night and provide slightly higher total power during the day for driving, even so we're talking about a fraction of a horse power to drive a nearly one tonne vehicle the size of an SUV. The Opportunity rover is smaller and lighter (180 kg) but also solar powered and so has much less total energy to work with per day.
If the goal were merely speed we could build faster rovers but to do so would mean removing a lot of scientific instruments so we'd be able to get to different locations but then we'd only be able to do a tiny amount of science compared to what we can do with Curiosity or Opportunity.
How much of this is also a reflection of autonomous navigation, risk avoidance, and proceeding at a deliberate pace? While we've got vehicles on Earth which can navigate established highways at, well, highway speed (Google cars), the established road network on Mars is substantially less extensive, and the downside risks (in terms of mission outcome) of even a small mishap on Mars would be very high.
So: for both engineering reasons (power supply & motors vs. scientific payload) and risk mitigation, you end up with systems which are mobile, but only at a very slow crawl.
Incidentally: Mars also limits the options for higher-mobility systems. The atmosphere is too thin for conventional winged aircraft to be terribly effective (they'd have huge wingspan requirements relative to payload, and very large turning radius and stall speeds). Balloons would be impractical. The gravitational force is high enough that a multi-hop lander relying on rocket thrust would be expensive.
Some sort of robotic tumbleweed / beachball might work, though unless these had some means of getting themselves unstuck, would likely just scatter over an area of terrain (erm, marscape?), before settling against an outcropping or at the bottom of a ravine, crater, canyon, etc.
Another reason why the rovers are slower than cars: cars have air-breathing engines. On Mars, your propulsion system needs to be totally self-contained, or else solar powered.
Why can't they just use nuclear power? Didn't the viking probes from the 70's use that? I might be wrong, but I thought that curiosity actually did use nuclear.
Curiosity does use a nuclear power source (an RTG) but it only provides a little over 100 Watts of power. As I said, the primary use of the RTG is not to drive the rover but to power the batteries over night to drive the rover during the day. Even so, this still amounts to less than one horsepower available to drive a nearly one tonne vehicle.
Like the Viking probes, Curiosity uses the heat from natural decay, not fission. It's a much more foolproof system than a reactor, but it only generates 110W, meaning it needs batteries to handle bursts of demand over 110W.
This stuff blows me away. I think, holy crap this planet has all sorts of real exo-planet kinds of weirdness. I love the idea of reverse icicles although for the life of me I can't imagine what would hold them up once the CO2 gas has vaporized out.
One part of me wants to build another Curiosity style rover and catch the next Earth/Mars orbital cycle and put it down near stuff like this.
I can believe folks would find this as inspiring as looking back at the planet from the Moon.
Certianly do seem to follow a frost/freeze pattern in some ways, even if they do tend to have a bag of flour type directional point. So can see the reverse icicles. Question is it a biological or a chemical reaction. I do feel that it could be chemical but thats just a hunch and that is what makes it a holy crap mystery.
Is there any chance they could be plants? relying on underground water reserves and appearing every spring to throw around some pollen before slinking back into the cool darkness.
I'm not a xenobiologist so I couldn't quantify the relative chance of them being 'plants'. But this is the kind of stuff we can speculate on.
First, we'll need to be a bit loose with our definitions since 'plant' means a very specific kind of thing.
So if we define a 'plant' as a chemical process which creates structure in the presence of certain chemicals such that a transformative chemical reaction is enabled whereby energy in the form of sunlight or heat is used to build additional structure. Then we can see if there is a chemical mix that would have this characteristic output.
It is critical to note though that this would also classify a stalactite as a 'plant' which converts calcium carbonate into 'structure' (in this case rock) by exploiting a transfer agent (water).
Interesting questions would be "Why vanish in the winter?" what ever hypothesis we come up with has to include the observed effect and behaviors. This is my biggest issue with my 'frozen geyser' hypothesis, it seems like they would continue to exist during winter.
Finding better imagery from HiRise would be good too, in particular it would be useful to know if these were vertical structures or not. that would show up as shadows.
Why not literally a plant? Like leafy, relies on water, comes from a small seed, reproduces via pollen/wind, based on a cell structure.
We have plants in the desert here on Earth that blossom once every X years or decades. Is there a reason such a "plant" could not have survived the harsh later years of mars post surface water?
Bonus idea: if these are plants relying on ground water, their location would give away the position of said ground water. They could be mapped and their spacial density used to find source pools for humans to tap.
Because plants, of the leafy green variety, have a complex evolutionary history with lots of side trips (like lichen and mold and algae). Further earth based plants are based on the same basic DNA structure as earth based animals.
So while it is not "impossible" that an equivalent to plants evolved into exactly one species or micro-eco-system which exists in this one place on Mars, the chance that this occurred and didn't cause the whole planet to have evidence of their existence is really really small.
But don't let that discourage you from trying various plant hypotheses. The way to pursue that is to then try to figure out what things would be true if they were plants, and see if any of the data we have from Mars would allow you to get closer to proving or disproving your hypothesis. The last time I checked you could ask for and get the a copy of the raw data from JPL if you asked for it (well not some 'give me all your data' kind of ask, but "I'd like to get HiRise imagery from this part of the planet ...")
Yes, they could. But can you include some reasoning with how they would have done that? Some sound more likely than others.
The panspermia theory [1] is based on the idea that perhaps some forms of life could exist in space as it transits from place to place. One of the things that has always bothered me about that hypothesis is the orbital mechanics. Which is to say if you posit a supernova or other energetic event that accelerated a planet (or fragments of that planet) into space, and somehow the life on those fragments survived both the radiation and the effects of vacuum on volatiles, and then it arrived in our solar system, what would the relative velocities be of that material with respect to our planets? And then when that material impacted a local rocky planet how much energy would be released and how would it survive that?
The 'primordial soup' theories have thus always held more interest for me as being more probable. With papers like this one: http://arstechnica.com/science/2012/10/simple-reaction-makes... lending a bit of narrative around how it might have occurred. But the primordial soup theories also need evolution to get from a happenstance chemical mixture into something like multi-cellular organisms.
So follow your chain of reasoning and see what questions it leads you to:
"down from an external source" ...
From where?
How did the plant get there to come down?
What is needed to survive a fall from space? At what velocities?
If we ever confirm life on Mars (or anywhere else for that matter), I really hope we don't find that it shares a common ancestor with life on Earth. Panspermia is cool, but two instances of abiogenesis in a single solar system? That is huge.
Here's to hoping it's life, but not as we know it.
>"I really hope we don't find that it shares a common ancestor with life on Earth". Could you give a definition here, please?
I cannot respond to you directly, but sure. When I say I hope there is not a "common ancestor" I mean that I hope life on Earth and life anywhere else we may discover it do not have "common descent" (http://en.wikipedia.org/wiki/Common_descent). That is strongly believed to be the case with all life we have encountered so far. This is also a pretty good wikipedia page about this: http://en.wikipedia.org/wiki/Last_universal_ancestor
For plants to be on Mars, either A) the immeasurably chaotic process of evolution yielded carbon-based, cellular, stationary, metabolizing, photosynthetic, reproductive things on two planets with vastly different geological and climatic histories, or B) Earth-borne plant material, which has evolved to the point that it can only produce a viable organism in certain rather specific environmental niches on its home planet, has somehow reached a foreign planet and developed into a more-or-less thriving colony of vegetation upon it.
We obviously are operating with an extremely limited dataset (currently of size "1"), but there are a few things we can look at that may tell us something about the likelihood of particular characteristics evolving.
We know that flight has evolved on Earth at least four completely distinct times (no common flying ancestors): birds, bats, bugs, and pterosaurs. The basics of eyes are thought to share a common ancestor, but complex image forming eyes are thought to have evolved dozens of times.
I'm sure there are many better examples; I have only studied biology in my spare time as an adult, so maybe a biologist can step in.
The basic idea though is that since the driving force behind the change is not random certain general ideas are likely to keep on popping up over time. Now, are the building blocks likely to be the same? Hard to say, the chemistry for carbon based life works particularly well, but there are hypothetical alternatives. I can't speak to which is more likely than the other.
The question of "how likely is this" is really quite involved.
It really does. However, one should keep in mind that humans have overzealous pattern-matching engines. We are really good at erroneously seeing things that we recognize.
And when it comes to Martian geography, we are hopelessly bad at judging scale. It's very easy to be several orders of magnitude off without a guide or legend.
True. While there are examples of life getting this large or larger on Earth (blooms, clonal colonies, etc), this seems unexpectedly large for a planet that seems otherwise lifeless.
It seems like we'd be able to tell if they are geysers or something else by having a few frames of photos? A geyser would be moving in some way you'd think?
> they might be colonies of photosynthetic Martian microorganisms, warmed from the sun, now sunbathing in plain view.
That's incredible. Is that really possible? I wonder why the rover doesn't check them out? It seems weird it's digging through soil looking for chemicals possibly related to life when there's potential life out in plain view.
When planning a landing site for each rover mission, NASA considers a variety of factors and makes a best-guess as to the fruitfulness of each site from a scientific perspective.
Clearly a team of brilliant scientists has not failed to consider the possibility of exploring these strange spidery features, but they have decided against it for the time being.
It doesn't really make sense to assess their "strange priorities" as an outsider looking in with very limited knowledge as to how their decision making process actually works.
Yeah; just for starters, such a sandy area seems like a serious risk on its own to a rover, never mind the risk actual geysers would pose. The geysers are interesting, but are they worth jeopardizing an entire rover expedition for?
There is, to a first approximation, no atmosphere on Mars. To a slightly better approximation, there is an atmosphere on Mars, but only enough to cause trouble, not enough to actually be useful for anything.
On the other hand, the loss of a rover to one of these plumes could itself provide interesting information: It would conclusively prove that they occur explosively, and if we can photograph the rover afterwards then the displacement of an object with known mass would let us gauge the amount of force these things exert.
From what I read, there's a big concern about contaminating Mars with Earth-based bacterium. To ensure the drill would be useful after landing, they pre-set one of the drill bits. By doing that, they broke the sanitized enclosure, and there may be contaminants present that survived the trip. They are supposedly avoiding signs of life with Curiosity.
The guess is random geyser's powered by CO2 plumes, so probably dangerous for the rover to check out directly. Or, maybe they will check it out during the time of the year it's cold. Not sure how far away the rover is from this, either.
Not necessarily. The rock may only be a few centimetres underneath the sand dune, in which case it would not appear to protrude out from the dune significantly. There is also the possibility that the "spiders" are black sand[0][1] or silt, as they look suspiciously like some formations on Earth (albeit on a much larger scale):
[2]: This is a sand dune on a sand island, but has some black discolouration from rock just below the surface. I'm not sure how far down this rock extends, but its visibility varies depending on the time of year and number of visitors to the island. Note that there is also some grass (brown) and other vegetation (green) around the edge of the clearing (particularly on the southern edge), which is difficult to distinguish from the black rock.
[3]: Same island, different clearing. There is still some vegetation in the picture, but it's easier to see the black sand and rock underneath the top layer of white sand.
Try playing with the time slider at the top of the page to see how the exposure of the rock changes.
Yeah these do kind of look like they have shadows. Plus a rocky outcrop could still be fairly flat and cast minimal shadows. I say it's rock and call Occam's razor on the other theories.
Dangerous how? Toxic to humans? At risk of unsettling sand around a rover/human? Is the question asking if they are something that would consciously attack someone?
Everything is dangerous. The key to mitigating that danger is planning ahead for it. A leaf seems harmless, but infection from a cut the leaf gave you could kill you. A marshmallow is fluffy and soft, but if you swallow it without chewing, it could expand and suffocate you.
Asking if something is dangerous is ridiculous. Asking what it is and how to safely handle it is not. The article does a much better job portraying this than the headline does.
I downvoted because it's not relevant to its parent. As freehunter points out, the answer's not "no" it's "please refine the question". Perhaps you found my mini-analysis on the frequency of Betteridge references informative, in which case I welcome your upvotes.
It feels weird to realize that according to Mars, we're the aliens invading the planet. Makes me wonder about all the extraterrestrial "rovers" on our planet.
In particular, the geology of Mars in an incredibly fascinating topic. If you're looking for a good primer on the subject, I highly recommend Mapping Mars by Oliver Morton.
Mapping Mars contains a history of the science, highlighting the major contributors to the field and augmented with interviews from such notable science fiction authors as Kim Stanley Robinson. A good discussion is, for example, how much water exists on the planet. Consensus is now that there is water somewhere, but exactly how much water, where it sits, how it flows: great questions that are attacked with lucid explanations.
Hats off to NASA and human curiosity for this grand adventure.