I clicked the "speculation" link thinking it would be a forum thread full of scientist debating whether it was caused by volcanism or something similar, I didn't expect to be trolled by APOD.
I always thought that in some parallel universe, Clifford Stoll has a pretty successful stand-up career. In this one he makes lovely klein bottles for people though, so we might have the better deal - http://www.kleinbottle.com/
It looks remarkably like a sinkhole. Although one could joke, "Hey guys we found your Mars Climate Explorer!"
Given the fact that its on the side of a volcano it could also be a hole in a lava tube. But whatever it is, it is really cool and damn wouldn't it be nice to have someone there we could ask to roll over and check it out?
Funny I visited #1 "Meteor Crater" or Barringer Crater last year with my wife.. It's hard to understand the scale of this thing until you're on the ground walking around it. Makes you feel very small in the grand scheme of things.. :)
Just the link color was borrowed from Twitter Bootstrap. Rest is pretty much white background, max-width, padding between <center> elements on the page, bigger line-height :)
If you send me the CSS (by comment or email from my profile), I know a few people that work at Goddard, and might have a better shot at getting them to add it :)
Perhaps this feature or one like it could be incorporated in to a future colony by sealing up the hole and artificially stabilizing the interior structure? I know similar ideas have been floated in the past for the conversion of lunar lava tubes into habitable space.
In lieu of Curiosity landing on Mars in just two weeks, I wonder if one of these is within reach for the rover to do some exploration? Although it's probably too dangerous and the rover is probably not equipped to explore something like this.
The chances of this being within single digit kms of the Opportunity rover are very very slim. Mars is a big planet. The MERs are amazing, and have outdone all expectations, but they're not magical.
Yeah, I figured it would be slim, but I'm guilty of letting my imagination run away from me. Btw, what's an MER - Mars Exploration Rover? Agreed, if yes: I wish I was more into Astronomy when Opportunity and Spirit landed, but thankfully, they lasted long enough for me to appreciate the feat, while in progress.
actually the correct article for the nominative of "Maus" is "die", in the title "Die Abenteuer der Maus" "der Maus" is genitive so that's why it stands with "der" but the correct nominative is "die Maus" ("Maus" is feminine). Also note that "Abenteuer" has nothing to do with "Abend" (evening) so there's no "d" in it. SCNR.
"Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life"
Isn't that grasping at straws a little? I'm not a biologist, but it seems highly unlikely to me that life would develop in a hole 35 meters across.
Life wouldn't develop there, but if life used to cover the surface of Mars, and largely died over time, but was still surviving in some places, this would be one of the likely spots.
The caves and small places of Earth say otherwise. So do the intense environments on Earth that we've found life in. It's at least as plausible that life can hang on, sheltered in the smallest of places, as it can anywhere else. Micro organics often don't mind if you put them in a small place, with little sunlight, high or low heat, high or low oxygen, etc.
The biggest problem would be if the changes Mars underwent were too fundamentally anti-life for anything to survive whether it was in a cave or anywhere else.
In my opinion, we're going to find out on Mars that there are forms of microbes that can hang on in sedentary 'ready' state for a billion years, in extreme environments, just waiting to jump back to activity. Most of Mars will be barren, but there will be small pockets of microbes (most likely in a sheltered cave, under ice, or similar) in a form of extreme suspended animation.
They're not saying that life developed there, they're saying that if there ever were martian life, this is one of the few places on the planet that has a (relatively) less-severe environment, and therefore a higher likelihood of finding surviving specimens.
This is fascinating, especially whether the hole was created from a top impact or from the bottom such as volcanic eruption.
On another note, why are we discovering this just now? I was under the amateur impression that the entire surface of Mars was scanned and imaged by NASA at some point. But again, I may have interpreted that incorrectly.
> why are we discovering this just now? I was under the amateur impression that the entire surface of Mars was scanned and imaged by NASA at some point.
It's easy to forget just how large Mars is, as a comparison, if we scaled Mars up to the size of Earth, the hole would only end up being about 120 meters, or about %30 larger than an American football field. And when it's a feature that we pretty much need human eyes on to determine it's significance, it's easy to imagine how we've missed it. Just imagine trying to find a random football field sized thing in Google Earth, somewhere on the planet.
And to make the comparison even more valid, Mars isn't covered in water, and has a very comparable amount of land surface area as Earth does. in that case, it makes the hole only about 36 meters when scaled up to the surface are of Earth, which is likely what you'd be searching for in Google Earth.
Not to mention that I have no idea to what resolution Mars was scanned and imaged at, considering imagery I see of Earth often, the mentioned scans could easily have pixels larger then the entire size of that feature.
Hence it's easy to imagine that many more interesting features of similar size exist on the martian surface, sitting there in plain view, waiting to be discovered.
I don't have the tools on this CPU to get good numbers, but if that hole is about 35 Meters, I'd estimate to resolution to be about 20 CM/Pixel. I know it's often difficult to find civilian access to Imagery at a better resolution than 5 M/Pixel for some places on Earth.
It's probably safe to assume we don't have imagery this good for the entire surface of Mars.
Macro-level features have been mapped for a while, but even from earth orbit (Hubble) it's not possible to resolve features at high resolution. I'm not sure what the precise limits are, but according to one photo (http://commons.wikimedia.org/wiki/File:Mars_HST_Mollweide_ma...), Hubble's imaging of Mars is at a resolution of approximately 20 km/pixel, which is several orders of magnitude too low to resolve the "hole" here, which is <100m.
Since 2006, there's been a high-resolution camera platform orbiting Mars (http://en.wikipedia.org/wiki/HiRISE), and it's doing this high-res imaging, at up to 30cm/pixel (!), for the first time. Though Wikipedia says that as of 2010, it's only mapped 1% of Mars's surface to that degree.
If we had one of the surplus Hubble-diameter Naval Reconnaissance Office mirrors orbiting Mars with a suitable camera, would we have better pictures than this?
And could one of those mirrors be mounted in the trunk of a SpaceX Dragon spacecraft?
Actually, because it is circular the chance of it being a meteorite is slim. This is because the ejecta of a meteor crater is related to the angle at which the meteor hits, the more oblique the angle, the more oval the crater. A circular crater would suggest a perpendicular collision. That would suggest a very slow or very fast meteor, the latter would have caused a bigger crater. The third challenge with the meteor hypothesis is that the 'hole' suggests a cavern, and the cavern would have undergone a lot of compressive stress when struck. One would have to figure out how the meteor went through the top of the cavern without collapsing it (the shock wave from the impact would have pushed all along the top).
So its not impossible that it was a meteorite but it is improbable.
To be clear, I wouldn't rule out a meteorite, I'm just saying that in order for it to be a meteorite some things need to be understood. The sinkhole hypothesis fits the picture precisely, but requires that someone explain how the top of the cavern got opened in the first place.
In a traditional research setting the next thing we would be doing is coming up with ideas that would rule out a hypothesis in order to give us higher confidence in the ones that remain. To that end, you've added data which doesn't help us rule out either of our hypotheses so it doesn't advance us toward our goal of understanding.
Finding a circular meteor crater on the moon with a cavern underneath it would be useful.
Another useful thing is to look at the sides of the hole. If the material was removed by pushing outwards, the sides will have one shape, if it was removed by 'draining' into the hole in the center they will have another shape. A good experiment you could run on earth to think about that would be a put some sand over a hole and drain it, take that shape. And then to take the same setup, cover the hole lightly, and blow on it with a directed stream of air until you punch through the thin covering on the hole and then take that shape.
If we can figure out the probable way in which the material was removed, that too can inform our hypothesis. I encourage you to keep coming up with ways to figure this out.
What does it take to make flight happen on Mars? The air is thinner, so would more force be required for airplanes and helicopters to fly? How well would hot-air or helium inflatables work, compared to Earth?
Yes, there is work going on to achieve that. Airplanes can fly quite well in thinner air, they just have to fly faster or have bigger wings. I don't know about helicopters or balloons, but there is a project which aims to bring a solar-powered airplane to Mars. The main problem are the batteries as they have to hold enough energy to fly trough the night.
See e.g.:
Noth A., Engel W., Siegwart R. Recent Progresses on the Martian Solar Airplane Project Sky-Sailor In Proceedings of the 9th ESA Workshop on Advanced Space Technologies for Robotics (ASTRA 2006), Noordwick, Netherland, 2006.
[http://www.sky-sailor.ethz.ch/docs/Sky-Sailor-ASTRA2006_Noth...]
Noth, A., Bouabdallah, S., Michaud, S., Siegwart, R. and Engel, W. SKY-SAILOR Design of an autonomous solar powered martian airplane. In Proceedings of the 8th ESA Workshop on Advanced Space Technologies for Robotics, (ASTRA 2004), Noordwick, Netherland,2004.
[http://www.sky-sailor.ethz.ch/docs/Sky-Sailor-ASTRA2004_Noth...]
Noth, A., Engel, W. and Siegwart, R. Flying Solo and Solar to Mars - Global Design of a Solar Autonomous Airplane for Sustainable Flight. IEEE Robotics & Automation Magazine, Volume 13, Issue 3, pp 44-52, Sept. 2006.
[http://www.sky-sailor.ethz.ch/docs/Flying_Solo_and_Solar_to_...]
The air is much thinner but they made a manned plane fly 85000 feet high at Mach 3.3 in the 70s. It wouldn't probably be that hard to make an unmanned drone capable of flying on Mars.
To transport and ensure it's operational by the time it gets there, might be a completely different matter, though.
I don't really understand how come no-one was able to see it before... I don't know how it works, but since telescopes are looking for stars and stuff much more distant that mars, I was confident that they scanned the whole surface of neighbors planets decades ago... Some explanation?
There's a limit for how big/small an object you can see with a telescope due to diffraction. For instance, the Hubble telescope can not distinguish features on the moon that are less than approximately 100 meters. Obviously it gets much worse for Mars and the other planets.
Mars (according to Wikipedia) has a surface area of 144,798,500km^2. This thing is within an area of 35 meters^2 and I'm guessing it's not very flashy when viewed on a screen.
anything that gratifies one's intellectual curiosity
I just spent a whole day in AES encryption, specifications and code. Being reminded there is a wider world out there, quite literally, is fine by me, especially a world where the answers are not obvious or wrapped in politics - why is the surface white? Is it impact or collapse?
Yes, yes, I know the guidelines and I agree with you ofcourse. I'm not against discussing non CS / Startup related topics. I just felt that this particular topic isn't interesting enough for whole of HN to rank it at #1.
I also realize the absurdity of complaining about a topic that doesn't match my interest in a news aggregator, but oh well.
I suspect you might be, like me, beginning to suffer from deja-HN
I think I would like to capture the opinions of HN's best discussions, categorise them and then be able to filter on - oh look another discussion on web security best practises. Fine - does it add anything beyond what we already have filed under best-of-HN-security - no? Ok ignore.
It's what I suspect kills most forums, not really going downhill, but going round and round the same hill.
Instead of some of our more prolific members saying "I have posted on this before (a lot)" maybe they could say "look at the HNBrain on #dontdropyourdayrate "
