What is Digg?63 Comments
- trolleyfan, on 11/19/2008, -0/+40Now if only the Martians had had a few nuclear bombs and a drilling machine made of unbelivium...
- Diggworthy, on 11/20/2008, -0/+27"20 asteroids between 124 and 311 miles in diameter [hit Mars], each leaving a crater. By contrast, the object thought to have killed of the dinosaurs on Earth is estimated to have been 5 to 6 miles wide. "
"One of the last giant meteors blew a hole 1,864 miles wide in the planet, creating Utopia basin in the planet's northern hemisphere."
Wow. - SpanishMongoose, on 03/02/2009, -0/+25well that sucks... good thing those twenty asteroids hit mars and not earth...
- andypop481, on 11/20/2008, -0/+20"Earth probably took the same kind of punishment," Roberts said. "But it's primarily a function of size. Earth has more than 10 times more heat than Mars, and much more vigorous convection."
Yeah woo go earth! - milkshaker, on 11/20/2008, -2/+19God planted those asteroid craters on mars to test our faith.
- doublefelix, on 11/20/2008, -1/+15So, if you use your compass on Mars does it point to Earth?
- TSK05, on 11/20/2008, -0/+13"Then, beginning around 4.2 billion years ago, it [Mars] was suddenly pummeled with at least 20 asteroids between 124 and 311 miles in diameter, each leaving a crater. By contrast, the object thought to have killed of the dinosaurs on Earth is estimated to have been five to six miles wide."
Well hey, at least Mars wasn't pummeled by a Mars sized object...unlike Earth. Which probably formed the moon. No, I'm not high: http://en.wikipedia.org/wiki/Giant_impact_hypothes ... - lebondarken, on 11/20/2008, -0/+13yet...
*crosses fingers* - postitnote, on 11/20/2008, -0/+12WE'RE NUMBER ONE! WE'RE NUMBER ONE! SUCK ON THAT, MARS!
- inactive, on 11/20/2008, -0/+10chill dude. We got Bruce Willis to save us.
- TSK05, on 11/20/2008, -1/+10No they don't. Most researchers don't get paid anywhere near that much. Jobs in physics and astronomy are very hard to find as well.
- McNash, on 11/20/2008, -0/+6We already have landed on mars... Several times...
- FolkTheory, on 11/20/2008, -1/+7good thing Heavy Bombardment is over.
- FurtThePirate, on 11/20/2008, -0/+5Could you imagine another "earth" in this solar system? and then actually seeing aliens that close. we would have landed on mars a long time ago...
- SawButter, on 11/20/2008, -0/+4So does it mean that Mars will never be livable planet ?
- TSK05, on 11/20/2008, -0/+4We got hit by Mars (well, a Mars sized object). Mars can't exactly top that.
- dotorg, on 11/20/2008, -0/+4Actually, ones like that very well could've. The article didn't make it clear but part of the difference in mass of Earth and Mars means (as it stated) that Earth has 10x the thermal energy of Mars... What that means is at a period of time on Mars where an impact that size would cause a persistent crater, impacts of that size on Earth could very well have been "absorbed" through plate subduction or through massive volcanic outflows that hid the crater.
Remember, this is talking about a period of time very close to the formation of the planets -- and Mars will have cooled and solidified at a faster rate than Earth. - AgentMull, on 11/20/2008, -0/+4... and had a base plate of prefamulated ammulite, surmmounted by a malleable logarithmic casing in such a way that the two spurving bearings ran a direct line to the panametric fam.
- ZenFu, on 11/20/2008, -0/+3It WAS Unobtainium.
- warriorscot, on 11/20/2008, -0/+3You would have to restore the magnetic field and regenerate a new atmosphere from scratch to do it, and there isn't any way to do that, regenerating an atmosphere might be possible in the future you could capture asteroids and comets and use them to produce new O2 and H2O but a magnetic field would be tougher.
You would either need to create it artificially which isn't impossible its just absurdly difficult and expensive or reheat the Mars core to start convection without destroying the planet in the process, and we don't understand enough about the processes at that depth to even begin to fathom how to even attempt it. Not to mention that Mars might just be to small to sustain a hot core for any length of time earth is much larger than Mars.
Venus has a much heavier atmosphere which is why it hasn't been eroded, and to clear up the tectonics question: Tectonics are a result of the same conditions causing the dynamo effect, tectonics seem big effects to us but they are really a small part the earth is almost entirely molten we just live on the ultra thin skin layer on the outside, if the earth was a big orange the plates we live on would be about as thick as a postage stamp.
But all these Mars questions will take a long time to solve until we actually get boots on the ground, an actual Mars mission with a proper geology team and all the tools would be able to get allot of the answers quite quickly. - arkboysooner, on 11/20/2008, -0/+3I'm not an expert, but I'm assuming at this point Mars is a dead planet. There may be a way for us to terraform it and make it habitable though.
- posaunepat, on 11/20/2008, -0/+3If only there was an article somewhere about this. If there was, maybe it would be called "Did An Asteroid Kill Mars' Magnetic Field?" and show up on MSNBC or something.
FTA:
"Roberts and a team of researchers calculate that the Utopia impact could have done in the magnetic dynamo, which was already flagging as the planet cooled. It injected approximately one trillion megatons of energy into the Martian mantle, or close to 10 trillion times the explosive energy of the nuclear bomb used at Hiroshima.
The heat spread in an instant as a supersonic shockwave rippled through the planet. Then, over the next 30 million years, the overheated mantle acted as a blanket for the core, preventing it from circulating enough to maintain a magnetic field." - jpop, on 11/20/2008, -0/+3There's been multiple times in the past where the Earth's magnetic field has been highly reduced/disappeared. At the very least, it means more radiation getting in and causing mutation problems.
- TSK05, on 11/20/2008, -0/+3No. Venus has a very small magnetic field (and what magnetic field there is not driven by the core either) and has no magnetosphere so it's not protected against solar radiation. And yet it still has a very thick atmosphere.
posaunepat is right that we believe that Mars' atmosphere was blown away partially by solar wind (and the water on Venus too) but we're not exactly sure about how much impact that has because Venus basically has no magnetic field and yet it has a very thick atmosphere. We're also not sure why Venus has such a weak magnetic field, based on what we currently know...it should have one driven by the core because it's almost Earth sized and should not have had time to cool. So basically the answer is that we don't know but as Venus obviously has an atmosphere and yet no magnetosphere, it's way too soon to rule out making Mars livable. - Grin23, on 11/20/2008, -0/+3Mars is dead for the simple fact that its atmosphere is in chemical equilibrium..
- FurtThePirate, on 11/20/2008, -1/+4"We" as in people, not robots with little cameras.
- schnikies79, on 11/20/2008, -2/+5200-300k? Really? I work with a well known researcher and he makes a little over $85k.
Most of this type of research comes from Academia which rarely pays over $100k. - TSK05, on 11/20/2008, -0/+2Grin23 - yes, it only got clipped..well...clipped...not clipped like barely touched but not head on, here is a good animation: http://en.wikipedia.org/wiki/Image:Big_Slash.gif
But the fact that this occurred at about the same (relatively) time is not a coincidence. There would not have been anything large enough left to hit either of the planets after this time period. Well, that's not necessarily true because there are still rocks the size of the asteroid that hit Mars out there but much fewer so the probability would have been far less.
Bub978 - it's a little more complicated than just getting hit. The title is of this article is actually misleading - even if there was no asteroid, Mars would not have a magnetic field any more, it's core would have cooled by now and there would be no convection of molten material. This is noted [somewhat] in the article:
"Roberts and a team of researchers calculate that the Utopia impact could have done in the magnetic dynamo, which was already flagging as the planet cooled."
"As the mantle cooled form the impact, there wasn't enough energy in the core to restart a dynamo from scratch, Roberts reasons, and so the magnetic field was gone forever. "
The core was ALREADY cooling (and had cooled significantly) and only because of this the impact was enough to stop the dynamo (and because the core had cooled to a good extent already, there was not enough energy to restart the dynamo afterward). The Earth is more massive than Mars and it takes a longer time period to cool (this is why our core is still warm even though Mars' core would already been mostly frozen (it would at most have a weak magnetic field) even if it hadn't been hit by anything). This article is also a theory still early in development, it's not a sure thing - we can't just say "Mars' magnetic field is gone, must have been an asteroid" because it would have been gone by now anyway. - inactive, on 11/20/2008, -0/+2Thanks god, Mars saved EARTH.
- unclecaveman, on 11/20/2008, -0/+2haha what?
- arkboysooner, on 11/20/2008, -0/+2But think of those poor unborn martians!
- posaunepat, on 11/20/2008, -0/+2The thick atmosphere on Venus is mostly carbon dioxide, a heavy molecule that couldn't escape the planet's gravity and isn't affected by solar wind (the solar wind isn't strong enough to "blow away" CO2). Unlike the lighter hydrogen, which floated away - due mostly to the fact that most of the hydrogen (99%) was bound up in H2O molecules that were ripped apart by the unimpeded solar wind (thanks to the weak magnetic field). Which also explains where Venus's water went.
Mars probably lost it's liquid water the same way, since H2O molecules can't avoid being broken up by the solar UV radiation, which our magnetic field (mostly) protects us from. It also explains why Mars is so red, as the oxygen that was split up from the water molecules ended up oxidizing (rusting) the rocks on Mars. - anachronaut, on 11/20/2008, -0/+2You might want to recheck the location of the asteroid belt. Mars is between the main belt of asteroids and the Sun -- if they were to move away from the Sun for whatever reason, they'd obviously be moving away from Mars as well, not towards it.
Sun - Mercury - Venus - Earth - Mars - main asteroid belt - Jupiter, etc. - fuzzybeard, on 11/20/2008, -0/+2If by "livable" you mean walking around outside like you can on Earth, no; it wouldn't be possible even with terraforming. Building habitats...maybe, but the radiation shielding would be a bitch of a problem to solve,
- Mujokan, on 11/20/2008, -0/+2Colonization doesn't necessarily require reconstituting the atmosphere as per Total Recall -- which would be a pretty unlikely scenario even if the magnetic field reappeared, anyway. Can't really think why they'd want to go there, but never say never. Probably a moon colony is more likely -- turn moon rock into concrete for decent orbital environments, maybe (well, it was in William Gibson).
- fuzzybeard, on 11/20/2008, -0/+2I though it was Unobtainium?
I loved the movie; the science was laughably weak, but it was still fun to watch. - fuzzybeard, on 11/20/2008, -0/+1I didn't know you spoke fluent Technobabble! :)
- fuzzybeard, on 11/20/2008, -0/+1What about something like the Genesis Device from the Star Trek universe? The premise is taking a planetary mass and reconfiguring it as we see fit. It would also be a very potent weapon.
- InfiniteNothing, on 11/20/2008, -0/+1Well, mars is rather close to the astroid belt
- nOcoNtrol926, on 11/20/2008, -0/+1well, i know its wikipedia but ironically was reading about this very problem. Why does venus have super dense atmosphere when it is only protected by the ionosphere, similar to that of mars? neither have a magnetosphere like earth.
from what i've read, solar wind removed the hydrogen from both planets, leaving only co2 on the surface-on venus(along with few other elements) in the form of a super dense atmosphere, and on mars co2 ice caps. mars has an atmosphere that is somewhere around .01% of ours, mostly CO2. You can see some pics of co2 clouds on mars when the sun melts ice from the polar caps.
venus does not have plate tectonics like earth which i believe explains why there is no convection in the core to start a dynamo effect. Unfortunately my understanding of geology is far from making me an expert so if someone wants to clarify that would be great - Bub978, on 11/20/2008, -0/+1Well, the bottom of the oceans contain little in the way of resources. If our only goal is to find ways to make room for more people, I think we have a lot of land to cover before the oceans need to be colonized. But you're right, it would make more sense than Mars, if that's our purpose.
But odds are, colonization will be driven by resources. There's nothing at the bottom of the ocean that we can't reach from the top (oil). Mars, however, could have a similar geologic composition to Earth, meaning it could contain a wide range of metals and minerals we'll probably run out of soon. - posaunepat, on 11/20/2008, -2/+3Yes. Without a magnetic field, any substantial atmosphere that once existed was blown away by the solar wind. Let's keep sending robots for the cool, relatively cheap science...and forget about colonization. Not going to happen.
- 1professional, on 11/20/2008, -0/+1Well the Earth's magnetic field is what holds it together in terms of weather cycles and even on a deeper level, birds' migration routes. We don't understand much about it yet apparently, but they say if it is removed it could create an apocalypse...those more into science than me might be able to explain it better.
If this happened to Mars like 4.2 billion years ago, it would have been way before life was formed, given that it is the same age as Earth. - Grin23, on 11/20/2008, -0/+1someone correct me if i'm wrong..... the earth only got clipped by the mars sized object. sparing our planet a fate worse than death but in the process breaking off material that formed the moon.
Mars more than likely got hit head on and its a plain miracle it still even exists. - TSK05, on 11/20/2008, -0/+1lol, you're right. I had a momentary fluke there, sorry. That's probably the dumbest mistake I've made in .. years..
- TSK05, on 11/20/2008, -0/+1Oh, side note:
"The core has to have organized convection to form a dynamo," Mario Acuna of NASA's Goddard Spaceflight Center in Maryland, said. "If you disturb it with an impact, it will shut off."
-- I guess the movie "The Core" wasn't THAT far off after all...? (just kidding, but apparently there was a hint of science in that movie) - TSK05, on 11/20/2008, -0/+1"Venus does not have plate tectonics like earth which i believe explains why there is no convection in the core to start a dynamo effect. Unfortunately my understanding of geology is far from making me an expert so if someone wants to clarify that would be great"
That could be the case, but not necessarily. I believe you got this from Wiki: "Since Venus has no plate tectonics to let off heat, it is possible that it has no solid inner core, or that its core is not currently cooling, so that the entire liquid part of the core is at approximately the same temperature. Another possibility is that its core has already completely solidified."
No solid inner core? That is a possibility. It's core has to be cooling because there is a lot of volcanic activity and some believe there are huge outbursts of Volcanic activity at times (because the entire surface of Venus is about the same [young] age, why? It had to be covered over in lava at around the same time - ie, huge outburst of Volcanic activity). The core being completely solidified would not be congruent with our current theories, Venus is the same size as Earth and right now we pretty much think it's only size that matters, thus it should not have had time to cool off.
The truth is that I know for a fact (because I was speaking with my astrophysics professor on this a few days ago) that we don't really know why Venus still has an atmosphere or what's going on inside the planet (which is unlike our knowledge of all other solar planets). Wiki confirms this - as you can see, there are only guesses there and not any definitive statements. Anything definitive you see, like this "Venus has a much heavier atmosphere which is why it hasn't been eroded" is wrong. - inactive, on 11/20/2008, -1/+2"20 asteroids between 124 and 311 miles in diameter [hit Mars], each leaving a crater."
As opposed to the asteroids that don't leave a crater? - Bub978, on 11/20/2008, -0/+1I was going to bring up the fact that this article contradicts this. If we got hit with something so hard that the moon broke off from the rest of the planet, and we still have a magnetic field, how could Mars get pelted with something and 1.) Not have a moon and 2.) Not have a magnetic field?
I can't tell which is more likely to be true, but it seems like they can't both be. - TSK05, on 11/20/2008, -0/+1I already know about everything you wrote and it is correct. However I also know that there is a big debate about whether solar wind would be strong enough to prevent the terraforming of Mars. The Earth has had periods where the magnetosphere has essentially collapsed but we still have an atmosphere - some believe the ionosphere takes over. The truth is that there is a large debate so while all you said is true, it still does not preclude the transforming of Mars. Magnetic fields are quite mysterious, for instance we still don't know exactly how they are able to heat up the suns corona.
(Also, no need to quote "blow away" - I am well aware of what that actually means. The solar wind is strong enough [protons and elections lost by the sun have enough energy] to separate the atoms forming the molecules (like H2O) up and then because H is a very light element (the lightest) it is able to escape. And actually it's average speed of an H atom and an H2 molecule is still below escape velocity but the tail escapes and the distribution re-equalizes and the new tail escapes and this repeats. So anyway, you can use the actual terms in the discussion if you want instead of "hand wavy" terms.) -
Show 51 - 63 of 63 discussions
Check out the new & improved 
© Digg Inc. 2009
— Content created and posted by Digg users is 