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Chance for a Tunguska Sized Impact on Mars
Multiple users have written to tell us of an LA Times report that an asteroid may hit Mars on January 30th. The asteroid is roughly 160 feet across, and JPL-based researchers say that it will have a 1-in-75 chance of striking Mars. Those odds are very high for this type of event, and scientists are hoping to witness an impact of a similar scope to the Tunguska disaster. From the LA Times:
"Because scientists have never observed an asteroid impact -- the closest thing being the 1994 collision of comet Shoemaker-Levy with Jupiter -- such a collision on Mars would produce a 'scientific bonanza,' Chesley said."
From the article:
"Normally, we're rooting against the asteroid," when it has Earth in its cross hairs, Chesley said. "This time we're rooting for the asteroid to hit."For all we know mars is a lifeless planet, but still....rooting for the asteroid to hit is just plain mean, bad karma. I hope it doesn't hit. Not only because of my ...uhmmmm.... nickname connection.
It'll probably take something as dramatic as a direct hit from a meteorite to finish Spirit or Opportunity off.
informed the UAC base on Mars of the impending DOOM that is heading there way?
Um, so first a huge collection of rocks smacks into Jupiter, now another may hit Mars, and they're excited?
They sound awfully like ranging shots to me, I'm more inclined to get Venus to light the third cigarette and then be wery, wery, qwiet...
If it does hit or in some other way cloud the atmosphere of Mars, would this put the brakes on current and planned future studies of the planet?
A few years of darkened skies could finish off the rovers, or require better orbiting surveillance equipment, no?
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Caesar si viveret, ad remum dareris.
We'd be talking about it for decades. It might actually wake up some people to the NEA threat to our own planet. It might have a devastating and instant effect on the atmosphere of Mars.. which could actually make the planet a little warmer and a little more hospitable.
How we know is more important than what we know.
Even if it misses it should still be a little interesting. If it comes that close, its orbit will be greatly affected, observing the results should be useful?
...if an Tunguska-sized impact occurs on the side of the planet we can't see, did it really happen at all?
-Rob
Biblical fiscal responsibility
Nothing in solar orbit can stay occluded by our moon for that long. That's for about half of the moon's orbit! If I'm wrong about that, someone please draw me a diagram. *mutters something about lousy science reporting*
*** Ponder
If the asteroid does hit the impact site would probably make for a good rover mission. Fresh samples of long buried rock without the extra hassle of having to dig it up!
Murphey's fighting Occam, and we're in the stands.
How long would it take to get to the impact site, bearing in mind that it travels at an average speed of 1cm per second, and that dust in the atmosphere from the impact will probably drastically reduce it's recharge ability?
I think you'd get there quicker by launching another rover mission!!
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
It doesn't actually say it will be occluded for 2 weeks behind the Moon, it just says that it is currently occluded and it will be 2 weeks until they can calculate it's course. I assume the need to watch where it's going to predict it accurately.
Get the cameras rolling, I'm sure it'll be a better impact then the Beagle meteorite simulation of a few years ago.
:-)
(I do feel bad for poking fun at Beagle, many people much smarter then me put a lot of work into that probe.)
If it's gonna take two weeks to get enough observations in to pin down its orbit, fine. Throwing in the fact there happens to be an occultation somewhere in there, which will last, what, an hour at most? That confuses the issue to the lay public. It's irrelevant for refining the asteroid's orbit. The article makes it sound like the asteroid will be hiding behind the moon for the entire period, when that can't possibly be the case.
*** Ponder
The received wisdom used to be that the meteorite, that caused the disaster in Tunguska, exploded above the surface of the earth. It entered the atmosphere at a relatively shallow angle and heated up much more than it would have if it had come straight down. The result was that a long relatively narrow area of forest was knocked down and there was no impact crater.
On Mars, the atmosphere is much less dense than that of the earth. The meteor in question is large. If it hits Mars, it will reach the surface, it won't vaporize in the atmosphere. The result will be much more like other impacts on the earth that did leave craters. In that light, the comparison with Tunguska doesn't make much sense. I don't know where Steve Chesley got his information on the size of the rock that exploded over Siberia but I bet it wasn't 160 feet across. Something that size would make it to the Earth's surface.
"Disaster" is a pretty hypy label for an event which led to no known loss of human life or property, and caused no significant environmental damage (yes, a lot of trees fell and some wildlife may have died, but it's not like it destroyed an ecosystem or led to an extinction of any species).
Most modern industrial projects are a bigger "disaster" in this sense than Tunguska. The event should be referred to as "phenomenon", or maybe just a "boom", but not a "disaster".
I'll bet they are. Because we have this nice dense atmosphere to sustain our breathing, we tend to forget that mars has only 2 or 3% of the surface air pressure to heat and absorb energy from an incoming rock like we have. The damage will be from a direct surface hit at the rocks full speed and should be visible if it hits on our side of mars, and it will no doubt toss up a few megatons of ejecta, which due to the speed of the wind, will take a while to settle. That does have the possibility of finishing off the rovers. There is a slim chance some of the ejecta may even make it to earth and be found on the antarctic snow eventually, giving us a few more samples of our neighbor to study.
:)
If it hits where we can see it, it should be quite a show and I hope they have a good number of our telescopes, even Hubble, recording like crazy.
I guess we'll find out January 30th. But if its on the far side, we may have to do before and after photo comparisons to find the crater once the dust has settled, and that won't be near as informative as a near side hit would be.
Humm, recently the chinese were accused of doctoring a moon photo. Makes me wonder if the moved crater might in fact be a new one?
--
Cheers, Gene
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-Ed Howdershelt (Author)
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-- Wichert Akkerman
That's the funny thing about mega-events in chaotic systems, you never know what might happen.
How we know is more important than what we know.
Except that the whole "nuclear winter" thing works by increasing the albedo of the planet. Venus is under constant, DEEP (the tropopause is at around 65km up) cloud cover already. Greenhouse effects massively outweigh the cooling from cloud cover.
"I Know You Are But What Am I?"
Prime Directive and all that.
Genesis 1:32 And God typed
The article makes it sound like the asteroid will be hiding behind the moon for the entire period, when that can't possibly be the case.
Intelligent asteroid?
It just occurred to me that the astronomer being quoted might not have been referring to an occultation at all. That's a pretty rare event for any given asteroid. It's possible that the astronomer was referring to needing to wait for the bright moon to get out of the sky at the same time the asteroid is up, which can take a week or more, depending on its current phase. The extra extinction caused by a bright moon might be enough to prevent the detailed observations needed to get a good orbital fix on the asteroid. This still doesn't excuse the lousy science reporting, which flat-out declared the asteroid was behind the moon, and implied it would remain there for two weeks.
*** PonderIf the picture's upside-down and the rover's not going anywhere, it was a big one.
This article is worthless to me because it doesn't give information in standard astronomical units of measure. I need to know how many hiroshimas and how many school buses this thing represents!
Ack ack ack ack, ack-ack ack ack-ack.
Ack, ack ACK-ack-ack, ack-ack ack-ack ack. Ack ack, ack-ack-ack-ack, ack ack ack.
Ack ack,
Ack-ack Ack-ack-ack-ack.
The nuclear winter is a concept that works only on Earth due to our unique atmosphere which lets a bit of sunlight in and prevents a bit of that from radiating out, thus warming our planet. If our atmosphere grew a bit more dusty, we'd reflect more sunlight and become colder.
You cannot apply this concept to Mars, which has no greenhouse effect in the first place. Its surface reflects most of the sunlight already, so reflective dust in its thin atmosphere would make no difference. You also can't apply it to Venus, which is a greenhouse. Its atmosphere is already highly reflective, and it is only as hot as it is because the tiny amount of sunlight it absorbs is prevented from escaping.
Remember the famous Face on Mars?
The Sandia labs simulation of the Tunguska impact has its own face - forward the video to 3.13e+00 seconds to see the Face of Tunguska!
Clearly, the Face on Mars is the "thumbprint" of a previous Tunguska event!
The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
This isn't a big impactor. It won't cause any serious global effects, on Mars, Venus or Earth.
I think they'd be less worried about the loss of communications than about the fact that the dust will block sunlight from reaching the rovers' solar panels. If they lose communications with the rovers for a while, there's still a chance to restore that communication. If the rovers lose power, it may not be possible to restore communication with them (short of having future manned Mars missions seek them out and jump start them.)
..."
I wonder if NASA has AAA service -- that would be one hell of a service call. "Hello, yes, our batteries are dead and we need a jump start. You'll never guess where we are
Orbit viewer for 2007 WD5: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007%20WD5;orb=1;cov=0;log=0#orb
Loos like the asteroid could come close to Earth's orbit in 2011. Hope it hits Mars before that!
All Rights Reversed.
If the crater is a kilometer away, then I'm sure it will be visited. If it's 10,000 km away, then it will have to wait for a completely new rover mission.
:)
If the crater is a kilometer away, then it's unlikely the rover will be in any state to visit it, or even report its state, and it will have to wait for a new rover mission anyway.
Working for one of the companies that were involved in the Beagle 2, what is believed now is that the Beagle 2 made an orthogonal impact against the wall of a meteorite crater. The airbags and the rest of the landing system were designed to cope with a nice impact at an angle against flat ground. In the end it just flew straight into a wall.
"Civis Europaeus sum!"
That's where Phobos and Deimos came from as well.
Maybe they get a baby brother for Christmas!
-Styopa
It's currently a 24th magnitude object which means it's extremely faint and can only be viewed from earth by very large scopes on dark nights. The moon's illumination makes observation that much harder.
The Nasa neo page for this object has more info about the asteroid.
The greenhouse effect isn't the point at all, here. In the nuclear winter scenario, you've merely reflected more sunlight (or kept it from the ground, at any rate). No greenhouse effect is required, only an atmosphere that isn't *so* thick that high deck of clouds or dust are irrelevant. (You're correct, this *is* the case at Venus.) Not only is Mars susceptible to this same effect, it was the global Martian dust storm in 1971 (which caused surface cooling on that planet) that led Sagan, Pollock, and Toon to apply the principles to Earth in the first place.
Also, Mars's albedo is 0.15, significantly lower than Earth's. I'm not sure what you mean by "Its surface reflects most of the sunlight already," but I have a hard time seeing Mars's surface as being very reflective.