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Relief organizations
Dec. 27th, 2004 10:01 amThe Command Post has a roundup of organizations collecting aid related to the recent earthquake and tsunamis around the Indian Ocean.
Dec. 27th, 2004
Tsunami from asteroid impact
Dec. 27th, 2004 03:29 pmGiven yesterday's horrific tsunamis and the concurrent interest in the possible impact of asteroid 2004 MN4 in 2029 (one chance in 37), this subject is going to get a lot of attention.
2004 MN4 is too small to destroy civilization, though it would be a pretty significant bang: an energy yield 30 times as large as the biggest bomb ever exploded, considerably bigger than Krakatoa, and about as big as the Tambora eruption of 1815 that caused "the year without a summer" of 1816 (and terrible tsunamis). Any populated area that 2004 MN4 hit would be pretty effectively erased (but there would be decades' worth of advance warning); aside from the possibility of global climatic effects, one question is whether it would be capable of doing more widespread damage through tsunamis.
Surprisingly to me, according to this interesting Australian Spaceguard page, some scientists think that it would not, except locally; the tsunamis might not be as powerful as yesterday's, because of the lower efficiency of energy conversion to coherent ocean waves. There would still be some serious trouble if it hit a hundred kilometers from a populated coast. 2004 MN4 is estimated to be somewhere in between this paper's "200m" and "500m" scenarios. Others estimate worse waves, and the issue seems to be somewhat contentious.
The page also has links to a lot of other interesting stuff, including information on the apparently obscenely overhyped threat of "mega-tsunami" from a volcano collapse in the Canary Islands.
2004 MN4 is too small to destroy civilization, though it would be a pretty significant bang: an energy yield 30 times as large as the biggest bomb ever exploded, considerably bigger than Krakatoa, and about as big as the Tambora eruption of 1815 that caused "the year without a summer" of 1816 (and terrible tsunamis). Any populated area that 2004 MN4 hit would be pretty effectively erased (but there would be decades' worth of advance warning); aside from the possibility of global climatic effects, one question is whether it would be capable of doing more widespread damage through tsunamis.
Surprisingly to me, according to this interesting Australian Spaceguard page, some scientists think that it would not, except locally; the tsunamis might not be as powerful as yesterday's, because of the lower efficiency of energy conversion to coherent ocean waves. There would still be some serious trouble if it hit a hundred kilometers from a populated coast. 2004 MN4 is estimated to be somewhere in between this paper's "200m" and "500m" scenarios. Others estimate worse waves, and the issue seems to be somewhat contentious.
The page also has links to a lot of other interesting stuff, including information on the apparently obscenely overhyped threat of "mega-tsunami" from a volcano collapse in the Canary Islands.
Another remark on 2004 MN4
Dec. 27th, 2004 03:52 pmEven though this is probably the most significant asteroid-impact threat since systematic search efforts began, it's also the first instance in which I haven't seen news media saying stupid overblown things about it at all. This is, if nothing else, a major triumph in scientific media relations (so far).
earthquake information
Dec. 27th, 2004 04:49 pmI also have to say that Wikipedia has really come through on the Indian Ocean earthquake: one of the things it's best at is aggregating information about breaking events. This is a good place to start if you want to find something out.
I know, Phil Plait already made this joke
Dec. 27th, 2004 05:34 pmLook! Look! An artifact on Mars!
(It's what is left of the lander's heat shield. Update: If you're wondering why there isn't more debris and a big messy streak on the ground, it's because that is just out of frame to the right.)
Meanwhile, it sounds as if the Huygens probe release went fine. Cassini still has to make the course correction to keep it from falling into Titan right along with the probe, but given that, it sounds as if things are go for the Iapetus flyby on New Year's Day. This isn't a close flyby as these things go (there is a closer one in 2007), but it should yield the best pictures of Iapetus ever taken. Cassini has already exceeded Voyager's pictures of some parts of its surface, and found giant ringed craters in the dark area and a weird dotted line of mountains.
(I think the flyby distance of 65,000 km given on that page is too low. In recent plan adjustments it was revised to 117,000 km in order to improve the margin for error for the Titan probe entry given uncertainty in the mass of Iapetus. That's a little bit further than the recent untargeted Dione flyby, but should still be close enough for great pictures.)
(It's what is left of the lander's heat shield. Update: If you're wondering why there isn't more debris and a big messy streak on the ground, it's because that is just out of frame to the right.)
Meanwhile, it sounds as if the Huygens probe release went fine. Cassini still has to make the course correction to keep it from falling into Titan right along with the probe, but given that, it sounds as if things are go for the Iapetus flyby on New Year's Day. This isn't a close flyby as these things go (there is a closer one in 2007), but it should yield the best pictures of Iapetus ever taken. Cassini has already exceeded Voyager's pictures of some parts of its surface, and found giant ringed craters in the dark area and a weird dotted line of mountains.
(I think the flyby distance of 65,000 km given on that page is too low. In recent plan adjustments it was revised to 117,000 km in order to improve the margin for error for the Titan probe entry given uncertainty in the mass of Iapetus. That's a little bit further than the recent untargeted Dione flyby, but should still be close enough for great pictures.)
2029 impact ruled out
Dec. 27th, 2004 06:32 pmIt sounds as if the scary 2029 impact possibility for asteroid 2004 MN4 has been ruled out this evening on the basis of "precovery" pictures from Spacewatch archives. It will make a nice close approach, though.
Mold marks
Dec. 27th, 2004 09:29 pmTake a look at this crummy-looking picture of Iapetus:
( crummy-looking picture of Iapetus )
This is a picture from the Cassini raw image archive, taken just yesterday, that I downloaded in JPEG form, then brightened excessively and unsharp-masked to hell and gone. The curious thing about it is that, besides the gigantic craters that Cassini found earlier, Iapetus seems to have a tremendous, absolutely straight mountain range on it that runs right down the axis of the dark area like a seam on a badly made plastic toy. The thing's so tall it's poking right out along the horizon.
I'm not sure about the orientation of this image, but I wonder if it connects to the line of white mountains pictured here. Yeah, I think it does! In that color picture you can see the faint streak continuing off to the right... that straight ridge goes at least halfway around the moon!
Let me just say, what the hell?
( crummy-looking picture of Iapetus )
This is a picture from the Cassini raw image archive, taken just yesterday, that I downloaded in JPEG form, then brightened excessively and unsharp-masked to hell and gone. The curious thing about it is that, besides the gigantic craters that Cassini found earlier, Iapetus seems to have a tremendous, absolutely straight mountain range on it that runs right down the axis of the dark area like a seam on a badly made plastic toy. The thing's so tall it's poking right out along the horizon.
I'm not sure about the orientation of this image, but I wonder if it connects to the line of white mountains pictured here. Yeah, I think it does! In that color picture you can see the faint streak continuing off to the right... that straight ridge goes at least halfway around the moon!
Let me just say, what the hell?