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Asteroid on Course to Earth Was Spotted Just Hours Before It Hit The Atmosphere
Witnesses reported a fireball streaking across the sky above Botswana on Saturday night. The asteroid hurtling toward Earth at 10 miles (16 km) a second looked like it could be the harbinger of catastrophe. A webcam in a rural area west of Johannesburg captured it, showing a luminous orb igniting the sky in a bright flash.
NASA had only discovered the asteroid on Saturday and determined it was on a collision course for the planet, charted for entry in a vast expanse from Southern Africa and across the Indian Ocean to New Guinea and given the name 2018 LA.
The reality of the asteroid's fiery end was less dramatic than the video shows. The asteroid was estimated at just six feet (1.8 metres) across, otherwise known as boulder-sized, NASA's Jet Propulsion Laboratory said in a statement. It burned up "several miles" above the Earth's surface.
2018 LA aka ZLAF9B2 (25-35 tons).
2014 AA (40 tons).
2008 TC3 (80 tons).
(Score: 2) by c0lo on Wednesday June 06 2018, @12:25PM (4 children)
I feel marginally better than in the Chelyabinsk case [wikipedia.org], but a window of less than 24h from discovery to impact is too close to "I discovered myself dead due to this bullet in my back".
Please do better next time, even when younger Bruce Willis needed more time to prepare.
https://www.youtube.com/watch?v=aoFiw2jMy-0
(Score: 1, Informative) by Anonymous Coward on Wednesday June 06 2018, @12:38PM (1 child)
uhm. I realize you're trolling, but there are people out there who will not, so please don't troll.
for everyone else: the more dangerous an asteroid is, the earlier it will be discovered, because it will be bigger.
my only assumption when stating this is that asteroids all have more or less the same density, which is not true, but still a reasonable approximation.
In other words: an asteroid made of solid iron (high density) that is big enough to really hurt us (the high density means that it wouldn't need to be very big) would still be seen quite early.
(Score: 2) by c0lo on Wednesday June 06 2018, @10:53PM
Really?
Note to myself: be more subtle next time.
True... Unless it won't, that is.
I mean, look, the Chelyabinsk one was larger than the ones linked in TFS.
https://www.youtube.com/watch?v=aoFiw2jMy-0
(Score: 0) by Anonymous Coward on Wednesday June 06 2018, @02:04PM (1 child)
The recent Chelyabinsk meteor actually did some damage, but in general only the smallest impactors are not going to have years of advance warning.
These interstellar asteroids could be a bigger problem. Unknown trajectories and sizes with higher velocities. It may be impossible to deflect them.
(Score: 2) by HiThere on Wednesday June 06 2018, @06:23PM
I think your certainty is unwarranted. It doesn't take that large an asteroid to do immense damage, and if they're dark enough, they are quite difficult to see.
We're certainly doing better about mapping asteroids than we were, but we are far from "nearly complete for anything large enough to matter". And ones we don't know about can come up on our "blind side", where they're nearly invisible until quite late. (Looking into the sun to resolve details is difficult.)
Of course, in addition to the color, the density is important. A chunk of loosely joined frozen methane could be quite large, and still not do any damage. A chunk of nickel-iron much smaller could be a lot more dangerous. And would be a lot harder to see. The Chicxulub impactor that closed the cretaceous period is guessed to have been between 5 and 10 miles in diameter. Something a quarter that size could probably do about 1/64th as much damage. OTOH, I don't know what they were assuming the composition of the impactor was. Analog once did an article ("Giant Meteor Impact", IIRC) about an impact by a metal meteor 5 miles in diameter that seemed to be even worse...but the assumptions were "back of envelope" calculations, so they could be wrong.
Still, even something 2 miles in diameter would probably be a civilization ending disaster. 1 mile would be a disaster worse than any in history. etc. And as you get smaller, there are LOTS more. Fortunately, space is big enough that we're a small target, and nothing's really aiming at us. But don't be certain that we know about anything that could cause a problem. Even if we do, asteroid orbits get altered all the time when we aren't watching.
It's not a major danger, but it's nothing to feel certain about, either. It's not at all unreasonable to wish for a better job of mapping. (IIRC, just this year something that had been classified as a star turned out to be an asteroid. And just last year they lost track of one that was of significant size. They thought (in the article that I read) that its orbit had been altered, but they didn't know what it was now. If they find it again, they won't know it was the same one.)
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by AssCork on Wednesday June 06 2018, @12:50PM
This happens, what, maybe two or three times a century? It's not like they're planet-killers or anythi
Just popped-out of a tight spot. Came out mostly clean, too.
(Score: 2) by All Your Lawn Are Belong To Us on Thursday June 07 2018, @07:54PM (3 children)
Source: https://www.nasa.gov/mission_pages/asteroids/overview/fastfacts.html [nasa.gov]
This JPL release [nasa.gov], cool on its own, states there were 556 bolide events over a 20 year span. That works out to 27.8 per year. or 2.3 per month.
I think I'm more worried about a tornado destroying my home, but glad there is a spacewatch nevertheless.
This sig for rent.
(Score: 3, Interesting) by takyon on Friday June 08 2018, @01:29PM (2 children)
The news item is accurate. This is only the third asteroid in human history that has been detected in space before slamming into Earth. This could be taken as a testament to our improving capabilities: now we can detect even tiny objects that have a high probability of impact. However, because the interval between detection and impact is so small, and there are so many small asteroids, we get an immediate test of the accuracy of our predictions.
With improvements in telescopes, we can get earlier and earlier warnings of Chelyabinsk-level impacts, and prevent possible deaths. Impact events could be detected to the hour/day of impact years in advance, unlike tornadoes, volcanic eruptions, earthquakes, etc.
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(Score: 2) by All Your Lawn Are Belong To Us on Friday June 08 2018, @02:41PM (1 child)
It was a good find, it is accurate, but it is also over-hyped as written. A fireball you can see is not something to worry about, often enough to make that a certainty, even though it is amazing. (Pre-Chelyabinsk, what was the most prior meteorite event that caused impactor damage on any significant scale?) But you have to get deeper into the story to get to, "this wasn't one to worry about."
I agree that it is a field worthy of study and needs expansion. Hopefully the geographic prediction capability will also improve beyond arcs of 7,700 miles which to my mind has questionable predictive value. (Yeah, if you're somewhere between the West Coast of the US and the East Coast of the US, twice over, you had better be prepared for a problem on Tuesday...)
But qualitatively, that this was detected before impact to Earth doesn't carry any more weight than the 15,000 plus NEO's that have also been cataloged. (Or the 30 or so per month that are added to the registry). That doesn't mean funding shouldn't be improved, it's a cool story and interesting, and that there isn't risk that can be mitigated by continuing to improve our space defense capability. But also even though a big event could happen that causes mass casualties from a local to global scale, it hasn't happened often in any well-documented way, either. [gizmodo.com]
This sig for rent.
(Score: 3, Insightful) by takyon on Friday June 08 2018, @04:04PM
I think you know the answer.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]