Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883 • Hacker News Board

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#11

Post by mistercow » Fri, Nov 23, 2012, 4:16 AM UTC

temphn wrote: post #6

No photographic evidence. No corresponding accounts. No raw data. Bonilla published his account of this event in a French journal called L'Astronomie in 1886. Unable to account for the phenomenon, the editor of the journal suggested, rather incredulously, that it must have been caused by birds, insects or dust passing front of the Bonilla's telescope. As the saying goes: when you hear hoof-steps, think horses, not ze…

Yeah the prior probability of "fragmenting comet within 8000 km of Earth" seems kind of a lot lower than that of "dust in front of the telescope".

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#12

Post by ChuckMcM » Fri, Nov 23, 2012, 4:17 AM UTC

mchouza wrote: post #9

A more skeptical analysis by Phil Plait: http://blogs.discovermagazine.com/badastronomy/2011/10/17/di...

Was going to add this one as well. A comet of that size, that close, would have raised questions in other places. The point that we didn't have nearly the observational capacity a couple of hundred years ago that we have today is well made, we certainly might have dodged a bullet, we have seen two comments hit the bigger planets (Jupiter and Saturn) but we only noticed because we were looking.

So I share the skepticism that this was a Comet in 1883 but I don't doubt for a moment comets have come that close to the planet.

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#13

Post by TimJRobinson » Fri, Nov 23, 2012, 4:19 AM UTC

I'm confused as to why this is coming up now, did they find some new evidence or residual rock from this comet? If not how do they now know that it was actually a comet and not simply a mistake on the astronomers part as they previously thought it was?

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#14

Post by polarcuke » Fri, Nov 23, 2012, 4:20 AM UTC

Well if this is true I guess there is one more thing for us to be thankful for today!

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#15

Post by jacquesm » Fri, Nov 23, 2012, 4:37 AM UTC

rorrr wrote: post #10

venus wrote: post #5

> A sobering thought. An even more sobering thought is that even in the present day, if we detected something like that heading our way, there'd be absolutely nothing we could but sit and wait for it to arrive.

That's not true. If we knew for a fact that it would cause global extinction, we would throw everything at it. We could blow it up with nukes. We could put a relatively heavy space probe next to it and deflect its course.

It's not Hollywood, it's ballistics.

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#16

Post by lifeformed » Fri, Nov 23, 2012, 4:40 AM UTC

jacquesm wrote: post #15

rorrr wrote: post #10

Earlier quoted context omitted.

That's not true. If we knew for a fact that it would cause global extinction, we would throw everything at it. We could blow it up with nukes. We could put a relatively heavy space probe next to it and deflect its course.

It's not Hollywood, it's ballistics.

With early enough detection, even a slight change in it's trajectory can make the asteroid veer off course enough to save earth.

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#17

Post by [deleted] » Fri, Nov 23, 2012, 4:45 AM UTC

rorrr wrote: post #10

venus wrote: post #5

> A sobering thought. An even more sobering thought is that even in the present day, if we detected something like that heading our way, there'd be absolutely nothing we could but sit and wait for it to arrive.

That's not true. If we knew for a fact that it would cause global extinction, we would throw everything at it. We could blow it up with nukes. We could put a relatively heavy space probe next to it and deflect its course.

[deleted]

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#18

Post by rizzom5000 » Fri, Nov 23, 2012, 4:46 AM UTC

rorrr wrote: post #10

venus wrote: post #5

> A sobering thought. An even more sobering thought is that even in the present day, if we detected something like that heading our way, there'd be absolutely nothing we could but sit and wait for it to arrive.

That's not true. If we knew for a fact that it would cause global extinction, we would throw everything at it. We could blow it up with nukes. We could put a relatively heavy space probe next to it and deflect its course.

When faced with impending doom, optimism and pessimism are both equally fine sentiments. The caveat is that only one of them accurately reflects reality, not that it matters at that point.

I also suppose that industriousness would be helpful for taking one's mind away from the reality of that impending doom.

But hell, nukes to deflect a comet? Sure, we may as well try it -- but I only suggest doing this if we are 100% certain that the comet will both hit us and destroy us. We could conceivably cause our own extinction via a false positive provided by some faulty monitoring device - wait, did that already happen? Nevermind.

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#19

Post by Geee » Fri, Nov 23, 2012, 4:51 AM UTC

polarcuke wrote: post #14

Well if this is true I guess there is one more thing for us to be thankful for today!

It doesn't matter because we wouldn't be here thinking about it. On the other hand, the extinction event would have been a gold mine for the future archaeologists that would have evolved on Earth in the next 100 million years.

Re: Billion-Ton Comet May Have Missed Earth by a Few Hundred Kilometers in 1883

#20

Post by AlexMennen » Fri, Nov 23, 2012, 4:53 AM UTC

rizzom5000 wrote: post #18

rorrr wrote: post #10

Earlier quoted context omitted.

That's not true. If we knew for a fact that it would cause global extinction, we would throw everything at it. We could blow it up with nukes. We could put a relatively heavy space probe next to it and deflect its course.

When faced with impending doom, optimism and pessimism are both equally fine sentiments. The caveat is that only one of them accurately reflects reality, not that it matters at that point. I also suppose that industriousness would be helpful for taking one's mind away from the reality of that impending doom. But hell, nukes to deflect a comet? Sure, we may as well try it -- but I only suggest doing this if we are 100…

If there is a significant chance that a comet will hit and destroy us, it makes sense to do everything we can to prevent it from doing so. Given the stakes, .1% chance should be more than enough for us to take it seriously. It does not seem plausible that we could harm ourselves much by nuking a comet that wasn't going to hit us anyway.