Comments on: Jupiter gets rocked by an impact again

By: Nigel Depledge

Nigel Depledge — Thu, 20 Sep 2012 12:25:12 +0000

Ryan the biologist (12) said:

@Pete- I’m not sure that it is necessarily true that the ~6000K temps of a 1MT bomb will extend as far as 2km, but if all of your calculations are correct, it would mean that a mere 1MT bomb would be visible to the naked eye from the average distance to Jupiter.

Wait, can you see the Galilean satellites with the naked eye?

While it is technically true that mag +6 is (roughly) the limit of what a human eye can see under ideal seeing conditions, you forget that the impact flash will be on top of the fourth-brightest object in the sky.

By: Joseph G

Joseph G — Thu, 20 Sep 2012 00:02:30 +0000

@25 Matt: Heh, we really do need a new punctuation mark for that. It’d keep so many from getting caught in a sarchasm*.

*The gulf of understanding between the ironic statement and the writer’s actual intent.

By: Matt B.

Matt B. — Wed, 19 Sep 2012 22:55:46 +0000

“…which means significantly increasing the odds of seeing something like this.”

And yet we still have no solid UFO evidence. I wonder why.! (Note: I use an exclamation point after other sentential punctuation as a sarcasm mark.)

By: KAE

KAE — Wed, 19 Sep 2012 09:59:31 +0000

I saw this video when it first came out and immediately thought it was a fake because it hadn’t been mentioned on BA. Thanks for the update!
I originally read the last line as “The Universe is worth investigating, if only for *it’s* own self-interest.” – Either version is true I suppose.

By: Joseph G

Joseph G — Wed, 19 Sep 2012 07:44:08 +0000

@21 The Math Skeptic: Yeah, there’s the whole “evolutionary pump” idea, too. I guess it’s hard to say. There’s probably some sort of optimum time period between mass extinction events to maximize the rate of change while allowing for some some ecological equilibrium to be restored in between. Hard to say where we fit on that scale.

@22 reidh: Depends what you mean by “impact”? For instance, at shallow angles especially, it’s possible for surprisingly large stony objects to explode high in the atmosphere, when a similarly sized metallic object at a different anglemight easily make it to the ground (see the Tunguska event). And stuff impacts Earth (or our atmosphere) every day, it’s just that most of it is tiny. It’d be more accurate to say that the Earth gets hit by an object of X size every Y hours, with Y getting greater as the cube of X. Or something like that.

By: reidh

reidh — Wed, 19 Sep 2012 02:40:23 +0000

I dare say Tom. That the rate for overall impacts around the whole solar system is way above what those who say that an earth impact is only once every 100,000 or more years. I like the amazing Randi would like to bet a million dollars that the earth has a major impact within 25 years.

By: The Math Skeptic

The Math Skeptic — Wed, 19 Sep 2012 01:09:29 +0000

@Joseph G #17
I’ve heard that too, though I’m not sure I buy it. On Earth, life flourished after mass extinctions, with plants and animals rapidly evolving to fill newly-vacated niches. The Cambrian Explosion is one example. The ascent of mammals after the K-T extinction (and to a lesser extent the PETM extinction) are a few others. I think a bolide impact now and then is good for a life-bearing planet. It may be that Jupiter’s holding us back…

By: MadScientist

MadScientist — Tue, 18 Sep 2012 22:52:45 +0000

@Messier#16: Maybe you mean any planet other than earth?

By: Joseph G

Joseph G — Tue, 18 Sep 2012 21:09:38 +0000

@17 Tom: I’m not sure what the current consensus is among astronomers, but I’ve heard it hypothesized that one of the prerequisites for extrasolar life would be (along with the usual “Goldilocks zone”, liquid water etc stuff) a huge Jovian world, not too far out, to absorb bolides and keep the hypothetical biosphere from getting disrupted too often by impacts.

By: Joseph G

Joseph G — Tue, 18 Sep 2012 21:06:43 +0000

Just amazing!!!
I’m a bit surprised that the flash was so short, though. You’d think that something that big would leave a glowing trail of hot gas. For instance, in a nuclear explosion on Earth, though the nuclear reaction itself is over in a split second, the fireball continues to glow for many seconds as it radiates all that energy that it absorbed.