Nearby, Recent Interplanetary Collision Inferred

The Bad Astronomer writes about a new discovery by the Spitzer Space Telescope, which detected signs of an interplanetary smashup only 100 light-years from here, and only a few thousand years ago. There's a NASA-produced animation of the collision between a Mercury-sized planet and a moon-sized impactor. The collision's aftermath was detected by the presence of what are essentially glass shards in orbit around the star. Here's NASA's writeup.

From the NASA writeup

[Brian Gordon]

Giant impacts are thought to have stripped Mercury of its outer crust, tipped Uranus on its side and spun Venus backward, to name a few examples

Is it just me or is that coolest thing ever? Forget massive trains [imageshack.us].. the male mind cannot help but drool at the idea of planets colliding.

Venus is awesome; I can't even imagine what that would look like. The impactor rapidly accelerating the rock around it while the rock on the other side of the planet crumples and deforms under titanic pressure. Maybe the crust would be rigid enough to accelerate rapidly in big chunks while the big oceans of rock in the mantle churn and slowly come up to speed.. or maybe it would just blast most of the mass spaceward, leaving the planet to be pelted by continent-sized rocks for the next thousand years..

But undoubtedly Uranus is the coolest collision. Gas giants are already terrifying (imagine falling straight down into the north pole of Jupiter, falling straight into the bullseye of roaring winds and bottomless stormclouds).. but a mass large enough to alter its inclination exploding through the upper atmosphere as a fireball, and slowly ablating as it buries itself deeper into progressively denser gases, and plunging deeper and deeper into the unplumbed depths of unimaginably violent, raging, endless storms, and finally sinking to the crushing depths of the great core furnace.. come on Hollywood, put your obscene special effects budget to use doing something like this.

Re:And nothing of value got lost?

[__aasqbs9791]

FTL would only make them think the trip was shorter, not make them go back in time.

Bad Astronomy? More like Bad Statistics.

[__aajfby9338]

TFA wrote:

And there's another thing that I find personally very cool. Remember, HD 172555 is only 100 light years away. That is extremely close on a galactic scale (our galaxy is 100,000 light years across, so this star is our next door neighbor). It seems incredibly unlikely that this is a rare event in the galaxy, since this happened so close by and so recently.

That's like saying "somebody living within five miles of me was struck by lightning last week, so it seems incredibly unlikely that being struck by lightning is a rare event on this planet". A single sample says nothing about the probability of the event, other than that it's nonzero.