I gotcher extinction event RIGHT HERE, buddy.

[unixronin]

New data from the Mars Reconnaissance Orbiter and Mars Global Surveyor are strong evidence that the Borealis basin on Mars, long believed to be of volcanic origin, is in fact the largest known impact structure in the solar system.

We're talking an impact structure 5300 miles in diameter, left by an impactor estimated at 1200 miles diameter.  Holy CRAP, that had to have been one hell of a bang.  I'm not even going to attempt to calculate the approximate equivalent yield.

According to the NASA article, it covers about 40% of the surface of Mars.

Comments

[radarrider.livejournal.com]

The first thing that came to mind when I read that is that it may be the origin of Phobos and/or Deimos.

[unixronin.livejournal.com]

You're thinking they formed from ejecta? You may be onto something there. With an impact that big, it's a distinct possibility. After all, a preliminary ballpark suggests the total ejecta amounts to a hundred meters' depth or more over almost half the planetary surface. Odd are good a fair amount of that made it to orbit or better.