The largest asteroid impact in the past few hundred million years and a poll on near-Earth asteroids

Dailygalaxy has an article here on the "biggest asteroid impact ever", but it really refers to the biggest asteroid impact in the past few hundred million years as the Late Heavy Bombardment had many larger impacts than that. Still, the impact it refers to in Antarctica is huge, eclipsing even the Chicxulub crater in Mexico.

The article also has one typo - it says that the Chicxulub crater had an impact of 100 megatons, but that should be 100,000,000.

Now that we're on the subject I also added a new poll you can see on the right that I've been meaning to put up for some time, on the view of space enthusiasts (so if you're not one you don't have to answer) on future asteroid impacts. Space enthusiasts often hope for an asteroid collision, nothing too large but just large enough to scare us into a realization of our position in space and that we may need to develop the capability to detect and deter these giant rocks if we are to survive in the long term. My view is that an asteroid of some 10 metres or so in diameter with at least a few days' warning would be sufficient. 2008 TC3 was an asteroid of 2 to 5 metres in diameter that exploded over Sudan in 2008, and unfortunately we didn't detect its presence until just 20 hours before it reached the Earth. If we had detected it a week or so before then it would have been front page news during that entire time until it hit.