Friday, July 23, 2010
The Planetary Society has a great post here from about two days ago showing the vast difference in size between 21 Lutetia (thus far the largest asteroid ever visited by a probe) and every other one we have close-up pictures of. The direct link to the image itself is here.
And to put it into even more perspective the post also has an image showing the size of 4 Vesta (the most massive asteroid in the Solar System) next to them as well, whereupon the previously giant 21 Lutetia suddenly looks like a dwarf in comparison.
I wrote a post here last week showing the surface gravity and escape velocity for asteroids of average density based on their size, which shows the minimum size an asteroid will generally need to be to move from a Little Prince-style make a wrong step and you're now orbiting the Sun too-type asteroid, and all the larger ones where a human couldn't escape its gravity without a rocket, or at least some sort of mechanical device to propel him at high velocity.