Via Emily Lakdawalla at the Planetary Society Blog is this amazing 3D animation of the EPOXI spacecraft’s close approach to the nucleus of comet Hartley 2!
You’ll need red/green glasses to see it in 3D, but if you prefer the folks at EPOXI HQ put together a nice flat version:
Incredible! Also at Emily’s blog is an awesome size comparison of various small solar system bodies like comets Halley and Tempel 1 (which EPOXI took a close look at in 2005 when it was still called Deep Impact). The nucleus of Hartley 2 is actually pretty dinky compared to the other comets, but note how similar in shape it is to Halley and Borrelly. Clearly, two-lobed peanut-shaped nuclei are not rare among comets, and even though we’ve only gotten a close look at a handful of them, I’d even wager they’re downright common! That surprises me, and I am not at all sure I understand why that shape is prevalent.
We see it in asteroids like Hektor and Kleopatra, and those may be due to two small asteroids having a slow collision and sticking together. I’d think that’s unlikely with such small objects as Hartley’s nucleus, but the evidence suggests otherwise. I will be very curious indeed to read some papers on this.
The more we look at the Universe – and the more closely we look – the weirder and more wonderful it gets.