7 September 2010: Dawn is now just 28 million km away from 4 Vesta

This is an update to this post, as we watch Dawn slowly but surely approach the asteroid 4 Vesta and picture the remaining distance. Now at just 28 million km away, or 0.1883 AU, 4 Vesta is now well within the distance that counts as a close approach when an asteroid flies by the Earth. You'll remember that the asteroid 21 Lutetia with a diameter of 100 km looked like this at 900,000 km away to the Rosetta probe:

And so here is an image showing 21 Lutetia and 4 Vesta to scale, as well as the distance between the probe and 21 Lutetia to scale with the current distance to 4 Vesta to scale. The size of the probe, of course, is not even close to scale. Reaching 4 Vesta now requires almost no scrolling down at all.

The monthly update is also worth reading, and it mentions that Dawn is now so far away from the Sun compared to when it began its mission that solar power is now at more of a premium. No mention of when we will receive our first images of Vesta though.