Long wait to other side of Mercury nearly over

you are probably right. i did notice that some of the ejecta around craters looks a little lighter...a trick of the light or my imagination?

Probably, just like the Moon, a result of a fresh (relatively seaking) impacts. Mercury (until now) was thought to be very similar to our Moon in make-up, but with a very large iron-based core. I will be very curious to see what information Messenger is going to be able to verify, and change, from old data as a result of the Mariner missions of old. Some text books are about to be rewritten I'd say, just like after the Pluto debate.

I wonder does Mercury get hit a lot. Some pictures show a lot of craters with bright ejecta around them. Being close to the sun, and hence the attraction of all manner of debris to it, surely Mercury gets in the way more often then not?

Seanie.

Maybe the impact speeds are alot higher on Mercury.
Been closer to the sun most orbiting objects would go alot faster in the region of Mercury then then would further out in the solarsystem, so creating bigger and thus more visible ejecta blankets.

Maybe the bright ejecta is a result of "toast syndrome" (just made that up). perhaps the surface is darker due to a slow roasting from the sun, and the brighter material is protected beneath. anyway where our own moon shows Lava plains - Mercury does not. - or not to the same extent. Anyway no place for a Holiday. I wonder, as our own Moon is tidally locked, whether this has an effect on the pattern of cratering. does this fact mean that some of the moons surface is shielded from the worst ravages of asteroid bombardment -?

You hit the nail on the head, the lunar surface darkens with age due to solar radiation, so newer craters like Tycho are white because the surface is newer then its surroundings, Mercurys surface would be getting a stronger solar radiation dose due to its closer proximity.

Looking at the images from Mercury Messanger mission, I also notice areas where there are "series" of craters, almost looks like a bombing run. Or where perhaps a larger body broke up before impact. It looks like the kind of effect that was seen on the famous Jupiter strike, some years ago - the name escapes me? Is it possible that impactors would be torn up by the increased gravity before impact??? or is Mercury rotating to slowly for that effect to be seen.

I should clarify....some craters appear to be in lines

Declan

"Time flies like an arrow, fruit flys like bananas"