Stereo Options

[tedstryk]

That really is an amazing shot!

[Paolo]

There was an interesting result by STEREO reported in arXiv a few days ago http://arxiv.org/abs/1009.2710
STEREO A has managed to detect for the first time some sort of activity or gas release on the near Earth asteroid Phaethon, long suspected to be an extinct comet because it shares the orbit with a meteor stream

[Paolo]

This seems to have gone unnoticed: http://sirius.bu.edu/News/
STEREO A has photographed the comet-like tail of Mercury. and it was noticed by an amateur accessing STEREO images!

[scalbers]

Interesting to see the tail and the solar corona wafting by in the animation. Would this increase the odds for aurorae on Mercury?

[ZLD]

Probably not. The tail is point away from the sun in an elongated teardrop-like shape. Very little (if any) of the tail is present at a high or low enough latitude for ions to interact with the tail. I suppose it could be possible to see some very faint aurora if the tail were pointing toward the sun. However, the tail is extremely thin and its likely there wouldn't be enough diffusion/inhibitance within it to produce auroras in Mercury's already lightweight magnetosphere.

What would be incredible to see though is if very faint aurora could be produced on the surface in some way. Possibly it could look like the rainbow colors in a soap bubble? We honestly don't understand magnetospheres very well, especially around terrestrial bodies, Mercury being the only other planet aside from Earth to have one in our solar system. Messenger will definitely answer a lot of questions and expand a lot in the ways of knowledge.

[algorimancer]

This brings to my mind the question of whether this might lead to indirect detection of the existence of sub-mercurial asteroids.

[ugordan]

I can't see how you could detect such asteroids when the tail itself is many times less bright than the parent object. Scattered light would be a pain.