[X] My Assistant

[SigurRosFan]

Reporting today:

- http://spaceflightnow.com/news/n0604/04deepimpact/

--- Tempel 1 is usually a rather dim, weak comet with a water production rate of 16,000 tonnes per day. However, after the Deep Impact probe hit the comet this rate increased to 40,000 tonnes per day over the period 5-10 days after impact. Over the duration of the outburst, the total mass of water released by the impact was 250,000 tonnes. ---

[djellison]

laymans guestimate of implications....

DI spotted a lot of dusty material, and less water than was expected - but ground based obs show lots of water over time following the impact.

So - perhaps what we have is an object that was once a comparatively even mix of dust and ice, but the ice in the upper layers of the body slowly sublimes away under the influence of the warmth of the sun. However, the deeper the ice, the slower it can escape. This leaves the comet being more dust rich near the surface, and more ice rich toward the centre.

You whack it hard, and out flies a huge ammount of the dust, but what you also do is expose some of the more water rich material under the upper layers - so you get an initial outbusrt of dust, and then over the hours and days that follow, the exposed area returns to the dust rich balance near the surface as the sun warms the newly exposed material, forcing the higher water content to sublime out.

Maybe I'm a million miles from the mark, but it would seem to add up.

Doug

[Bob Shaw]

Doug:

Sounds reasonable - and all the more reason for a second flyby, if possible, so we can see the evolution of the crater. If the edges of the initial void have boiled away, then we might see Bruce's pet 'sun traps' in action, eroding the surface into strange non-impacty (you know what I mean!) shapes.

Bob Shaw