Odin observed the impact

On Monday, July 4 at 7.52 am, the Americans crashed their space projectile "Deep Impact" straight into Comet Tempel 1. Impressive close-up images were taken from the flyby spacecraft (a link to the NASA homepage of Deep Impact is here).

The Swedish satellite "Odin" closely studied the impact, and monitored the development of the water vapor production on the comet for about 90 orbits around the time of impact. Odin had already on June 18 and 23 discovered water around Tempel 1 (which arises naturally - when parts of the comet are heated as it approached the Sun - through some of the comet's ice being vaporized). As much as 240 kg of water was produced from Tempel 1 every second.

A short time after impact, the water signal from Tempel 1 changed dramatically! The interpretation of this change will take time, but very preliminary calculations may indicate that a powerful jet of water vapor left the comet during a period of 15 hours, in a direction perpendicular to the line of sight towards the comet - the jet contained about 4000 tons of water.

Eventually, after a few days, the water signal from Tempel 1 returned to what it had been before the impact.