The Rosetta interplanetary station measured the surface temperature of the comet Churyumov-Gerasimenko

Only 2 days are left before the planned approach of the Rosetta station with the comet Churyumov-Gerasimenko (this event should take place on August 6). Nevertheless, many measurements of various characteristics of the comet, including the size of the nucleus, the rate of evaporation of water have already been made.

Now measured and the temperature of the nucleus of the comet. Looking ahead, it is worth mentioning that the comet's core is covered with dark dust, which leads to an increase in temperature. This, in turn, means that not all the cometary nucleus is covered with ice, in some parts of the nucleus the temperature is too high to form a crust of ice on the surface.
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Temperature measurements were taken with the VIRTIS instrument, between July 13 and 21. Then the distance of the station to the comet decreased from 14,000 kilometers to only 5,000 kilometers.

At such a distance, the Rosetta station saw a comet in the size of several pixels. The VIRTIS instrument made it possible to measure the thermal radiation of a comet, as a result of which it was found that the average temperature of this cosmic body is -70 degrees Celsius. This is about 20-30 degrees warmer than necessary so that ice completely covers the entire core.

The measurement results allowed us to draw the first conclusions about the physical properties of the cometary nucleus surface and its structure. Now scientists assume that the nucleus of the comet is covered with dark dust, which is the cause of the increased core temperature. Soon, with the help of VIRTIS, it will be possible to construct a detailed heat map of the comet, both current, static, and “seasonal”, with the display of the change in core temperature depending on the influence of the Sun.

Now the distance to the comet is only a little more than 100 kilometers - the planned distance of the approach of the Rosetta station to the comet.

Via esa