Astronomers are studying the rapid changes that have taken place with comet 67P / Churyumov - Gerasimenko as it approaches the Sun: the changes are so serious that it may soon fall apart.
The analysis of the data collected on comet 67P / Churyumov - Gerasimenko by the European spacecraft Rosetta continues. In 2014–2016, when the probe approached it, the trajectory of 67P passed through the inner regions of the Solar System, and the comet showed noticeable geological activity. Cracks grew on it, rocks collapsed, stones rolled over. An article published by scientists from the Rosetta team in the journal Nature Astronomy is devoted to this activity, and another article is being prepared for publication in the journal Science.
Astrophysicist from the University of Padua Maurizio Pajola and his colleagues tell how, approaching in its motion to the Sun, comet 67P / Churyumov-Gerasimenko experiences an ever stronger effect of its radiation, is bombarded by fast particles and heats up. All of this leads to significant changes in its icy surface - changes that were previously assumed, but thanks to the work of the Rosetta probe, for the first time, they were observed directly and in high resolution.
ESA / Rosetta
Comet 67P / Churyumov - Gerasimenko consists of separate "stuck together" porous fragments, and most of its volume is void. The ice core material itself is rich in water ice, but contains a host of other substances, including carbon dioxide. The core consists of two parts with dimensions of about 4x3x1 km and about 2.5x2.5x2 km, in its composition it was possible to find small amounts of simple organic substances, as well as molecular oxygen.
As it approaches the Sun, part of the ice material sublimes, passing from the solid phase directly to the gaseous phase and dissipating in the cosmic vacuum. This leads to visible rearrangements on the comet's surface. In particular, the cameras of the Rosetta probe recorded how a fragment weighing about 130 thousand tons moved along the core by about 140 m, and before the start of this movement, emissions of matter from the surface near this rock were noted. And this is just one example of a whole series of changes that scientists are describing.
In addition, the heating of the solar side by 67P accelerated its rotation. This led to increased centrifugal forces and further accelerated changes on the comet's surface. Thus, under their action, back in August 2014, a crack formed on the bridge connecting the two parts of the core. By December, it had already extended by 500 m and expanded to 30 m, and in the summer of 2016, a second crack up to 300 m long appeared parallel to it. According to scientists, comet 67P will not last long, and after a while it will split into two fragments. Let's hope that this moment will be able to be considered in all details.
Sergey Vasiliev
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