Comets

Blogs about comets

Dry ice detected with its spectral data and indication of the area (Image Data: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; Reprinted with permission from G. Filacchione et al., Science 10.1126/science.aag3161 (2016); context image: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)

Two articles published in the journal “Science” describe the discovery of dry ice, meaning frozen carbon dioxide, on the surface of the comet 67P/Churyumov-Gerasimenko. A team of researchers led by Gianrico Filacchione of the Italian National Institute for Astrophysics and another led by Sonia Fornasier the French LESIA-Observatoire de Paris and Université Paris Diderot used the observations conducted with the VIRTIS spectrometer aboard ESA’s Rosetta space probe to find for the first time dry ice on a comet’s nucleus.

The comet 67P/Churyumov-Gerasimenko with its two-lobed shape (Photo ESA/Rosetta/NAVCAM)

Two articles to be published in the journal “Astronomy & Astrophysics” describe various aspects of a research on the age of the comet 67P/Churyumov-Gerasimenko. Martin Jutzi and Willy Benz of the University of Bern, Switzerland, together with several colleagues conducted a series of computer simulations to study its two-lobed structure concluding that the collision that gave it its present shape hardly occurred over a billion years ago.

Some outbursts on the comet 67P/Churyumov-Gerasimenko (Image OSIRIS: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; NavCam: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)

An article published in the journal “Monthly Notices of the Royal Astronomical Society” describes a research about the outbursts detected by ESA’s Rosetta space probe on the surface of the comet 67P/Churyumov-Gerasimenko. During the three months around its closest approach to the Sun, on August 13, 2015, Rosetta’s cameras captured 34 outbursts. A team led by Jean-Baptiste Vincent from the Max Planck Institute for Solar System Research in Gottingen, Germany, traced their origin on the comet’s surface.

The possible scenario of the impact that created the Moon (a) and the following arrival of water (b) (Image Jessica J. Barnes et al.)

An article published in the journal “Nature Communications” describes a research about the water on the Moon and concluded that it was brought mostly by asteroids that struck it between 4.5 and 4.3 billion years ago. Until now, scientists generally thought that water was transported by comets but according to the international team led by Jessica Barnes of the British Open University things are different.