Comets

Blogs about comets

Plume on comet 67P/Churyumov-Gerasimenko (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

Two articles published in the journal “Monthly Notices of the Royal Astronomical Society” describe two researches on comet 67P/Churyumov-Gerasimenko based on data collected by ESA’s Rosetta space probe. In an article, a team led by Jürgen Blum of the Technische Universität Braunschweig, Germany, used the data collected to find out how the comet formed. In the other article, a team led by Jessica Agarwal of the Max Planck Institute for Solar System Research in Göttingen, Germany, described a plume on the surface of the comet that could have been generated by pressurized underground gas or by the crystallization of amorphous water ice.

Reconstructed last image from Rosetta (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

ESA has released the last image taken by its Rosetta space probe before clashing on the surface of comet 67P/Churyumov-Gerasimenko at the end of its mission along with the story of its reconstruction. The image was incomplete, so initially it wasn’t recognized as such by the automatic processing software among the packets containing telemetry data it was transmitted with.

Illustration of the method to estimate a comet's size (Image NASA/JPL-Caltech)

An article published in “The Astronomical Journal” describes a research on long-period comets concluding that they’re more common than expected. A team of researchers led by James Bauer of the University of Maryland used data collected by NASA’s WISE Space Telescope to discover that those at least one kilometer (0.6 miles) across are more common than expected and are, on average, twice as large as those of the Jupiter family.

The Fomalhaut system seen by ALMA and Hubble (Image ALMA (ESO/NAOJ/NRAO), M. MacGregor; NASA/ESA Hubble, P. Kalas; B. Saxton (NRAO/AUI/NSF))

Two articles to be published in “The Astrophysical Journal” describe two studies concerning the ring of debris surrounding the star Fomalhaut. An international team of astronomers used the ALMA radio telescope to get the first complete image of those debris, which are probably the product of a series of collisions among comets near the outer edges of that solar system. Carbon monoxide and carbon dioxide have also been found in abundance.

Scheme of the molecular oxygen production process (Image courtesy Caltech)

An article published in the journal “Nature Communications” provides an explanation for the presence of oxygen molecules on the comet 67P/Churyumov-Gerasimenko. Konstantinos Giapis, a chemical engineer at Caltech, conducted this research after noting that the chemical reactions that took place on the comet’s surface were similar to those he had been generating for years. The most likely hypothesis initially offered was that it had “survived” since the solar system’s formation but perhaps the correct explanation has now been found.