February 2019

The starts that form the cosmic river in red with a Gaia map in the background (Image Meingast et al / Gaia DR2 skymap)

An article published in the journal “Astronomy & Astrophysics” reports the discovery of what was called a river of stars, a stream of stars a little over 300 light years away from us that occupies most of the southern sky. Astronomers of the University of Vienna used information collected by ESA’s Gaia space probe and published in the so-called Data Release 2 (DR2) to discover at least 4,000 stars that have been moving together in space since their formation, which was about a billion years ago.

Supernovae and water in rocky planets

An article published in the journal “Nature Astronomy” reports the results of a series of computer simulations conducted to better understand the mechanisms of rocky planets formation. A team of researchers concluded that there are probably two types of planetary systems: those similar to the solar system, with planets containing relatively little water, and those in which there are above all the so-called ocean planets or waterworlds. The difference may have been caused by the presence of a massive star nearby that ejected radioactive materials that have at least partially dried out the planets. This might have led to the emergence of a temperate climate on Earth.

The Mars Exploration Rover Opportunity's shadow (Image NASA/JPL-Caltech)

NASA announced the end of the existing possibilities to re-establish contacts with its Mars Rover Opportunity and consequently declared the end of its mission. Oppy, as it’s affectionately called, interrupted communications after June 10, 2018 following the global storm that covered the planet Mars with a blanket of dust that prevented it from obtaining energy from its solar panels. This extraordinary mission ends in this sad way because caused by an extrnal cause after over 15 Earth’s years in which it collected a wealth of information on Mars.

The protoplanetary disk surrounding the star Orion Source I (Image ALMA (NRAO/ESO/NAOJ); NRAO/AUI/NSF; Gemini Observatory/AURA)

An article published in the journal “The Astrophysical Journal” reports the discovery of the presence of salts and in particular of the ordinary table salt, in the protoplanetary disk surrounding the young star Orion Source I. A team of astronomers used the ALMA radio telescope to detect the “chemical signatures” that indicate the presence of a number of molecules including two salts. In particular, sodium chloride seems to make up a considerable part of the disk given that the estimated mass is around one sextillion kilograms, more or less equivalent to the water of the Earth’s oceans.

Ultima Thule has a shape even stranger than expected

NASA and the Johns Hopkins University Applied Physics Laboratory have published new images of the Kuiper belt Object cataloged as 2014 MU69 and nicknamed Ultima Thule along with animations that show new details of its shape. A sequence of 14 images captured by the New Horizons space probe during its January 1, 2019 flyby shows that the this object’s two lobes are not vaguely spherical as it seemed but in particular the larger one is definitely flat, to the point that it was compared to a pancake, and it’s not clear why it has that shape.