September 2020

Radar map of the Mars area where the lake system was found (Image courtesy Sebastian Emanuel Lauro et al. Nature Astronomy, 2020)

An article published in the journal “Nature Astronomy” reports the discovery of new underground lakes of very salty liquid water under the planet Mars’ south pole cap. A team of researchers led by Elena Pettinelli and Sebastian Lauro, both of the Italian Roma Tre University, used data collected by ESA’s Mars Express space probe’s Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument to discover what form a lake system consisting of three main lakes surrounded by other smaller lakes. This confirms the discovery of a lake announced in July 2018 and offers evidence that this is not a unique case. It remains an extreme environment, so it takes some speculation to imagine life forms in those lakes, but the authors of this new research also recommend increasing the exploration of those areas to understand their potential is to host life.

Jupiter's South Pole (Image NASA-JPL/Caltech)

An article published in the journal “Proceedings of the National Academy of Sciences” reports a study on storms at the planet Jupiter’s south pole and their regular geometric pattern. A team of researchers from the University of Berkeley and Caltech used mathematical models derived from 19th-century research by Lord Kelvin based on experiments by physicist Alfred Mayer to explain why those storms concentrated in that area and why on Jupiter they’re arranged in that geometric formation.

Simulations and observations of M87*

An article published in “The Astrophysical Journal” reports a study on the data collected during the years of the area around the supermassive black hole at the center of the galaxy M87, the one in the image presented in April 2019 by the Event Horizon Telescope project (EHT) project. A team of researchers led by Maciek Wielgus of the Center for Astrophysics | Harvard & Smithsonian (CfA) also analyzed data not published but was part of the observations carried out between 2009 and 2013 with fewer radio telescopes. Those observations were very useful to show the changes in that area, with the shadow of the black hole M87* wobbling and with a variation in its orientation.

Artist's concept of Pi Earth (Image courtesy NASA Ames/JPL-Caltech/T. Pyle, Christine Daniloff, MIT)

An article published in “The Astronomical Journal” reports a study on the exoplanet K2-315b, nicknamed Pi Earth because its year lasts 3.14 Earth days, an approximation of the value of pi. A team of researchers from the SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) project, a network of ground-based telescopes, used them to confirm the planet’s existence by verifying data collected by NASA’s Kepler Space Telescope. Pi Earth is very close to its star so the temperature on its surface is very high even if the star is very small and relatively cold. Any life forms should be analogous to terrestrial extremophiles. It may be lifeless but it is an interesting candidate for studying its atmosphere.

Bright boulders on asteroids Ryugu and Bennu

Three articles published in the journal “Nature Astronomy” report the results of as many researches on asteroids Ryugu and Bennu, which are being explored respectively by JAXA’s Hayabusa 2 and NASA’s OSIRIS-REx space probes. The two asteroids already showed some similarities and, in a news & views editorial, Maria Cristina De Sanctis talks about the catastrophic events that might have generated them and the bright rocks discovered on the surface of both despite their dark color. Catastrophic events are also the object of the other two articles, and in the one focused on Bennu, there are indications that some rocks on its surface come from Vesta, one of the largest objects in the asteroid belt between Mars and Jupiter.