Four image montage of pictures of the comet 67P/Churyumov–Gerasimenko taken by the space probe Rosetta (Image ESA/Rosetta/NAVCAM)

During the past weekend, ESA’s space probe Rosetta has taken a new flyby about 14 kilometers (about 8.6 miles) away from the comet 67P/Churyumov-Gerasimenko. This means that it hasnt come as close as in February, however, the comet’s increasing activity caused some problems in Rosetta. Among the consequences, it had serious difficulties in communicating with ESA’s mission control.

The Planck all-sky map at submillimetre wavelengths with the protoclusters indicated as black dots. The inset images showcase some of the observations made by Herschel’s SPIRE instrument (Image ESA and the Planck Collaboration/ H. Dole, D. Guéry & G. Hurier, IAS/University Paris-Sud/CNRS/CNES)

An article published in the journal “Astronomy & Astrophysics” describes the results of a research carried out by combining the observations made with ESA’s Herschel and Planck space telescopes. The purpose was to find protoclusters, the precursors of today’s galaxy clusters seen in the distant past when the universe was only three billion years. This will help to understand how these huge groups of tens, hundreds and even thousands of galaxies formed and evolved.

Hubble Space Telescope images of Ganymede's aurorae colored blue overlaid on a Galileo space probe image of the moon (Image NASA/ESA)

The Hubble Space Telescope has been used to study Ganymede, the largest Jupiter’s moon, and in particular its aurorae. Analyzing their characteristics, it was possible to get the best clues found so far of the existence of a Ganymede underground ocean of liquid salt water. This ocean may contain more water than it exists on the surface of the Earth.