ESA

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.

Montage of four pictures of the comet 67P/Churyumov-Gerasimenko taken by the Rosetta space probe's NAVCAM (Image ESA/Rosetta/NAVCAM)

After the flyby performed a few weeks ago, the Rosetta space probe moved away from the comet 67P/Churyumov-Gerasimenko and was able to observe its increasing activity. In late February, from a distance between 80 and 100 km (from 50 to 52 miles) its Navigation Camera (NAVCAM) instrument took several photographs that ESA processed to make the best observations of the jets of steam and dust emitted by the comet.