The ATLAS catching the particle "splashes" when one of the first beams passed through the Large Hadron Collider (Image courtesy CERN. All rights reserved)

This Easter represented for CERN the time of the Large Hadron Collider (LHC) full operation restart. After the testing that began a few weeks ago, in the morning of last Sunday a proton beam has covered all 27 kilometers (about 17.7 miles) of the giant ring. After less than two hours, a second beam was sent in the opposite direction. The energy was “only” 450 GeV but it was a major event for the restart of the scientific activity.

Images of eight galaxies containing green filaments that are the last effect of ancient quasars (Image NASA, ESA, and W. Keel (University of Alabama, Tuscaloosa))

The Hubble Space Telescope photographed a series of ghosts of quasars that existed in the past. They are seen as ethereal green objects in various forms and are the last effects of ancient quasars. These phenomena are very interesting from a scientific standpoint because they can provide information about the past of those galaxies, which were once very active.

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.