Astronomy / Astrophysics

The region on the planet Mercury where the Messenger space probe crashed (Image NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

NASA has confirmed that a few hours ago the Messenger (MErcury Surface, Space ENvironment, GEochemistry and Ranging) space probe ended its mission by crashing on the surface of the planet Mercury. Messenger ran out of fuel and some maneuvers were recently programmed to prolong its life of a few more days. Eventually, even the helium normally used to pressurize the propellant was released in a jet that gave the probe one last push. It was a very successful mission that allowed us to discover many things about Mercury.

On the left, a common Supernova with no engine, on the right a Supernova with a strong engine that emits a gamma-ray burst, in the middle an intermediate case such as SN 2012ap (Image Bill Saxton, NRAO/AUI/NSF)

An article published in “Astrophysical Journal” describes the diskovery made by a group of astronomers led by Sayan Chakraborti of the Harvard-Smithsonian Center for Astrophysics (CfA). They studied a supernova called 2012ap (SN 2012ap) which is a missing link between ordinary ones and the ones that cause the emission of a gamma-ray burst.

Scheme of a three-body interaction in which a galaxy is turned into a compat elliptical then is ejected from a cluster (Image NASA, ESA, and the Hubble Heritage Team)

There are several known cases of runaway stars such as Zeta Ophiuchi but now the Russian astronomers Igor Chilingarian and Ivan Zolotukhin of the Moscow State University’s Sternberg Astronomical Institute have found runaway galaxies. In an article published in the journal “Science”, the list 11 galaxies ejected from the clusters they used to be part of because of the gravitational interaction with their neighbors.

The sky around the star 51 Pegasi (Image ESO/Digitized Sky Survey 2)

A team of astronomers used the HARPS (High Accuracy Radial velocity Planet Searcher) instrument at ESO’s La Silla Observatory in Chile to obtain for the first time a direct detection of the spectrum of visible light from an exoplanet. It’s 51 Pegasi b, already well known by astronomers because it was the first exoplanet discovered among those orbiting a star on the main sequence.

The Hubble Space Telescope (Photo NASA)

On April 24, 1990, the Space Shuttle Discovery was launched in its STS-31 mission. In its cargo bay it carried a really special payload, the Hubble Space Telescope. The day after it was deployed in its orbit, just over 550 km (about 342 miles) altitude. On June 25, Hubble sent its first images, which revealed a flaw in its primary mirror that reduced its usefulness. The first of a series of service missions turned what had threatened to turn into a terrible failure into a symbol for science and technology that goes far beyond astronomy.