What is the origin of the large heart-shaped nitrogen glacier on Pluto revealed by NASA’s New Horizons spacecraft in 2015? Two French researchers show that Pluto’s peculiar insolation and atmosphere favour nitrogen condensation near the equator, in the lower altitude regions, leading to an accumulation of ice at the bottom of Sputnik Planum, a vast topographic basin.
The mystery of a rare change in the behaviour of a supermassive black hole at the centre of a distant galaxy has been solved by an international team of astronomers using ESO’s Very Large Telescope along with the NASA/ESA Hubble Space Telescope and NASA’s Chandra X-ray Observatory. It seems that the black hole has fallen on hard times and is no longer being fed enough fuel to make its surroundings shine.
Chariklo is the largest confirmed centaur, a minor planet orbiting the Sun between Saturn and Uranus. In 2014, two rings were discovered around Chariklo. Soon after, scientists discovered that rings likely exist around another centaur, Chiron, but the origin of these rings remained a mystery — until now.
When a star passes within a certain distance of a black hole, the stellar material gets stretched and compressed as the black hole swallows it, briefly releasing an enormous amount of energy as a flare. Astronomers have now observed infrared light echoes from these “stellar tidal disruption” events reflected by dust encircling a black hole.
After more than 12 years studying Saturn, its rings and moons, NASA’s Cassini spacecraft has entered the final year of its epic voyage. The Grand Finale will come on 15 September 2017 as Cassini dives into Saturn’s cloud tops, where friction with the atmosphere will cause the spacecraft to burn up like a meteor.