Scientists found evidence that magnetic waves in a polar coronal hole contain enough energy to heat the corona and moreover that they also deposit most of their energy at sufficiently low heights for the heat to spread throughout the corona. The observations help to answer a 70-year-old solar physics conundrum about the unexplained extreme temperature of the Sun's corona - known as the coronal heating problem.
Astronomers have found the shattered remains of an asteroid that contained huge amounts of water orbiting an exhausted star, or white dwarf. This suggests that the star GD 61 and its planetary system - located about 150 light years away and at the end of its life - had the potential to contain Earth-like exoplanets, they say.
The beautiful, petal-like shells of galaxy PGC 6240 are captured in intricate detail by the NASA/ESA Hubble Space Telescope, set against a sky full of distant background galaxies. This cosmic bloom is of great interest to astronomers due to both its uneven structure, and the unusual clusters of stars that orbit around it - two strong indications of a galactic merger in the recent past.
ESA's test rover has been fitted with scientific instruments and made its first tracks in the sands of Chile's Atacama Desert. Meanwhile, team members have explored the area to select a suitable site for testing, flying a drone to produce an aerial map.
ESO's Very Large Telescope has captured a remarkably detailed image of the Toby Jug Nebula, a cloud of gas and dust surrounding a red giant star. This view shows the characteristic arcing structure of the nebula, which, true to its name, does indeed look a little like a jug with a handle.
The first ever evidence of a comet entering Earth's atmosphere and exploding, raining down a shock wave of fire which obliterated every life form in its path, has been discovered by a team of South African scientists and international collaborators.