While not bursting with activity like its sister moon Enceladus, the surface of Saturn’s moon Dione is definitely not boring. Some parts of the surface are covered by linear features, called chasmata — bright icy cliffs among myriad fractures — which provide dramatic contrast to the round impact craters that typically cover moons.
Scientists on the Dark Energy Survey, using one of the world’s most powerful digital cameras, have discovered eight more faint celestial objects hovering near our Milky Way galaxy. Signs indicate that they, like the objects found by the same team earlier this year, are likely dwarf satellite galaxies — the smallest and closest known form of galaxies.
Nomination number nine from the prestigious Insight Astronomy Photographer of the Year competition, an annual celebration of the most beautiful and spectacular visions of the cosmos by astrophotographers worldwide. The 2015 competition received 2700 spectacular entries from over 60 countries and the winners will be announced 17 September.
The Moon’s thin atmosphere contains neon, a gas commonly used in electric signs on Earth because of its intense glow. While scientists have speculated on the presence of neon in the lunar atmosphere for decades, NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft has confirmed its existence for the first time.
A spectacular galaxy collision has been discovered lurking behind the Milky Way, the closest such system ever found. “Kathryn’s Wheel” was found during a special wide field survey of the Southern Milky Way with the UK Schmidt Telescope in Australia. Such systems are very rare and arise from “bull’s-eye” collisions between two galaxies of similar mass.
A new analysis of 13 supernovae — including archived data from NASA’s Hubble Space Telescope — is helping astronomers explain how some young stars exploded sooner than expected, hurling them to a lonely place far from their host galaxies. It’s a complicated mystery of double-star systems, merging galaxies, and twin black holes.
In developing the beautifully minimalist Dobsonian, the resourceful John Dobson quite rightly earned himself a kind of immortality, telescope-wise. Yet even after the decades of development and tweaking that have occurred since, the concept continues to evolve today. Steve Ringwood casts his expert eye over a new line of Dobsonians from Explore Scientific.
Are you looking for something to whet your observing appetite and celebrate the return of late summer dark skies to the British Isles? Why not welcome back the Andromeda Galaxy to the Northern Hemisphere night sky in this observing guide to one of the annual harbingers of autumnal celestial delights.
ESA’s Rosetta spacecraft has witnessed 67P/Churyumov–Gerasimenko make its closest approach to the Sun (perihelion) at 3:03am BST on 13 August, when the comet came within 116 million miles of our nearest star. Rosetta’s measurements suggest the comet is currently spewing up to 300kg of water vapour and a metric tonne of dust every second, creating dangerous working conditions for the spacecraft.
NASA’s Cassini spacecraft will zip within 295 miles of Saturn’s moon Dione on Monday, 17 August — the final close flyby of this icy satellite during the probe’s long mission. After close flybys of other moons in late 2015, Cassini will depart Saturn’s equatorial plane to begin a year-long setup of the mission’s grand finale: repeatedly diving through the space between Saturn and its rings.
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