The UK under a curtain of aurora

Unlike the Earth, Mars lost a global protective magnetic field billions of years ago, so solar particles can directly strike the atmosphere. NASA’s MAVEN spacecraft recently detected extensive auroral activity in the Red Planet’s northern hemisphere, plus an unexplained high-altitude dust cloud.

French astrophotographer Thierry Legault travelled to the suburbs of Philadelphia, USA to capture both the International Space Station and planet Mercury transiting the Sun on 9 May. This image includes multiple stacked frames to show the Station’s path in the fraction of a second it took to cross the Sun, while Mercury appears as a black dot at bottom-centre.

Former astronaut Piers Sellers, a British-born climate scientist who flew on three space shuttle missions to help construct the International Space Station, has died of pancreatic cancer at the age of 61.