The curious case of Earth’s leaking atmosphere

8 July 2016 Astronomy Now

Overall, about 1 kg of material is escaping our atmosphere every second. Every day, around 90 tonnes of material escapes from our planet’s upper atmosphere and streams out into space. Although missions such as ESA’s Cluster fleet have long been investigating this leakage, there are still many open questions. How and why is Earth losing its atmosphere?


Solar storms ignite X-ray aurorae on Jupiter

22 March 2016 Astronomy Now

Solar storms are triggering X-ray aurorae on Jupiter that are about eight times brighter than normal over a large area of the planet and hundreds of times more energetic than Earth’s “northern lights,” according to a new study using data from NASA’s Chandra X-ray Observatory when a giant solar storm arrived at the planet.


Close comet flyby threw Mars’ magnetic field into chaos

10 March 2016 Astronomy Now

The close encounter between comet Siding Spring and Mars in October 2014 flooded the planet with an invisible tide of charged particles from the comet’s coma, according to data from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. The comet’s powerful magnetic field temporarily merged with, and overwhelmed, the planet’s weak field.


Understanding pulsating aurorae

8 October 2015 Astronomy Now

Thanks to a lucky conjunction of two satellites, a ground-based array of all-sky cameras, and some spectacular aurorae boreales, researchers have uncovered evidence for an unexpected role that electrons have in creating the dancing aurorae. Though humans have been seeing aurorae for thousands of years, we have only recently begun to understand what causes them.


Cassini catches Titan naked in the solar wind

30 January 2015 Astronomy Now

Researchers analysing data from NASA’s Cassini spacecraft were able to study the effect of a powerful solar outburst on Saturn’s largest moon, Titan, when it was unprotected from a raging stream of energetic solar particles.