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?
Astronomers are using the NASA/ESA Hubble Space Telescope to study aurorae — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the solar system, Jupiter. This observation program is supported by measurements made by NASA’s Juno spacecraft, shortly to arrive at the gas giant.
Planetary scientists have discovered pieces of opal in a meteorite found in Antarctica, a result that demonstrates that meteorites delivered water ice to asteroids early in the history of the solar system. Opal, familiar on Earth as a precious stone used in jewellery, is made up of silica (the major component of sand) with up to 30 percent water in its structure.
Using data gathered by NASA’s New Horizons spacecraft on its Pluto flyby in July 2015, the dwarf planet has some characteristics less like that of a comet and more like much larger planets, according to the first analysis of Pluto’s unique interaction with the solar wind — the charged particles that spew off from the Sun into the solar system at a supersonic 1 million mph.
Scientists have determined that comets produce X-ray emission when particles in the solar wind strike the comet’s atmosphere. Recently, astronomers announced the results of a study using data collected with NASA’s Chandra X-ray Observatory of two comets — C/2012 S1 ISON and C/2011 S4 PanSTARRS — when both were relatively close to Earth.