As the icy, ocean-filled moon Europa orbits Jupiter, it withstands a relentless pummeling of radiation. Jupiter zaps Europa’s surface night and day with electrons and other particles, bathing it in high-energy radiation. But as these particles pound the moon’s surface, they may also be doing something otherworldly: making Europa glow in the dark.

New research from scientists at NASA’s Jet Propulsion Laboratory in Southern California details for the first time what the glow would look like, and what it could reveal about the composition of ice on Europa’s surface. Different salty compounds react differently to the radiation and emit their own unique glimmer. To the naked eye, this glow would look sometimes slightly green, sometimes slightly blue or white and with varying degrees of brightness, depending on what material it is.

Scientists use a spectrometer to separate the light into wavelengths and connect the distinct “signatures,” or spectra, to different compositions of ice. Most observations using a spectrometer on a moon like Europa are taken using reflected sunlight on the moon’s dayside, but these new results illuminate what Europa would look like in the dark.

Centaurs are minor planets believed to have originated in the Kuiper Belt in the outer solar system. They sometimes have comet-like features such as tails and comae—clouds of dust particles and gas—even though they orbit in a region between Jupiter and Neptune where it is too cold for water to readily sublimate, or transition, directly from a solid to a gas.

Only 18 active Centaurs have been discovered since 1927, and much about them is still poorly understood. Discovering activity on Centaurs is also observationally challenging because they are faint, telescope time-intensive and because they are rare.

A team of astronomers, led by doctoral student and Presidential Fellow Colin Chandler in Northern Arizona University’s Astronomy and Planetary Science PhD program, earlier this year announced their discovery of activity emanating from Centaur 2014 OG392, a planetary object first found in 2014. They published their findings in a paper in The Astrophysical Journal Letters, “Cometary Activity Discovered on a Distant Centaur: A Nonaqueous Sublimation Mechanism.” Chandler is the lead author, working with four NAU co-authors: graduate student Jay Kueny, associate professor Chad Trujillo, professor David Trilling and Ph.D. student William Oldroyd.

A team of European researchers discovered a new high-pressure mineral in a lunar meteorite which is helping to explain what happens to materials within the extreme pressures of the Earth’s mantle.

The new mineral donwilhelmsite is the first high-pressure mineral found in meteorites with application for terrestrial sediments dragged deep into the Earth mantle by plate tectonics. Mainly composed of calcium, aluminum, silicon, and oxygen atoms, donwilhelmsite was discovered within the lunar meteorite Oued Awlitis 001 found in 2014 in the Western Sahara.

The meteorite is compositionally similar to rocks comprising the Earth’s continents. Eroded sediments from these continents are transported by wind and rivers to the oceans, and subducted into the Earth’s mantle as part of the dense oceanic crust. Once dragged to depths of about 460–700 km, their constituent minerals transform at high pressures and high temperatures existing at those depths into denser mineral phases, including the newly discovered mineral donwilhelmsite. In the terrestrial rock cycle, donwilhelmsite is therefore an important agent for transporting continental crustal sediments through the transition zone of the Earth’s mantle (460−700 km depth).