Science Daily: Comets and Asteroids

Jupiter’s complex transient auroras

Combined observations from three spacecraft show that Jupiter's brightest auroral features recorded to date are powered by both the volcanic moon Io and interaction with the solar wind. 

Juno mission to Jupiter delivers first science results

NASA's Juno mission is rewriting what scientists thought they knew about Jupiter specifically, and gas giants in general, according to a pair of Science papers released today. The Juno spacecraft has been in orbit around Jupiter since July 2016, passing within 3,000 miles of the equatorial cloudtops.

How radioactive decay could support extraterrestrial life

In the icy bodies around our solar system, radiation emitted from rocky cores could break up water molecules and support hydrogen-eating microbes. To address this cosmic possibility, a team modeled a natural water-cracking process called radiolysis. They then applied the model to several worlds with known or suspected interior oceans, including Saturn's moon Enceladus, Jupiter's moon Europa, Pluto and its moon Charon, as well as the dwarf planet Ceres.

New type of planetary object proposed: Synestia

There's something new to look for in the heavens, and it's called a 'synestia,' according to planetary scientists. A synestia, they propose, would be a huge, spinning, donut-shaped mass of hot, vaporized rock, formed as planet-sized objects smash into each other.

History of Titan's landscape resembles that of Mars, not Earth

In a paper published in Science, researchers report that Titan, like Mars but unlike Earth, has not undergone any active plate tectonics in its recent past. The upheaval of mountains by plate tectonics deflects the paths that rivers take. The team found that this telltale signature was missing from river networks on Mars and Titan.

NASA mission uncovers a dance of electrons in space

NASA's MMS mission studies how electrons spiral and dive around the planet in a complex dance dictated by the magnetic and electric fields, and a new study revealed a bizarre new type of motion exhibited by these electrons.

Icy ring surrounds young planetary system

ALMA has made the first complete millimeter-wavelength image of the ring of dusty debris surrounding the young star Fomalhaut. This remarkably well-defined band of rubble and gas is likely the result of exocomets smashing together near the outer edges of a planetary system 25 light-years from Earth.

Space weather events linked to human activity

Human activities, like nuclear tests and radio transmissions, have been changing near-Earth space and weather, and have created artificial radiation belts, damaged satellites and induced auroras.

How hard did it rain on Mars?

Heavy rain on Mars reshaped the planet's impact craters and carved out river-like channels in its surface billions of years ago, according to a new study. Scientists show that changes in the atmosphere on Mars made it rain harder and harder, which had a similar effect on the planet's surface as we see on Earth.

Space weather model simulates solar storms from nowhere

A kind of solar storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs. Now, scientists have developed a model simulating their evolution.

Chemical engineer explains oxygen mystery on comets

A chemical engineer who normally develops new ways to fabricate microprocessors in computers has figured out how to explain a nagging mystery in space -- why comets expel oxygen gas, the same gas we humans breathe.

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