JAXA tagged posts

JAXA and NASA satellite observations show where killer electrons are generated in the Van Allen radiation belts surrounding Earth. The finding, published in the journal Geophysical Research Letters, could help scientists more accurately forecast when these killer (relativistic) electrons will form.

Professor Yoshizumi Miyoshi of the Institute for Space-Earth Environmental Research at Nagoya University and colleagues compared data from two satellites situated on opposite sides of the Earth: the Arase satellite, developed by the Japanese Aerospace Exploration Agency (JAXA)...

Photograph of lunar meteorite NWA 2727. Credit: Photo by Masahiro Kayama, Tohoku University

A team of Japanese scientists led by Masahiro Kayama of Tohoku University’s Frontier Research Institute for Interdisciplinary Sciences, has discovered a mineral known as moganite in a lunar meteorite found in a hot desert in northwest Africa. This is significant because moganite is a mineral that requires water to form, reinforcing the belief that water exists on the Moon.

“Moganite is a crystal of silicon dioxide and is similar to quartz. It forms on Earth as a precipitate when alkaline water including SiO2 is evaporated under high pressure conditions,” says Kayama. “The existence of moganite strongly implies that there is water activity on the Moon...

The Marius Hills Skylight, as observed by the Japanese SELENE/Kaguya research team. Credit: NASA/Goddard/Arizona State University

A study published in Geophysical Research Letters confirms the existence of a large open lava tube in the Marius Hills region of the moon, which could be used to protect astronauts from hazardous conditions on the surface. No one has ever been on the moon longer than 3 days, largely because space suits alone can’t shield astronauts from its elements: extreme temperature variation, radiation, and meteorite impacts. Unlike Earth, the moon has no atmosphere or magnetic field to protects its inhabitants.

The safest place to seek shelter is the inside of an intact lava tube, according to the study...

The figure shows how surface air pressure changed throughout Martian history. A bar at 4 billion years ago denotes a lower limit shown by this study. Constraints suggested by other studies are also shown by arrows. Credit: Image courtesy of

Exploration missions have suggested that Mars once had a warm climate, which sustained oceans on its surface. To keep Mars warm requires a dense atmosphere with a sufficient greenhouse effect, while the present-day Mars has a thin atmosphere whose surface pressure is only 0.006 bar, resulting in the cold climate it has today. It has been a big mystery as to when and how Mars lost its dense atmosphere.

An old meteorite has been known to contain the ancient Martian atmosphere...