regolith tagged posts

Illustration showing how solar energetic particles may cause dielectric breakdown in lunar regolith in a permanently shadowed region (PSR). Tiny breakdown events could occur throughout the floor of the PSR. Credits: NASA/Andrew Jordan

Powerful solar storms can charge up the soil in frigid, permanently shadowed regions near the lunar poles, and may possibly produce “sparks” that could vaporize and melt the soil, perhaps as much as meteoroid impacts. This alteration may become evident when analyzing future samples from these regions that could hold the key to understanding the history of the moon and solar system.

The moon has almost no atmosphere, so its surface is exposed to the harsh space environment...

Images of one of the many pieces of opal found in meteorite EET 83309. At top right is a backscattered electron image (the long thin dark object is opal). At bottom left is an image of silica concentrations in opal and surrounding meteoritic minerals. At top left is an image of oxygen concentrations in opal and surrounding minerals. At bottom right is an image nickel concentrations in opal and surrounding minerals. Credit: H. Downes

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. Led by Professor Hilary Downes of Birkbeck College London, the team announce their results at the National Astronomy Meeting in Nottingham on Monday 27 June.

Craters on the surface of the asteroid 21 Lutetia. Credit: ESA

An international study reveals that asteroids have endured a multitude of impact strikes since their formation 4,565 million years ago. Scientists have reconstructed a timeline of these collisions using a physics-based model which reproduces the process through time, comparing its results with present-day information about chondrite meteorites.

The size distribution of the objects which make up the asteroid belt between Mars and Jupiter indicates that these asteroids have been struck by projectiles >20cm in size at least 100 million times. The resultant craters from these strikes are proportional to both the diameters and the velocities of these projectiles.

The information compiled on ordinary chondrites indicates that these m...