Rocks are rarely blue in colour, so when bright blue outcrops are noted, a geologist knows they’re onto something interesting! Formed at high pressure and low temperature, blueschist rocks contain a high proportion of glaucophane, a blue metamorphic amphibole. These rocks are quite rare, and their pressure/temperature (P/T) profile, indicates a very quick process of subduction where pressure increases before the rock has time to equilibrate its temperature to the surroundings.
The blue of the glaucophane is clearly visible in the above picture as well as some sizeable garnets. This photo comes from this fantastic blog and the post containing this photo can be reached by clicking the image!
Amazing fossils found while constructing the Pan-American highway in Chile.
Personally, I’d like to hear more about this “bazaar aquatic sloth”.
"Yes, this is a bit of windy Mars…"
from this post on cosmicdiary.org
The missing craters of asteroid Itokawa
Where are the craters on asteroid Itokawa? Missing — unexpectedly. The Japanese robot probe Hayabusa approached the Earth-crossing asteroid in 2005 and returned pictures showing a surface unlike any other Solar System body yet photographed — a surface possibly devoid of craters. The leading hypothesis for the lack of common circular indentations is that asteroid Itokawa is a rubble pile — a bunch of rocks and ice chunks only loosely held together by a small amount of gravity. If so, craters might not form so easily — or be filled in whenever the asteroid gets jiggled by a passing planet or struck by a massive meteor. Recent Earth-based observations of asteroid Itokawa have shown that one part of the interior even has a higher average interior density than the other part, another unexpected discovery. The Hayabusa mission returned soil samples from Itokawa which are also giving clues the ancient history of the unusual asteroid and our entire Solar System.
Image credit & copyright: ISAS, JAXA
(Source: apod.nasa.gov, via circuitdesign)