Hematite is a fairly common iron oxide mineral. The particular sample seen above comes from the iron range of northern Minnesota. It is about 2.7 billion years old, and is a type of hematite known as gray hematite. It doesn’t look very gray in the picture, since it has been exposed to air and water since its formation. Typically when you see hematite, it is carved and polished so that it looks like gray metallic stone, but in its raw form its surface is usually reddish in color, which is why it is also known as “blood ore.
Life Finds a Way
Yesterday I mentioned how cutting edge research can sometimes lead to false positives. Sometimes what looks like a result turns out not to be. This is part of the reason we have peer review, and why we keep testing new results. Another way to eliminate false positives is to try to discover how your experiment could be fooled. If you are looking for a result, what else could produce a similar result? This is the goal of a new paper in the Proceedings of the National Academy of Sciences, which outlines how evidence of life on an exoplanet could be a false positive.
Forever Alone
It’s estimated that there are between 8 and 20 billion potentially habitable Earth-like worlds within our galaxy alone. Those are just the ones that orbit Sun-like stars. If you add in stars like red dwarfs, the number of potentially habitable planets rises to over 40 billion.
Flying Purple People Eater
Purple aliens are in the popular press as of late, with headlines claiming “First Aliens We Discover May Be Purple!” and such. It all stems from an article appearing in the Astrophysical Journal, which is a bit more interesting (and certainly more cautious) than many of the popular articles.