A combination of a once-debunked 19th-century identification of a water-carrying iron mineral and the fact that these rocks are extremely common on Earth, suggests the existence of a substantial water reservoir on Mars, according to a team of geoscientists.

“One of my student’s experiments was to crystalize hematite,” said Peter J. Heaney, professor of geosciences, Penn State. “She came up with an iron-poor compound, so I went to Google Scholar and found two papers from the 1840s where German mineralogists, using wet chemistry, proposed iron-poor versions of hematite that contained water.”

In 1844, Rudolf Hermann named his mineral turgite and in 1847 August Breithaupt named hi...

New research conducted by scientists at Caltech and Northwestern University shows that thin films of rust – iron oxide – can generate electricity when saltwater flows over them. These films represent an entirely new way of generating electricity and could be used to develop new forms of sustainable power production.

Interactions between metal compounds and saltwater often generate electricity, but this is usually the result of a chemical reaction in which one or more compounds are converted to new compounds. Reactions like these are what is at work inside batteries.

In contrast, the phenomenon discovered by Tom Miller, Caltech professor of chemistry, and Franz Geiger, Dow Professor of Chemistry at Northwestern, does not...

1. FeO can be prepared by the thermal decomposition of iron (II) oxalate.