Saturn, Venus, Neptune, Uranus, Jupiter, Mars and Mercury will be visible in an uncommon planetary alignment this month.

Purple Earth Hypothesis suggests Earth was once a purple planet. Early microbes used retinal, not chlorophyll, for ...

Martian clouds are almost always made of dry ice, or frozen carbon dioxide. 95% of the planet's atmosphere is CO2.

Mars is often seen as a barren, rust-colored wasteland, but NASA’s Curiosity rover has just revealed a surprising burst of ...