Some viruses have mysterious and unique genetic alphabet not found anywhere else on the planet

In the search for life, oxygen in a planet’s atmosphere is one potential sign of biological activity that might be detected by future telescopes. A new study, however, describes several scenarios in which a lifeless rocky planet around a sun-like star could evolve to have oxygen in its atmosphere.

NASA extends Mars helicopter Ingenuity's high-flying mission on Red Planet

Witness the Formation of a Planet: Hubble Watches How a Giant Exoplanet Grows