The NASA Cassini mission revealed the existence of an ocean and hydrothermal activity underneath the Saturnian moon’s icy surface. Earth's hydrothermal systems team with microbial life. How likely are Enceladus’ hydrothermal vents habitable to Earth-like microorganisms?

A new technique leads to the discovery of two closely separated pairs of supermassive black holes in the early universe.

What is the source of the highest-energy cosmic rays in our Galaxy? We report here the observation of the ultra-high-energy gamma-ray emission from a stellar superbubble in the Cygnus region, powered by the massive stellar complex called Cygnus OB2 in an attempt to answer this question.