We know our sun is surrounded by a great bubble-like heliosphere, which sets our solar system apart from the rest of interstellar space. ESA's Solar Orbiter - due to launch in February 2020 - will probe how the sun creates and controls this heliosphere.

The interior of Saturn's moon Enceladus is geochemically complex, making its subsurface ocean quite habitable for possible life, according to a new study from Southwest Research Institute.

Observational astronomy and astrophysics work together to further our understanding of the cosmos. Astrophysicists apply the laws of physics and physical theories to interpret the light gathered by observational astronomers.

Proxima Centauri, the closest star to our sun, may have a second planet, according to researchers from the National Institute of Astrophysics. If confirmed, it would be an ideal candidate for direct imaging by new upcoming space telescopes.

Why isn't there an endless variety of planet sizes in the universe? Why are most planets like those in our solar system: small and rocky, or big and gaseous? 

New laboratory studies - simulating conditions on the planet Mars and using salt-loving microbes - suggest that similar organisms could be producing Mars' mysterious methane.

Watch the last of January's 3 International Space Station spacewalks tomorrow.

A new research study suggests that K-type dwarf stars (smaller and cooler than our sun) are the best place to search for alien life. These stars are not too hot, not too cool, and not too violent for life to evolve.

Cast your vote to help name the next Mars rover, scheduled to launch in July or August 2020. The names were drawn from 9 finalist essays written by K-12 students. The voting will remain open through January 27.

For future homes on the moon, Mars, and other worlds, NASA is exploring technologies that would use mushrooms to grow self-repairing, self-replicating habitats.