No one knows for certain when Saturn's iconic rings formed, but a new study suggests that they are much older than some scientists think.

A newly discovered comet has excited the astronomical community this week because it appears to have originated from outside the solar system. The official confirmation that comet C/2019 Q4 is an interstellar comet has not yet been made, but if it is interstellar, it would be only the second such object detected.

Saturn is so beautiful that astronomers cannot resist using the Hubble Space Telescope to take yearly snapshots of the ringed world when it is at its closest distance to Earth. These images, however, are more than just beauty shots. They reveal a planet with a turbulent, dynamic atmosphere.

Researchers have described a new, lower size limit for planets to maintain surface liquid water for long periods of time, extending the so-called Habitable or 'Goldilocks'' Zone for small, low-gravity planets. This research expands the search area for life in the universe and sheds light on the important process of atmospheric evolution on small planets.

Data from NASA's Cassini spacecraft may help explain why some methane-filled lakes on Saturn's moon Titan are surrounded by steep rims that reach hundreds of feet high. The models suggests that explosions of warming nitrogen created basins in the moon's crust.

A rocky extrasolar moon (exomoon) with bubbling lava may orbit a planet 550 light-years away from us. This is suggested by an international team of researchers on the basis of theoretical predictions matching observations. The 'exo-Io' would appear to be an extreme version of Jupiter's moon Io.

Astronomers have discovered a planet three times the mass of Jupiter that travels on a long, egg-shaped path around its star. If this planet were somehow placed into our own solar system, it would swing from within our asteroid belt to out beyond Neptune. Other giant planets with highly elliptical orbits have been found around other stars, but none of those worlds were located at the very outer reaches of their star systems like this one.

An icy ocean world in our solar system that could tell us more about the potential for life on other worlds is coming into focus with confirmation of the Europa Clipper mission's next phase.

The Hall thruster is a propulsion system that is often used by spacecraft engaged in longer missions. A recent study has shown how the operating lives of these systems can be further extended.

The rare isotope iron-60 is created in massive stellar explosions. Only a very small amount of this isotope reaches the earth from distant stars. Now, a research team has discovered iron-60 in Antarctic snow for the first time. The scientists suggest that the iron isotope comes from the interstellar neighborhood.