Ocean Worlds: Enceladus Looks Increasingly Habitable, and Europa’s Ocean Under the Ice More Accessible to Sample

It wasn't that long ago that Enceladus, one of 53 moons of Saturn, was viewed as a kind of ho-hum object of no great importance.  It was clearly frozen and situated in a magnetic field maelstrom caused by the giant planet nearby and those saturnine rings. That view was significantly modified in 2005 when scientists …

A Solar System Found Crowded With Seven Earth-Sized Exoplanets

Seven planets orbiting one star.  All of them roughly the size of Earth.  A record three in what is considered the habitable zone, the distance from the host star where liquid water could exist on the surface.  The system a mere 40 light-years away. The latest impressive additions to the world of exoplanets orbit the …

NASA Panel Supports Life-Detecting Lander for Europa

It has been four long decades since NASA has sent an officially-designated life detection mission into space.  The confused results of the Viking missions to Mars in the mid 1970s were so controversial and contradictory that scientists -- or the agency at least -- concluded that the knowledge needed to convincingly search for extraterrestrial life …

Waiting on Enceladus

Of all the possible life-beyond-Earth questions hanging fire, few are quite so intriguing as those surrounding the now famous plumes of the moon Enceladus:  what telltale molecules are in the constantly escaping jets of water vapor, and what dynamics inside the moon are pushing them out? Seldom, if ever before, have scientists been given such …

The Ever More Puzzling, And Intriguing, "Tabby’s Star."

Substantial, sun-like stars are not supposed to dim.  They start with gravity and pressure induced nuclear reactions, and then they burn brighter and brighter until they either explode (go supernova) or burn all their fuel and become small, enormously dense, and not very bright "white dwarfs." Of course, the transit technique of searching for exoplanets …

Rocky, Close and Potentially Habitable Planets Around a Dwarf Star

Forty light-years away is no small distance. But an announcement of the discovery of two planets at that separation that have been determined to be rocky and Earth-sized adds a significant new twist to the ever-growing collection of relatively close-by exoplanets that just might be habitable. The two planets in the TRAPPIST-1 system orbit what …