As the Cassini mission embarks on its final dive this Friday into Saturn, it will continue taking photos all the way down (or as far as it remains operations.) We've grown accustomed to seeing remarkable images for the mission and the planet, but clearly the show is not over, and perhaps far from it. …
Continue reading "Cassini Nearing the End, Still Working Hard"
Asteroid, we've long been told, started tiny in our protoplanetary disk and only very gradually became more massive through a process of accretion. They collected dust from the gas cloud that surrounded our new star, and then grew larger through collisions with other growing asteroids. But in recent years, a new school of thought …
Continue reading "Primordial Asteroids, And The Stories They Are Telling"
An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has made the first complete millimeter-wavelength image of the ring of dusty debris surrounding the young star Fomalhaut. This well-defined band of rubble and gas is likely the result of comets smashing together near the outer edges of a planetary system 25 light-years from …
Continue reading "Elegant Image of Icy Disk Around The Young Fomalhaut System"
As I prepare for the Astrobiology Science Conference (Abscicon) next week in Arizona, I'm struck by how many speakers will be discussing Europa missions, Europa science, ocean worlds and habitability under ice. NASA's Europa Clipper mission to orbit that moon, scheduled for launch to the Jupiter system in the mid 2020s, explains part of the …
Continue reading "NASA Panel Supports Life-Detecting Lander for Europa; Updated"
Seldom has the planned end of a NASA mission brought so much expectation and scientific high drama. The Cassini mission to Saturn has already been a huge success, sending back iconic images and breakthrough science of the planet and its system. Included in the haul have been the discovery of plumes of water vapor spurting …
Continue reading "What Scientists Expect to Learn From Cassini’s Upcoming Plunge Into Saturn"
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 …
Continue reading "A Solar System Found Crowded With Seven Earth-Sized Exoplanets"
Understanding the make-up and dynamics of atmospheric clouds is crucial to our interpretations of how weather and climate behave on Earth, and so it should come as no surprise that clouds are similarly essential to learning the nature and behavior of exoplanets. On many exoplanets, thick clouds and related, though different, hazes have been …
It is often discussed within the community of exoplanet scientists that a danger lies in the description of intriguing exoplanets as "Earth-like." Nothing discovered so far warrants the designation, which is pretty nebulous anyway. Size and the planet's distance from a host star are usually what earn it the title "Earth-like," with its inescapable expectation …
The race is on to find the giant planet that several teams of astronomers are convinced orbits far out beyond Pluto, but is nonetheless still part of our solar system. Proving the existence of what has become known as Planet X, or Planet 9, would be a discovery for the textbooks and would inevitably change …
The search for life beyond our solar system has focused largely on the detection of an ever-increasing number of exoplanets, determinations of whether the planets are in a habitable zone, and what the atmospheres of those planets might look like. It is a sign of how far the field has progressed that scientists are now …
Many Worlds 