A new study analyzing data from NASA’s Cassini spacecraft suggests that the lake, known as Ontario Lacus, behaves most similarly to what we call a salt pan on Earth.
A group led by Thomas Cornet of the Université de Nantes, France, a Cassini associate, found evidence for long-standing channels etched into the lake bed within the southern boundary of the depression. This suggests that Ontario Lacus, previously thought to be completely filled with liquid hydrocarbons, could actually be a depression that drains and refills from below, exposing liquid areas ringed by materials like saturated sand or mudflats.(more…)
Massive detector homes in on cosmic ray production
IceCube, an international collaboration involving University of Delaware scientists, is shedding new light on cosmic ray production.
Although cosmic rays were discovered 100 years ago, their origin remains one of the most enduring mysteries in physics. Now, the IceCube Neutrino Observatory, a massive detector in Antarctica, is homing in on how the highest energy cosmic rays are produced. (more…)
A Martian dust devil roughly 12 miles high (20 kilometers) was captured whirling its way along the Amazonis Planitia region of Northern Mars on March 14. It was imaged by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Despite its height, the plume is little more than three-quarters of a football field wide (70 yards, or 70 meters).
Dust devils occur on Earth as well as on Mars. They are spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground. As heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to rotate, if conditions are just right.(more…)
One particular mountain on Mars, bigger than Colorado’s grandest, has been beckoning would-be explorers since it was first sighted from orbit in the 1970s. Scientists have ideas about how it took shape in the middle of ancient Gale Crater and hopes for what evidence it could yield about whether conditions on Mars have favored life.
No mission to Mars dared approach it, though, until NASA’s Mars Science Laboratory mission, which this August will attempt to place its one-ton rover, Curiosity, at the foot of the mountain. The moat of flatter ground between the mountain and the crater rim encircling it makes too small a touchdown target to have been considered safe without precision-landing innovations used by this mission.(more…)
A group of scientists from Hawaiʻi, Brazil and California has measured the diameter of the Sun with unprecedented accuracy by using a spacecraft to time the transits of the planet Mercury across the face of the Sun in 2003 and 2006.
The measurements of the Sun’s size were made by University of Hawaiʻi at Mānoa Institute for Astronomy scientists Drs. Marcelo Emilio (visiting from Ponta Grossa, Brazil), Jeff Kuhn and Isabelle Scholl in collaboration with Dr. Rock Bush of Stanford University. They used the Michelson Doppler Imager (MDI) aboard NASA’s Solar and Heliospheric Observatory (SOHO) to make the measurements. (more…)
FLAGSTAFF, Ariz. – More than 400 years after its discovery by Galileo, the innermost large moon of Jupiter – Io – can finally rest on its geologic laurels. A group of scientists led by Dr. David A. Williams of Arizona State University has produced the first global geologic map of the Jovian satellite. The map, which was published by the U. S. Geological Survey, technically illustrates the geologic character of some of the most unique and active volcanoes ever documented in the solar system.
Since its discovery in January 1610, Io has been the focus of repeated observation, first by Earth-based telescopes, and later by fly-by and orbiting spacecraft. These studies depict an otherworldly celestial body whose gravitational relationships with Jupiter and sister moons Europa and Ganymede cause massive, rapid flexing of its surface and interior. This flexing generates tremendous heat in Io’s interior, which is relieved through surface volcanism, resulting in 25 times more volcanic activity than occurs here on Earth. (more…)
A new atlas and catalog of the entire infrared sky with more than a half-billion stars, galaxies and other objects captured by NASA’s Wide-field Infrared Survey Explorer (WISE) mission was unveiled by NASA Wednesday.
“Today WISE delivers the fruit of 14 years of effort to the astronomical community,” said Edward L. (Ned) Wright, a UCLA professor of physics and astronomy and the mission’s principal investigator, who began working on the mission in 1998. (more…)
Washington, D.C. — NASA’s Kepler Mission has discovered the first super-Earth orbiting in the habitable zone of a star similar to the Sun. A team of researchers, including Carnegie’s Alan Boss, has discovered what could be a large, rocky planet with a surface temperature of about 72 degrees Fahrenheit, comparable to a comfortable spring day on Earth. This landmark finding will be published in The Astrophysical Journal.
The discovery team, led by William Borucki of the NASA Ames Research Center, used photometric data from the NASA Kepler space telescope, which monitors the brightness of 155,000 stars. Earth-size planets whose orbital planes are aligned such that they periodically pass in front of their stars result in tiny dimmings of their host star’s light–dimmings that can only be measured by a highly specialized space telescope like Kepler. (more…)
