WASHINGTON — Scientists have taken a major step toward accurately determining the amount of energy that the sun provides to Earth, and how variations in that energy may contribute to climate change.
In a new study of laboratory and satellite data, researchers report a lower value of that energy, known as total solar irradiance, than previously measured and demonstrate that the satellite instrument that made the measurement—which has a new optical design and was calibrated in a new way—has significantly improved the accuracy and consistency of such measurements. (more…)
One of the most enduring mysteries in solar physics is why the Sun’s outer atmosphere, or corona, is millions of degrees hotter than its surface.(more…)
A new Mars movie clip gives us a rover’s-eye view of a bluish Martian sunset, while another clip shows the silhouette of the moon Phobos passing in front of the sun.
America’s Mars Exploration Rover Opportunity, carefully guided by researchers with an artistic sense, has recorded images used in the simulated movies.
These holiday treats from the rover’s panoramic camera, or Pancam, offer travel fans a view akin to standing on Mars and watching the sky. (more…)
Web users around the globe will be able to help professional astronomers in their search for Earth-like planets thanks to a new online citizen scienceproject called Planet Hunters that launched Dec. 16. at www.planethunters.org.
Planet Hunters, which is the latest in the Zooniverse citizen science project collection, will ask users to help analyze data taken by NASA’s Kepler mission. The space telescope has been searching for planets beyond our own solar system—called exoplanets—since its launch in March 2009.(more…)
Astronomers detected the faint signature of small, dim red dwarf stars in nearby galaxies (right), and found they are much more numerous than in our own Milky Way (left). Image credit: Patrick Lynch/Yale University
Astronomers have discovered that small, dim stars known as red dwarfs are much more prolific than previously thought — so much so that the total number of stars in the universe is likely three times bigger than previously believed.
Because red dwarfs are relatively small and dim compared to stars like our Sun, astronomers hadn’t been able to detect them in galaxies other than our own Milky Way and its nearest neighbors before now. Therefore, they did not know how much of the total stellar population of the universe is made up of red dwarfs.
Now astronomers have used powerful instruments on the Keck Observatory in Hawaii to detect the faint signature of red dwarfs in eight massive, relatively nearby galaxies called elliptical galaxies, which are located between about 50 million and 300 million light years away. They discovered that the red dwarfs, which are only between 10% and 20% as massive as the Sun, were much more bountiful than expected. (more…)
WASHINGTON — Conditions at the edge of our solar system may be much more dynamic than previously thought, new observations suggest. Future exploration missions are expected to benefit in design and mission objectives from a better understanding of the changing conditions in this boundary region. (more…)
