Friday, April 17, 2014: NASA astronaut Terry Virts tweeted this photo of the Scandinavian countries seen from the International Space Station on April…Read More »
13, 2015. He wrote: "Most of Scandinavia seen at night. #Norway, #Sweden, #Denmark, and my former home #Finland in the distance. http://t.co/0HCtqalsIH" A green aurora glows over the limb of the Earth.
Tuesday, April 14, 2015: Elliptical galaxy NGC 2865 lies just over 100 million light-years away from Earth in the constellation of Hydra, the Sea Serpent.…Read More »
Old, dying stars usually fill elliptical galaxies. NGC 2865, however, is relatively youthful, containing a rapidly rotating disc filled with young stars and metal-rich gas. In fact, it holds an unusually high number of young stars, suggesting that a galaxy-wide starburst occurred about one billion years ago. The starburst stemmed from a merger between a spiral galaxy and much more massive elliptical galaxy, the progenitor galaxy of NGC 2865. The faint halo surrounding the galaxy also resulted from the merger, when cold gas tore away from the spiral galaxy.
Friday, April 10, 2015: The HiRISE camera on Mars Reconnaissance Orbiter (MRO) spacecraft obtained this image of a circular depression in a dark-toned…Read More »
unit, associated with a field of cones to the northeast. A Context Camera image of the area shows apparent layers exposed by the depression, especially on its sides or walls, overlain by dark sands presumably associated with the dark-toned unit. The higher resolution of HiRISE camera can help identify possible layers.
Thursday, April 9, 2015: Globular cluster Messier 22, also known as M22, lies 10,000 light-years away in the constellation of Sagittarius, making the cluster…Read More »
one of the closest to Earth. Globular clusters consist of densely packed stars in spherical collections, dating from early years of the universe, typically with ages of 12 to 13 billion years. Intriguingly, M22 contains six planet-sized objects not orbiting a star, two black holes and — unsually for a globlular cluster — a planetary nebula, a short-lived gaseous shell ejected by a massive star at the end of its life. Image released April 6, 2015.
Wednesday, April 8, 2015: Stars appear to trail over one of the 66 antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) on the Chajnantor…Read More »
Plateau in the Chilean Andes. This location possesses very little moisture in the air, a condition optimal for detecting radio waves passing through the atmosphere. A long exposure creates the trailing effect in the image, which was provided by courtesy of the National Astronomical Observatory of Japan (NAOJ). Image released April 6, 2015.
Tuesday, April 7, 2015: Astrophotographer Dylan Martin caught the zodiacal light near the base of Kitt Peak, Arizona, on March 22, 2015. The moon and Venus…Read More »
appear in the center of the image. Zodiacal light, the triangular shape at center, arises from sunlight reflecting from dust particles lying in the plane of the ecliptic, the sun's apparent path in the sky.
Credit: NASA & ESA; Acknowledgement: A. Riess (STScI)
Friday, April 3, 2015: Spiral galaxy NGC 3021 lies about 100 million light-years away in the constellation of Leo Minor (The Little Lion), as seen in this…Read More »
Hubble Space Telescope image. The presence of Cepheid variable stars in this galaxy can be used to calculate the distance to the galaxy, as the variable stars’ pulsation correlate with their intrinsic brightness. Measurements of their pulsation rate and observed brightness.. Image released March 30, 2015.