保护地球，探索宇宙，发现文明
2021年01月18日 The Medulla Nebula Supernova Remnant Image Credit & Copyright: Russell Croman Explanation: What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could...
2021年01月17日 Jets from Unusual Galaxy Centaurus A Image Credit: ESO/WFI (visible); MPIfR/ESO/APEX/A. Weiss et al. (microwave); NASA/CXC/CfA/R. Kraft et al. (X-ray) Explanation: The jets emanating from Centaurus A are over a million light years long. These jets of streaming plasma, expelled by a giant black hole in the center of this spiral galaxy, light up th...
2021年01月16日 The Mountains of NGC 2174 Image Credit: NASA, ESA, Hubble Heritage Team (STScI/AURA) Explanation: This fantastic skyscape lies near the edge of NGC 2174 a star forming region about 6,400 light-years away in the nebula-rich constellation of Orion. It follows mountainous clouds of gas and dust carved by winds and radiation from the region’s n...
2021年01月15日 A Plutonian Landscape Image Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Institute Explanation: This shadowy landscape of majestic mountains and icy plains stretches toward the horizon on a small, distant world. It was captured from a range of about 18,000 kilometers when New Horizons looked back toward Pluto, 15 minutes after the sp...
2021年01月14日 Aurora Slathers Up the Sky Image Credit: Jack Fischer, Expedition 52, NASA Explanation: Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this 2017 June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting station is itself within the upper realm of the auroral...
2021年01月13日 Arches Across an Arctic Sky Image Credit & Copyright: Giulio Cobianchi Explanation: What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky. Visible below the stellar arch is ...
2021年01月12日 A Historic Brazilian Constellation Image Credit & Copyright: Rodrigo Guerra Explanation: The night sky is filled with stories. Cultures throughout history have projected some of their most enduring legends onto the stars above. Generations of people see these stellar constellations, hear the associated stories, and pass them down. Featured h...
2021年01月11日 Moon Phases in 2021 Video Credit: Data: Lunar Reconnaissance Orbiter ; Animation: NASA’s Scientific Visualization Studio; Music: Brandenburg Concerto No4-1 BWV1049 (Johann Sebastian Bach), by Kevin MacLeod via Incompetech Explanation: What will the Moon phase be on your birthday this year? It is hard to predict because the Moon’s appe...
2021年01月10日 Star Cluster R136 Breaks Out Image Credit: NASA, ESA, & F. Paresce (INAF-IASF), R. O’Connell (U. Virginia) et al. Explanation: In the center of nearby star-forming region lies a huge cluster containing some of the largest, hottest, and most massive stars known. These stars, known collectively as star cluster R136, part of the Tarantula...
2021年01月09日 Titan: Moon over Saturn Image Credit: NASA, JPL-Caltech, Space Science Institute Explanation: Like Earth’s moon, Saturn’s largest moon Titan is locked in synchronous rotation. This mosaic of images recorded by the Cassini spacecraft in May of 2012 shows its anti-Saturn side, the side always facing away from the ringed gas giant. The o...