保护地球，探索宇宙，发现文明
2023年12月17日 Geminids over China’s Nianhu Lake Image Credit & Copyright: Hongyang Luo Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids — because shower meteors all appear to come...
2023年12月16日 Crescent Enceladus Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Peering from the shadows, the Saturn-facing hemisphere of tantalizing inner moon Enceladus poses in this Cassini spacecraft image. North is up in the dramatic scene captured during November 2016 as Cassini’s camera was pointed in a nearly sunward directi...
2023年12月15日 Betelgeuse Eclipsed Image Credit & Copyright: Sebastian Voltmer Explanation: Asteroid 319 Leona cast a shadow across planet Earth on December 12, as it passed in front of bright star Betelgeuse. But to see everyone’s favorite red giant star fade this time, you had to stand near the center of the narrow shadow path starting in central M...
2023年12月14日 Supernova Remnant Cassiopeia A Image Credit: NASA, ESA, CSA, STScI; D. Milisavljevic (Purdue University), T. Temim (Princeton University), I. De Looze (University of Gent) Explanation: Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their ...
On Aug. 8, 2023, Artemis II crew members (from left) Jeremy Hansen, Victor Glover, Reid Wiseman, and Christina Koch took a photo in front of their Orion crew module at NASA’s Kennedy Space Center in Florida. Announcing the crew and continuing work on the Space Launch System rocket and Orion are part of the significant steps taken this year toward the agency’...
2023年12月13日 Deep Field: The Heart Nebula Image Credit & Copyright: William Ostling, Telescope Live Explanation: What excites the Heart Nebula? First, the large emission nebula on the left, catalogued as IC 1805, looks somewhat like a human heart. The nebula glows brightly in red light emitted by its most prominent element, hydrogen, but this long-exposu...
NASA’s James Webb Space Telescope’s new view of Cassiopeia A (Cas A) in near-infrared light is giving astronomers hints at the dynamical processes occurring within the supernova remnant. Tiny clumps represented in bright pink and orange make up the supernova’s inner shell, and are comprised of sulfur, oxygen, argon, and neon from the star itself. A large, st...
2023年12月12日 Aurora and Milky Way over Norway 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 arc...
In this image from Dec. 8, 1993, astronaut Kathryn C. Thornton works with equipment during a spacewalk. The spacewalk was part of an 11-day mission, Servicing Mission 1, to service the Hubble Space Telescope. Shortly after Hubble was launched in 1990, NASA discovered a flaw in the observatory’s primary mirror that affected the clarity of the telescope’s earl...
2023年12月11日 Solar Minimum versus Solar Maximum Video Credit: NASA, SDO, SVS Explanation: The surface of our Sun is constantly changing. Some years it is quiet, showing relatively few sunspots and active regions. Other years it is churning, showing many sunspots and throwing frequent Coronal Mass Ejections (CMEs) and flares. Reacting to magnetism, our SunR...