保护地球，探索宇宙，发现文明
2021年8月18日 Rings Around the Ring Nebula Image Credit: Hubble, Large Binocular Telescope, Subaru Telescope; Composition & Copyright: Robert Gendler Explanation: The Ring Nebula (M57), is more complicated than it appears through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure – a c...
2021年8月17日 M57: The Ring Nebula from Hubble Image Credit: NASA, ESA, Hubble Legacy Archive; Processing: Judy Schmidt Explanation: Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial circle. Its classic appearance is understood to be due to our own perspective, though. The recent mapping of the expanding nebula’s ...
2021年8月16日 Perseid Meteor, Red Sprites, and Nova RS Ophiuchus Image Credit & Copyright: Daniel Korona Explanation: This was an unusual sky. It wasn’t unusual because of the central band the Milky Way Galaxy, visible along the image left. Most dark skies show part of the Milky Way. It wasn’t unusual because of the bright meteor visible on the...
2021年8月15日 Perseid Rain Image Credit & Copyright: Luo Hongyang Explanation: Comet dust rained down on planet Earth last week, streaking through dark skies in the annual Perseid meteor shower. The featured picture is a composite of many images taken from the same location over the peak night of the Perseids. The umbrella was not needed as a shield from m...
2021年8月14日 Island Universe, Cosmic Sand Image Credit & Copyright: Marzena Rogozinska Explanation: Stars in our own Milky Way Galaxy are scattered through this eye-catching field of view. From the early hours after midnight on August 13, the 30 second exposure of the night sky over Busko-Zdroj, Poland records the colorful and bright trail of a Perseid me...
2021年8月13日 A Perfect Spiral Image Credit: NASA, ESA, Hubble, HLA; Processing: Mehmet Hakan Ozsarac Explanation: If not perfect then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view. Classified as an Sc gal...
2021年8月12日 A Beautiful Trifid Image Credit & Copyright: Mike Selby Explanation: The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astrono...
2021年8月11日 Mammatus Clouds over Saskatchewan Image Credit & Copyright: Michael F Johnston Explanation: When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water ...
2021年8月10日 Fire in Space Image Credit: NASA Explanation: What does fire look like in space? In the gravity on Earth, heated air rises and expands, causing flames to be teardrop shaped. In the microgravity of the air-filled International Space Station (ISS), however, flames are spheres. Fire is the rapid acquisition of oxygen, and space flames meet new oxygen...
2021年8月9日 Perseus and the Lost Meteors Image Credit & Copyright: Tomas Slovinsky (Slovakia) & Petr Horalek (Czech Republic; Institute of Physics in Opava) Explanation: What’s the best way to watch a meteor shower? This question might come up later this week when the annual Perseid Meteor Shower peaks. One thing that is helpful is a dark sky, ...