保护地球，探索宇宙，发现文明
2021年9月1日 Dancing Ghosts: Curved Jets from Active Galaxies Image Credit: Jayanne English & Ray Norris, EMU-ASKAP, DES; Text: Jayanne English (U. Manitoba) Explanation: Why would galaxies emit jets that look like ghosts? And furthermore, why do they appear to be dancing? The curled and fluffy jets from the supermassive black holes at the centers of two h...
2021年8月31日 A Blue Moon in Exaggerated Colors Image Credit & Copyright: Robert Fedez Explanation: The Moon is normally seen in subtle shades of grey or gold. But small, measurable color differences have been greatly exaggerated to make this telescopic, multicolored, moonscape captured during the Moon’s full phase. The different colors are recognize...
2021年8月30日 A Fire Rainbow over West Virginia Image Credit: Christa Harbig Explanation: What’s happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon. For a circumhorizontal arc to be visi...
2021年8月29日 Orbits of Potentially Hazardous Asteroids Image Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and cat...
2021年8月28日 Mars Rock Rochette Image Credit: NASA, JPL-Caltech Explanation: Taken on mission sol 180 (August 22) this sharp image from a Hazard Camera on the Perseverance rover looks out across a rock strewn floor of Jezero crater on Mars. At 52.5 centimeters (21 inches) in diameter, one of the rover’s steerable front wheels is at lower left in the fram...
2021年8月27日 Elephant’s Trunk and Caravan Image Credit & Copyright: Robert Eder Explanation: Like an illustration in a galactic Just So Story, the Elephant’s Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Also known as vdB 142, seen on the left the cosmic...
2021年8月26日 A Blue Hour Full Moon Image Credit & Copyright: Giorgia Hofer Explanation: Nature photographers and other fans of planet Earth always look forward to the blue hour. That’s the transition in twilight, just before sunrise or after sunset, when the Sun is below the horizon but land and sky are still suffused with a beautiful blue light. Af...
2021年8月25日 Solar System Ball Drop Video Credit & Copyright: James O’Donoghue (JAXA) & Rami Mandow (Space Australia); Text: James O’Donoghue Explanation: Does a ball drop faster on Earth, Jupiter, or Uranus? The featured animation shows a ball dropping from one kilometer high toward the surfaces of famous solar system bodies, assuming no...
2021年8月24日 PDS 70: Disk, Planets, and Moons Image Credit: VLT/MUSE (ESO); M. Benisty et al. Explanation: It’s not the big disk that’s attracting the most attention. Although the big planet-forming disk around the star PDS 70 is clearly imaged and itself quite interesting. It’s also not the planet on the right, just inside the big disk, that...
2021年8月23日 Abell 3827: Cannibal Cluster Gravitational Lens Image Credit: ESA/Hubble & NASA, R. Massey Explanation: Is that one galaxy or three? Toward the right of the featured Hubble image of the massive galaxy cluster Abell 3827 is what appears to be a most unusual galaxy — curved and with three centers. A detailed analysis, however, finds that ...
