保护地球，探索宇宙，发现文明
2021年7月30日 Mimas in Saturnlight Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Peering from the shadows, the Saturn-facing hemisphere of Mimas lies in near darkness alongside a dramatic sunlit crescent. The mosaic was captured near the Cassini spacecraft’s final close approach on January 30, 2017. Cassini’s camera was pointe...
2021年7月29日 The Tulip and Cygnus X-1 Image Credit & Copyright: Carlos Uriarte Explanation: This tall telescopic field of view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula, the brightest glowing cloud of interstellar gas and dust above center is also found in the ...
2021年7月28日 Ring Galaxy AM 0644-741 Image Credit: NASA, ESA, Hubble, HLA; Processing: Jonathan Lodge Explanation: The rim of the large blue galaxy at the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. AM 0644-741 is known as a ring galaxy and was caused by an immense galaxy co...
2021年7月27日 Fleming’s Triangular Wisp Image Credit & Copyright: Anthony Saab Explanation: Chaotic in appearance, these tangled filaments of shocked, glowing gas are spread across planet Earth’s sky toward the constellation of Cygnus as part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the...
2021年7月26日 CG4: A Ruptured Cometary Globule Image Credit & Copyright: Nicolas Rolland & Martin Pugh Explanation: Can a gas cloud grab a galaxy? It’s not even close. The “claw” of this odd looking “creature” in the featured photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary g...
2021年7月25日 Crescent Neptune and Triton Image Credit: NASA, Voyager 2 Explanation: Gliding silently through the outer Solar System, the Voyager 2 spacecraft camera captured Neptune and Triton together in crescent phase. The elegant picture of the ice-giant planet and its cloudy moon was taken from behind just after closest approach in 1989. It could not have ...
2021年7月24日 The Edge of Space Image Credit & Copyright: Ralf Rohner Explanation: Where does space begin? For purposes of spaceflight some would say at the Karman line, currently defined as an altitude of 100 kilometers (60 miles). Others might place a line 80 kilometers (50 miles) above Earth’s mean sea level. But there is no sharp physical boundar...
2021年7月23日 Elephant, Bat, and Squid Image Credit & Copyright: Patrick Hsieh Explanation: Sprawling emission nebulae IC 1396 and Sh2-129 mix glowing interstellar gas and dark dust clouds in this 10 degree wide field of view toward the northern constellation Cepheus the King. Energized by its bluish central star IC 1396 (left) is hundreds of light-years a...
2021年7月22日 NGC 7814: Little Sombrero with Supernova Image Credit & Copyright: CHART32 Team, Explanation: Point your telescope toward the high flying constellation Pegasus and you can find this expanse of Milky Way stars and distant galaxies. NGC 7814 is centered in the pretty field of view that would almost be covered by a full moon. NGC 7814 is sometim...
2021年7月21日 Colors: Ring Nebula versus Stars Image Credit: Robert Vanderbei (Princeton U.) Explanation: What if you could see, separately, all the colors of the Ring? And of the surrounding stars? There’s technology for that. The featured image shows the Ring Nebula (M57) and nearby stars through such technology: in this case, a prism-like diffraction g...