保护地球, 探索宇宙, 发现文明
2022年6月13日 M51: The Whirlpool Galaxy from Hubble Image Credit: NASA, ESA, Hubble, HLA; Processing & Copyright: Bernard Miller Explanation: The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on ...
2021年01月20日 The Magnetic Field of the Whirlpool Galaxy Image Credit: NASA, SOFIA, HAWC+, Alejandro S. Borlaff; JPL-Caltech, ESA, Hubble; Text: Jayanne English (U. Manitoba) Explanation: Do magnetic fields always flow along spiral arms? Our face-on view of the Whirlpool Galaxy (M51) allows a spectacularly clear view of the spiral wave pattern in a disk-shaped...
2019 December 31 M33: The Triangulum Galaxy Image Credit & Copyright: Rui Liao Explanation: The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies...
2019 August 29 M27: Not a Comet Image Credit & Copyright: Bob Franke Explanation: While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st century astronomers would ide...
不同波长的光能够揭示天体的不同特征。最左边是漩涡星系（Whirlpool galaxy）的可见光图像，第二张结合了可见光和红外光，而右边的两个图像对应不同波长的红外光。 Credits: NASA/JPL-Caltech 加入了NASA斯皮策太空望远镜（Spitzer Space Telescope）的观测，这个星系的不同色调记录了它从可见光到红外光下的外观变化。 漩涡星系（又名Messier 51或NGC 5194/5195）实际上是一对相互作用的星系，它们通过引力互相吸引、拉扯扭曲。它距离我们大约2300万光年，位于猎犬座（Canes Venatici）。 最左边的图像（a）显示了可见光下的漩涡星系，就像我们的眼睛可以通过强大的望远镜看到它一样。事实上，这张照片来自基特峰国家天文台（Kitt Peak Na...