扭曲的日出带食

扭曲的日出带食

ByNASA中文

2019 December 28 A Distorted Sunrise Eclipse Image Credit & Copyright: Elias Chasiotis Explanation: Yes, but have you ever seen a sunrise like this? Here, after initial cloudiness, the Sun appeared to rise in two pieces and during partial eclipse, causing the photographer to describe it as the most stunning sunrise of his life. The dark circle near the top of the atmospherically-reddened Sun is the Moon — but so is the dark peak just below it. This is because along the way, the Earth’s atmosphere had an inversion layer of unusually warm air which acted like a gigantic lens and created a second image. For a normal sunrise or sunset, this rare phenomenon of atmospheric optics is known as the Etrucan vase effect. The…

日偏食序列与倒影

日偏食序列与倒影

ByNASA中文

2019 December 27 A Partial Solar Eclipse Sequence Reflected Image Credit & Copyright: Majid Ghohroodi Explanation: What’s happened to the Sun? Yesterday, if you were in the right place at the right time, you could see the Sun rise partially eclipsed by the Moon. The unusual sight was captured in dramatic fashion in the featured image not only directly, in a sequence of six images, but also in reflection from Soltan Salt Lake in Iran. The almost-white Sun appears dimmer and redder near the horizon primarily because Earth’s atmosphere preferentially scatters away more blue light. Yesterday’s partial solar eclipse appeared in the sky over much of Asia and Australia, but those with a clear enough sky in a thin band across the Earth’s surface were…

新墨西哥州上空的日环食

新墨西哥州上空的日环食

ByNASA中文

2019 December 25 An Annular Solar Eclipse over New Mexico Image Credit & Copyright: Colleen Pinski Explanation: What is this person doing? In 2012 an annular eclipse of the Sun was visible over a narrow path that crossed the northern Pacific Ocean and several western US states. In an annular solar eclipse, the Moon is too far from the Earth to block out the entire Sun, leaving the Sun peeking out over the Moon’s disk in a ring of fire. To capture this unusual solar event, an industrious photographer drove from Arizona to New Mexico to find just the right vista. After setting up and just as the eclipsed Sun was setting over a ridge about 0.5 kilometers away, a person unknowingly walked right into…

在火星上看日食是一种怎样的体验？好奇号最近连看了两场！

在火星上看日食是一种怎样的体验？好奇号最近连看了两场！

ByNASA中文

地球上的我们是幸运的， 因为我们可以看到日全食， 可以看到瑰丽的日冕。 地球上的我们大约每16个月可以看到一次日全食（当然，每次能看到的地方是不同的）。来源：ESA[1] 这并不是一件容易的事，基本只能靠宇宙的馈赠。因为这要求太阳和月亮在地球上看起来大小差不多才行——而刚刚好，太阳的大小是月球的约400倍，而太阳到地球的距离是月亮到地球距离的约400倍。 日全食的原理，月亮几乎刚好可以完全遮住太阳。来源：ESA[1] 将来的火星移民们就没那么幸运了。 火星虽然有两颗卫星，但它们都太小了。 [rml_read_more] 火星的两颗卫星火卫一（Phobos）和火卫二（Deimos），直径分别只有26公里和16公里（火星平均半径3389.5公里） 火卫一、火卫二和火星，大小和距离没有按比例。来源：NASA[2] 日全食是不可能的，大个儿一点的火卫一引起的日食有点儿类似地球上的日环食，而更小个儿也更远的火卫二引起的日食，则更经常被称为“凌日”（transit）。 火星上的日食长什么样？NASA的好奇号火星车最近连拍了两场[3]。多亏了NASA专门给好奇号火星车的Mastcam相机配了日食眼镜，让好奇号可以“直视”太阳。 好奇号火星车MASTCAM的位置和定标器件。来源：NASA[4] 2019年3月26日(Sol 2359)，好奇号拍到的火卫一（Phobos）引起的日食 来源：NASA[3] 2019年3月17日(Sol 2350)，好奇号拍到的火卫二（Deimos）凌日 来源：NASA[3] 这并不是好奇号第一次拍到火星上的日食。例如： 2013年8月20日（Sol 369），好奇号就拍到过火卫一引起的日食 来源：NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ[5] 除了好奇号，勇气号和机遇号的Pancam也可以拍摄日食。 2004年3月10日，机遇号火星车拍到的火卫一引起的日食 来源：NASA[6] 2004年3月14日，勇气号火星车拍到的火卫二凌日 来源：维基/NASA[7] 火星上的日食罕见吗？ 并不。 由于两颗卫星的公转速度很快，火星上的日食其实比地球上要频繁得多 火卫一和火卫二的轨道。改编自：维基/MagentaGreen 仅仅是观测到的，勇气号、机遇号、好奇号三辆火星车也已经拍到了约40次火卫一日食和8次火卫二凌日[3]。实际发生过的远远不止这么多。 所以呀，对将来的火星移民来说，日食会是很常见的景色呢。 最后上个小彩蛋，好奇号拍摄的火卫一从火卫二前面飞过 来源：NASA[2] 参考 [1] https://www.esa.int/spaceinvideos/Videos/2018/07/What_is_an_eclipse [2] https://svs.gsfc.nasa.gov/11326 [3] https://www.nasa.gov/feature/jpl/curiosity-captured-two-solar-eclipses-on-mars [4] https://www.nasa.gov/mission_pages/msl/multimedia/pia16798.html [5] https://www.nasa.gov/mission_pages/msl/multimedia/pia17356.html [6] https://photojournal.jpl.nasa.gov/catalog/PIA05553 [7] https://www.wikiwand.com/en/Transit_of_Deimos_from_Mars