M16: 恒星诞生之柱

M16: 恒星诞生之柱

ByNASA中文

2020年12月06日 M16: Pillars of Star Creation Image Credit: NASA, ESA, Hubble Space Telescope, J. Hester, P. Scowen (ASU) Explanation: These dark pillars may look destructive, but they are creating stars. This pillar-capturing image of the inside of the Eagle Nebula, taken with the Hubble Space Telescope in 1995, shows evaporating gaseous globules (EGGs) emerging from pillars of molecular hydrogen gas and dust. The giant pillars are light years in length and are so dense that interior gas contracts gravitationally to form stars. At each pillars’ end, the intense radiation of bright young stars causes low density material to boil away, leaving stellar nurseries of dense EGGs exposed. The Eagle Nebula, associated with the open star cluster M16, lies about 7000 light years away. The pillars…

风暴洋的吕姆克山

风暴洋的吕姆克山

ByNASA中文

2020年12月05日 Mons Rumker in the Ocean of Storms Image Credit & Copyright: Jean-Yves Letellier Explanation: Mons Rumker, a 70 kilometer wide complex of volcanic domes, rises some 1100 meters above the vast, smooth lunar mare known as Oceanus Procellarum, the Ocean of Storms. Daylight came to the area late last month. The lunar terminator, the shadow line between night and day, runs diagonally across the left side in this telescopic close-up of a waxing gibbous Moon from November 27. China’s Chang’e-5 mission landing site is also in the frame. The probe’s lander-ascender combination touch down on the lunar surface within a region right of center and north of Mons Rumker’s domes on December 1. On December 3 the ascender left the Ocean of Storms carrying…

M63: 向日葵星系

M63: 向日葵星系

ByNASA中文

2020年12月04日 Curly Spiral Galaxy M63 Image Credit & Copyright: Fabian Neyer, Rainer Spani Collaboration Credit: I.D. Karachentsev, F. Neyer, R. Spani, T. Zilch Explanation: A bright spiral galaxy of the northern sky, Messier 63 is nearby, about 30 million light-years distant toward the loyal constellation Canes Venatici. Also cataloged as NGC 5055, the majestic island universe is nearly 100,000 light-years across, about the size of our own Milky Way. Its bright core and majestic spiral arms lend the galaxy its popular name, The Sunflower Galaxy, while this exceptionally deep exposure also follows faint, arcing star streams far into the galaxy’s halo. Extending nearly 180,000 light-years from the galactic center the star streams are likely remnants of tidally disrupted satellites of M63. Other satellite galaxies of…

碰撞中的触须星系

碰撞中的触须星系

ByNASA中文

2020年12月03日 The Antennae Galaxies in Collision Image Credit: ESA/Hubble NASA Explanation: Sixty million light-years away toward the southerly constellation Corvus, these two large galaxies are colliding. The cosmic train wreck captured in stunning detail in this Hubble Space Telescope snapshot takes hundreds of millions of years to play out. Cataloged as NGC 4038 and NGC 4039, the galaxies’ individual stars don’t often collide though. Their large clouds of molecular gas and dust do, triggering furious episodes of star formation near the center of the wreckage. New star clusters and interstellar matter are jumbled and flung far from the scene of the accident by gravitational forces. This Hubble close-up frame is about 50,000 light-years across at the estimated distance of the colliding galaxies. In wider-field views…

月之眼

月之眼

ByNASA中文

2020年12月02日 Eye of Moon Image Credit & Copyright: Zachery Cooley Explanation: Who’s watching who? The featured image of the Moon through a gap in a wall of rock may appear like a giant eye looking back at you. Although, in late October, it took only a single exposure to capture this visual double, it also took a lot of planning. The photographic goal was achieved by precise timing — needed for a nearly full moon to appear through the eye-shaped arch, by precise locating — needed for the angular size of the Moon to fit iconically inside the rock arch, and by good luck — needed for a clear sky and for the entire scheme to work. The seemingly coincidental juxtaposition was actually engineered with…

NGC 346：小麦哲伦星系内的恒星形成区

NGC 346：小麦哲伦星系内的恒星形成区

ByNASA中文

2020年12月01日 NGC 346: Star Forming Cluster in the SMC Image Credit & License: NASA, ESA, Hubble; Processing: Judy Schmidt Explanation: Are stars still forming in the Milky Way’s satellite galaxies? Found among the Small Magellanic Cloud’s (SMC’s) clusters and nebulas, NGC 346 is a star forming region about 200 light-years across, pictured here in the center of a Hubble Space Telescope image. A satellite galaxy of the Milky Way, the Small Magellanic Cloud (SMC) is a wonder of the southern sky, a mere 210,000 light-years distant in the constellation of the Toucan (Tucana). Exploring NGC 346, astronomers have identified a population of embryonic stars strung along the dark, intersecting dust lanes visible here on the right. Still collapsing within their natal clouds, the stellar infants’…

移除恒星后的天鹅座

移除恒星后的天鹅座

ByNASA中文

2020年11月30日 Cygnus Without Stars Image Credit & Copyright: Bowen James Cameron Explanation: The sky is filled with faintly glowing gas, though it can take a sensitive camera and telescope to see it. For example, this twelve-degree-wide view of the northern part of the constellation Cygnus reveals a complex array of cosmic clouds of gas along the plane of our Milky Way galaxy. The featured mosaic of telescopic images was recorded through two filters: an H-alpha filter that transmits only visible red light from glowing hydrogen atoms, and a blue filter that transmits primarily light emitted by the slight amount of energized oxygen. Therefore, in this 18-hour exposure image, blue areas are hotter than red. Further digital processing has removed the myriad of point-like Milky Way…

维罗纳峭壁: 太阳系现知最高耸的悬崖

维罗纳峭壁: 太阳系现知最高耸的悬崖

ByNASA中文

2020年11月29日 Verona Rupes: Tallest Known Cliff in the Solar System Image Credit: Voyager 2, NASA Explanation: Could you survive a jump off the tallest cliff in the Solar System? Quite possibly. Verona Rupes on Uranus’ moon Miranda is estimated to be 20 kilometers deep — ten times the depth of the Earth’s Grand Canyon. Given Miranda’s low gravity, it would take about 12 minutes for a thrill-seeking adventurer to fall from the top, reaching the bottom at the speed of a racecar — about 200 kilometers per hour. Even so, the fall might be survivable given proper airbag protection. The featured image of Verona Rupes was captured by the passing Voyager 2 robotic spacecraft in 1986. How the giant cliff was created remains unknown, but…

NGC 6822: 巴纳德星系

NGC 6822: 巴纳德星系

ByNASA中文

2020年11月28日 NGC 6822: Barnard’s Galaxy Image Credit & Copyright: Data – Martin Pugh, Processing – Mark Hanson Explanation: Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small galaxies form stars too, like nearby NGC 6822, also known as Barnard’s Galaxy. Beyond the rich starfields in the constellation Sagittarius, NGC 6822 is a mere 1.5 million light-years away, a member of our Local Group of galaxies. A dwarf irregular galaxy similar to the Small Magellanic Cloud, NGC 6822 is about 7,000 light-years across. Brighter foreground stars in our Milky Way have a spiky appearance. Behind them, Barnard’s Galaxy is seen to be filled with young blue stars and mottled with the…

嫦娥五号发射

嫦娥五号发射

ByNASA中文

2020年11月27日 Chang’e 5 Mission Launch Image Credit & Copyright: Jeff Dai (TWAN) Explanation: This Long March-5 rocket blasted off from the Wenchang launch site in southernmost Hainan province on Tuesday November 24, at 4:30 am Beijing Time, carrying China’s Chang’e-5 mission to the Moon. The lunar landing mission is named for the ancient Chinese goddess of the moon. Its goal is to collect about 2 kilograms (4.4 pounds) of lunar material from the surface and return it to planet Earth, the first robotic sample return mission to the Moon since the Soviet Union’s Luna 24 mission in 1976. The complex Chang’e-5 mission landing target is in the Oceanus Procellarum (Ocean of Storms). The smooth volcanic plain was also visited by the Apollo 12 mission in…