李奥纳德彗星的超长彗尾

李奥纳德彗星的超长彗尾

ByNASA中文

2021年12月30日 The Further Tail of Comet Leonard Image Credit & Copyright: Daniele Gasparri Explanation: Comet Leonard, brightest comet of 2021, is at the lower left of these two panels captured on December 29 in dark Atacama desert skies. Heading for its perihelion on January 3 Comet Leonard’s visible tail has grown. Stacked exposures with a wide angle lens (also displayed in a reversed B/W scheme for contrast), trace the complicated ion tail for an amazing 60 degrees, with bright Jupiter shining near the horizon at lower right. Material vaporizing from Comet Leonard’s nucleus, a mass of dust, rock, and ices about 1 kilometer across, has produced the long tail of ionized gas fluorescing in the sunlight. Likely flares on the comet’s nucleus and buffeting by…

圣诞彗星的彗尾

圣诞彗星的彗尾

ByNASA中文

2021年12月25日 The Tail of a Christmas Comet Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST) and Lukas Demetz Explanation: The tail of a comet streams across this three degree wide telescopic field of view captured under dark Namibian skies on December 21. In outburst only a few days ago and just reaching naked eye visibility Comet Leonard (C/2021 A1) is this year’s brightest comet. Binoculars will make the diffuse comet easier to spot though, close to the western horizon after sunset. Details revealed in the sharp image show the comet’s coma with a greenish tinge, and follow the interaction of the comet’s ion tail with magnetic fields in the solar wind. After passing closest to Earth on December 12 and Venus on December 18,…

三行星与一颗彗星

三行星与一颗彗星

ByNASA中文

2021年12月23日 Three Planets and a Comet Image Credit & Copyright: Tunc Tezel (TWAN) Explanation: Are you still looking for that perfect holiday gift for an astronomer? If your night sky is dark and horizon clear enough, the Solar System may have done your shopping for you. Send them outside after sunset to see three planets and a comet. In this snapshot of the December solstice evening sky from the village of Kirazli, Turkey the brightest celestial beacon is Venus, close to the southwestern horizon at the right. Look left and up to find Saturn shining between clouds. Follow that line farther left and up to bright Jupiter, the Solar System’s ruling gas giant. This year’s surprise visitor to the inner Solar System, Comet Leonard (C/2021…

李奥纳多彗星与鲸鱼星系

李奥纳多彗星与鲸鱼星系

ByNASA中文

2021年12月03日 Comet Leonard and the Whale Galaxy Image Credit & Copyright: Gregg Ruppel Explanation: Sweeping through northern predawn skies, on November 24 Comet Leonard (C/2021 A1) was caught between two galaxies in this composite telescopic image. Sporting a greenish coma the comet’s dusty tail seems to harpoon the heart of NGC 4631 (top) also known as the Whale Galaxy. Of course NGC 4631 and NGC 4656 (bottom, aka the Hockey Stick) are background galaxies some 25 million light-years away. On that date the comet was about 6 light-minutes from our fair planet. Its closest approach to Earth (and even closer approach to Venus) still to come, Comet Leonard will grow brighter in December. Already a good object for binoculars and small telescopes, this comet will…