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…

伦纳德彗星

伦纳德彗星

ByNASA中文

2021年11月21日 Introducing Comet Leonard Image Credit & Copyright: Dan Bartlett Explanation: Here comes Comet Leonard. Comet C/2021 A1 (Leonard) was discovered as a faint smudge in January 2021 when it was out past Mars — but its orbit will take the giant shedding ice-ball into the inner Solar System, passing near both Earth and Venus in December before it swoops around the Sun in early January 2022. Although comets are notoriously hard to predict, some estimations have Comet Leonard brightening to become visible to the unaided eye in December. Comet Leonard was captured just over a week ago already sporting a green-tinged coma and an extended dust tail. The featured picture was composed from 62 images taken through a moderate-sized telescope — one set of…