埃特纳火山上空的ZTF彗星

埃特纳火山上空的ZTF彗星

ByNASA中文

2023年1月28日 Comet ZTF over Mount Etna Image Credit & Copyright: Dario Giannobile Explanation: Comet-like plumes are blowing over the volcanic peaks of Mount Etna in this wintry mountain-and-skyscape from planet Earth. The stacked and blended combination of individual exposures recorded during the cold night of January 23, also capture naked-eye Comet ZTF just above Etna’s snowy slopes. Of course increasing sunlight and the solar wind are responsible for the comet’s greenish coma and broad dusty tail. This weekend Comet ZTF is dashing across northern skies between north star Polaris and the Big Dipper. From a dark site you can only just spot it as a fuzzy patch though. That’s still an impressive achievement if you consider you are gazing at a visitor from the distant…

ZTF彗星: 穿过其轨道面所见的景观

ZTF彗星: 穿过其轨道面所见的景观

ByNASA中文

2023年1月27日 Comet ZTF: Orbital Plane Crossing Image Credit & Copyright: Dan Bartlett Explanation: The current darling of the northern night, Comet C/2022 E3 ZTF is captured in this telescopic image from a dark sky location at June Lake, California. Of course Comet ZTF has been growing brighter in recent days, headed for its closest approach to Earth on February 1. But this view was recorded on January 23, very close to the time planet Earth crossed the orbital plane of long-period Comet ZTF. The comet’s broad, whitish dust tail is still curved and fanned out away from the Sun as Comet ZTF sweeps along its orbit. Due to perspective near the orbital plane crossing, components of the fanned out dust tail appear on both sides…

肉眼可见的ZTF彗星

肉眼可见的ZTF彗星

ByNASA中文

2023年1月21日 Naked-eye Comet ZTF Image Credit & Copyright: Óscar Martín Mesonero (Organización Salmantina de la Astronáutica y el Espacio) Explanation: Comet C/2022E3 (ZTF) is no longer too dim to require a telescope for viewing. By January 19, it could just be seen with the naked eye in this rural sky with little light pollution from a location about 20 kilometers from Salamanca, Spain. Still, telescopic images are needed to show any hint of the comet’s pretty green coma, stubby whitish dust tail, and long ion tail. Its faint ion tail has been buffeted by recent solar activity. This visitor from the distant Oort cloud rounded the Sun on January 12. and is now sweeping through stars near the northern boundary of the constellation Bootes. Outward…

彗星2022 E3 (ZTF)

彗星2022 E3 (ZTF)

ByNASA中文

2022年12月24日 Comet 2022 E3 (ZTF) Image Credit & Copyright: Dan Bartlett Explanation: Comet C/2022 E3 (ZTF) was discovered by astronomers using the wide-field survey camera at the Zwicky Transient Facility this year in early March. Since then the new long-period comet has brightened substantially and is now sweeping across the northern constellation Corona Borealis in predawn skies. It’s still too dim to see without a telescope though. But this fine telescopic image from December 19 does show the comet’s brighter greenish coma, short broad dust tail, and long faint ion tail stretching across a 2.5 degree wide field-of-view. On a voyage through the inner Solar System comet 2022 E3 will be at perihelion, its closest to the Sun, in the new year on January 12…

七年的哈雷尘埃

七年的哈雷尘埃

ByNASA中文

2022年10月28日 Seven Years of Halley Dust Image Credit & Copyright: Petr Horalek / Institute of Physics in Opava Explanation: History’s first known periodic comet Halley (1P/Halley) returns to the inner Solar System every 75 years or so. The famous comet made its last appearance to the naked-eye in 1986. But dusty debris from Comet Halley can be seen raining through planet Earth’s skies twice a year during two annual meteor showers, the Eta Aquarids in May and the Orionids in October. Including meteors near the shower maximum on October 21, this composite view compiles Orionid meteors captured from years 2015 through 2022. About 47 bright meteors are registered in the panoramic night skyscape. Against a starry background extending along the Milky Way, the Orionid meteors…

南天的二颗彗星

南天的二颗彗星

ByNASA中文

2022年10月8日 Two Comets in Southern Skies Image Credit & Copyright: Jose J. Chambo (Cometografia) Explanation: Heading for its closest approach to the Sun or perihelion on December 20, comet C/2017 K2 (PanSTARRS) remains a sight for telescopic observers as it sweeps through planet Earth’s southern hemisphere skies. First time visitor from the remote Oort cloud this comet PanSTARRS sports a greenish coma and whitish dust tail about half a degree long at the upper left in a deep image from September 21. It also shares the starry field of view toward the constellation Scorpius with another comet, 73P/Schwassmann-Wachmann 3, seen about 1 degree below and right of PanSTARRS. Astronomers estimate that first time visitor comet C/2017 K2 (PanSTARRS) has been inbound from the Oort cloud…

星尘与彗尾

星尘与彗尾

ByNASA中文

2022年8月20日 Stardust and Comet Tails Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST) Explanation: Heading for its closest approach to the Sun, or perihelion, on December 19 comet C/2017 K2 (PanSTARRS) remains a sight for telescopic observers as it sweeps through planet Earth’s skies in the constellation Scorpius. The comet currently sports a greenish coma, long whitish dust tail, and short ion tail in this deep image from August 18. The 2×3 degree wide field of view includes part of the dusty nebula IC 4592 reflecting blue starlight. Also known as the Blue Horsehead Nebula, IC 4592 is about 400 light-years distant while the comet is just under 17 light-minutes away. First spotted at a distance well beyond the orbit of Saturn C/2017 K2…

M10与彗星

M10与彗星

ByNASA中文

2022年7月21日 Messier 10 and Comet Image Credit & Copyright: German Penelas Perez Explanation: Imaged on July 15 2022, comet C/2017 K2 (PanSTARRS) had a Messier moment, sharing this wide telescopic field of view with globular star cluster Messier 10. Of course M10 was cataloged by 18th century comet hunter Charles Messier as the 10th object on his list of things that were definitely not comets. While M10 is about 14 thousand light-years distant, this comet PanSTARRS was about 15 light-seconds from our fair planet following its its July 14 closest approach. Its greenish coma and dust tail entertaining 21st century comet watchers, C/2017 K2 is expected to remain a fine telescopic comet in northern summer skies. On a maiden voyage from our Solar System’s remote…

彗星C/2017 K2（PanSTARRS）

彗星C/2017 K2（PanSTARRS）

ByNASA中文

2022年6月30日 Comet C/2017 K2 (PanSTARRS) Image Credit & Copyright: Jose J. Chambo (Cometografia) Explanation: Imaged on June 20 2022, comet C/2017 K2 (PanSTARRS) shares this wide telescopic field of view with open star cluster IC 4665 and bright star Beta Ophiuchi, near a starry edge of the Milky Way. On its maiden voyage to the inner Solar System from the dim and distant Oort cloud, this comet PanSTARRS was initially spotted over five years ago, in May 2017. Then it was the most distant active inbound comet ever found, discovered when it was some 2.4 billion kilometers from the Sun. That put it between the orbital distances of Uranus and Saturn. Hubble Space Telescope observations indicated the comet had a large nucleus less than 18…

从星际空间来的博里索夫彗星

从星际空间来的博里索夫彗星

ByNASA中文

2022年3月5日 Interstellar Comet 2I Borisov NASA, ESA, and D. Jewitt (UCLA) et al. Explanation: From somewhere else in the Milky Way galaxy, Comet 2I/Borisov was just visiting the Solar System. Discovered by amateur astronomer Gennady Borisov on August 30, 2019, the first known interstellar comet is seen in these two Hubble Space Telescope images from November and December 2019. On the left, a distant background galaxy near the line-of-sight to Borisov is blurred as Hubble tracked the speeding comet and dust tail about 327 million kilometers from Earth. At right, 2I/Borisov appears shortly after perihelion, its closest approach to Sun. European Southern Observatory observations indicate that this comet may never have passed close to any star before its 2019 perihelion passage. Borisov’s closest approach to…