Starship Asterisk*

Messier 10 and Comet

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-minutes 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 Oort Cloud this comet PanSTARRS was discovered in May 2017 when it was beyond the orbit of Saturn. At the time that made it the most distant active inbound comet known. Its closest approach the Sun will be within 1.8 astronomical units on December 19, beyond the orbital distance of Mars.

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Hi,

At its closest approach to Earth, the comet was at a distance of 15 light-minutes (not 15 light-seconds), right?

jks wrote: ↑Thu Jul 21, 2022 4:22 am Hi,

At its closest approach to Earth, the comet was at a distance of 15 light-minutes (not 15 light-seconds), right?

You must be absolutely right about that!

Ann

Thanks Ann, I was wondering if there was something that I was missing.

Have stereo viewing images been made before of a comet in two adjacent positions in time? I wonder what could look like.

jks wrote: ↑Thu Jul 21, 2022 4:22 am Hi,

At its closest approach to Earth, the comet was at a distance of 15 light-minutes (not 15 light-seconds), right?

I believe you're right. If I recall a light second is approximately 300,000 kilometers. For easy calculation. From the Wikipedia article on PanStarrs; "and then on 14 July 2022, it passed 1.8 AU (270 million km) from Earth." Now, 270 million km would be about 900 light seconds. (270 divided by 0.3) And 900 seconds equals 15 minutes. They've actually changed the description at the top to minutes although the main web page still reads 15 seconds.

"Every day; it's a getting closer" ! Do you suppose this may turn
out to be an OMG view of a comet? 'It would be nice!

APOD Robot wrote: ↑Thu Jul 21, 2022 4:05 am Messier 10 and Comet

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-minutes 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 Oort Cloud this comet PanSTARRS was discovered in May 2017 when it was beyond the orbit of Saturn. At the time that made it the most distant active inbound comet known. Its closest approach the Sun will be within 1.8 astronomical units on December 19, beyond the orbital distance of Mars.

Ah, "this comet PanSTARRS was discovered in May 2017" - because, of course the PanSTARRS project has discovered a few other comets as well. From https://en.wikipedia.org/wiki/List_of_P ... iscoveries

https://en.wikipedia.org/wiki/List_of_Pan-STARRS_discoveries wrote:
Comets
C/2011 L4
2012: C/2012 K1, C/2012 S4
2013: 311P/PANSTARRS
2014: C/2014 G3, C/2014 Q1 (PANSTARRS), C/2014 OG392 (PANSTARRS)
C/2015 ER61 (PANSTARRS)
C/2016 R2 (PANSTARRS)
C/2017 K2
C/2018 F4 (PANSTARRS)
C/2021 O3

Keeping track of comets these days is a little less messy.