# Comet C/2025 A6 (Lemmon) closest approach to Earth on Tuesday 10/21 **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 19, 2025, 3:42am UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089 "2025-10-19T03:42:05Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 19, 2025, 3:42am UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089/1 "2025-10-19T03:42:05Z")
It’s not as impressive at last years Tsuchinshan-Atlas, but it might still be worth a try on the evening of 10/21. I saw it this morning, from the very light-polluted Phoenix area. It was just barely a naked-eye object. Hopefully, it will be better in two days. I’m going to take a trip up to the Grand Canyon, and try to get some long-exposure images, with my nifty new iOptron tracker. I was fooling around with it tonight, and it works well. If I get anything worthwhile, I’ll post back. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [October 19, 2025, 11:51am UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089/2 "2025-10-19T11:51:55Z")
I have a telescope I got as a gift recently and haven’t used yet; this could be a good opportunity. Is a comet a difficult target to find for a first timer? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 19, 2025, 2:51pm UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089/3 "2025-10-19T14:51:54Z")
Stellarium is your friend. Download it, it’s free. It’s a bit of a pain getting current comet orbits loaded into it, but there are instructions on the web. That said, the comet will be 10-20° above the horizon, around 293° azimuth on the evening of 10/21, an hour after sunset. So, I would scan the area above the NW horizon with binoculars as soon as it starts to get dark. It should be naked-eye visible, but it’s not bright. Just don’t despair - it’s there. It should look really awesome through a telescope. Get it set up ahead of time, and pointed in that direction. Oh, yeah - it will be close to (almost vertically above) Arcturus, one of the brightest stars in the sky. So look for a very bright star, starting just after dusk, and as that sets, the comet will take it’s place. Important: you need a clear view of the western horizon. No, houses, trees, mountains, etc. Go find a hill that allows that view. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [October 19, 2025, 4:52pm UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089/4 "2025-10-19T16:52:56Z")
> [@beowulff](#): > > Oh, yeah - it will be close to (almost vertically above) Arcturus, one of the brightest stars in the sky. So look for a very bright star, starting just after dusk, and as that sets, the comet will take it’s place. Important: you need a clear view of the western horizon. No, houses, trees, mountains, etc. Go find a hill that allows that view. We live on a hill, but not the very top of it - so I’m not sure if I’ll have an unobstructed view or not. I won’t have a chance to go hiking after dark tonight, but I put the telescope together and see it has an attachment for my phone camera. So what I will do is take the telescope on the flat part of my roof, find the comet, and then view it through the phone camera while casting my screen to a tv inside the house where my kids can watch. I’d rather they be able to view the telescope directly, but climbing to the roof isn’t exactly safe for a 3 year old! ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 19, 2025, 5:24pm UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089/5 "2025-10-19T17:24:59Z")
That sounds really great! Good luck. BTW - it’s visible for the next few days, in more-or-less the same part of the sky, so you might want to try starting tonight. ---
**Author:** ![Ponderoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponderoid/32/19221_2.png) [@Ponderoid](https://boards.straightdope.com/u/Ponderoid)\ **Post date:** [October 19, 2025, 7:21pm UTC](https://boards.straightdope.com/t/comet-c-2025-a6-lemmon-closest-approach-to-earth-on-tuesday-10-21/1024089/6 "2025-10-19T19:21:23Z")
Heavens Above has a list of current comets already loaded, including this one. > **[Comet C/2025 A6 Lemmon](https://www.heavens-above.com/comet.aspx?cid=C%2F2025%20A6)** > > Satellite predictions and other astronomical data customised for your location.