SKY GUY VIEWING ALERT! COMET WATCH STARTS TONIGHT!

 Hey, Space Placers!

Comet Lemmon was a beautiful sight near this star in the telescope October 6 at Shenandoah National Park.

CREDIT

Greg Redfern

A year ago today we were enthralled with Comet A3 https://wtop.com/the-space-place/2024/10/comet-watch-a3-may-be-visible-from-dc-area/ adorning our skies. 

We now have another comet, C/2025 A6 Lemmon  https://earthsky.org/space/comet-lemmon-best-comet-of-2025-finder-maps/?mc_cid=10a798c412&mc_eid=9aeb2a4318   , possibly becoming bright enough to be seen with just our eyes in the coming days. It has been a fine view in a telescope and/or binoculars since its discovery in January with the last few weeks becoming even better. 

Comets are left over debris from the formation of our solar system  https://science.nasa.gov/solar-system/comets/facts/     and they are constantly on the prowl in the solar system at any given time. 

As explained by NASA:

“Each comet has a frozen part, called a nucleus, often a few miles across. The nucleus contains icy chunks, frozen gases with bits of embedded dust. A comet warms up as it nears the Sun and develops an atmosphere, or coma. The Sun's heat causes the comet's ices to change to gases so the coma gets larger. The coma may extend hundreds of thousands of kilometers. The pressure of sunlight and high-speed solar particles (solar wind) can blow the coma dust and gas away from the Sun, sometimes forming a long, bright tail. Comets actually have two tails – a dust tail and an ion (gas) tail.”

It has been 5 years since the Northern Hemisphere had a really bright and beautiful comet to see which was Comet NEOWISE https://wtop.com/gallery/the-space-place/photos-passing-comet-is-visible-at-shenandoah/  .

Skywatchers can now start looking for the comet about ninety-minutes before dawn and starting on October 16, it may be possible to see the comet in the pre-dawn and after sunset, dark skies. Refer to the star charts in the above EarthSky.org link to help find the comet. 

Try to find the darkest skies you can for pre-dawn and after it gets dark following sunset, along with good horizon views free of trees and tall buildings.

Check the weather for clear or partly cloudy skies  https://wtop.com/weather/  which will hopefully give us a chance to see Comet Lemmon.

If predictions hold true - comets are notoriously difficult to predict their behavior, just like cats - the comet will get brighter and easier to see in the October days to come and even possibly in November. 

If you have a telescope and/or binoculars, I highly recommend you use them to improve your view and actually see some details in the coma, nucleus and tail of Comet Lemmon.

Use your smartphone and/or camera to image Comet Lemmon using the appropriate exposure and image composition. Your best bet is to use a tripod to take an image and see how it turns out and make the necessary corrections, then image again.

Guess what? 

We have TWO other comets that are capturing our attention - Interstellar comet 3I/ATLAS https://wtop.com/national/2025/10/interstellar-comet-swinging-past-mars-as-a-fleet-of-spacecraft-looks-on/ , only the third such object ever seen so far - and comet C/2025 R2 (SWAN) https://earthsky.org/space/new-comet-swan25b-2025/ .

3I/ATLAS will likely remain a telescopic, perhaps even a binoculars comet while C/2025 R2 (SWAN) is brightening but a difficult sighting for Northern Hemisphere observers due to its low altitude in the West after it gets dark. 

Comet SWAN will be getting higher in the sky each day. Check this link for daily star charts https://www.timeanddate.com/news/astronomy/comet-c-2025-r2-swan .

Check our link https://wtop.com/the-space-place/2025/10/whats-up-in-the-sky-for-october-2025-demon-star-orionid-meteor-shower-full-harvest-supermoon/   for other October sky sights.

Good luck and clear skies!

Sky Guy in VA