Is it a Meteor? Maybe not!

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If you've taken a photo of the night sky, whether with a camera or your phone, you may find it contains a few unexpected streaks. Think you captured a meteor? Or that comet you've read about in the news lately? While it could be one of those, it might also be something else. 

People post questions about this so often in places like Facebook that I wrote about it last year. Now, I'm posting an update, focusing on how to quickly identify what you've captured; the details of why are in the earlier post.

Length?

First, how long was your exposure? If it was just a few seconds or even a fraction of a second, any streak will be relatively short, and its length may not be much help in identifying what caused it. However, if it was a long exposure—5 seconds, 10, or even longer—a short streak may be a meteor as they only last a fraction of a second, but a long streak is more likely an airplane or a satellite.

Dots?

Next, is the streak solid, or is it a line with dots? If there are dots, it is most likely an airplane. If there are multiple parallel lines with dots, the aircraft is flying at a relatively low altitude.

Shape?

No dots? What do the ends look like? If both ends are blunt, then what you've captured is most likely a satellite. Larger satellites (like the ISS) will leave a thicker trail. If only one end is blunt but the other is tapered, or both ends are tapered, you might have caught a satellite passing in or out of Earth's shadow, fading into or out of view. 

Meteors generally also have tapered ends though usually starting very thin, getting gradually thicker and then quickly coming to a point at the end of its journey. 

Frames?

If you took multiple, successive photos and the streak only appears in one frame, that's another sign it is probably a meteor. If it shows up in more than one image, then it's either an airplane (any dots?) or it is a satellite. 

Color?

If the streak has noticeable color, especially different colors along its length, then it is probably a meteor. With aircraft there may be colors but the streaks are a constant color and the dots generally differ in color from the streaks. With satellites, there's usually no discernible color as they just reflect sunlight. 

Fuzzy?

What if the streak is not so much a line as something cloudy with a bright spot at the lower end? Then maybe you did capture that comet!

For a deeper dive on these and more, go here.

Start of the 37th America's Cup

Although it may seem from most of my posts that this blog is all about astronomy, sailing is also one of my passions so it's time to talk about that for a change. 

Saturday was the start of the latest round of the America's Cup, the longest running sporting event in the world. It's always been a rich man's sport, seeing who can build the biggest, fastest boat. The defender this time is Emirates Team New Zealand and they are battling the challenger, Ineos Britannia who beat out 4 other teams (including American Magic) for the privilege. Although the regatta is usually sailed on home waters of the defender, for 2024 New Zealand opted to have the racing held in Barcelona, Spain. 

This time, the "biggest, fastest boats" are the AC75, a 75 foot long foiling sailboat built to sail up to 50 knots (58mph). Actual speeds have been clocked at 55.5 knots (63.9mph)! They have crews of 8 and that includes 4 "cyclors", guys pedaling on equipment like a stationary bike to provide all the power required to operate the boat. 

Starting in the 2013 edition (raced on San Francisco Bay with AC72s, wind-sailed foiling catamarans), the America's Cup introduced cutting-edge technology originally developed for football broadcasts. Using special cameras with precision positioning, they can now digitally draw the race course on screen. Remember the first time you watched a football game and noticed the down line seemingly painted on the field, yet players could walk in front of it? Since 2013, this same tech has been applied to the America's Cup, growing more sophisticated with each edition. 

Watch this 1 minute clip from the Louis Vuitton challenger series, featuring Great Britain racing against Italy whom they later defeated for the right to face New Zealand. It showcases what makes the America's Cup so captivating: the speed and size of the boats, the mind-boggling sight of sailboats flying across water at near-freeway speeds, the intense competition and tactics, and even the digital augmentation. The latter is used to illustrate how the wind coming off the sails of the lead boat creates "disturbed air," which the tailing boat tacks (turns) to avoid. 

While this is worlds apart from the typical sailing we do on Dallas lakes, the America's Cup has long held a fascination for me!

First Glimpse of Comet C/2023 A3

Comet C/2023 A3 Tsuchinshan-ATLAS, having swung around the sun and headed to the outer reaches of the solar system, is now climbing higher in our evening sky each night. Today marks its closest approach to Earth, so I went out to capture it.

I took this shot from the east shore of White Rock Lake, with the old Pump Station and its distinctive smokestack in view. Despite A3's brightness, it's a challenge to spot in urban areas without optical aids. Even with my Nikon D750, while the coma is easily visible, the tail remains quite faint.

Over the next week, the comet will rise higher above the horizon's haze, improving visibility. However, it's a double-edged sword - as it climbs, it will also retreat from Earth, gradually dimming until it's only visible through a telescope.

I'm planning another attempt in a few days, hoping to capture a better shot of that elusive tail. If you're interested in catching a glimpse of this cosmic visitor, find a spot with a clear western horizon in the hour after sunset between now and the end of the month. It's worth the effort!

Click on the image to view full-size.