Tonight’s the night that Comet NEOWISE F3 is closest to Earth. This is not to say that it’s actually really close at all (approximately 64,300,000 miles), but it is the closest it will come as it heads back out to the dim, cold, empty regions of the solar system.
But first, before it gets dark, the monthly cycle has rolled around and the three-day-old crescent moon is back in our skies.
As always, the crescent Moon is a high dynamic range object. The illuminated crescent is quite bright, to to capture it you need a short exposure (1/25 second), but doing so makes it hard to see the palm trees that it was sharing that spot of sky with – perhaps if you have a good, high contrast monitor you can see their faint silhouettes.
Shoot a two-second exposure and the darkened face of the moon starts to come out due to Earthshine, sunlight reflected off of the Earth, onto the Moon, and then back to us. You can also start to see the brighter stars, as well as the aforementioned palm tree silhouettes. But the illuminated portion of the Moon is completely overexposed.
Finally, if you wait until about 21:45 and shoot a 15-second exposure, you’ll catch the comet with a distinct green color showing around the head, but not as much tail visible in the hazy, light-polluted skies of Los Angeles.
That’s the big difference in location – you’ll notice in all of the really fantastic comet photos taken from dark sky locations, the sky is almost jet black and a ton of detail can be seen in the tail, including the ion tail which is split off from the dust tail. Here in the big city, a long exposure just starts to turn everything grey.
So while I’ll still be going out and watching the comet, I don’t anticipate too many more photos, if any, unless something dramatic happens. “Dramatic” could include getting my telescope cleaned and repaired, getting the chance to drive for a few hours to get off to a dark sky location, or both.
The odds of either or both happening are…astronomical!
But the comet is still visible easily with binoculars, even from a city with all of its lights, and in a dark sky it’s still (barely) a naked eye object, so if you haven’t seen it yet, take your shot!