For northern hemisphere skywatchers, it might just be the century’s best comet so far.
Every once in a while, large, icy objects pass through the inner Solar System.
When they near the Sun, the ices sublimate, emitting volatile gases.
Both dust and ions are blown off, creating spectacular cometary tails.
From Earth, these comets typically appear brightest during closest approach.
Bright, naked-eye comets are rare, with 1997’s Hale-Bopp serving as our most recent “great comet.”
Since then, only 2007’s Comet McNaught was comparable, primarily to southern hemisphere observers.
But in July of 2020, Comet NEOWISE will put on Earth’s greatest cometary show in 13 years.
With a 6,800 year orbital period, it last appeared before the wheel was invented.
On July 3, 2020, it reached perihelion, surviving a perilous encounter with the Sun.
Since then, it’s graced our pre-dawn skies, but relative motion changes everything.
On July 12/13, 2020, Comet NEOWISE finally becomes visible after sunset.
Although it’s brighter than all but around 20 stars, its extended, diffuse nature makes it a challenge for human eyes.
It’s easiest to first locate with binoculars, below the Big Dipper in the northwest skies.
It will peak on July 23: reaching its closest approach to Earth.
For many skywatchers, it’s already humanity’s best comet since 1997.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.Ethan Siegel is the author of Beyond the Galaxy and Treknology. You can pre-order his third book, currently in development: the Encyclopaedia Cosmologica.