June 28, 2022: For the past 3 million years, Comet C/2017 K2 (PanSTARRS) has been falling toward the sun–a long, slow journey from the Oort cloud. Finally, it’s here. Austrian astrophotographer Michael Jaeger photographed “Comet K2” entering the inner solar system on June 25th:
“This is a 22-minute exposure with my 16-inch telescope,” says Jaeger. “The comet was about 9th magnitude.”
Comet K2 caused a sensation when it was discovered in 2017. At first, it appeared to be one of the biggest comets in modern history, with a nucleus as much as 160 km wide. Hubble Space Telescope observations have since downsized it to 18 km. That’s still big (typical comet nuclei measure 1 to 3 km), but not a record setter. K2 is comparable in size to Halley’s Comet.
The comet will make its closest approach to Earth (1.8 AU away) on July 14th, brightening to 7th or 8th magnitude. This is too dim to see with the naked eye, but an easy target for backyard telescopes. A good time to look is now before the full Moon of July 13th interferes. Comet K2 may be found high in the midnight sky in the constellation Ophiuchus.