‘Green’ Comet to Make Rare Flyby of Earth

January 12, 2023
A comet flying through space

Comets are notoriously unpredictable, but if this one continues its current trend in brightness, it’ll be easy to spot with binoculars, and it’s just possible it could become visible to the unaided eye under dark skies.

Preston Dykes, NASA, on a rare, green comet making its closest approach to the sun on Thursday. The comet is expected to make its closest approach to Earth on February 1.

Why It Matters: The last time humans could have seen this green comet was during the ice age, at a time when they "were using crude stone tools to hunt" (Indianapolis Star). This rare, green comet takes about 50,000 years to travel around the sun, which is why the opportunity to see it is described as a "once-in-a-civilization event."

  • The comet should be visible with a telescope and binoculars, and potentially the unaided eye "under dark skies," Dyke says. You can watch a livestream of the comet at 10 pm central time HERE.
  • What Are Comets, Anyway? NASA explains: "Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets. The dust and gases form a tail that stretches away from the Sun for millions of miles." Currently, there are more than 3,700 known comets!
  • Dykes said viewing this particular green comet – named Comet 2022 E3 (ZTF) – is "an awesome opportunity to make a personal connection with an icy visitor from the distant outer solar system."
  • NASA discovered the comet inside Jupiter's orbit last March. The comet is expected to become visible to the Northern Hemisphere during January, and will become visible to observers in the Southern Hemisphere in early February.

What's Up – January 2023 (NASA, Jet Propulsion Laboratory)

Rare, green comet to pass by Earth starting this week (ABC News)

Rare Comet Will Pass Earth For First Time IN 50,000 Years: How To Watch And What It Means For The Past (Forbes)

by Jenna Lee,