Green comet streaks across the sky in 2023 for first time since Stone Age
AUSTIN, Texas (KXAN) — This month, skygazers will be treated to a once-in-a-civilization sight: a green comet named C/2022 E3 (ZTF) approaching Earth. The comet, which last passed through our solar system a little more than 50,000 years ago, will reach its perihelion (or its closest point to the sun) on Jan. 12, when it will be within 100 million miles of the sun, according to NASA's Jet Propulsion Laboratory.
On February 2, the comet will only be about 26 million miles from Earth. This is the closest it has passed since the Upper Paleolithic era, an epoch of human history when Homo sapiens are believed to have left Africa and settled in Asia and Europe. To put it into perspective, Neanderthals still walked the Earth the last time the comet passed over.
What will the E3 comet look like?
According to NASA, predicting the brightness of a comet is difficult. NASA said that if it continues to brighten, it should be visible with the naked eye. It'll also be bright green.
NASA said that in the Northern Hemisphere, the comet will be visible in the mornings toward the northwest. In February, it will move below the horizon and become visible in the Southern Hemisphere. Viewers may be able to see the comet with the naked eye, but binoculars or a telescope will be the best bet.
How was the E3 comet discovered?
Discovered by astronomers Bryce Bolin and Frank Masci at the Zwicky Transient Facility in March 2022, the E3 comet was first spotted near Jupiter. It was initially believed to be an asteroid, according to Space.com. As it traveled closer to the sun, it grew brighter. Comets do this as the heat of the sun causes frozen dust and gas beneath the surface to be released. Sunlight reflects off of these gases, giving them the appearance of tails.
The comet was named for where it was discovered (ZTF) and the year it was discovered (2022). Since it was discovered in the first part of March, or the fifth "half-month" of the year, it was designated E, the fifth letter of the alphabet. Finally, it was third object discovered that half-month, hence "E3."
What were humans doing the last time C/2022 E3 passed by?
It's been 18,930,412 days since the comet last completed its orbit, according to data released by NASA's JPL. At that time, Homo erectus, the predecessor to Homo sapiens, and Neanderthals were using stone tools. Some settlements were believed to have existed in valleys. The first bladed weapons were invented, as well as the fishhook and rope.