Cape Canaveral, Florida (AP) – A comet is heading our way 50,000 years later.
Dirty Snowball was last visited during the Neanderthal days, according to NASA. It will come within 26 million miles (42 million kilometers) of Earth on Wednesday before drifting away again and is unlikely to return for millions of years.
So look up, in contrast to the Killer-Comet title “Don’t Look Up”.
Discovered less than a year ago, this harmless green comet is already visible in the northern night sky with binoculars, small telescopes and possibly the naked eye in the darkest corners of the northern hemisphere.
It is expected to clear as it approaches and rise higher on the horizon by the end of January, and is best seen before dawn. On February 10th, it will be close to Mars, which is a good reference point. Skygazers in the Southern Hemisphere will have to wait until next month to get a glimpse.
While many comets have graced the sky over the past year, “it looks like this one probably looks a little bigger and therefore a little brighter as it gets a little closer to Earth’s orbit,” said the asteroid and comet tracking expert. from NASA, Paul Chodas.
This long-period comet green of all carbon in the gas cloud, or coma, surrounding the nucleus, was detected last March by astronomers using the Zwicky Transit Facility, a wide-field camera at Caltech’s Palomar Observatory.
This explains its onerous official name: Comet C/2022 E3 (ZTF).
On Wednesday, it will pass between the orbits of Earth and Mars at a relative speed of 207,000 km. Their cores are believed to be about a mile (1.6 kilometers) in diameter and their tails extend for millions of miles (kilometers).
The comet is not expected to be as bright as Neowise in 2020, or Hale-Bopp and Hyakutake in the mid-1990s.
“It will be bright thanks to its close-Earth pass… which allows scientists to do more experiments and the public to see a beautiful comet,” Karen Meek, an astronomer at the University of Hawaii, said in an email.
Scientists are confident in their orbital calculations, which pinpoint the last passage of the comet through the planetary neighborhood of the solar system 50,000 years ago.
They don’t know how close it was to Earth or if it was visible even to Neanderthals, said Chodas, director of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory in California.
However, when he returns, the verdict is even more difficult.
Each time a comet passes the sun and planets, its gravitational tugs slightly alter the trajectory of the ice ball, causing significant changes in trajectory over time. Another wild card: jets of dust and gas expelled from the comet as it warmed up near the sun.
“We don’t know exactly how far they are pushing this comet,” Chodas said.
The comet – a time capsule of the nascent solar system 4.5 billion years ago – came from what is known as the Oort Cloud outside Pluto. This frozen paradise for comets is believed to extend more than a quarter of the way to the next star.
Chodas said that although comet ZTF originated in our solar system, we cannot be sure it will remain there. He added that if he was kicked out of the solar system, he would never return.
Don’t worry if you missed it.
“In the field of comets, you just have to wait for the next one, because there are dozens of them,” Chodas said. “And the next one could be bigger, it could be brighter, it could be closer.”
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