A comet called Nishimura, which was discovered only a month ago, may appear within visible range this weekend, providing stargazers with a once-in-437-year opportunity to observe an extraterrestrial visitor. The orb of rock and ice, whose exact size is unknown, is named after Japanese amateur astronomer Hideo Nishimura, who first discovered the comet on August 11.
Nicolas Biver, an astrophysicist at the Paris Observatory, said it was very rare for a comet to reach its peak visibility so soon after its discovery. "Most comets were discovered months or even years before they were closest to the sun," he told AFP.
He said that comets only pass by the sun every 437 years, which is a long orbital period, and they spend most of their time in the icy outer solar system. As a comet approaches the sun from the vastness of space, the heat causes its icy core to turn into dust and gas, creating a long tail. Sunlight reflects off this tail, allowing us to observe the comet from Earth.
Comet Nishimura, named C/2023P1, will be closest to the sun on September 17. It will be 33 meters (20 meters) from the sun, less than a quarter of the distance between Earth and the sun, Beaver said. The comet will then pass harmlessly by Earth at a distance of 125 meters.
For stargazers, the comet will be easiest to spot this Saturday and Sunday, especially in the Northern Hemisphere. "It's best to look northeast and to the left of Venus before sunrise in a clear, pollution-free sky," Beaver said.
This spectacle can easily be appreciated by those using a small telescope. However, if conditions permit, comets can also be seen with the naked eye.
The comet's tail is green because it contains more gas than dust, Beaver said.