New Comet Approaching Earth Might Soon Be Visible to Naked Eye

In the wake of the spectacular green comet lighting up the skies at the beginning of the year, a brand new comet is approaching our planet.

This comet, named C/2023 P1, or Nishimura, may be visible to the naked eye within the next few months.

The comet was discovered by Hideo Nishimura, an amateur astronomer in Japan, as it approached the inner solar system from the other side of the sun to the Earth on August 11. It is now moving towards the sun and the Earth, getting brighter as it goes.

Nishimura can currently be spotted using a telescope in the constellation of Gemini, EarthSky reports, and has a magnitude of 9.4. A larger positive number means a dimmer object, while a negative number means an object is brighter: the sun has a magnitude of -27, the full moon is -13, while Venus has a magnitude of -5.

Objects with a magnitude of 6 or smaller are visible to the naked eye.

The comet is due to move into the constellation of Cancer in late August and early September, then into Leo in the middle of September, and then Virgo. It will reach its brightest in mid-September, reaching a magnitude of up to 3.2, when it's closest to the sun and Earth, before getting dimmer again as it moves away.

"A comet is like a dirty snowball," Keith Horne, a professor of astronomy at the University of St. Andrews in Scotland, told Newsweek in January. "Comets and planets both orbit the sun, but unlike the circular orbits of planets, comets follow highly elliptical orbits."

During its brightest period, the comet will hopefully be visible to the naked eye, with a long tail that is lengthening as it approaches the sun and heats up.

"This leaves it with lots of loose particles, both charged and neutral, that come away from it while it is moving," Ian Whittaker, a senior physics lecturer in physics at Nottingham Trent University in the U.K., previously told Newsweek. "The neutral particles come off in a cone behind the comet as it moves—a bit like being behind a big truck on the motorway while it's raining, all the excess water hits whatever is directly behind it.

"The charged particles will do the same unless there are any electric or magnetic fields nearby. The sun itself has a magnetic dipole (like the Earth) and has a magnetic field flowing out into the solar system. So the charged particles coming off of the comet are picked up by this magnetic field and sent directly away from the sun (anti-sunward)."

The comet will be closest to Earth on September 13 at a distance of 27 million miles, but will be brightest at its closest point to the sun on September 18 as it skims closer to our star than the planet Mercury. Stargazers will have their best shot of spotting the comet after sunset on this day, when Virgo is visible near to the horizon.

This comet is thought to be a hyperbolic comet, according to NASA's Small-Body Database. Hyperbolic comets are comets that only visit the inner solar system once, being flung out into deep space by the sun's gravity.

Most hyperbolic comets come from the Oort cloud at the far reaches of our solar system. The start of the Oort cloud is around 2,000 to 5,000 astronomical units (AU) away, where one AU is the distance between the Earth and sun: 93 million miles. Pluto's orbit is only 50 AU away. The outer edge of the Oort cloud may be up to 10,000 AU or even 100,000 AU from our star, according to NASA.

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