Weather permitting, Sedonans will have a rare chance to spot a comet without the aid of a telescope or binoculars over the next couple of weeks.

According to the International Astronomical Union’s Minor Planet Center, comet C/2022 E3 was first detected on March 2, 2022, by the Palomar Mountain Observatory at a distance of approximately 400 million miles from the sun. The comet reached perihelion on Jan. 12, 2023, and is now outbound on its return to the Oort cloud. It will make its closest approach to earth on Wednesday, Feb. 1, passing 26 million miles from our planet.

C/2022 E3 had an apparent magnitude of 17.3 when discovered. By December 2022, it had brightened to magnitude 9. Astronomers expect its brightness to increase to between magnitude 6 and magnitude 5 at closest approach, which should make it visible to the naked eye at dark sky sites such as Sedona. For comparison, Comet NEOWISE, which made its closest approach to earth in July 2020, reached magnitude 1, which is 100 times brighter than C/2022 E3 is expected to become.

Atypically for a visible comet, C/2022 E3 lacks a prominent tail, instead presenting as a diffuse circular cloud. It appears bright green in color in long-exposure images, although this green coloration may not be apparent to naked-eye observers. The green color is due to the comet’s emission of diatomic carbon, which fluoresces when struck by ultraviolet radiation.

For viewers looking to locate the comet in the night sky, on Jan. 26 and 27, C/2022 E3 will pass to the east of the Little Dipper’s bowl, and on Feb. 1, at the time of its closest approach, it will be within the constellation Camelopardalis. By Feb. 5, it will be just to the west of Capella. Excessive moonlight is likely to interfere with observations after Jan. 28. After Feb. 10, the comet should be visible between twilight and 11 p.m. without lunar interference.

Astronomers are currently unsure about C/2022 E3’s future course. Initial observations suggested it had an orbital period of around 50,000 years, meaning it has not been seen by human eyes since the Upper Paleolithic, at the same time that humans were beginning to develop art, technology and social systems. However, more recent observations indicate that C/2022 E3 is on a parabolic orbit and will escape the solar system altogether unless its orbit is subsequently altered by outgassing or gravitational perturbations in the Oort cloud.

C/2022 E3 will likely be the last naked-eye visible comet to pass the earth until March 2024, when the periodic Comet Pons-Brooks is expected to reach magnitude 5, although viewing conditions for Pons-Brooks in the Northern Hemisphere will probably be unfavorable.