In March of 2022, astronomers discovered a comet from the outer reaches of the Solar System making its way toward the Sun. Called C/2022 E3 ZTF, the object will be passing by Earth in February, leaving a bright trail of gas and dust behind it.
There’s even a chance that Comet E3 will be visible to the naked eye in February. That’s a rare occurrence for comets — the last one bright enough to be observed without a telescope was NEOWISE in 2020. To find out whether this comet will make a naked-eye appearance, scientists need more observations of how its brightness is changing as it gets closer to the Sun. Comets contain ice, and as they approach the Sun, that ice warms up and sublimates, or turns directly from a solid to a gas. This process creates a comet’s tails, which can stretch for millions of miles, as well as the bright cloud of gas and dust that surrounds the comet’s body, known as the coma.

The orbit of Comet 2022 E3 ZTF. Credit: Tony Dunn
Comet E3 comes from the Oort Cloud, a region of the Solar System far from the Sun inhabited by comets, asteroids and dwarf planets. At some point, a gravitational push nudged Comet E3 from its orbit and sent it flying inward toward the Sun. Astronomers actually thought Comet E3 was an asteroid at first because they couldn’t see any coma or tail. However, further observations revealed that it did indeed have a coma, meaning it had to be a comet.


eVscope images of Comet 2022 E3 ZTF from citizen astronomers Georges S. (left) and Aad V. (right). The images, taken nearly two weeks apart, show the brightening of the comet over time.
The incoming comet will pass closest to the Sun on January 12, 2023, and then draw nearest to Earth on February 2, 2023, when it will be about 42,500,000 km (~26,400,000 miles) away. By the time of its close approach, Comet E3 will only be visible to the Northern Hemisphere in the constellation Camelopardalis.
Before that happens, scientists need more observations to see how its brightness is changing. That’s where you come in! Observe Comet E3 with your Unistellar Telescope and share your data with astronomers. This may be the first and last time we will see E3 pass near our home planet, so don’t miss your chance to catch this comet! With luck, we’ll soon know if an upwards gaze will be enough to witness Comet E3’s beauty.
How to observe this comet with your Unistellar telescope:
Comet 2022 E3 ZTF is registered in the Unistellar App Catalog, so it’s easy to observe. You’ll be using the Unistellar app’s science mode, which can be found under the Cometary Activity tab.
For more information on how to observe, visit the Tutorial Page. You will point to your target using the instructions detailed under Observation 1a: The comet is in the Unistellar app’s catalog.
In the Recording field enter the following information: 3970 ms / Gain: 25 dB / Duration: 20 min.
You can find more information on our Missions Page.
Further readings
A Year in Citizen Science: Unistellar Observers Make 2022 a Success
Last year, Unistellar citizen scientists broke multiple records. From DART to JWST, 2022 was great - but 2023 will be even better!
A Galactic Voyage
Join us on a galactic voyage as we kick off galaxy season with some of our all-time favorites - besides for the Milky Way, that is!
A Year in Citizen Science: Planetary Defense Rocks 2022
Unistellar Planetary Defense had its biggest year yet as the leading citizen science network contributing official near-Earth asteroid data.
A Year in Citizen Science: Observers Break Record Watching JWST from Launch to Space
Last year, the Unistellar Network made the only continuous observations of the James Webb Space Telescope from launch to its final destination.
A Year in Citizen Science: Unistellar Network Breaks Exoplanet Record
Unistellar Exoplanet Hunters made waves in 2022, with a new world record and scientific papers! 2023 is bound to be even better.
Valentine’s Observing Guide
It's the right time of year for viewing celestial objects that will remind you why you fell in love with the night sky.