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Science & Technology

E/2022 E3 (ZTF) – The “Green” Comet

By Elyas Layachi

E/2022 E3 (ZTF) – The “Green” Comet

Image provided by Marca

In March 2022, the comet E/2022 E3 (ZTF) was spotted by astronomers Bryce Bolin and Frank Masci near Jupiter. This comet contains a form of diatomic carbon, causing the comet to appear green when it is blasted by ultraviolet radiation from the Sun. This property of E/2022 E3 is the comet’s defining characteristic. However, what makes E/2022 E3 even more special is that the last time it has been visible to humans with the naked eye was during the Last Ice Age, over 50,000 years ago. Now, in 2023, the green comet is its closest to Earth, making for a marvelous sight for humans across the globe. 

The green comet (E/2022 E3) has a large elliptical orbit around the Sun located around the inner solar system, and it takes the object 50,000 Earth years to travel once around the Sun. As a result of its slow orbit in comparison to Earth’s one-year orbit, the comet is impossible to see for much of its orbit without technological aid. This was the case for the past 50,000 years, until February 1st and February 2nd of 2023, when the comet was a mere 26 million miles (about 41,842,944 km) from the surface of Earth. At such a distance, and with its distinct green hue, the green comet was visible to the naked eye at locations with low light pollution and clear skies.  

Viewers across the globe had the opportunity to view the rare green comet, and it is highly likely that we are the last humans to be able to view the green comet from Earth’s surface without technological aid for the next 50,000 years, due to the comet’s large orbit around the sun. The comet provided scientists with insight into the properties of diatomic carbon; the compound is not easily studied on Earth due to its high instability and reactivity. Furthermore, it can only be found in extremely energetic or low-oxygen environments like stars, comets, and the interstellar medium, according to  

Comet E/2022 E3 is an incredibly special phenomenon, and its passage near Earth is a rare occurrence. However, the green comet is not the only rare celestial object set to illuminate the night sky, with objects such as other small asteroids and meteor showers set to appear regularly throughout the rest of the year. Additionally, with the recent launch of the James Webb Space Telescope, more phenomena than ever before will be able to be studied by NASA (National Aeronautics and Space Administration), expanding our knowledge of the universe. 


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