Photographing the Green Comet C/2022 E3 (ZTF)

In early March, astronomers discovered Comet C/2022 E3 (ZTF) using the wide-field survey camera at the Zwicky Transient Facility. This comet's vivid green color is due to sunlight's effect on cyanogen and diatomic carbon within the comet's nucleus. What's especially unique about this comet is that Comet ZTF has two tails directed almost in different directions. This is extremely rare because at least two factors must coincide: the object's specific position in relation to our planet and the presence of two tails. Such coincidences don't happen very often.

According to NASA's Jet Propulsion Laboratory (NASA JPL), the comet is, or was, on a 50,000-year orbit around the sun. Comet ZTF's approach to the inner solar system may have altered its trajectory sufficiently to ensure it is now on a one-way trip out of the solar system. This means that this will be the first and last time in 50,000 years Comet ZTF will come to visit Earth, so say your goodbyes as we have our last sights of C/2022 E3.

What is a Comet?

Comets are large dust and ice objects that orbit the Sun. These ancient objects, best known for their long, streaming tails, are leftovers from the solar system's formation 4.6 billion years ago. There are four types of comets: periodic, non-periodic, comets with no meaningful orbit, and lost comets.

Periodic Comets: Have orbital periods of less than 200 years or have been observed during more than one perihelion passage.

Non-Periodic Comets: Comets that have only made one pass through the Solar System.

Comets with No Meaningful Orbit: Comets that only pass through the solar system once before being slingshot by the Sun's gravity out into interstellar space.

Lost Comets: Comets that were periodic comets but have not been detected during its most recent perihelion passage.

The diagram above shows the anatomy of a comet. Every comet has a nucleus, which is its solid, frozen core around the size of 10 miles (16 kilometers) in diameter. However, as a comet approaches the Sun, its core begins to warm up. Through this process, the ice eventually starts to transform into gas. This may also cause gas jets to erupt from the comet, ejecting a dust and ion tail. The coma, which is formed by the gas and dust, surrounds the nucleus.

When and Where?

Having the chance to observe a comet is a breathtaking moment that anyone can enjoy, you just have to know the time and place. There are many resources on the web for when to view one; however, many are overwhelming with unnecessary information. For C/2022 E3 (ZTF), the finder chart below shows its position in the sky for each day of the month, starting in January. This can be extremely helpful in locating the moving comet as it flies across our sky at high velocities.

Sadly this will be the last time C/2022 E3 (ZTF) will be visiting our planet, but at least we got to see it once during our lifetime. On February 15, the comet was about 2 degrees from the red giant star Aldebaran. The comet is estimated to be about magnitude 6.5 and requires optical aid, such as binoculars.

C/2022 E3 (ZTF)

In December 2021, I was fascinated with Comet Leonard (C/2021 A1). With its strong and majestic dust tail, I was dying to capture a picture of it. However, that was before I had my own equipment to photograph space. So, now with the opportunity to photograph a one-in-a-lifetime comet, I did my best to capture Comet ZTF.

The gif above is my own 30-minute timelapse of C/2022 E3 (ZTF). In it are 60 frames, each being 30 seconds of exposure time. It's fascinating to see how this comet moved across the center of my field of view in such a short period of time, really showing how fast the comet is moving! My photo of this comet below was captured using a one-shot CCD Camera (ZWO ASI294MC Pro) and a refractor telescope (100mm Aperture, 900mm focal length) while guiding the stars in the background.

Since this was the first time photographing a comet, I am immensely satisfied with the results. I was able to capture the nucleus and tail of the comet, all while keeping track of the stars behind it. I still have much to learn and improve with my astrophotography, and I can't wait to explore even further into the depths of our universe in the future.

Related Articles:

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Comet 2022 E3 (ZTF) (NASA)

See Comet ZTF - C/2022 E3 (Sky & Telescope)