Space and Physics
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Comet C/2020 F3 NEOWISE was the brightest comet visible in the Northern Hemisphere in 23 years, an exciting sight for astrophiles, professional astronomers, and astrophotographers alike. In August, the Hubble Space Telescope took the closest image yet of the comet after it passed by the Sun, and it's beautiful.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Comets are made of ice so when they approach a star, the intensity of its light heats them up. The surface of these frozen bodies sublimates, and the gases and dust particles released form a dusty atmosphere or "coma" around the nucleus and a long tail that stretches away from the Sun. Encounters with the Sun can easily break comets apart, which happened to Comet ATLAS and even interstellar Comet Borisov this year.
Thanks to Hubble's observations, this doesn't appear to be the case with Comet NEOWISE. The space telescope witnessed two powerful jets of material erupting from the small nucleus, suggesting that the 4.5-kilometer (2.8-mile) central body stayed intact.
The core of the comet is too small to see in this Hubble image. The heat of the Sun released the frozen gas, and the rotation of the nucleus shapes the jets into this intriguing fan shape. What we are seeing spans an area 18,000 kilometers (11,200 miles) across, where the activity of the comet is at its most intense.
The two images in this video were take three hours apart on 8 August 2020 and feature the comet’s prominent jets that are emerging from the nucleus. NASA, ESA, Q. Zhang (California Institute of Technology), A. Pagan (STScI), and M. Kornmesse
Hubble will continue to observe Comet NEOWISE and measure its properties. Astronomers are interested in knowing how it will change as it moves further away from the Sun. The color of the comet will be a particular interesting litmus test, as it is linked to the chemical species liberated from the nucleus.
However, these will be among the last images of comet NEOWISE that humans will have for a while. The comet is on its way back out to the edge of the Solar System and despite moving at 60 kilometers (37 miles) per second, it won’t come back near us for another 7,000 years.
