Comet NEOWISE lit up skies in the Northern Hemisphere with its spectacular forked tail and dazzled astronomers and enthusiasts alike in recent months, before careening back into outer space and out of our view. Now, new close-up photos from NASA’s Hubble Space Telescope suggest that NEOWISE survived its journey around the sun intact, and might make its way back to Earth’s skies the next time it repeats this part of its orbit—in roughly 6,800 years, that is.
NEOWISE orbits the sun in an elliptical pattern, with an estimated aphelion, or farthest point, at about 630 astronomical units (AU) away, where one AU is the distance between the Earth and the sun, researchers Gareth Dorrian and Ian Whittaker note in the Conversation. On July 3 of this year, the comet reached its perihelion, or closest point to the sun, cruising just 27 million miles away from the boiling-hot star, per a NASA statement.
As George Dvorsky reports for Gizmodo, the three-mile-long comet is now cruising back out into outer space at about 37 miles per second. On August 8, scientists at the Hubble telescope were able to capture a rare image of the object as it speeds away from Earth. According to the NASA statement, this is the first time that a comet of “such brightness” has been captured up-close on camera after such a close shave with the sun.
The icy core, or “heart” of the comet is too small to be seen, even with the powerful Hubble telescope, the scientists note. Instead, the August 8 image shows the 11,000-mile-long “gossamer shell of gas and dust” that surrounds the comet’s frozen center, also known as its “coma,” per a Caltech statement.
“Hubble has far better resolution than we can get with any other telescope of this comet,” lead NASA researcher and Caltech graduate student Qicheng Zhang says in the statement. “That resolution is very key for seeing details very close to the nucleus. It lets us see changes in the dust right after it’s stripped from that nucleus due to solar heat, sampling dust as close to the original properties of the comet as possible.”
The image also revealed one, and possibly two, “jets” of material, which scientists suspect are streams of ice that emanate from within the comet’s core and sublimate, emerging as cone-like structures of gas, dust and ice that fan out from the comet’s surface. By studying data collected from the Hubble images, Zhang and his team hope to identify more details about the composition of the jets, per the NASA statement.
Officially known as Comet C/2020 F3 NEOWISE, the interstellar object is considered to be the brightest comet visible from the Northern Hemisphere since Comet Hale-Bopp crossed paths with our sun in 1997, according to NASA.
As the NEOWISE passed by the sun and heated up, parts of its interior structure broke apart into a cloud of dust and gas, which was responsible for the comet’s bright tail. Often, bodies that come so close to the sun, such as 2013’s Comet ISON, will break apart entirely, reports Amanda Kooser for CNET. NEOWISE, on the other hand, seems to have made this leg of its trip without disintegrating completely.
“Because comets are made of ice, they are fragile,” notes Zhang in the Caltech statement. Zhang adds, “we weren’t entirely sure whether Comet NEOWISE would survive the journey around the sun.”
Scientists estimate that the comet has an orbital period of roughly 6,800 years—so be on the lookout for another NEOWISE sighting in about 8820 A.D.