Comet will cross Earth’s sky after 50,000 years

Comet C/2022 E3 (ZTF) will cross Earth’s sky again after 50,000 years since the last visit and will be visible to the naked eye later this month.

The small, icy, rocky body is just one kilometer in diameter and was discovered in March 2022 by the Zwicky Transient Facility (ZTF) program, which operates the Samuel-Oschin telescope at the Palomar Observatory in California, United States.

50,000 years ago, C/2022 E3 (ZTF) visited the inner solar system and passed close to Earth. It was detected again in the path of Jupiter’s orbit and will pass this week close to the Sun.

Astronomers, who calculated its trajectory after months of observation, pointed out that it will reach its perihelion, the closest point to the Sun, next Thursday (12).

When a comet approaches the Sun, the ice in its core changes to a gaseous state and releases a long tail that reflects the star’s light.

This bright phenomenon is what will be seen from Earth, initially in the northern hemisphere, as C/2022 E3 (ZTF) approaches.

The comet will shine in all its splendor “when it is closest to Earth”, says the professor of physics at the California Institute of Technology, Thomas Prince, who works for the ZTF.

However, it will be less spectacular than Comet Hale-Bopp (1997) or Comet Neowise (2020), which were much larger.

The space object can be seen at night with a good pair of glasses or even with the naked eye, as long as the sky is clear, there is no light pollution and the brightness of the Moon is not disturbing.

“Maybe we’re lucky and it’s twice as bright as expected”, ventures astrophysicist at the Paris-PSL Observatory, Nicolas Biver.

Best observation period

The best observation period will be the weekend of the 21st and 22nd of this month and the following week.

During this time, it will pass between the constellations Ursa Minor and Ursa Major. Later, it can be seen in the Southern Hemisphere to then leave for the limits of the solar system, where it was probably born.

According to current models, comets come either from the Kuiper belt, located beyond Neptune’s orbit, or from the Oort cloud, an immense area located almost a light-year from the Sun, at the limit of its gravitational field.

This comet “comes initially from the Oort cloud”, according to Biver when considering its orbit. This time, it will likely “get out of the solar system once and for all,” he adds.

Preparations for viewing it are complete, and scientists hope to learn a little more about the composition of comets, thanks in particular to the powerful James Webb Space Telescope.

“We will observe from all sides. It is not the comet of the century, but we are happy to be able to see comets like this every one or two years, as we consider them vestiges of the formation of the solar system”, says the astrophysicist.