▲ Video of Comet Nishimura captured by NASA’s Stereo-A spacecraft. After the comet is struck by a huge prominence plasma wave emitted from the Sun, the comet’s tail disappears. Source = NASA/NRL/Karl Battams The recently discovered green comet Nishimura survived a close encounter with the Sun before its body was hit by a powerful coronal mass ejection (CME). This incredible impact, in which the comet’s tail was briefly blown away, was captured by NASA’s space probe camera.
In a video taken by NASA’s Stereo-A (Solar Terrestrial Relations Observatory) spacecraft, Comet Nishimura collided with a column of solar plasma, causing the comet’s tail to ‘pull out’ for a moment before completely dispersing and disappearing. Carl Battums, an astrophysicist at the U.S. Naval Research Laboratory who produced a video of this scene, reported this fact to ‘Live Science’ by email.
Comet Nishimura, also known as C/2023 P1, was first discovered by Japanese amateur astronomer Hideo Nishimura on August 12. Falling toward the Sun at high speed, Nishimura’s steep trajectory initially made it look like an interstellar object like ‘Oumuamua (Comet 2I/Borisov) leaving the solar system after circling the Sun. However, subsequent observations revealed that this object originated in the Oort Cloud, an asteroid-space rock repository beyond the orbit of Neptune, and was a comet with an elongated elliptical orbit that enters the inner solar system approximately every 430 years.
On the 12th, Comet Nishimura reached its closest point to Earth, passing within 125 million km, which is about 330 times the average distance between the Earth and the Moon. Until then, the comet was clearly visible near the horizon just before sunrise and just after sunset, resulting in some stunning photos of the space rock streaking across the night sky. In some of these images, the core (coma) surrounding the rocky core called Nishimura was clearly visible, emitting a green glow due to the high concentration of carbon dioxide contained in the gas and dust cloud. ▲ Comet Nishimura shaking after hitting the CME on the 6th. On the 17th, the comet reached perihelion, the shortest distance from the Sun, and orbited our star at a distance of 33 million km. Such close encounters often result in the comet burning and breaking up. But astronomers soon discovered that Nishimura had survived the sudden acceleration of the sun’s rotation.
As Nishimura began to move away from the Sun, it passed in front of Stereo-A, which was closely observing the comet. Then, on September 22, strong solar winds erupted in huge amounts of plasma, or ionized gas, and coronal mass ejections blew away the comet’s tail. But Battums said the effect was only temporary and the comet was “completely harmless.” Afterwards, the comet soon recovered and more dust and gas erupted, causing the comet’s tail to grow again.
This isn’t the first time Nishimura has lost his tail. At least one such event occurred in early September when a pair of solar coronal mass ejections collided with a comet. However, Nishimura surprisingly remains ‘resolute’ and maintains its original orbit despite constant attacks from the sun, said Battums.
Gwangsik Lee, Science Columnist joand999@naver.com
