Take a Journey Through the Universe with CNN’s Wonder Theory Science Newsletter
Are you ready to explore the universe? CNN’s Wonder Theory science newsletter is the perfect way to stay up-to-date on all the fascinating discoveries, scientific advancements, and more. This week, a green-hued comet has made its closest approach to Earth, offering sky watchers in the Northern Hemisphere a spectacular view.
Discovered in March by astronomers using the Zwicky Transient Facility’s wide-field survey camera at the Palomar Observatory in San Diego County, California, this comet was last visible in the night sky during the Stone Age — about 50,000 years ago. Named C/2022 E3 (ZTF), the comet has an orbit around the sun that passes through the outer reaches of the solar system, which is why it’s taken such a long time to swing by Earth again.
At its closest, the comet was expected to be 26 million miles to 27 million miles (about 42 million kilometers to 44 million kilometers) away, according to EarthSky. Even during its closest approach, the comet was still more than 100 times the moon’s distance away from Earth. Astronomer Dr. Gianluca Masi at the Bellatrix Astronomical Observatory in Italy watched the comet make its closest approach at 17:56 UTC or 12:56 p.m. ET Wednesday. The comet came within 26.4 million miles (42.5 million kilometers) of Earth.
As the comet neared Earth, observers were able to spot it as a faint green smudge near the bright star Polaris, also called the North Star. Comets reflect different colors of light due to their current positions in orbit and chemical compositions. A comet can be distinguished from stars by its streaking tails of dust and energized particles as well as the glowing green coma surrounding it. The coma is an envelope that forms around a comet as it passes close to the sun, causing its ice to sublimate, or turn directly to gas.
Astrophysics graduate student Imran Sultan at the Center for Interdisciplinary Exploration and Research in Astrophysics at Northwestern University has been observing the comet since January 19, about a week after the cosmic object’s closest approach to the sun. Sultan used remote observatories in the US and Europe as well as those at Northwestern. In his images, Sultan was able to capture the comet’s anti-tail, or material opposite the tail of the comet. Watching the comet zip through the inner solar system has created an ever-changing backdrop of the universe, where distant galaxies gleam in the background, Sultan said.
Sultan plans to continue capturing images of the comet over the next month. After passing by Earth, the comet will make its closest approach of Mars on February 10, according to EarthSky. Masi’s Virtual Telescope Project is sharing a live stream of the comet in the skies above Rome.
CNN’s Wonder Theory science newsletter is the perfect way to stay up-to-date on all the fascinating discoveries, scientific advancements, and more. Don’t miss out on the opportunity to take a journey through the universe and explore all the wonders it has to offer.