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Labor Day Comet Stars in Slooh Webcast Tonight!

Celebrate Labor Day tonight (Sept. 3) by watching a bright-green comet approach the sun in a live webcast by the Slooh online observatory.

Comet 21P/Giacobini-Zinner will make its closest approach to Earth on Sept. 10. That same day, it will swing by the sun, appearing bigger and brighter as solar radiation strips particles from its icy surface, creating that characteristic comet "tail."

This evening, the Slooh online observatory will broadcast live views of the comet starting at 10 p.m. EDT (0200 GMT on Sept. 4). You can watch it on Slooh's website with a free membership, or stream it here on, courtesy of Slooh. [Photos: Spectacular Comet Views from Earth and Space

Astrophotographer Alexander Vasenin captured this photo of Comet 21P/Giacobani-Zinner from Moscow Oblast, Russia, on Aug. 18, 2018, at 12:32 a.m. local time (2132 GMT on Aug. 17). (Image credit: Alexander Vasenin/Wikimedia Commons CC BY-SA 4.0)

Comet 21P is a periodic comet that orbits the sun about once every 6.6 years. It is the source of the Draconid meteor shower, which happens every year in October when Earth passes through the trail of debris that Comet 21P leaves behind as it orbits the sun.

When Comet 21P flies by Earth on Sept. 10, it will be 36 million miles (58 million kilometers) away. "On the night of September 3rd, the comet will lie just over 1 degree from bright star Capella in Auriga, making it far easier to spot," Slooh officials said in a statement.

While the comet can be seen with small telescopes and binoculars, it won't be quite bright enough to spot with the naked eye, according to "The comet is expected to reach a visual magnitude of 6.5 to 7. That means it will not be visible to the eye … but nearly," reports.

During the Labor Day webcast, Slooh astronomers Paul Cox and Paige Godfrey will join Slooh's storyteller Helen Avery to talk "all about comets and what they mean to us ground observers," Slooh officials said.

Email Hanneke Weitering at or follow her @hannekescience. Follow us @Spacedotcom, Facebook and Google+. Original article on

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Hanneke Weitering

SPACE.COM ASSOCIATE EDITOR — Hanneke joined the team at in August 2016 as a staff writer and producer. She has previously written for Scholastic, MedPage Today, Scienceline and Oak Ridge National Lab. After studying physics at the University of Tennessee in her home town of Knoxville, she earned her graduate degree in Science, Health and Environmental Reporting (SHERP) from New York University.