Comet-Chasing Rosetta Spacecraft Wakes from Deep Sleep Monday: Watch It Live

Rosetta Spacecraft Artist Impression
In August 2014, the ESA's Rosetta Spacecraft will rendezvous with Comet 67P/Churyumov-Gerasimenko and deploy its Philae lander, as seen in this artist's impression. (Image credit: ESA–C. Carreau/ATG medialab)

Editor's Note: The comet-chasing Rosetta spacecraft successfully woke up Monday (Jan. 20) for its encounter with Comet 67P/Churyumov–Gerasimenko later this year. Read our full wrap story here: Sleeping Rosetta Spacecraft Wakes Up for Historic Comet Rendezvous and Landing

A European spacecraft destined to visit a comet later this year will get the ultimate wake-up call Monday (Jan. 20) and you can watch it live online.

After more than two years in a deep sleep, the European Space Agency's Rosetta spacecraft is due to awake from its "hibernation" mode at 5 a.m. EST (1000 GMT) on Monday to gear up for an August arrival at its comet target. To mark the occasion, ESA officials will celebrate with a special day-long series of press briefings from the European Space Operations Center in Darmstadt, Germany.  

You can watch the Rosetta comet probe wake-up webcast live here beginning at 4:15 a.m. EST (0915 GMT), courtesy of ESA. The webcast will run from 4:15 a.m. EST to at least 1:30 p.m. EST (1830 GMT). In the Central European Time zone, the schedule runs from 10:15 to 19:30 CET, according an ESA update. [Europe's Rosetta Comet Mission in Photos]

The two-part Rosetta spacecraft is designed to orbit and land on the Comet 67P/Churyumov-Gerasimenko in November 2014. See how the Rosetta spacecraft works in this infographic. (Image credit: by Karl Tate, Infographics Artist)

The Rosetta spacecraft launched in 2004 on a decade-long journey to the Comet 67P/Churyumov-Gerasimenko. The spacecraft is slated to arrive in orbit around the comet in August of this year to begin studying its target and, ultimately, land the small Philae lander on the comet's surface.

Rosetta flew by Earth three times, and Mars once, to build up enough speed to reach the comet. Along the way, it also visited two asteroids —Steins and Lutetia.

But in mid-2011, Rosetta entered a 31-month "hibernation" as it sailed out toward the orbit of Jupiter — where the available sunlight was too low to power all of its systems. Only the probe's main computer and some heaters stayed on to keep it alive, ESA officials said.

Rosetta's internal clock is programmed to wake the comet-chasing spacecraft on Monday to begin preparing for the August comet encounter. ESA officials have described it as "the most important alarm clock in the solar system."

It will take Rosetta several hours after its 5 a.m. reactivation to warm its star trackers enough to orient itself to face Earth and beam its wake-up announcement to Earth.

"Because of Rosetta's vast distance — just over 807 million kilometers (501 million miles) from Earth — it will take 45 minutes for the signal to reach the ground stations," ESA officials wrote in a statement. "The first opportunity for receiving a signal on Earth is expected between 17:30 GMT and 18:30 GMT (12:30 to 1:30 p.m. EST)."

ESA's deep-space listening station in New Norcia, Australia, will be awaiting that signal, as will NASA's Deep Space Network radio antennas in Canberra, Australia, and Goldstone, Calif. Once the first signal is received, it will be transmitted to ESA's Space Operations Center and announced publicly using the Rosetta mission's Twitter feed @ESA_Rosetta.

Currently, Rosetta is nearly 5.6 million miles (9 million km) from Comet 67P/Churyumov-Gerasimenko, but the probe is expected to close that gap to about 1.2 million miles (2 million km) by May, when it is scheduled to fire its thrusters to place it on a trajectory to arrive at the comet in August. The Philae lander is expected to be released to land on the comet in November, according to ESA officials.

Visit on Monday for coverage of the comet-chasing Rosetta spacecraft's cosmic wakeup call in deep space.

Email Tariq Malik at or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on

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Tariq Malik

Tariq is the Editor-in-Chief of and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.