Two space rocks will make close flybys past Earth this week, but they pose no threat to our planet's safety.
The two asteroids are called 2018 CB and 2018 CC, and they were both discovered Sunday (Feb. 4) through an automated telescope search called the Catalina Sky Survey, according to NASA's Minor Planet Center. The Catalina telescopes belong to just one of many observatories worldwide that regularly scan the sky to track and search for space rocks, also known as asteroids.
While the majority of asteroids in Earth's solar system orbit in the asteroid belt between Mars and Jupiter, asteroid flybys of Earth happen several times a year. The last known close asteroid flyby was on Sunday (Feb. 4). The flybys are useful to astronomers because the researchers can examine the asteroids relatively close-up, gaining more information about the space rocks' size, shape and composition.
You can watch livestreams of this week's flybys courtesy of the Virtual Telescope Project, which uses remote-controlled telescopes to track near-Earth objects. (More details on the broadcast times are below.)
Both 2018 CB and 2018 CC are roughly the same size as a 17-meter (56-foot) space rock that exploded over Cheylabinsk, Russia, in 2013, causing property damage and thousands of injuries. 2018 CB is about 12 to 38 meters in diameter (39 to 124 feet), while 2018 CC's diameter is estimated to be 9 to 28 meters (30 to 91 feet), according to the Minor Planet Center.
Unlike Chelyabinsk, however, both asteroids will fly past Earth instead of hitting it.
2018 CC will fly by today (Feb. 6), at 12:58 p.m. EST (1958 GMT), with a closest approach of about half the distance between Earth and the moon. The Virtual Telescope Project will start livestreaming views from a telescope in Arizona at 5 a.m. EST (1000 GMT), and from a telescope in Italy at 3 p.m. EST (2000 GMT).
2018 CB will zoom past Earth on Feb. 10 (Saturday) at 5:06 a.m. EST (1006 GMT), at 20 percent of the distance from the Earth to the moon. The Virtual Telescope Project will livestream this event from Italy only, starting Feb. 9 (Friday) at 3 p.m. EST (2000 GMT).
NASA and its Planetary Defense Coordination Office are among several agencies that regularly examine the sky to look for near-Earth objects such as 2018 CB and 2018 CC. Telescopes around the world and in orbit provide information about asteroids to NASA; details about those small bodies are typically uploaded to the agency's Small-Body Database Browser website that is available worldwide for scientists and the public to see.
There are currently no known asteroids that pose an imminent threat to life on Earth, but NASA and its partners are figuring out strategies to divert or destroy a potentially threatening object. Future mission concepts include ideas such as nets, lasers, gravitational diversion — or simply blowing up the asteroid.
NASA has a dedicated near-Earth object hunter in orbit called NEOWISE, which is expected to end its mission this year when the spacecraft's orbit brings the machine into an area with too much sunlight to look for asteroids. A newer proposal by the same team, called NEOCam, failed to make the cut for NASA's Discovery program in January.NEOCam did, however, receive more funding for another year.
Several asteroid missions are also in progress for the coming years. Japan's Hayabusa2and NASA's OSIRIS-RExare both in-flight to their target asteroids, where they will each collect samples to return to Earth. This year, NASA selected two new Discovery-class missions called Lucy and Psyche; between them, they will fly past eight asteroids in the 2020s and 2030s.
In 2005, Congress tasked NASA with identifying at least 90 percent of "potentially hazardous near-Earth asteroids" or those that are at least 140 meters (460 feet) wide and will come to within about 4.65 million miles (7.48 million kilometers) of Earth, or about 20 times the distance from Earth to the moon, according to the agency. NASA was given a deadline of 2020, but just four years later, a National Academy of Sciences reportsaid NASA likely wouldn't meet the goal unless more funding arrived, and multiple reports since have stated that the agency is behind in meeting the goal. In 2010, the agency met another goal previously set by Congress of finding 90 percent of NEOs 1 km (0.6 mile) wide in 2010, according to NASA.