An enormous asteroid flew by Earth today (Oct. 25), and you can watch it zip by in a video from the Virtual Telescope Project.
Asteroid 1998 HL1 was 3.86 million miles (6.21 million kilometers) away from Earth — about 10 times the average distance to the moon — when it makes its closest approach at 1:17 p.m. EDT (1717 GMT), according to NASA (opens in new tab).
The Virtual Telescope Project, an online observatory founded by astrophysicist Gianluca Masi of the Bellatrix Astronomical Observatory in Ceccano, Italy, hosted a live webcast about the asteroid during the close encounter today. You can watch a replay here at the Virtual Telescope Project's website (opens in new tab).
NASA classifies asteroid 1998 HL1 as "potentially hazardous" because the space rock has the "potential to make threatening close approaches to the Earth." That doesn't mean the asteroid poses a threat this time around. The agency defines (opens in new tab) all asteroids whose orbits around the sun come within 4.6 million miles (7.8 million km) of Earth's orbit, and that have a diameter of at least 500 feet (meters) as "potentially hazardous asteroids."
Asteroid 1998 HL1 measures about 1,800 feet (550 m) in diameter, or about the height of the Sears Tower in Chicago, according to NASA's Jet Propulsion Laboratory (opens in new tab). "This will make it quite bright around the time of the flyby," Masi wrote in a description of today's webcast (opens in new tab).
Today's flyby will be the closest one until Oct. 26, 2140, when it will be just slightly closer to Earth at a distance of 3.84 million miles (6.18 million km). So, 1998 HL1 won't pose a real threat to Earth for the foreseeable future.
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