Watch online as asteroid PHA 2012 QG42 brushes by Earth tonight

It sounds like something from the cineplex, but it’s real: Tonight, an asteroid will pass uncomfortably close to Earth. And you can track its progress live over the Internet.

The asteroid in question has the ungainly name of PHA 2012 QG42. It was discovered just a few weeks ago, on Aug. 26, by the Catalina Sky Survey in Arizona.

Here’s what we know about the “potentially hazardous asteroid” (which is why the rock’s name starts with PHA):

-- It is estimated to be 625 to 1,400 feet across. That means it could be as tall as a 14-story building.

-- It is expected to get within 1.8 million miles of Earth. That may sound far, but it’s less than 7.5 times the distance between the Earth and the Moon.

-- Viewed through a backyard telescope, it would appear about as faint as the dwarf planet Pluto.

Though it will not hit us this time around, it could be on a collision course with our planet in the distant future. Such impacts have happened before – in 1908, a meteoroid entered the atmosphere over Siberia in an event known as the Tunguska impact. When scientists first investigated the site 19 years later, they found “eight hundred square miles of remote forest had been ripped asunder. Eighty million trees were on their sides, lying in a radial pattern,” according to this feature on NASA’s website.

PHA 2012 QG42 is being monitored by a telescope at the Canary Islands Observatory belonging to Slooh, an organization that operates robotic telescopes and broadcasts their images online. Interested viewers can log on to Slooh.com beginning at 4 p.m. PDT to watch the asteroid’s approach.

You can also watch the asteroid from on a webcast -- already streaming as of early Thursday afternoon -- operated by the Virtual Telescope Project 2.0.

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