House-sized asteroid to fly close to Earth Thursday — Watch live from your computer, backyard

NASA to Test Planetary Defense Systems When Asteroid Comes Close to Earth

Scientists at NASA's Center for Near Earth Object Studies (CNEOS) in Pasadena, California, and others around the globe, are tracking an asteroid the size of a house as it nears Earth.

The asteroid, 2012 TC4, is expected to sweep closest to the planet at approximately 1:42 a.m. EST on Thursday, Oct. 12, near Antarctica. It will pass around 26,000 miles above the Earth’s surface, within the moon’s orbit.

It’s estimated to be 50-100 feet in size.

Later on Thursday, at 3:19 p.m. EST, the asteroid will pass approximately 172,000 miles from the moon.

According to NASA, there is no impact risk associated with the asteroid. In fact, CNEOS scientists are planning to use the flyby as an opportunity to test their planetary defense systems, which protect against asteroid collisions on Earth.

"We are going to use this asteroid to practice the system that would observe an asteroid, characterize it and compute how close it is going to come, in case some day we have one that is on the way inbound and might hit," CNEOS manager Pal Chodas told BBC.

No asteroid is currently expected to impact the planet for the next 100 years, according to NASA.

Still, according to brightness measurements, 2012 TC4 is similar in size (30-100 feet) to the meteor that "caused a shock wave and explosion" in the atmosphere as it passed over Chelyabinsk, Russia, in 2013, EarthSky reported.

The 66-foot Chelyabinsk meteor struck Earth’s atmosphere, injured 1,500 people and destroyed more than 7,000 buildings.

Astronomers with small telescopes will be observing the asteroid as it passes safely, but closely. And you can tune in to the coverage, too.

The Virtual Telescope Project in Italy, in partnership with Tenagra Observatories in Arizona, has set up an observing page for space enthusiasts to follow along.

How to watch live stream

Astronomer Gianluca Masi in Italy will stream the event live at 3 p.m. Thursday from Italy and again at 10 p.m. from Arizona.

How to watch from your backyard

According to astronomer blogger Astrobob, you'll need to create your own tracking map using sky charting software, such as Starry Night or Megastar.

Those programs can plot asteroid paths. Here are some of AstroBob’s tips once you have the software:

  • Go to the Minor Planet and Comet Ephemeris Service,
  • Type 2012 TC4 in the box
  • Key in your latitude and longitude
  • Select your software program (bottom of the page)
  • Click Generate ephemerides/HTML
  • Save the file
  • Open the software
  • Select the asteroid
  • Create a custom map with custom time intervals and a magnitude range

According to AstroBob, the asteroid will have peak shine for about two hours.

“By 12:30 a.m., it will have already faded to magnitude 14 and at 1 a.m. to magnitude 15. See it while you can!” he wrote.