Earth just had a ‘close shave’ with a 180ft asteroid – and no one saw it coming

By RYAN O’HARE FOR MAILONLINE PUBLISHED: 07:34 EST, 31 August 2016 | UPDATED: 07:36 EST, 31 August 2016
Via: Dailymail.co.uk

[Editors note: for comparison, the asteroid that exploded over Chelyabinsk, Siberia on 2/15/13, was ~17m or ~56 ft in diameter, it exploded with the force of 30 Hiroshima bombs.]

• Earth just had a ‘close shave’ with a 180ft asteroid – and no one saw it coming
• Astronomers in Brazil discovered asteroid 2016 QA2 on Saturday
• Asteroid thought to be between 80 and 180ft wide (25 and 55m)
• The rock passed to within 50,000 miles of Earth just a day later
  That’s less than a quarter of the distance between Earth and the moon

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That’s less than a quarter of the distance between Earth and the moon.[pullquote]HOW CLOSE DID IT PASS?
Astronomers in Brazil believe asteroid 2016 QA2 passed within 50,000 miles (80,000 km)
of Earth.
For comparison, the average distance to the moon is 239,000 miles (384,000 km).[/pullquote]
Astronomers at the Sonear observatory in Brazil discovered the rock on Saturday 27th August, and estimate its size to be between 80 and 180 feet wide (25 and 55 metres).
The upper end of the range would make it far larger than the object which exploded over Chelyabinsk in Russia in 2013, smashing windows and injuring more than 1,000 people.
The team at Sonear believes the asteroid has been travelling in an elliptical orbit around the sun, completing a lap of the star approximately once every 350 days.
But its orbit is more elliptical than Earth’s, sending it slightly further out from the sun – around 1.2 times the distance from the Earth to the sun.

A network of telescopes is trained on the skies to watch for asteroids coming within striking distance of Earth.
While the majority of these near Earth objects (NEOs) pose little real threat to us, but astronomers are closely monitoring a number which are potentially hazardous.

An object the size of 2016 QA2 – as named by the Minor Planet Center – would certainly do significant damage at the local scale, it wouldn’t be enough to wipe out civilisation.
For comparison, the rock which caused the Chicxulub crater – believed to be responsible for the demise of the dinosaurs – was about 6.2 miles (10km) across.

But the rock which hit Tunguska in Siberia in 1908, scorching forest and flattening trees across thousands of square miles, is believed to have been between 200 and 620 feet wide (60 and 190 metres).
According to Space.com, an asteroid would need to be of larger than 0.6 miles wide (1 km) to have the force to wipe out humanity.

A video released by Nasa this year revealed all of the near Earth objects being tracked. It was created using data by Neowise mission, which launched in 2009. Green circles represent NEOs. The orbits of Mercury, Venus and Mars are in blue and Earth’s orbit is in teal.