A massive “planet-killing” asteroid will make a very close approach to Earth today (June 27), safely zipping past our planet at around 58,000 mph (93,000 km/h). A ‘potentially dangerous’ mountain-sized object is one of the largest space rocks to pass close to Earth in more than a century – and you can watch the close encounter live.
The asteroid, 2011 UL21, is a near-Earth asteroid, meaning that its orbit occasionally places it within 1.3 astronomical units (AU) of sun — or roughly 1.3 times the average distance between Earth and the Sun.
It orbits our home star once every three years. Based on previous observations, the space rock is somewhere between 1.1 to 2.4 miles (1.7 to 3.9 kilometers) wide SpaceReference.orgmeaning it is larger than 99% of known near-Earth asteroids European Space Agency (ESA).
2011 UL21 is probably at least 10 times smaller than the largest space rock ever to hit Earthasteroid Vredefort and about five times smaller than the rock that wiped out the dinosaurs about 66 million years ago.
However, even if any potential impact from 2011 UL21 would be less extreme than these historic impacts, the asteroid still has the potential to cause continental-scale damage and eject enough debris into the atmosphere to cause significant climate change, and is therefore considered a “planet killer” .
Asteroid 2011 UL21 will come within about 4.1 million miles (6.6 million km) of Earth, the closest it has been to our planet in at least 110 years. a NASA Jet Propulsion Laboratory simulation (JPL). At this distance, it is considered a potentially dangerous object from NASA. However, this is still about 17 times farther from our planet than Moon.
Although the space rock poses no threat to Earth – now or in the future – it is interesting because it is likely one of the 10 largest asteroids to pass within 7.5 million km of our planet since 1900. Gianluca Masiastrophysicist and director of the Virtual Telescope Project (VTP), wrote va recent statement.
Related: “Planet-killing” asteroids hide in the glare of the sun. Can we stop them in time?
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You can track the nearest UL21 2011 approach thanks to a free live streaming from VTP, which will share a view of the asteroid from the Bellatrix Astronomical Observatory in Ceccan, Italy. The stream begins at 4:00 PM ET on June 27, with a close approach expected 15 minutes later.
You may also be able to spot an asteroid in the night sky using a decent binoculars. It will be brightest on June 28 and 29 and should be visible from the Northern Hemisphere if you know where to look. At its brightest, it will have a similar brightness to Proxima Centauri – the closest known star to the Sun, according to VTP.
2011 UL21 won’t come this close to Earth again until 2089, when the space rock will come within 1.7 million miles (2.7 million km) of our planet—more than two and a half times closer to us than its current approach, according to JPL simulations.
There is zero chance of any known planetary killer asteroid hitting Earth at least for the next 1000 years. However, there will be several close calls with smaller asteroids in the next few years. For example, the asteroid Apophis, which is large enough to destroy an entire city slip closer to Earth than some satellites in 2029.