NASA expects the asteroid, dubbed 2019 OD, to skim our homeworld on a so-called “Earth Close Approach” trajectory. The asteroid will come flying by on the afternoon of Wednesday, July 24, less than three weeks after first being spotted. NASA’s asteroid trackers estimate the space rock will close in on Earth around 2.31pm BST (1.31pm UTC) on Wednesday. When this happens, the giant asteroid will come hurtling by closer than the Moon.
Asteroid 2019 OD is an Apollo-type Near-Earth Object or NEO.
All NEOs are asteroids and comets that circle the Sun within the confines of the Asteroid Belt between Mars and Jupiter.
NASA said: “Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighbourhood.
“Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter.
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Occasionally, an NEO will cross paths with the Earth’s orbit of the Sun and shoot past the planet.
Rarer yet, NEOs will unexpectedly strike the Earth such as the Chelyabinsk meteor that exploded over Russia in 2013.
The space rock only measured about 65.ft (20m) across but the force of eruption blew out windows in a wide radius, injuring more than 1,000 people with shards of glass.
In this case, Asteroid OD is estimated to measure somewhere in the range of 170.6ft to 393.7ft (52m to 120m) in diameter.
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At the upper end of that estimate, the asteroid stands taller than Big Ben’s clock tower in London as well as the Statue of Liberty in New York, US.
So, just how close does NASA expect the asteroid to fly by and is there any real danger from the rock?
On Wednesday afternoon, the asteroid will zip by at breakneck speeds of about 19.17km per second or nearly 43,000mph.
The same rock will then approach the Earth from a distance equivalent to 0.92 Lunar Distances (LD), where one Lunar Distance measures the distance to the Moon.
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This means the asteroid will safely skim the Earth from a distance of around 219,375 miles (353,050km).
In other words, the asteroid will approach the planet from 0.00236 astronomical units (AU).
A single AU represents the distance from the Earth to the Sun or about 93 million miles (149.6 million km).
After the close flyby, the asteroid will briefly approach the Moon but then NASA does not expect it to visit our corner of space again.