An asteroid has passed so close to earth it was within the ring of satellites and NASA only discovered six hours before it arrived, NASA has revealed.
The rock, named 2017 EA, made its closest approach to Earth at 6.04am US West Coast time at an altitude of only 9000 miles above the eastern Pacific Ocean.
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"A small near-Earth asteroid less than 3 meters (10 feet) across whizzed safely past Earth today at a distance so close that it passed well inside the ring of geosynchronous satellites," the Centre for Near Earth Object Studies said.
"At its closest point, this asteroid was 20 times closer than the Moon; it then quickly moved into the daytime sky and can no longer be observed by ground-based telescopes."
According to NASA, 2017 EA was originally detected only 6 hours before closest approach by astronomers.
This detection was made by the NASA-funded Catalina Sky Survey, near Tucson, Arizona.
It was observed by several other observatories before it passed into the Earth's shadow just before closest approach.
Even though 2017 EA was tracked for only a single day, its orbit is now known quite accurately.
Computations by CNEOS indicate that the asteroid will not approach our planet this close again for at least a hundred years.
The revelations come a day after a NASA satellite orbiting Mars was forced to swerve to avoid colliding with one of the planet's two small moons.
Flight controllers at NASA's Jet Propulsion Laboratory in Pasadena, California, commanded the MAVEN spacecraft, which is studying Mars' vanishing atmosphere, to fire up its engine on Tuesday to boost its speed by about 1.3 feet per second (0.4 meters per second).
The acceleration was necessary to slightly shift MAVEN's orbit and steer the satellite clear of the Martian moon Phobos.