Live just nu: Asteroid TC4 testar NASAs warning system

The asteroid, called 2012 TC4, was first spotted five years ago.
It is estimated to be between 15m and 30m (50-100ft) in size, which is relatively small.
...
The space rock will hurtle past our planet at a distance of about 42,000km (26,000 miles), bringing it within the Moon's orbit and just above the altitude of communication satellites.
...
JPL/CNEOS: "We are going to use this asteroid to practise the system that would observe an asteroid, characterise 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."
...
Nasa scientists who have spent the last two months tracking this new rocky visitor say their calculations show that it will safely clear the Earth and poses no threat.

Instead, they will use this close approach to rehearse for future potential strikes.

More than a dozen observatories, universities and labs around the world will be watching 2012 TC4 as it flies past.

This will help them to refine how asteroids are tracked and provide a chance to test international communication systems.

This asteroid was discovered by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) in Hawaii in 2012. Pan-STARRS conducts a near-Earth object (NEO) survey funded by NASA's NEO Observations Program, a key element of NASA's Planetary Defense Coordination Office. However, 2012 TC4 traveled out of the range of asteroid-tracking telescopes shortly after it was discovered.

Based on the observations they were able to make in 2012, asteroid trackers predicted that it should come back into view in the fall of 2017. Observers with the European Space Agency and the European Southern Observatory were the first to recapture 2012 TC4, in late July 2017, using one of their large 8-meter aperture telescopes.Since then, observers around the world have been tracking the object as it approaches Earth and reporting their observations to the Minor Planet Center.

This "test" of what has become a global asteroid-impact early-warning system is a volunteer project, conceived and organized by NASA-funded asteroid observers and supported by the NASA Planetary Defense Coordination Office (PDCO).