Asteroid whizzed past Earth
A large asteroid whizzed past Earth - Representational image Nasa

The Earth has seen a few close shaves this year already when it comes to asteroids. So far, 17 large spacefaring rocks have passed between our planet and the Moon in 2018 alone. And the most recent one whizzed by this weekend.

This rock, named Asteroid 2018 DU, was estimated to be about 10m across and was travelling at a speed of over 4.6km per second. It missed Earth by just 280,000km, reported Australia's News.com.

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The object was captured as a speck of light by a robotic telescope in Arizona, which is operated by the Virtual Telescope Project (VTP) based in Rome. The project tracks Near-Earth Objects (NEOs) and there are about 17,850 of them that have orbits that bring them within 194 million kilometres from the Sun, noted the report.

On 21 February, another asteroid, 2018 DQ, passed by the Earth even closer at just 100,000 km away. This one was even faster at 21 km per second.

The planet seems to be passing through a cosmic shooting gallery, according to the report. There are possibly several thousand large asteroids that regularly orbit the Sun between Jupiter and Mars in the asteroid belt, but they rarely come near the Earth. This year has seen a lot more action though, with several of them already whizzing past, some quite close the planet.

While most of these asteroids might not do much damage on impact, they are known to burst and disintegrate in the atmosphere and burn up during entry. Depending on how fast they enter, what they are composed off, and how they react with the massive amounts of heat and energy released during entry, they can create massive explosions.

The Chelyabinsk incident, for example, was due to a meteor that caused a superbolide which injured 1,500 people and damaged 7,200 buildings in Russia. The NEO asteroid that caused this was 20m across.

Currently, a lot of asteroids of this size are not even monitored, noted the report. Nasa's Planetary Defense Coordination Office is constantly on the lookout for asteroids that are classified as being "potentially hazardous" and they are required to be at least 140m wide and also have to pass by the planet at a distance of about 7.4km.

They reportedly have eyes on about 90% of objects this size. However, they sometimes fail to spot large asteroids, like the big 747 aircraft-sized rock that flew by Earth last year.