A path that brings nearly 30,000 asteroids close to Earth has been detected.

Asteroids are chunks of rock thrown out during the early stages of solar system creation about 4.6 billion years ago.

key points:

1. The earliest known Earth-approaching asteroid was (433) Eros

1. So, none of the asteroids that have come close to Earth has been dangerous.

1. Scientists have discovered the vast majority of these space rocks in the last ten years.

The European Space Agency stated that the number of known asteroids had passed the 30,000 mark, just days after Nasa announced that it had successfully altered the path of an asteroid in deep space. The orbits of these NEOs are dangerously close to Earth as we travel around the Sun.

The vast majority of these interstellar rocks were only discovered within the previous decade, within 1.3 au of the Sun (1 au being the distance between the Sun and Earth). The asteroid's orbit can bring it within 45,000,000 kilometres of Earth's. More than a million asteroids have been discovered by astronomers so far.

Asteroids are chunks of rock that were left over during the assembly of the solar system about 4.6 billion years ago. According to the Nasa Joint Propulsion Laboratory, an asteroid is considered a near-Earth object if its average distance from Earth is less than 1.33 times the distance from Earth to the Sun (the Earth-Sun distance is roughly 93 million miles) (JPL).

In 1898, Carl Gustav Witt and Felix Linke at Berlin's Urania Observatory found the first near-Earth asteroid (433). According to the European Space Agency, the stony asteroid would come within 22 million kilometres of Earth during its orbit.

Hubble and other observatories, like Gaia, are used with ground-based telescopes to track the asteroid and analyse their orbital motion. Gaia's primary objective is cataloguing one billion stars in the galaxy; knowing asteroid dangers is an added bonus.

Gaia has increased our understanding of the galaxy's star system, which serves as a backdrop for asteroid observations. Tineke Roegiers, a community supporter of the Gaia mission, explained that accurate calculations of asteroid orbits depend on a thorough understanding of the sky's star distribution.

While astronomers have stated that none of the recently identified near-Earth asteroids poses a threat to Earth for at least the next century, it is possible that some of these objects could yet enter Earth's atmosphere and survive.

"Most large, potentially destructive asteroids (1 km in diameter or more) have been found, and none appear to pose an impact risk for at least another century. Those that may have an effect in the future can be studied and a deflection mission planned in advance "The European Space Agency said.