UN Space Agency Vigilant Over Threat Posed By ‘Near-Earth Objects’

With over 18,000 near-Earth objects (NEOs) lurking beyond the stratosphere, 2,000 of which are classified as potentially hazardous, the UN Office for Outer Space Affairs (UNOOSA) is using Friday’s International Asteroid Day to raise awareness across the planet.

NEOs are asteroids or comets that come relatively close to the Sun, to about 50 million kilometres from Earth’s orbit. Some of them, ‘potentially hazardous objects’ (PHOs), come even closer – in interstellar terms – with a minimum distance of less than 7.5 million kilometres.

Measuring more than 140 meters across, the PHOs have the potential to cause regional devastation with possible global consequences.

Do Look Up

Even smaller objects can still cause significant, although localized, damage. The object responsible for the Tunguska event on 30 June 1908 over Siberia, is believed to have been up to 60 metres in diameter.

The largest asteroid impact event in recorded history, it was chosen in 2017 as a fitting anniversary to commemorate International Asteroid Day.

Even smaller NEOs can be hazardous, damaging buildings and injuring people. On 15 February 2013, a large fireball approximately 20 meters across disintegrated in the skies over the Russian city of Chelyabinsk.

According to US Space Administration (NASA), the explosion released the energy equivalent of around 440,000 tons of TNT and generated a shock wave that blew out windows and even damaged buildings. Over 1,600 people were injured in the blast, mostly due to shattered glass.