Asteroid comes close to Earth! |
On Friday 14 June, an asteroid the size of a football pitch made one of the closest ever recorded approaches to Earth. Astronomers working on the LINEAR search programme, near Socorro, New Mexico first detected the giant rock on 17 June, a few days after its close approach.
The Near Earth Object, known to astronomers as '2002MN', was travelling at over 10 km/s (23,000 miles per hour) when it passed Earth at a distance of around 120,000 km (75,000 miles), bringing it well inside the Moon's orbit. The last time a known asteroid passed this close was back in December 1994.
Asteroids are typically too small and distant to measure their size directly from Earth, so scientists use the amount of light they reflect, along with a basic understanding of the materials they are made of, to estimate their size. With a diameter between 50-120 metres, 2002 MN is a lightweight among asteroids and incapable of causing damage on a global scale, such as the object associated with the extinction of the dinosaurs.
However, if it had hit the Earth, 2002MN may have caused local devastation similar to that which occurred in Tunguska, Siberia in 1908, when 2000 square kilometres of forest were flattened. Whilst the vast majority of NEOs discovered do not come this close, such near misses do highlight the importance of detecting these objects. This reminder comes in a week when the UK telescopes on La Palma are being tested to search for NEOs.
Brief Description of Object
Object Designation: 2002MN
Date of First Observation: 17/06/02
Number of Observations: 14
Search Team: LINEAR (Lincoln Near Earth Asteroid Research)
Date of Closest Approach: 14/06/02
Closest Approach Distance: 0.000797 AU or 119,229 km (0.3 Lunar Distances)
Asteroids Velocity Relative to Earth at Closest Approach: 10.58 km/s (23,667
miles per hour)
Estimated Diameter of Asteroid: 50-120 metres
Orbital Period: 894.9 days
Click here for simulation or asteroid orbit.
Article from jpl.nasa.gov