Astronomers both amateur and professional will have a rare opportunity to observe a potentially hazardous asteroid in coming days. It will be the asteroid’s closest approach to Earth in 400 years, and will not come as close again for another 500 years.
The relatively large asteroid, known as 2014 JO25, will be at its most visible on April 19 (12:24 UTC) when it will come within 1.8 million km of Earth. This is very close for an asteroid of its size, according to NASA’s Planetary Defense Coordination Office.
Even though there is no chance the asteroid will collide with the planet – it will be almost 5 times as far away as the moon – it is still one of the small proportion of about 16,000 identified Near Earth Asteroids (NRAs) classified as potentially hazardous, coming within 7.48 million km of the planet.
The asteroid, with a diameter of about 600 metres, is the most significant near-approach since the 5-km-wide Toutatis asteroid passed Earth in 2004. The next close encounter with a sizeable asteroid is expected to be in 2027, when the 800-metre-wide 1999 AN10 comes within a mere 380,000 kilometres.
Just 5% of NRAs have a diameter of more than 1 km. About half are less than 140 metres. The asteroid that did in the dinosaurs – the Chicxulub impactor, considered responsible for the Cretaceous–Paleogene extinction event 66 million years ago – is estimated to have been at least 10 km wide.
With an albedo about twice as bright as the Moon, 2014 JO25 should be easy to spot with a small telescope, or even binoculars. Because of its relative proximity to Earth, its position it in the night sky will depend on your location. Fortunately for skygazers, NASA’s Jet Propulsion Laboratory has provided a handy tool that lets you enter your terrestrial co-ordinates and find out the celestial location to turn your eyes towards.
