A ‘potentially hazardous’ asteroid the size of a football stadium is set to skim past Earth later today.
The asteroid, called 2008 OS7, is expected to come as close as 1.7 million miles to our planet at 14:41 GMT – about seven times further out than the moon.
It is estimated to be up to 1,574 feet (480 metres) in diameter, which is longer than the Tottenham Hotspur stadium (820 feet or 250 metres).
As 2008 OS7 flies past Earth, it will be travelling at a speed of 18.1 km per second or just over 40,000 miles per hour – roughly 50 times the speed of sound.
The asteroid is ‘potentially hazardous’, although thankfully it’s not expected to pose a danger to our planet.
Asteroid 2008 OS7 – discovered in 2008 by the Catalina Sky Survey in Arizona – completes an orbit around the sun every 962 days (2.63 years).
But as it does so, it intersects with Earth’s orbit, according to Dr Minjae Kim, a space expert at the University of Warwick’s astronomy department.
He describes it as ‘very small’ relatively speaking, because the largest known asteroid in the solar system, Ceres, is 580 miles in diameter (more than 3 million feet) – big enough for humans to live on.
‘2008 OS7 – a very small asteroid whose orbit intersects with that of Earth – has been classified as a “potentially hazardous asteroid”,’ said Dr Kim.
‘While this will still approach close to the Earth, we don’t need to worry about it too much as this asteroid will not enter Earth’s atmosphere.
‘One of the most intriguing aspects of the 2008 OS7 is its estimated diameter based on its luminosity and reflective properties.
‘This places it in the category of a small to moderately-sized asteroid, roughly equivalent to the size of a football field.’
According to NASA, the asteroid is 210 to 480 metres (688 to 1,574 feet) in diameter.
Unfortunately, this asteroid will be too small to be seen by the naked eye, or even with an average telescope.
NASA lists 2008 OS7 as one of the upcoming close approaches on its online tracker, which compiles upcoming objects that are getting closer and closer to Earth.
An asteroid is defined as ‘potentially hazardous’ if it comes within 0.05 astronomical units (4.65million miles) of Earth and is larger than 459 feet (140 meters) in diameter.
Despite being seven times further out than the moon when it makes its close approach, the asteroid is classed as a near-Earth object (NEO) and is being tracked by the space agency.
‘NEOs are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighbourhood,’ said NASA.
‘Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter.
‘The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged remnant debris from the solar system formation process some 4.6 billion years ago.’
On average, Earth is hit by a football pitch-sized rock every 5,000 years, and a civilisation-ending asteroid every one million years, according to NASA’s Near-Earth Object Program.
Asteroid 2008 OS7 won’t be back our way again until 2032, but it will be a much more distant encounter, staying 45 million miles (72 million kilometers) away.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
