An enormous asteroid with the potential to destroy an entire city will skim past Earth tonight. Astronomers say the space rock, called 2026 JH2, is up to four times the size of a London bus and will get 'as close as you can without hitting'.
Close Encounter Details
It is expected to zoom by our planet at an estimated distance of around 56,000 miles (90,000 km) at 10:23 pm BST. This is exceptionally close – the equivalent of just a quarter of the distance between us and the moon. Estimates place the size of the space rock between 52 and 115 ft (16 and 35 metres) in diameter, and it is racing towards Earth at around 20,000 mph (32,000 km/h).
Despite having enough mass to wipe out a city, simulations suggest there is no chance of impact for at least the next 100 years. While it will be too faint to see with the naked eye, it may be visible through amateur telescopes under dark sky conditions. But for those without access to stargazing equipment, you can still watch the unusually close encounter.
How to Watch
Astronomers in Italy will be sharing a livestream of the flyby, recorded through a telescope, on The Virtual Telescope Project's YouTube channel. The broadcast will start at 8:45 pm BST. People in the UK will have the best chance of spotting asteroid 2026 JH2 from dark-sky locations with a clear northern horizon. Around closest approach, it should be moving through the region of Ursa Major, fairly high in the sky.
Binoculars probably won't be good enough unless they are very large. However, it should be visible with small telescopes. It will look like a faint moving dot, rather than a dramatic streak.
Discovery and Orbit
The asteroid was first discovered on May 10 by astronomers at the Mount Lemmon Observatory near Tucson in Arizona. Data suggests it likely circles the sun every 3.7 years on an oval-shaped orbit that takes it nearly as far out as Jupiter. The size of the asteroid is an estimate based on the amount of light reflecting off its surface, which means that measurements cannot be entirely certain. If the asteroid is made of a particularly dark or unreflective material, then it could be nearer to the higher end of the estimate range or potentially even larger.
Destructive Potential
However, even at the lower end of its estimated range, the asteroid still carries a huge destructive potential. 'It's the kind of thing that would ruin a city quite efficiently, if it hit,' Mark Norris, from the University of Lancashire, told New Scientist. Experts say if 2026 JH2 did strike Earth, it would cause an event comparable to the Chelyabinsk meteor. In 2013, an 18-metre (59 ft) meteor exploded over the city of Chelyabinsk in Russia, near the border with Kazakhstan. The resulting explosion was 30 times more powerful than the atomic bomb dropped on Hiroshima, producing a shockwave that travelled twice around the world.
Directly beneath the explosion, 28 miles (45 km) above the ground, the heat was so intense that people were left with burns and retinal damage. Around 1,500 people were injured and over 3,600 homes were damaged, even though only 0.05 per cent of the original rock made it to the ground. With a potential size up to 35 metres (115 ft) in diameter, 2026 JH2 has the potential to be even more destructive – possibly even ranking it as a 'city killer' size asteroid.
No Threat to Earth
However, although the asteroid will pass extremely close to the planet, it poses no threat whatsoever to Earth. Thanks to careful study by the network of planetary defence telescopes, astronomers are able to make very precise calculations of asteroids' orbits. The next sizable space rock that will get this close to Earth will likely be the 'God of Chaos' asteroid, 99942 Apophis, which will fly within 20,000 miles (32,000 km) of Earth on April 13, 2029. After Apophis, the next major flyby will be from 2024 YR4, also known as the 'city killer' asteroid, which will zoom past the moon at a minimum distance of around 13,200 miles (21,200 km) in 2032.
Potential Methods for Eliminating the Threat of an Asteroid
DART is one of many concepts of how to negate the threat of an asteroid that have been suggested over the years.
- Multiple bumps: Scientists in California have been firing projectiles at meteorites to simulate the best methods of altering the course of an asteroid. According to the results so far, an asteroid like Bennu that is rich in carbon could need several small bumps to change its course. 'These results indicate multiple successive impacts may be required to deflect rather than disrupt asteroids, particularly carbonaceous asteroids,' researchers said.
- Nuke: Another idea, known simply as 'nuke', involves blowing up a nuclear explosive close to the asteroid. However, this could create smaller but still potentially dangerous fragments of rock that could spin off in all directions, potentially towards Earth.
- Ion Beam Deflection: With Ion Beam Deflection, plumes from a space probe's thrusters would be directed towards the asteroid to gently push on its surface over a wide area. A thruster firing in the opposite direction would be needed to keep the spacecraft at a constant distance from the asteroid.
- Gravity tractor: And yet another concept, gravity tractor, would deflect the asteroid without physically contacting it, but instead by using only its gravitational field to transmit a required impulse. Professor Colin Snodgrass, an astronomer at the University of Edinburgh said: 'There have been a few concepts suggested, such as a 'gravity tractor' to slowly tow an asteroid away instead of pushing it with a kinetic impactor. But the kinetic impactor is definitely the simplest technology to use on the sort of timescale that is most likely to be of concern for this size of asteroid, i.e. years to decades warning time.'
