But data from sky surveys of asteroids of between 5 and 50 metres in diameter suggest that these objects should hit Earth less frequently than they actually do. Current telescopes are more accurately able to detect objects of several hundred metres or larger in diameter, and less sensitive to smaller objects — but this will change in the future as technology improves, he says.
Asteroid monitoring may also be affected by space junk, particularly the increase in satellite numbers as miniature satellites become commercially available, says Mattmann.
By Donna Lu If a meteor explodes over the ocean and nobody is around to hear it, does it make a sound? Read more: Revealed: First image of huge meteor explosion over Earth last year. Trending Latest Video Free. Will a scramble to mine metals undermine the clean energy revolution? Paralysed mice walk again after gel is injected into spinal cord How Minecraft is helping children with autism make new friends Covid news: Coronavirus deaths in Europe rise 10 per cent in a week Covid-resistant people point way to universal coronavirus vaccine.
We know it takes 2 years plus or minus 0. Read more: Extinction alert: saving the world from a deadly asteroid impact. However, we can work out the volume of space within which we can be confident that the asteroid will lie at a given time.
Imagine a huge bubble in space, perhaps 4 million km across at its largest. What does that mean for Earth? Well, it turns out the closest approach between the two this year will be somewhere between a direct hit and an enormous miss — with the asteroid coming no closer than 3.
We can also work out the likelihood the asteroid will hit Earth during this close approach. The odds are 0. In other words, by far the most likely outcome on November 2 is the asteroid will sail straight past us. Objects that size hit Earth all the time. Bigger asteroids do more damage, as we were spectacularly reminded back in February , when an asteroid around 20 metres across exploded in the atmosphere above the Russian city of Chelyabinsk.
It comes from the rest of the solar system. When Farnocchia and his colleagues ran their simulations, they had to account for many factors, including how sunlight heats up Bennu and how hundreds of other objects in the solar system, even as far away as Pluto, gravitationally tug at the asteroid. The trouble is, researchers had to estimate the masses for most of the objects within a key group: the largest bodies in the asteroid belt.
Future missions should help refine those estimates. The telescope is expected to discover hundreds of thousands more asteroids, as well as provide better data on the asteroids that have already been found. In September , the spacecraft will fly by Earth, drop a capsule full of Bennu samples into the Utah desert, and continue its journey through the solar system.
Earth is safe from Apophis for at least the next century. All rights reserved. Share Tweet Email. Read This Next Wild parakeets have taken a liking to London. Animals Wild Cities Wild parakeets have taken a liking to London Love them or hate them, there's no denying their growing numbers have added an explosion of color to the city's streets. India bets its energy future on solar—in ways both small and big.
Environment Planet Possible India bets its energy future on solar—in ways both small and big Grassroots efforts are bringing solar panels to rural villages without electricity, while massive solar arrays are being built across the country. Epic floods leave South Sudanese to face disease and starvation. Travel 5 pandemic tech innovations that will change travel forever These digital innovations will make your next trip safer and more efficient.
But will they invade your privacy? Go Further. Animals Wild Cities This wild African cat has adapted to life in a big city. Animals This frog mysteriously re-evolved a full set of teeth. Animals Wild Cities Wild parakeets have taken a liking to London.
0コメント