Near-Earth asteroid known as 2024 YR4 is estimated to be 40 to 100 metres across.

Look at it this way — there’s almost a 99 per cent chance an asteroid up to the size of a football field won’t hit the Earth in eight years.
Still, there’s up to a two per cent chance it will, according toNASA and theEuropean Space Agency (ESA). And it’s understandable if you don’t love those odds. As one popular spaceTikToker points out, sports fans know “those one per cent-ers sink all the time.”
But even though it’s rare for any asteroid impact risk to get above the one per cent mark, scientists stress that they’re not worried. An impact with Earth “is not very likely,” Richard Moissl, head of the Planetary Defence Office with the European Space Agency (ESA), told CBC’sThe Current Wednesday.
“We’re not at a direct threat. We’re not in immediate risk. This is not an alert. This is not a crisis situation,” Moissl said.
First spotted last month by a telescope in Chile, the near-Earth asteroid known as 2024 YR4 is estimated to be 40 to 100 metres across. It’s travelling at around 15 times the speed of a high-velocity bullet. It is now moving away from Earth but will return in 2028.
And if it does impact earth (again — a 98 to 99 per cent chance it won’t), it’s estimated to happen on Dec. 22, 2032. The probability of impact changes over time as more analysis comes in.
As of Wednesday, NASA put the impact probability at about one in 53, or 1.9 per cent. The day before, it was 1.6 per cent.
“It’s quite unusual. It’s not a danger yet, but it’s so unusual that we take a very close look at this one,” Moissl said.
It’s enough for theInternational Asteroid Warning Network (IAWN) to issue its first-ever Potential Asteroid Impact Notification. Its notification threshold is one per cent.
“Hitting the one per cent impact probability is a rare event indeed,” IAWN manager Tim Spahr told NPR this week.
IAWN predicts that the impact risk corridor extends across the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea and South Asia. Damage from the blast could extend 50 kilometres from the site of impact.

What we know about the asteroid
The asteroid came closest to Earth on Christmas Day — passing within roughly 800,000 kilometres of Earth, about twice the distance of the moon. It was discovered two days later.
“We are not worried at all — because of this 99 per cent chance it will miss,” Paul Chodas, director of NASA’s Center for Near-Earth Object Studies, said in a news conference last week. “But it deserves attention.”
The asteroid will gradually fade from view over the next few months, according to NASA and the European Space Agency. Until then, some of the world’s most powerful telescopes will keep monitoring it to better determine its size and path. Once out of sight, it won’t be visible until it passes our way again in 2028.
NASA explains the asteroid is rated a Level 3 on theTorino Impact Hazard Scale, a tool for categorizing potential Earth impact events. The scale describes Level 3 as “a close encounter, meriting attention by astronomers” and is capable of “localized destruction.”
A Level 10, on the other hand, is a certain collision “capable of causing global climatic catastrophe that may threaten the future of civilization as we know it.” These occur on average once per 100,000 years.
“Let me tell you, the most likely scenario is that by the time we lose sight of the object in April this year, the impact probabilities will have lowered enough not to worry about this object anymore,” Juan Luis Cano of the Planetary Defence Office told Reuters.
Scientists will soon meet to discuss Earth’s response if the asteroid’s impact probability remains above the one per cent threshold, which could include crashing a spacecraft into it to deflect it. Two UN-endorsed international asteroid response groups are considering their next steps, theESA explains on its website.
An asteroid the size of a football field is hurtling towards our planet, with a roughly 1.6 per cent chance of impact in 2032. Those may seem like good odds, but it’s prompted astronomers to issue the first ever Potential Asteroid Impact Notification. We look at what’s being done to avert catastrophe — and what researchers are learning from a different asteroid, which might contain clues about how life developed here on Earth.
Comparable to 1908 Siberia impact
To put the odds in perspective, Gizmodo spoke with a Harvard University statistician. He explained that you have a one-in-52 chance of pulling the ace of spades from a deck of cards — almost exactly the same as the odds calculated Wednesday of the asteroid hitting earth in 2032.
An asteroid of this size impacts Earth, on average, every few thousand years, ESA noted.
Moissl explained that — and again, it likely won’t — if 2024 YR4 does hit the Earth, it would be comparable to the 1908Tunguska asteroid impact. According to NASA, on June 30, 1908, an asteroid exploded in the sky over Siberia. It had an estimated diameter of about 40 metres.
This event, “flattened 2,000 square kilometres of forest and sent seismic waves through the area and was felt hundreds of kilometres away,” Moissl said.
Most of the witnesses were reindeer herders about 32 kilometres away, NASA explained.

Asteroid Bennu samples contain ‘building blocks’ of life on Earth
Scientists say samples harvested from NASA’s historic mission to the asteroid Bennu contain the precursors to life on Earth, including the building blocks to DNA, RNA and proteins. Canadians involved in the mission say future ones could reveal even more about how the planet was formed.
They “described seeing a fireball trailing smoke, then a flash brighter than the sun, followed by a loud noise like thunder. Those closest to the event reported being blown into the air and knocked unconscious, and their dwellings damaged or destroyed,” NASA says.
“Fortunately, because of the low population density, very few human casualties resulted, but many herds of reindeer perished.”
According to NASA, currently no other known large asteroids have an impact probability above one per cent.

ABOUT THE AUTHOR

Senior Writer & Editor
Natalie Stechyson has been a writer and editor at CBC News since 2021. She covers stories on social trends, families, gender, human interest, as well as general news. She’s worked as a journalist since 2009, with stints at the Globe and Mail and Postmedia News, among others. Before joining CBC News, she was the parents editor at HuffPost Canada, where she won a silver Canadian Online Publishing Award for her work on pregnancy loss. You can reach her at natalie.stechyson@cbc.ca.
With files from The Current, the Associated Press and Reuters
*****
Credit belongs to : www.cbc.ca