Three years earlier than the skyscraper-size asteroid Apophis makes its very shut (however secure) flyby of Earth, scientists have already begun charting precisely when and the place billions of individuals can watch it sweep throughout the sky.
Talking at an “Apophis T-3 Years” workshop held earlier this month on the College of Padua in Italy, retired cartographer Michael Zeiler and astronomer Rick Fienberg shared detailed visibility maps charting the asteroid‘s passage throughout Earth‘s skies.
In keeping with their calculations, roughly 90% of the world’s inhabitants — about 7.6 billion folks — lives in areas the place Apophis could, in principle, be seen with the naked eye on April 13, 2029. The actual viewing success will depend more on earthly considerations, however, including cloud cover and the extent of light pollution.
Known formally as 99942 Apophis, the space rock will not resemble a blazing meteor tearing through the sky. Instead, scientists say it will appear as a point-like speck of light gliding steadily across, which, at its closest approach, will appear to move by about the apparent width of the full moon every minute.
“It will definitely be noticeable,” Fienberg told Space.com. “It’s going to be moving more slowly than a satellite — it will cross the sky in hours, rather than minutes, and it will just be a point.”
According to the new maps, the asteroid should remain visible to the naked eye for about seven hours, beginning over Australia at 11:00 a.m. EDT (15:00 UTC) and concluding over the North Atlantic at 6:00 p.m. EDT (22:00 UTC).
At 4:35 p.m. EDT (20:35 UTC), Apophis is expected to reach its greatest apparent brightness as it passes over Cameroon, offering prime viewing to an estimated 3.9 billion people across Africa, Asia, eastern South America and parts of Europe.
About an hour later, at 5:45 p.m. EDT (21:45 UTC), the asteroid will make its closest approach to Earth, passing about 19,700 miles (31,600 kilometers) above the North Atlantic — well inside the orbit of Earth’s geostationary satellites. The event would be visible across much of South America, the United States, Africa and parts of Europe, reaching roughly 2 billion people.
“This is the first time we’ve been able to predict in human history an asteroid visibly passing by the Earth,” Richard Binzel, a professor of planetary sciences at the Massachusetts Institute of Technology (MIT), said during the workshop. “That’s part of a shared experience.”
As excitement ramps up for the once-in-a-millennium spectacle, Binzel opened the workshop with three messages: “Apophis will safely pass the Earth. Apophis will safely pass the Earth. Apophis will safely pass the Earth.”
That absolute certainty is the hard-won fruit of more than two decades of increasingly precise observations. When Apophis was discovered in 2004, early calculations suggested a 1-in-37 chance of an impact in 2029, making it the most potentially hazardous asteroid known at the time. Additional observations steadily refined the asteroid’s orbit, eliminating any possibility of a collision in 2029 and also ruling out any impact threat for at least the next century, according to NASA.
With the impression menace eliminated, scientists now view the flyby as a uncommon alternative to look at how Earth’s gravity impacts an asteroid throughout an exceptionally shut encounter.
Our planet’s gravity is anticipated to tug the asteroid into a brand new orbit across the solar with out posing any future hazard. In the course of the flyby, nevertheless, those self same gravitational forces might stretch and squeeze the asteroid sufficient to set off landslides or expose pristine materials hidden beneath its weathered floor. Or they could do nearly nothing.
“We merely do not know what is going on to occur,” Binzel stated throughout the workshop. “Apophis might go by and never care an excessive amount of, or perhaps we’ll see one thing vital.”
“That is why we now have to look,” he added. “We’re gonna be taught so much both manner.”
On the workshop, scientists stated they hope to watch the flyby from observatories in Spain’s Canary Islands, amongst different locations, as its location within the Atlantic Ocean gives an excellent view of the asteroid’s closest method in addition to favorable prospects for clear skies.
