Topline
A newly discovered asteroid will dash past Earth on Thursday night, dipping well below the orbit of most satellites—though viewers will need help to see it— in one of the planet’s closest near miss encounters since records began.
NASA said the asteroid, one of the closest near misses on record, has no risk of hitting Earth.
Key Facts
NASA believes the asteroid, designated 2023 BU, is between 11 ft and 28 ft across (3.5m to 8.5m), around the size of a delivery truck or a large African elephant.
It will whizz over the southern tip of South America at around 7:27 p.m. EST (4:27 p.m. PST) Thursday night, NASA said.
At its closest point, 2023 BU will come within 2,200 miles (3,600 kilometers) of the planet’s surface, the agency said, a tenth of the altitude most satellites orbit at.
NASA said there is “no risk” of the asteroid striking Earth and even if it were on a collision course the rock would most likely “disintegrate harmlessly in the atmosphere” while generating a brilliant fireball.
Davide Farnocchia, an engineer at NASA’s Jet Propulsion Laboratory in California, said the near miss “is one of the closest approaches by a known near-Earth object ever recorded.”
Further Viewing
Most asteroids aren’t visible with the naked eye or without access to a powerful telescope. The event can be watched through the Virtual Telescope Project, a group of robotic telescopes operated by the Bellatrix Astronomical Observatory in Italy. The project, and astronomer Gianluca Masi, will be broadcasting the asteroid’s encounter live.
Surprising Fact
The asteroid was discovered on Saturday, just a few days out from its expected encounter with Earth. It was identified by an amateur astronomer, Gennadiy Borisov, in Crimea. Borisov also discovered an interstellar comet in 2019, NASA said. Astronomy is one of the few scientific disciplines remaining where amateurs are still able to make significant contributions on a regular basis, though increasing light pollution is making this more difficult.
What To Watch For
The close fly-by encounter will significantly change 2023 BU’s orbit. Before encountering Earth, NASA said the asteroid’s orbit around the Sun took 359 days and was “roughly circular.” After the encounter, 2023 BU’s orbit around the Sun will be more elongated and take 425 days.
What We Don’t Know
While NASA and other space agencies closely monitor asteroids and other hazards in space—the agency recently tested a technique to nudge dangerous asteroids off a collision course—a great deal of what’s out there goes undetected. For most of the time, nobody knows what asteroids are out there or where they are going. NASA estimates it has only spotted around 40% of objects that could wipe out a city the size of New York. The laws of physics mean the paths of known objects can be predicted with high certainty. The agency’s Jet Propulsion Laboratory maintains an interactive visualization for thousands of asteroids and comets in near-Earth orbits and keeps a list of the five next near-Earth approaches.
