The largest potentially hazardous object identified in the last eight years was discovered in January 2022, with twilight observations using the Dark Energy Camera at Cerro Tololo Observatory in Chile.
The asteroid, known as 2022 AP7, is categorized a potentially hazardous asteroid approximately 1.5 kilometers across.
It was hidden in the sky only 45 degrees from the Sun, when detected by astronomers.
“Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids,” said lead study author Scott S. Sheppard, an astronomer at the Earth & Planets Laboratory of the Carnegie Institution for Science in Washington, DC.
“So far we have found two large near-Earth asteroids that are about 1 kilometer across, a size that we call planet killers,” he said.
Scientists determined that the asteroid crosses Earth’s orbit, but it occurs when Earth is on the opposite side of the sun – this pattern will continue for centuries since it takes the asteroid five years to complete an orbit around the sun. But over time, the asteroid’s orbital movement will be more in sync with Earth’s. Scientists don’t know the asteroid’s orbit with enough precision to say how dangerous it could become in the future, but for now, it “will stay well away from Earth,” Sheppard said.
A near-Earth asteroid measuring 1 kilometer (0.6 mile) or larger “would have a devastating impact on life as we know it,” he said. Dust and pollutants would fill the atmosphere for years, cooling the planet and preventing sunlight from reaching Earth’s surface.