(ORDO NEWS) — One of the asteroids is the largest potentially dangerous object that poses a danger to the Earth.
Asteroids belong to the group found in the orbits of Earth and Venus, but they are incredibly difficult to observe because the brightness of the sun hides them from telescope observations.
To avoid sunlight, astronomers took the opportunity to make their observations during a short window of darkness.
An international team has discovered space rocks using a special dark energy camera on the 4-meter Victor M. Blanco Telescope (Chile).
One of the asteroids, called 2022 AP7, is 1.5 kilometers wide and has an orbit that could bring it closer to Earth in the future, but scientists can’t give an exact date yet.
“Our twilight survey is scouring the region within the orbits of Earth and Venus looking for asteroids,” said lead author of the study, astronomer Scott S. Sheppard of the Carnegie Institute of Science in Washington.
“So far, we have detected two large near-Earth asteroids with a diameter of about 1 km, a size that we call planet killers.”
Scientists have determined that the asteroid crosses the Earth’s orbit, but this occurs when the Earth is on the opposite side of the Sun – a pattern that will continue for centuries as it takes the asteroid five years to complete an orbit around the Sun.
But over time, the asteroid’s orbital motion will be more synchronized with the motion of the Earth. Scientists don’t know the asteroid’s orbit with enough precision to tell how dangerous it could become in the future, but for now it “will stay away from Earth,” Sheppard said.
A near-Earth asteroid 1 km or larger “will have a devastating impact on life,” he said. Dust and pollutants will fill the atmosphere for years, cooling the planet and preventing sunlight from reaching the Earth’s surface.
“It would be a mass extinction that hasn’t been seen on Earth for millions of years,” Sheppard said.
The team expects to find more planet-killing asteroids in their surveys over the next few years.
Scientists believe that there are about 1,000 near-Earth objects larger than 1 km. Over the past decade, astronomers have discovered about 95 percent of them.
Two other asteroids, 2021 LJ4 and 2021 PH27, are in much safer orbits that pose no threat to Earth.
However, astronomers are intrigued by 2021 PH27 because it is the closest known asteroid to the Sun. As a space object approaches our star, its surface heats up to a temperature sufficient to melt lead.
Astronomers hunting for asteroids in the inner solar system face a very difficult task. To avoid sunlight, researchers only have two 10-minute windows each night to survey the area with ground-based telescopes.
During twilight, astronomers still face the complications of bright background skies due to the sun. And in order to explore the inner part of the solar system, their telescopes must focus near the horizon, that is, they must look through the Earth’s dense atmosphere.
If everything seems difficult for ground-based telescopes, then observations of the inner solar system are impossible for space telescopes such as Hubble and James Webb, because the sun’s heat and intense light can burn their instruments. Therefore, both space observatories are directed away from the Sun.
The broad capabilities of the Dark Energy Camera helped astronomers overcome observational difficulties, and they were able to view vast areas of the night sky in detail.
Near-Earth objects are asteroids and comets orbiting within 48.3 million kilometers of Earth.
Currently, no asteroid is in a direct collision path with Earth, but there are over 27,000 near-Earth asteroids of all shapes and sizes.
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