Jess Thomson -
The final data recording from the Arecibo Observatory, which collapsed in 2020, has warned of a large number of asteroids with the potential of coming near Earth, many of which could be dangerous to life.
Aerial view shows the damage at the Arecibo Observatory after one of the main cables holding the receiver broke in Arecibo, Puerto Rico, on December 1, 2020. Inset image of stock image of a meteor entering the earth's atmosphere
According to a paper published on September 22 in the Planetary Science Journal, Arecibo's final stint of data collection between December 2017 and December 2019 reveals observations of 191 near-Earth asteroids, 70 of which may be "potentially hazardous."
Built in Puerto Rico in 1963, the Arecibo Observatory was the largest single-aperture telescope in the world until 2016 when the Chinese Five-hundred-meter Aperture Spherical Telescope (FAST) began operations. It possessed a 1,000-foot-diameter spherical reflector dish designed to detect radio wavelengths from space. It collapsed on itself in late 2020. During its heyday, Arecibo detected up to 124 near-Earth asteroids per year.
Near-Earth asteroids are objects in the solar system that approach the sun at their closest point at a distance less than 1.3 astronomical units (AU), or 1.3 times the distance between the sun and the Earth, according to NASA. One AU is around 93 million miles. If one of these asteroids' orbits crosses the Earth's path, and the object is larger than 460 feet across, it is considered a "potentially hazardous" object or asteroid.
There are over 29,000 known near-Earth asteroids, and around 2,270 known potentially hazardous asteroids, 150 of which are thought to be larger than 0.6 miles in diameter.
According to the paper, the new Arecibo data found several binary asteroids, and one rarely seen "equal-mass" binary asteroid, named 2017 YE5. A binary asteroid consists of an asteroid that closely orbits another, as seen with the binary Didymos-Dimorphos system that was the target of the Double Asteroid Redirection Test (DART) mission in September. An equal-mass binary asteroid system is made of two nearly identical size rocks that are constantly orbiting one another. 2017 YE5 in particular is comprised of two asteroids each measuring around 2,600 and 2,950 feet in diameter.
Asteroid The Size Of One World Trade Center Set For Close Shave With Earth
Despite all these asteroids being located close to Earth, the chances of them colliding with us are extremely low.
"I believe there is no known object that will definitely hit us in a 1,000 years, Thomas Burbine, an astronomer at Mount Holyoke College, told Newsweek. "But we are discovering new objects all the time."
Collisions do occur frequently on a geological time scale: an asteroid impact was responsible for the death of the dinosaurs during the end-Cretaceous extinction around 66 million years ago. This fated asteroid was around 6 miles in diameter and left a 110 mile-diameter crater in the Yucatán Peninsula in Mexico.
"We could expect such an event every few tens of thousands of years—on the timescale of a normal civilisation, a significant risk," Jay Tate, the director of the Spaceguard Center observatory in the U.K., told Newsweek.
Depending on the size, speed and angle of collision of a large asteroid, an impact could have catastrophic effects on Earth.
"At the lower size estimate the immediate effects would take out a reasonably sized country—France for example," Tate said. "At the higher end the destruction would cover a continental sized area. Were it to land in the ocean the whole ocean rim would be subjected to significant tsunami as well as the other effects. The physical destruction would be, of course, only part of the problem, especially in our increasingly globalized society."
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Built in Puerto Rico in 1963, the Arecibo Observatory was the largest single-aperture telescope in the world until 2016 when the Chinese Five-hundred-meter Aperture Spherical Telescope (FAST) began operations. It possessed a 1,000-foot-diameter spherical reflector dish designed to detect radio wavelengths from space. It collapsed on itself in late 2020. During its heyday, Arecibo detected up to 124 near-Earth asteroids per year.
Near-Earth asteroids are objects in the solar system that approach the sun at their closest point at a distance less than 1.3 astronomical units (AU), or 1.3 times the distance between the sun and the Earth, according to NASA. One AU is around 93 million miles. If one of these asteroids' orbits crosses the Earth's path, and the object is larger than 460 feet across, it is considered a "potentially hazardous" object or asteroid.
There are over 29,000 known near-Earth asteroids, and around 2,270 known potentially hazardous asteroids, 150 of which are thought to be larger than 0.6 miles in diameter.
According to the paper, the new Arecibo data found several binary asteroids, and one rarely seen "equal-mass" binary asteroid, named 2017 YE5. A binary asteroid consists of an asteroid that closely orbits another, as seen with the binary Didymos-Dimorphos system that was the target of the Double Asteroid Redirection Test (DART) mission in September. An equal-mass binary asteroid system is made of two nearly identical size rocks that are constantly orbiting one another. 2017 YE5 in particular is comprised of two asteroids each measuring around 2,600 and 2,950 feet in diameter.
Asteroid The Size Of One World Trade Center Set For Close Shave With Earth
Despite all these asteroids being located close to Earth, the chances of them colliding with us are extremely low.
"I believe there is no known object that will definitely hit us in a 1,000 years, Thomas Burbine, an astronomer at Mount Holyoke College, told Newsweek. "But we are discovering new objects all the time."
Collisions do occur frequently on a geological time scale: an asteroid impact was responsible for the death of the dinosaurs during the end-Cretaceous extinction around 66 million years ago. This fated asteroid was around 6 miles in diameter and left a 110 mile-diameter crater in the Yucatán Peninsula in Mexico.
"We could expect such an event every few tens of thousands of years—on the timescale of a normal civilisation, a significant risk," Jay Tate, the director of the Spaceguard Center observatory in the U.K., told Newsweek.
Depending on the size, speed and angle of collision of a large asteroid, an impact could have catastrophic effects on Earth.
"At the lower size estimate the immediate effects would take out a reasonably sized country—France for example," Tate said. "At the higher end the destruction would cover a continental sized area. Were it to land in the ocean the whole ocean rim would be subjected to significant tsunami as well as the other effects. The physical destruction would be, of course, only part of the problem, especially in our increasingly globalized society."
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‘Planet Killer’ Asteroid Spotted That Poses Distant Risk to Earth
Robin George Andrews -
Astronomers on the hunt for modestly sized asteroids that could vaporize a city or bulkier beasts that could sterilize Earth’s surface have spotted a new potential threat. But there’s no immediate need to worry — it’ll be many generations until it may pose a danger to our planet.
The Dark Energy Camera at the Víctor M. Blanco 4-meter Telescope in Chile was used to aid the detection of asteroids that orbit between Earth and the sun and are otherwise difficult to spot.© CTIO/NOIRLab/NSF/AURA/D. Munizaga
Detecting uncharted space rocks relies on spying sunlight glinting off their surfaces. But some asteroids occupy corners of the sky in which the sun’s glare smothers them, and, like embers flitting in front of a thermonuclear bonfire, they fade from view.
Last year, in the hope of finding asteroids cloaked by excessive sunlight, an international team of astronomers co-opted a camera primarily designed to investigate the universe’s notoriously elusive dark matter. In an announcement Monday based on a survey first published in September in The Astronomical Journal, the researchers announced the discovery of three new light-drowned projectiles.
One of them, 2022 AP7, is roughly a mile long, and its orbit crosses Earth’s path around the sun, getting as near as 4.4 million miles to Earth itself — uncomfortably close by cosmic standards (although far more distant than Earth’s moon). That makes 2022 AP7 “the largest potentially hazardous asteroid found in the last eight years or so,” said Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C., and an author of the study.
An artist’s impression of an asteroid orbiting closer to the sun. Such asteroids are difficult to spot except during a few moments close to twilight.© DOE FNAL / DECam / CTIO / NOIRLab / NSF / AURA /J. da Silva – Space Engine
After the asteroid was discovered in January, additional observatories studied its motion and other astronomers retrospectively identified it in older images. This data set made it clear that it won’t be paying Earth a visit during the next century, and perhaps far longer.
“There is an extremely low probability of an impact in the foreseeable future,” said Tracy Becker, a planetary scientist at the Southwest Research Institute who was not involved with the study.
Related video: OTD in Space - Oct 31: Skull-Shaped Halloween Asteroid Flies by Earth
But the gravitational pull of objects around the solar system — including our own planet — ensures that Earth-crossing asteroids don’t dance the same way forever. The asteroid 2022 AP7 is no exception. “Over time, this asteroid will get brighter and brighter in the sky as it starts crossing Earth’s orbit closer and closer to where the Earth actually is,” Dr. Sheppard said.
It’s possible that “way down the line, in the next few thousand years, it could turn into a problem for our descendants,” said Alan Fitzsimmons, an astronomer at Queen’s University Belfast who was not involved with the study.
And if, in the unluckiest of timelines, 2022 AP7 ultimately impacts Earth?
“This is what we call a planet killer,” Dr. Sheppard said. “If this one hits the Earth, it would cause planetwide destruction. It would be very bad for life as we know it.”
But as we are safe for many generations, this asteroid’s orbit is not its most noteworthy feature. “The interesting thing about 2022 AP7 is its relatively large size,” said Cristina Thomas, a planetary astronomer at Northern Arizona University who was not involved with the study. Its existence suggests that other elephantine asteroids, veiled by the sun’s glare, remain disconcertingly undiscovered.
Today, astronomers looking for potentially hazardous asteroids — those that get at least as close as 4.6 million miles to Earth and are too chunky to be incinerated without incident by our atmosphere — focus on finding rocks around 460 feet across. There are most likely tens of thousands of them, and fewer than half have been identified. They could wreak destruction on a country-size scale. Such threats have motivated NASA and other space agencies to develop planetary defense missions like DART, the spacecraft that successfully adjusted the orbit of a small, nonthreatening asteroid in September.
Most asteroids that are two-thirds of a mile long and larger — far less common, but capable of global devastation — have already been found. But “we know some are still out there to find,” Dr. Fitzsimmons said.
Several no doubt sneak about near Mercury and Venus. But it’s “incredibly difficult to discover objects interior to Earth’s orbit with our current discovery telescopes,” Dr. Thomas said. During most hours of the day, the sun blinds Earth’s telescopes and objects can be hunted only in the few minutes around twilight.
To overcome this limitation, the astronomers who detected 2022 AP7 relied on the Dark Energy Camera on the Víctor M. Blanco 4-meter Telescope in Chile. Not only can it examine large swaths of the sky, but it is also sensitive enough to find faint objects engulfed by sunlight. So far, the camera found two additional near-Earth objects: a planet-killer in size whose orbit never crosses Earth’s but takes it closer to the sun than any other known asteroid, flambéing its surface at temperatures extreme enough to liquefy lead; and a smaller, country-killer-size rock that poses no risk.
The twilight survey’s capabilities will eventually be eclipsed by NASA’s Near-Earth Object Surveyor mission. Launching later this decade, this Earth-orbiting infrared observatory will stare into the sun’s glare and find most of the hazardous asteroids that other surveys have missed.
“We want to do everything possible to not be surprised,” Dr. Thomas said. That’s why these surveys exist: to find Earth-impacting asteroids many lifetimes in advance so that, through energetic prods or nuclear explosions, we can send these monsters back into the shadows.
Robin George Andrews -
Astronomers on the hunt for modestly sized asteroids that could vaporize a city or bulkier beasts that could sterilize Earth’s surface have spotted a new potential threat. But there’s no immediate need to worry — it’ll be many generations until it may pose a danger to our planet.
The Dark Energy Camera at the Víctor M. Blanco 4-meter Telescope in Chile was used to aid the detection of asteroids that orbit between Earth and the sun and are otherwise difficult to spot.© CTIO/NOIRLab/NSF/AURA/D. Munizaga
Detecting uncharted space rocks relies on spying sunlight glinting off their surfaces. But some asteroids occupy corners of the sky in which the sun’s glare smothers them, and, like embers flitting in front of a thermonuclear bonfire, they fade from view.
Last year, in the hope of finding asteroids cloaked by excessive sunlight, an international team of astronomers co-opted a camera primarily designed to investigate the universe’s notoriously elusive dark matter. In an announcement Monday based on a survey first published in September in The Astronomical Journal, the researchers announced the discovery of three new light-drowned projectiles.
One of them, 2022 AP7, is roughly a mile long, and its orbit crosses Earth’s path around the sun, getting as near as 4.4 million miles to Earth itself — uncomfortably close by cosmic standards (although far more distant than Earth’s moon). That makes 2022 AP7 “the largest potentially hazardous asteroid found in the last eight years or so,” said Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C., and an author of the study.
An artist’s impression of an asteroid orbiting closer to the sun. Such asteroids are difficult to spot except during a few moments close to twilight.© DOE FNAL / DECam / CTIO / NOIRLab / NSF / AURA /J. da Silva – Space Engine
After the asteroid was discovered in January, additional observatories studied its motion and other astronomers retrospectively identified it in older images. This data set made it clear that it won’t be paying Earth a visit during the next century, and perhaps far longer.
“There is an extremely low probability of an impact in the foreseeable future,” said Tracy Becker, a planetary scientist at the Southwest Research Institute who was not involved with the study.
Related video: OTD in Space - Oct 31: Skull-Shaped Halloween Asteroid Flies by Earth
But the gravitational pull of objects around the solar system — including our own planet — ensures that Earth-crossing asteroids don’t dance the same way forever. The asteroid 2022 AP7 is no exception. “Over time, this asteroid will get brighter and brighter in the sky as it starts crossing Earth’s orbit closer and closer to where the Earth actually is,” Dr. Sheppard said.
It’s possible that “way down the line, in the next few thousand years, it could turn into a problem for our descendants,” said Alan Fitzsimmons, an astronomer at Queen’s University Belfast who was not involved with the study.
And if, in the unluckiest of timelines, 2022 AP7 ultimately impacts Earth?
“This is what we call a planet killer,” Dr. Sheppard said. “If this one hits the Earth, it would cause planetwide destruction. It would be very bad for life as we know it.”
But as we are safe for many generations, this asteroid’s orbit is not its most noteworthy feature. “The interesting thing about 2022 AP7 is its relatively large size,” said Cristina Thomas, a planetary astronomer at Northern Arizona University who was not involved with the study. Its existence suggests that other elephantine asteroids, veiled by the sun’s glare, remain disconcertingly undiscovered.
Today, astronomers looking for potentially hazardous asteroids — those that get at least as close as 4.6 million miles to Earth and are too chunky to be incinerated without incident by our atmosphere — focus on finding rocks around 460 feet across. There are most likely tens of thousands of them, and fewer than half have been identified. They could wreak destruction on a country-size scale. Such threats have motivated NASA and other space agencies to develop planetary defense missions like DART, the spacecraft that successfully adjusted the orbit of a small, nonthreatening asteroid in September.
Most asteroids that are two-thirds of a mile long and larger — far less common, but capable of global devastation — have already been found. But “we know some are still out there to find,” Dr. Fitzsimmons said.
Several no doubt sneak about near Mercury and Venus. But it’s “incredibly difficult to discover objects interior to Earth’s orbit with our current discovery telescopes,” Dr. Thomas said. During most hours of the day, the sun blinds Earth’s telescopes and objects can be hunted only in the few minutes around twilight.
To overcome this limitation, the astronomers who detected 2022 AP7 relied on the Dark Energy Camera on the Víctor M. Blanco 4-meter Telescope in Chile. Not only can it examine large swaths of the sky, but it is also sensitive enough to find faint objects engulfed by sunlight. So far, the camera found two additional near-Earth objects: a planet-killer in size whose orbit never crosses Earth’s but takes it closer to the sun than any other known asteroid, flambéing its surface at temperatures extreme enough to liquefy lead; and a smaller, country-killer-size rock that poses no risk.
The twilight survey’s capabilities will eventually be eclipsed by NASA’s Near-Earth Object Surveyor mission. Launching later this decade, this Earth-orbiting infrared observatory will stare into the sun’s glare and find most of the hazardous asteroids that other surveys have missed.
“We want to do everything possible to not be surprised,” Dr. Thomas said. That’s why these surveys exist: to find Earth-impacting asteroids many lifetimes in advance so that, through energetic prods or nuclear explosions, we can send these monsters back into the shadows.
New potentially hazardous asteroid discovered
Issued on: 01/11/2022 -
Three near-Earth asteroids -- one potentially hazardous -- were found using a high-tech instrument at the Cerro Tololo Inter-American Observatory in Chile ROGER SMITH, AURA, NOAO, NSF
Washington (AFP) – An international team of astronomers on Monday announced the discovery of a large asteroid whose orbit crosses that of Earth, creating a small chance far in the future of a catastrophic collision.
The 1.5 kilometer- (0.9 mile-) wide asteroid, named 2022 AP7, was discovered in area notoriously difficult to spot objects due to the glare from the Sun.
It was found along with two other near-Earth asteroids using a high-tech instrument on the Victor M. Blanco telescope in Chile that was originally developed to study dark matter.
"2022 AP7 crosses Earth’s orbit, which makes it a potentially hazardous asteroid, but it currently does not now or anytime in the future have a trajectory that will have it collide with the Earth," said lead author of the findings, astronomer Scott Sheppard of the Carnegie Institution for Science.
The potential threat comes from the fact that like any orbiting object, its trajectory will be slowly modified due to myriad gravitational forces, notably by planets. Forecasts are therefore difficult on the very long term.
The newly-discovered asteroid is "the largest object that is potentially hazardous to Earth to be discovered in the last eight years," said NOIRLab, a US-funded research group that operates multiple observatories.
2022 AP7 takes five years to circle the Sun under its current orbit, which at its closest point to Earth remain several million kilometers away.
The risk is therefore very small, but in case of a collision, an asteroid of that size "would have a devastating impact on life as we know it," said Sheppard. He explained that dust launched into the air would have a major cooling effect, provoking an "extinction event like hasn’t been seen on Earth in millions of years."
His team's results were published in the scientific journal The Astronomical Journal. The two other asteroids pose no risk to Earth, but one is the closest asteroid to the Sun ever found.
Some 30,000 asteroids of all sizes -- including more than 850 larger than a kilometer wide -- have been catalogued in the vicinity of the Earth, earning them the label "Near Earth Objects" (NEOs). None of them threaten Earth for the next 100 years.
According to Sheppard, there are "likely 20 to 50 large NEOs left to find," but most are on orbits that put them in the Sun's glare.
In preparation for a future discovery of a more threatening object, NASA conducted a test mission in late September in which it collided a spacecraft with an asteroid, proving that it was possible to change its trajectory.
© 2022 AFP
Washington (AFP) – An international team of astronomers on Monday announced the discovery of a large asteroid whose orbit crosses that of Earth, creating a small chance far in the future of a catastrophic collision.
The 1.5 kilometer- (0.9 mile-) wide asteroid, named 2022 AP7, was discovered in area notoriously difficult to spot objects due to the glare from the Sun.
It was found along with two other near-Earth asteroids using a high-tech instrument on the Victor M. Blanco telescope in Chile that was originally developed to study dark matter.
"2022 AP7 crosses Earth’s orbit, which makes it a potentially hazardous asteroid, but it currently does not now or anytime in the future have a trajectory that will have it collide with the Earth," said lead author of the findings, astronomer Scott Sheppard of the Carnegie Institution for Science.
The potential threat comes from the fact that like any orbiting object, its trajectory will be slowly modified due to myriad gravitational forces, notably by planets. Forecasts are therefore difficult on the very long term.
The newly-discovered asteroid is "the largest object that is potentially hazardous to Earth to be discovered in the last eight years," said NOIRLab, a US-funded research group that operates multiple observatories.
2022 AP7 takes five years to circle the Sun under its current orbit, which at its closest point to Earth remain several million kilometers away.
The risk is therefore very small, but in case of a collision, an asteroid of that size "would have a devastating impact on life as we know it," said Sheppard. He explained that dust launched into the air would have a major cooling effect, provoking an "extinction event like hasn’t been seen on Earth in millions of years."
His team's results were published in the scientific journal The Astronomical Journal. The two other asteroids pose no risk to Earth, but one is the closest asteroid to the Sun ever found.
Some 30,000 asteroids of all sizes -- including more than 850 larger than a kilometer wide -- have been catalogued in the vicinity of the Earth, earning them the label "Near Earth Objects" (NEOs). None of them threaten Earth for the next 100 years.
According to Sheppard, there are "likely 20 to 50 large NEOs left to find," but most are on orbits that put them in the Sun's glare.
In preparation for a future discovery of a more threatening object, NASA conducted a test mission in late September in which it collided a spacecraft with an asteroid, proving that it was possible to change its trajectory.
© 2022 AFP
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