Asteroids lurking between the Earth and the Sun but obscured by the glow of our star could help shed light on history solar systemthe scientist thinks.
Astronomer Scott Sheppard of the Carnegie Institute of Science in Washington. COLUMBIA REGIONsays the discovery of near-Earth objects (NEOs) is just beginning.
This is because telescopes tend to look away from our planet to avoid bright sunlight; however, new studies pointing the other way show more NEOs, including never-before-seen asteroids.
Sheppard and other experts say finding and tracking these space rocks could be vital to improving our understanding of planet formation and solar system history.
“New telescopic surveys are challenging bright sunlight and looking for asteroids moving towards the sun at dusk,” Sheppard wrote in a column in the latest journal Science.
“These studies have found many previously undiscovered asteroids inside the Earth.”
Asteroids lurking between the Earth and the Sun but obscured by the glare of our star could help shed light on the history of the solar system, scientist says (file image)
What is a “potentially hazardous” asteroid?
A Potentially Hazardous Asteroid (POA) is an asteroid whose orbit approaches Earth closer than 0.05 AU. (about 7.5 million km).
It also has a diameter of at least 100 meters (300 ft).
The International Astronomical Union claims that there are about 1,500 potentially dangerous asteroids.
While they do not pose a threat to Earth at the moment, such large asteroids could cause havoc if they landed on our planet, especially in densely populated areas.
It is believed that once every 200-300 years it hits the Earth.
The discoveries include the first asteroid to orbit inside Venus, named Ayló’chaxnim 2020 AV2, and the asteroid that currently has the shortest known orbital period around the Sun, called 2021 PH27.
Simulations have predicted that these space rocks must exist, but now telescopes are actually starting to confirm their presence.
Observatories include the Zwicky Transient Facility Camera in California and the National Science Foundation’s 4-meter Blanco Telescope in Chile.
According to NASA, there are more than 26,000 near-Earth asteroids, although only about 10,000 of them are larger than 450 feet (140 m).
They are classified based on their position in our solar system – for example, Athiras’ orbit is inside the Earth, while Vathira’s is inside Venus.
The US space agency’s Near-Earth Object Surveyor (NEO Surveyor) is due to launch in 2026 to help detect more of these asteroids.
It will be positioned between the Earth and the Sun to better detect space rocks that are not currently visible due to their position in space.
According to experts funded by NASA, some asteroids can “sneak up” on us thanks to a quirk of the Earth’s rotation that makes them appear to barely move, making them difficult to detect.
Scientists investigated how telescopes nearly missed a 328-foot-wide asteroid that was 43,500 miles from Earth in 2019.
The space rock, dubbed “2019 OK”, was the first object of its size to come this close to our planet since 1908, but it was spotted just 24 hours before its closest approach.
The team determined that the reason was that it was moving towards us in such a way that the rotation of the Earth counteracted its movement through the night sky.
Thus, for early warning systems such as Pan-STARRS1 at Haleakala Observatory in Hawaii, 2019 OK appeared to be stationary, so the automatic detection software did not run.
In fact, up to half of the asteroids approaching Earth from the danger zone east of the “opposition” are likely to experience periods of this apparent slowdown, experts say.
This means that half of these asteroids are also currently difficult to detect, and computerized telescopes will need to be upgraded to account for this effect.
Scientists believe that most NEOs are asteroids knocked out of the main belt between Mars and Jupiter.
However, Sheppard believes that there may also be stable inner reservoirs of NEOs that replace asteroids that orbit the wider solar system, crash into a planet, or are obliterated by the sun.
Asteroids are classified according to their position in our solar system. For example, Atiras orbits inside the Earth, and Vathira inside Venus (pictured above).
Scientists know that the number of NEOs has remained stable over the past few billion years as they have observed craters on planets and moons, but the fact that they have such unstable orbits and unpredictable motions caused by the sun suggests that they are somehow replenished in this way.
“The motion depends on the rotation of the asteroid, its size, albedo and distance from the Sun,” Sheppard wrote.
“The smaller the asteroid and the more sunlight it absorbs, the stronger its movement.”
The discovery of NEOs should help scientists learn more about their movement and how their numbers remain stable over such long periods of time.
Experts believe that about 90 percent of the so-called planet-killing NEOs – those with a diameter of just over half a mile (1 km) or more – have already been found.
“The last few unknown NEOs with a diameter of 1 km are likely to have orbits close to the Sun, or high inclinations, which keeps them out of the fields of mainstream NEO research,” Sheppard added.
The perspective was published in The science.
Explanation: difference between asteroid, meteorite and other space rocks
An asteroid is a large piece of rock left over from collisions or the early solar system. Most of them are located between Mars and Jupiter in the Main Belt.
BUT comet rock covered with ice, methane and other compounds. Their orbits take them much farther from the solar system.
BUT meteor this is what astronomers call a flash of light in the atmosphere as debris burns up.
This rubbish is known as meteoroid. Most of them are so small that they evaporate in the atmosphere.
If any of these meteoroids reach the Earth, it is called meteorites.
Meteors, meteoroids and meteorites are usually formed from asteroids and comets.
For example, if the Earth passes through the tail of a comet, most of the debris burns up in the atmosphere, forming a meteor shower.