The ‘potentially dangerous’ monster asteroid is the largest seen in years: ScienceAlert


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Astronomers peering into the twilight sky have discovered three previously unknown near-Earth asteroids. One of them is the greatest potential danger asteroid Discovered in eight years.


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It’s about 1.5 kilometers (nearly one mile) wide, and it’s in an orbit that might, in the future, bring it close enough to Earth to pose a problem.

The other two asteroids have paths that are quite close and safe to the Sun from Earth’s orbit. This does not make their discovery less exciting, as well as the enumeration of hard-to-find objects that will allow us to better characterize the NEO group.

more than small planets In the solar system – objects in direct orbit around the sun that are neither planets nor comets – have been detected at orbital distances greater than those of Earth. There is an asteroid belt between Mars And the Jupiterthe Kuiper belt outside Neptune where Pluto resides, and a host of other rocks, such as Greek and Trojans Asteroids that share planetary orbits.

Not much has been discovered in the way of the minor planets near the Sun, and for very good reason. We have to look at a large, bright star, whose bright light makes small, faint asteroids undetectable. This means that we are more likely to find things when we look away from the sun in a direction that faces the outer solar system.

To get a chance to spot an inner solar system asteroid, astronomers need to wait until the twilight hours at dawn and dusk when the sun’s glare is often below Earth’s horizon, providing enough light to illuminate the inner asteroids that may sweep through space.

A research team led by astronomer Scott Sheppard of the Carnegie Institution for Science conducted such a search for large patches of sky closer to the sun than Earth and Venuswhich led to some wonderful discoveries.

was one 2021 PH27, which is an asteroid with the shortest orbit of any asteroid found so far, at just 113 days. Then there’s 2021 LJ4, which also revolves around the sun completely within Earth’s orbit. Both are known as asteroids atira.

“So far we have found two large asteroids near Earth that are about one kilometer in diameter, the size we call planet killers,” Sheppard says.

“It is possible that there are only a few near-Earth asteroids left of similar sizes, and these large, undiscovered asteroids likely have orbits that make them inland to the orbits of Earth and Venus most of the time. Only about 25 asteroids with orbits within them have fully been discovered Earth orbit so far. Because of the difficulty of observing near the glare of the sun.”

The third asteroid, 2022 AP7, is known as Apollo asteroid. These are asteroids that have elliptical paths that take them from space closer to the Sun and beyond the Earth’s orbit. by Crossing our orbit, Apollo asteroids like 2022 AP7 could venture close to our planet to risk collision, and win They are rated “Potentially Dangerous”.

there more than 2000 potentially dangerous asteroids ( bigger than her It has a diameter of about 7 kilometers) fortunately we know it. If we know about them, we can model their orbits, calculating if and when they are likely to be within Earth’s dangerous range. With enough notice, we might be able to do something about it, like Collided with a spacecraft on its surface to divert its course.

The discovery of new Atira asteroids is also important. Our understanding of the population of minor planets in the solar system depends primarily on the population of space rocks in the most distant regions. Getting a better idea of ​​what’s in the inner solar system can tell us more about the dynamics of the solar system — how asteroids are transported to different regions, as well as more accurate models of the system’s evolution over time.

“Our DECam survey is one of the largest and most sensitive ever searches for objects in Earth’s orbit and near the orbit of Venus,” Sheppard says. “This is a unique opportunity to understand the types of bodies lurking in the inner solar system.”

Interestingly, Despite being more sensitive to smaller things, The survey revealed a greater number of larger asteroids – those with a diameter of at least one kilometer. This could mean that smaller asteroids are less stable in the inner solar system, or more likely to split in the intense thermal and gravitational environment closer to the sun.

It may simply be that small asteroids are hard to spot. This makes an excellent case for more sensitive surveys in the future.

The paper describing the three asteroids was published in Astronomical Journal.

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