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Bennu asteroid is spinning faster and faster and the scientists do not know why



Bennu asteroid spins faster and faster, and scientists are not sure why: On the distant space rock being explored by a NASA probe, the days are getting shorter to find out why
  • NASA is exploring the asteroid which has a diameter of 494 m and turns once every 4.3 hours
  • The probe looks at data collected between 1999 and 2005 by two ground telescopes and published by Hubble
  • 5:55 EDT, March 15, 2019

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    A distant space rock called Bennu spins faster, meaning that its rotation period gets shorter by about a second every 100 years – but the scientists are there I'm still trying to figure out why.

    NASA observes the asteroid to help them understand the development of other similar objects, their potential threat to Earth, and whether they could be mined for resources.

    Scientists used data gathered during the OSIRIS REx mission prior to probe arrival to calculate that Bennu's rotation rate accelerated over time.

    Bennu is 110 million kilometers from Earth. As it moves through space at about 63,000 miles per hour (101,000 km per hour), it also turns and completes a full rotation every 4.3 hours.

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      A distant space rock called Bennu spins faster, which means that its rotation period gets shorter by about 1 second every 100 years - but scientists are still trying to figure out why. NASA is exploring the 492-meter-diameter B-type asteroid (picture), which rotates once every 4.3 hours.

    A distant space rock called Bennu spins faster, which means its rotation period gets shorter every 100 years for about 1 second – but scientists are still trying to figure out why. NASA is exploring the B-type asteroid (picture), which has a diameter of 492 m (1,614 feet) and turns once every 4.3 hours.

    What causes the acceleration?

    The OSIRIS REx mission is to bring a sample of Bennu to Earth in 2023.

    Even with Bennu, the observations leave the mystery of the cause.

    One possible explanation is that material is moving around Bennu's surface or leaving the asteroid could speed up the rotation speed.

    The idea that asteroid rotation could become faster over time was first predicted around 2000 and first discovered in 2007.

    So far, this acceleration has only been discovered in a handful of asteroids.

    The authors say the change in Bennu rotation could be due to a change in shape, "similar to how the skaters accelerate when they pull in their arms," ​​an asteroid could accelerate as it loses material.

    The increase in rotation could be It does not seem to be much, but experts say it can lead to dramatic changes in space rock over a long period of time.

    The probe looks at data collected from two ground telescopes between 1999 and 2005 and from the Hubble Space Telescope in 2012.

    When they looked at the Hubble data, they noticed that the rotational speed of the asteroid in 2012 did not live up to their predictions based on previous data.

    "You could not make all three of them fit," said Mike Nolan, principal author of the new research and geophysicist at the University of Arizona's Lunar and Planetary Laboratory, who is also head of OSIRIS The REX Mission Science Team.

    "That's when we came up with the idea that it had to be accelerated."

    According to the authors of the study, if the asteroid rotates faster and faster over millions of years, it could lose parts of itself or blow itself up.

    & # 39; As speed increases, things should change and so & # 39; When we look for these things, and recognize that speed, it gives us clues to the kinds of things we should look for, "Dr. Nolan added in a written statement.

    "We should look for evidence that something has been different in the recent past, and it is conceivable that things will change."

    "You could not make all three of them fit," Nolan said. "That's when we came up with the idea that it had to be accelerated."

      The scientists used data gathered during the OSIRIS REx mission prior to the arrival of the probe to calculate that Bennu's rotation rate accelerated over time. This image is a mosaic composite consisting of 12 PolyCam images collected on December 2, 2018.

    Scientists used data collected during the OSIRIS REx mission prior to probe arrival to calculate that Bennu's rotational speed accelerated over time. This image is a mosaic composite consisting of 12 PolyCam images collected on December 2, 2018.

    The OSIRIS REx mission is to bring a sample of Bennu to Earth in 2023.

    Even with Bennu, the observations leave the picture riddle of what caused it.

    One possible explanation is that material moving on the surface of Bennu or completely leaving the asteroid could accelerate the rotation speed.

    The idea that the rotation of asteroids could be accelerated over time was first predicted around 2000 and first discovered in 2007.

    This acceleration has so far only been discovered in a handful of asteroids.

      Bennu is 110 million kilometers from Earth. As it moves through space at about 63,000 miles per hour (101,000 km per hour), it also turns and completes a full rotation every 4.3 hours. This picture shows the impression of an artist from the Osiris Rex probe at the asteroid

    . Bennu is 110 million kilometers from Earth. As it moves through space at about 63,000 miles per hour (101,000 km per hour), it also turns and completes a full rotation every 4.3 hours. This picture shows the impression of an artist from the Osiris Rex probe at the asteroid

    . The authors say the change in Bennu rotation could be due to a change in shape. This is similar to the speed with which skaters swiftly pull arms, could accelerate an asteroid as it loses material.

    Dr. Nolan also said that the reason for the increase in Bennu's rotation is more due to a phenomenon known as the YORP effect.

    This means that sunlight that strikes the asteroid is reflected into space. Changing the direction of the incoming and outgoing light pushes the asteroid and may cause the asteroid to turn faster or slower depending on its shape and rotation.

    "The reason for the increase in Bennu's rotation is more likely due to a phenomenon known as the Yarkovsky-O .keefe-Radzievskii paddack effect," Dr. Nolan.

    The OSIRIS REx mission will independently determine Bennu's rotation rate this year, which will help scientists capture the reason for the increasing rotation.

    HOW IS NASA'S OSIRIS REX MISSION TAKEN SAMPLES FOR ASTEROID WORK? 19659050] Osiris-Rex is the first US mission to bring a piece of asteroids back to Earth.

    Scientists say the ancient asteroid could contain clues to the origin of life.

    It is believed to have formed 4.5 billion years ago, a remnant of the building blocks of the solar system.

    The spacecraft launched on September 8, 2016 at 19:05 EST aboard an Atlas V rocket.

    Following a careful study by Bennu to characterize the asteroid and find the most promising sample locations, Osiris-Rex will collect the sample with a robot arm of between 2 and 70 ounces (approximately 60 to 2,000 grams) of surface material removable capsule in 2023 to earth.

    To collect samples on the surface, the vehicle hovers over a certain range and is sent down (10 cm) per second at a very slow and gentle distance of 4 inches.

    The spacecraft will also carry a laser altimeter, a series of cameras provided by the University of Arizona, spectrometers and lidar, which are similar to radar and use light instead of radio waves to to measure the distance.

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