On December 3, after miles of miles from the earth, NASA's OSIRIS-REX spacecraft reached its target, Bennu, and started an…
On December 3, after miles of miles from the earth, NASA’s OSIRIS-REX spacecraft reached its target, Bennu, and started an almost two-year and astronomical investigation of the asteroid. It will inspect almost every square inch of this old clump of rubble left from the formation of our solar system. In the end, spacecraft will pick up a sample of rock and dust from Bennus’s surface and deliver it to earth in 2023.
Generations of planet science teachers will learn pieces of the primitive materials that formed our cosmic neighborhood and to better understand Roll asteroids may have played with delivering life-forming compounds to planets and moons.
But it’s not just history that the mission of Bennu will help reveal. Researchers studying the cliff through OSIRIS-REx’s instrument in space will also shape our future. When collecting the most detailed information than about the forces moving asteroids, experts from NASA’s planetary defense coordination agency, responsible for detecting potentially dangerous asteroids, will improve their predictions of who might be on a crash path with our planet.
How does the OSIRIS REX mission support this work:
How researchers predict Bennus residence
About a third of a mile or a half mile wide, Bennu is big enough to reach the surface of the earth; Many smaller space objects, on the other hand, burn in our atmosphere. If it affected the Earth, Bennu would cause widespread damage. Asteroid Experts at the Center for Near Earth Object Studies (NASA’s Jet Propulsion Laboratory in Pasadena, California), projecting Bennu close enough to earth during the next century to make it 1
in 2 700 chance to affect it between 2175 and 2196. Put another way , these odds mean there is a 99,963 percent chance that the asteroid will miss the ground. However, astronauts want to know exactly where Bennu is at all times.
Astronomers have estimated Bennus’s future courses after observing it several times since it was discovered in 1999. They have turned their optical, infrared and radio telescopes against the asteroid every time it came near the earth, about every six years, to derive functions like form , rotational speed and lane.
“We know within a few kilometers where Bennu is right now,” says Steven Chesley, senior researcher at CNEOS and an OSIRIS-REx group member whose job is to predict Benny’s future courses.
Why Bennus’s Future Banquet Predictions Becomes Fuzzy
Scientists have calculated the Bennus pathway around the sun far into the future. Their predictions are informed by field observations and mathematical calculations that account for the Bennu gravity of the sun, the moon, the planet and other asteroids, plus non-gravitational factors.
Given these parameters, astronomers can predict the next four exact dates (in September 2054, 2060, 2080 and 2135), Bennu will come within 5 million miles (7.5 million miles or 0.05 astronomical units) of the earth. It is close enough that the earth’s gravity will bend some Bennus orbital road as it passes. As a result, the uncertainty about where the asteroid will be every time it wobbles back around the sun will grow, making predictions about Bennus’s future circulation becoming increasingly foggy after 2060.
Bennu will arrive in 2060 by passing the earth at about twice a distance from here to the moon. But it could pass anytime in a 19-mile (30 kilometer) window window. A very small difference in position within this window will be greatly enlarged in future lanes and make it harder to predict Bennus’s course.
As a result, when this asteroid returns back to Earth in 2080, according to Chesley’s calculations, it is the best window we can get at its place of residence is nearly 9000 miles (14,000 miles) wide. By 2135, when Bennus’s displaced orbit is expected to bring it closer than the moon, its airfield windows grow wider to nearly 100,000 miles (160,000 miles). This will be Benny’s closest approach to the earth during the five centuries, for which we have reliable calculations.
“At the moment, Bennu has the best ball of any asteroid in our database,” said Chesley. “However, after the meeting in 2135, we can not really say exactly where it’s heading.”
There is another phenomenon that connects Bennus’s orbit and muddying future impact. It is called Yarkovsky effect. Has nothing to do with gravity, the Yarkovsky effect turns Bennus’s orbits due to heat from the sun.
“There are many factors that may affect the predictability of Bennus Lane in the future, but most are relatively small,” said William Bottke, an asteroid expert at the Southwest Research Institute in Boulder, Colorado, and a participating researcher on the OSIRIS REx mission . “The greatest one is Yarkvovsky.”
This heat poodle was named after the Polish civil engineer who first described 1901: Ivan Osipovich Yarkovsky. He suggested that sunlight warms one side of a small dark asteroid and a few hours later it radiates heat away because the asteroid rotates its hot side in cold darkness, which stretches the rock star a bit, either toward the sun or away from it, depending on the direction of rotation.
In Bennus’s case, astronomers have estimated that the Yarkovsky effect has changed its orbit 288 meters per year against Sunsince 1999. In fact, it contributed to delivering Bennu to our part of the solar system, primarily from the asteroid belt between M ars and jupiter over billions of years. Now Yarkovsky complicates our efforts to make predictions about Bennus’s path in relation to the earth.
Face-to-face with the asteroid will help
OSIRIS-REx spacecraft will use its suite of instruments to transmit radio tracking signals and capture optical images of Bennu that help NASA researchers determine its exact position in the solar system and its exact orbital path. In combination with existing field-based observations, space measurements will help clarify how Bennus’s path changes over time.
In addition, astronomers will try their understanding of the Yarkovksy effect on a steroid steroid for the first time. They will instruct the spacecraft to follow Bennu in its circulation about the sun for about two years to see whether it is moving along an expected road based on gravity and Yarkovsky theories. Any differences between predictions and reality can be used to deepen models of the Yarkovsky effect.
But even more important to understand Yarkovsky is the thermal measurements of Bennu. During its mission, OSIRIS-REX will track how much solar radiation emanates from the asteroid, and on the surface it comes from data that helps confirm and improve the calculations of the Yarkovsky effect on asteroids.
The spacecraft will also address some open questions about Yarkovsky theory. One of them, says Chesley, is how rotors and craters on the surface of an asteroid change how photons sprout of it when it cools, which removes momentum from the hot side and thus nudges the asteroid in the opposite direction? OSIRIS-REX will help researchers to understand by mapping Bennus’s surface.
“We know that the smoothness will affect the Yarkovsky effect, we have models,” says Chesley. “But the models are speculative. No one has been able to test them.”
Following the OSIRIS-REx mission, Chesley said that NASA’s Bennu Ban projections will be about 60 times better than they are now.