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Osiris Rex is on a mission to return a sample from asteroid Bennu. This space rock could collide with Earth in the 22nd century after an epic journey from the asteroid belt. What is the mysterious force that pushes Bennu ever closer to the center of the solar system? Astronomers believe that the heat from the sun unlocks the mystery. Bennu makes one full rotation every 4.3 hours as it flies through space. Sunlight warms the surface of the asteroid. As the heated rocks rotate away from the sun towards Bennu's dark side, they radiate their heat into space on the asteroid's leading edge.
This gives the asteroid a tiny push backwards. Astronomers call this process the Yarovsky effect. Like a low inensity thruster, it slows down Bennu and allows the sun to pull it closer with every orbit. The Arosovski effect is very small in any given moment, but over a large amount of time, it can actually have a big effect. It's already moved Bennu from the asteroid belt inward toward the Earth. Infrared cameras on board Osiris Rex measure how quickly the surface of Bennu heats up and cools down. This data will help astronomers calculate the influence that the Yakovsky effect has on Bennu's orbit around the sun.
This calculation could predict precisely if and when Bennu will pass through a deadly gravitational keyhole. Is it changing in such a way that it moves away from one of these keyholes? Or is it going to pass through a keyhole, moving it in a direction of a collision course with Earth? Rogue asteroids have the potential to devastate our planet. Osiris Rex will help astronomers accurately assess the threat that Bennu poses to life on Earth. But what secrets about the origins of life are buried inside this space rock? Scientists think that Bennu contains ancient organic material that could help solve the mystery. If we look at Bennu, it's primordial.
It's pure. It's untouched. It's been out there by itself, isolated from pretty much everything but sunlight. This material could be older than the Earth. It probably is. So, if we want to understand how our solar system formed, this is where we need to go. Osiris Rex photographs its first clue in January 2019. This image shows the surface of Bennu ejecting particles. Of all the amazing science and images that have come back from the Osiris Rex mission, the absolute coolest one to me is that Bennu is spitting rocks into space. Little rocks,
sometimes pebbles, sometimes a little bit bigger, are literally shooting out of the asteroid into space. What is blasting rocks from Bennu? One theory is that as Bennu rotates into the sunlight, the rocks on the surface heat up. This can stress them so much that they crack and throw asteroid fragments into space or into orbit around Bennu. Another theory is that sunlight heats up a material trapped in the rock. This vaporizes and builds up so much pressure that it can break bits off Bennu and fling them into space.
What is the mysterious material that produces this vapor? Osiris Rex uses special cameras to analyze the chemical composition of Bennu's rocks. The cameras discover that many of the minerals inside Bennu are hydrated. This means that the molecules of these minerals are chemically combined with molecules of water. Astronomers believe that this is evidence that Bennu was once part of a larger asteroid that contained a reservoir of liquid water. For a long time, it was thought that asteroids were very dry. They didn't have much water on them. Well, in recent
years, we've learned that's not the case. They are, in fact, loaded with water. Do these hydrated minerals unlock how Earth's vast oceans formed billions of years ago? And is it possible that asteroids like Bennu even brought the building blocks of life to our planet? NASA's Osiris Rex is on a mission to unlock the secrets of the asteroid Bennu. The spacecraft carries a suite of instruments that photograph, scan, and analyze Bennu in more detail than any asteroid before it. Osiris Rex finds evidence that Bennu was once part of a larger body loaded with water. Scientists think this could unlock the answer to a crucial question about our world.
How does life start on a planet like Earth? Of all of the bodies in the solar system, including moons and planets, Earth is the odd one out. It is the only body with liquid water on its surface. Water is crucial for organic life. The liquid mixes lifeless chemicals into biological systems. Water covers 70% of the Earth's surface today. But this hasn't always been the case. 4.5 billion years ago, rocky planets like Earth are hot, hellish worlds. One theory is that a crystalline material called ringuidite locked inside the Earth's crust releases vast amounts of liquid water. But many scientists think that
this internal water source will boil away in the super hot conditions of the early solar system. Anything very easy to evaporate like water vapor would have simply gone up and been blown away into space. So, how did this water come to the surface of the Earth? It couldn't have started here. So, something must have brought it. Billions of years ago, a cooler region of the solar system exists around 400 million miles away from the sun. Here, it is possible for water to exist as ice. It gets colder as you move away from the sun. So, there's a region in our outer solar system that is cold enough to allow for the existence of water ice. We think that asteroids that form out in this cold region of the solar system can lock up
this ice and bring it inwards toward the inner solar system. And that might have been how a dry Earth received its water. Asteroids laden with ice bombard the young earth. Over time, this barrage delivers enough water to turn our world blue. The hydrated minerals inside Bennu could be evidence that asteroids bring water to Earth billions of years ago. But is it also possible that they bring the chemicals needed to create life itself? A big question about asteroids is if they bring water from space to Earth, could they have more complex chemistry like amino acids? materials that they
could have brought to Earth and seated it here so that life could begin. NASA's New Horizon spacecraft uncovers a clue in the farthest reaches of the solar system. The probe takes this photograph of Pluto in 2015. It shows a strange red tar covering the surface of the dwarf planet. Analysis reveals that this tar calledtholin is made from a mixture of complex organic chemistry. It is possible that this chemistry could contain the building blocks of life.
