Banu, Ben Who, Nasa discussed on On a Mission
When an asteroid passes a spy. We can't just breathe a sigh of relief if they often come back there orbiting the sun just like we are but at different speeds and on different paths so when astronomers determined and asteroids is odds of hitting us they have to not only consider this loop around the sun but all of its future loops as well. JPL Scientists Steve Chancellor eslake keeps tabs on where asteroids going for tracking asteroids data source are these telescopes bitter constantly plowing the skies looking in for objects a whenever they find something they send it in and we update the orbit so we don't update the orbits necessarily when we want to we. We do that when we get more. Data sometimes objects are so interesting that we'd say. Hey we need to know where this is. Maybe because it's threatening the earth or maybe because of space mission wants to go there so then they will point to telescope where it's supposed to be now if those predictions for were supposed to be are. You're very approximate. They might have a lot of work to recover. The asteroid the fun thing and asteroids. Is You can do that in the past you can kind of do time travel. Because everybody we saving their images and even film from the Nineteen fifties all been digitized dope if you have an asteroid you wanted to where it was sometime in the past you can go to those files and update the that way. It's not as simple. Connect the dots exercise though because asteroids. Don't follow straight lines. Through the solar system sunlight that warms the surface of asteroids can steer them in unexpected directions. This is known as the are Kofsky. Effect Rusi see your Kofsky. Effect is very cool on a NASA web series. The robot astronomy talk show that actress Cameron Diaz schooled the robot host post about the your Kofsky effect. So you're saying that when an asteroid absorbs sunlight on one side that side in its infrared energy that pushes it out pitch normal orbit the exactly the more sunlight it's able to absorb the more infrared energy. It emits and the further it gets pushed asteroids all experience this effect in fact a different degrees in Steve says figuring out how it changes and asteroids orbit around the Sun can be difficult when asteroids. I discovered we really don't know even which way the asteroid is being pushed. Could push ahead or behind in its orbit. That can be a very complicated effect on Earth Hazard prediction for many the asteroids and now we have on the order of one hundred near Earth Asteroids for which we can see an estimate the amount of the aircraft offs key affect. But they're still twenty thousand more your asteroids for which we have no insight of what the Husky effect is doing to that buddy. Radar measurements can help narrow down. How an ashtray? Deviating from its expected path but such measurements can only be made when an asteroid asteroid is relatively close to us. Radar also can provide better details on an asteroid size and shape. which is good to know if you're trying to figure out house? Sunlight is heating their surfaces in asteroids. Come in a medley of forms. Some look like dog bones or walnut shells others are irregular jagged. Give Mishmash one Halloween. An asteroid with features like a human skull flew past us a wicked cosmic joke. Some Asteroids Zor enormous and some are very small they come in different colors and flavors metallic stony icy but why are the asteroids also different. Why are they even out there in the first place to answer such questions? NASA has sent missions to investigate them. The Galileo Mission to Jupiter was the first to fly by An asteroid back in nineteen ninety one. The first mission to orbit and land on an asteroid happened seven years later with the near Shoemaker spacecraft's visit to asteroid right arrows at nearly seventeen kilometers in length eros is the second largest near Earth object six kilometers bigger than the asteroid that led to the dinosaur extinction extinction luckily for us. Eros is not heading our way the asteroid Benue is another story. Benders orbit around the Sun. Brings it close close to Earth every six years and there's a small chance it could hit us in the year. Twenty one ninety. Six Banu is five hundred meters in diameter taller than the Empire Empire State Building. If it hit us the impact would unleash eighty thousand times energy an atomic bomb. This threat is enough to have motivated a recent study. Study about the best way to steer Ben off course hammer an acronym for hyper velocity mitigation. Mission would be a battering Ram of spacecraft. We have to throw a lot of hammers banner to move it between a dozen to eighty depending on the amount of time we have before it hit. But Ben you might not respond spawned the way we think it will. We need to learn more about it with that in mind. Nastase Osiris Rex mission is currently orbiting Banu and sending US images ages of it's rough craggy surface. Astronomers Think Banu is shattered fragment a remnant from a collision between two larger asteroids that impact Banu off and tossed it out of the asteroid belt the region of space between Mars and Jupiter that contains millions of asteroids. Ben Who still bears the marks of being being a crash survivor. It's a rubble pile of rocks. Loosely bound together by gravity. The lead scientist of the Cyrus rex mission. Dante Lauretta the university diversity of Arizona says they hadn't realized just how loosely bound some of those rocks are so yeah. The asteroid is regularly tossing material off into space. This certainly was unexpected. By surprise a lot of them are falling right back down and landing on the asteroid surface. Some of them are actually getting trapped in orbits around the asteroid which is really exciting because it allows us to track them over many days and even weeks and then start to learn something about the detail. Gravity field the asteroid and then some of them are at high enough philosophies above what we would call the escape velocity of the asteroid. And they're leaving Benny going into interplanetary space. There is no concern for spacecraft safety. It's a small enough amount of material and overall moving relatively slowly so even if one of these were to hit the space craft it. It wouldn't cause any damage that would impact our ability to achieve the mission the dance of rock particles around Bhanu is just one more challenge for the spacecraft were navigating in in a microgravity environment and that has a lot of unexpected in small forces that act on the spacecraft so in addition to the gravity of the asteroid Royd. We're also getting pushed around by the solar wind material outgassing from the spacecraft heat radiating off from the asteroid all of those have a substantial impact on the trajectory victory the spacecraft so we're constantly taking images and updating the position and figuring out where we're going to be in the future and that drives a very intense operational final timeline for the team basically within twenty four hours of making a science observation. We have to do a navigation. Solution determined the position and velocity of the spacecraft relative to the asteroid and then get that up on the spacecraft so that it can accommodate the differences in where we're actually going to be versus where we thought we would be when we first meet the design. Uh the difficulty of navigating spacecraft around and asteroids suggests that moving one could be a tough task but of Cyrus. REX is not there to move. It's goal is to gather a sample from it. Even though rock particles are drifting off. Banu your Cyrus. REX mission wasn't designed to capture them like the stardust mission. Did for comment built to instead a device at the end of a long arm extending from the underside of the space craft will collect material from the asteroid surface surface. After the device touchdown for five seconds springs will bounce the spacecraft. Backup kind of like a pogo stick. In those five seconds the device will gather asteroid dirt in a unique way touch and go sample acquisition mechanism or tag sandwiches device that we place on the surface is basically A vacuum cleaner working in reverse so with a vacuum cleaner. You create an area of low pressure and it pulls the air and the dirt through a filter with tag Sam and we actually bring our own air because the asteroid is an airless body and we blow it down into the regular or the soil on the asteroid creating region of high pressure Asher underneath a filter and then it grabs the gravel and rocky material and pushes it up into an air filter. The TAG SAM is designed to pick up a minimum of one hundred fifty fifty grams of material and its capacity is over two kilograms. One hundred and fifty grams is like a `Grande starbucks Coffee Cup. The samples styris. Rex will bring to Earth will reveal more about Banu and they could help us better understand the history of our solar system asteroids or leftovers from all the material swirled around our young son and came together to form the planets so we're really interested in the earliest stages of solar system formation. And there's no geologic nick record of that period on the Earth or on the moon or on Mars if you want to understand how planets formed then you need to go back to the small bodies the asteroids and comets.