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Time to catch a space rock
THIS WEEK
Time to catch a space rock The Hayabusa 2 probe will reveal asteroid mysteries, says Leah Crane
JAXA,ET AL.
6 | NewScientist | 30 June 2018
Back and forth Hayabusa 2 is at the end of its journey to asteroid Ryugu 2000
Distance from asteroid (km)
“Using an impactor and observing the explosion as it strikes the asteroid is going to tell us a lot – way more than we currently know – about the internal structure of these objects,” says Daniella DellaGiustina at the University of Arizona. “It’s a little bit cowboy, but it’s really cool.” The spacecraft will start heading home at the end of 2019. Ryugu’s close orbit makes sample return particularly easy: it swings from just within Earth’s orbit to just beyond Mars’s orbit . The dust samples will be only the second lot retrieved from an asteroid. But the first Hayabusa mission, which returned in 2010, managed to grab only a few micrograms. NASA also has a sampling mission, OSIRIS-REx, which is due to arrive at asteroid Bennu in August. These efforts are the first baby steps in what could eventually become a full-blown asteroid-mining industry. Hayabusa 2’s first detailed pictures of Ryugu (left) showed an angular rock with a ridge circling its equator – an unusual shape that may make it harder to land. There is a large boulder or cliff about 150 metres across sitting at the top of the image, as well as other apparent clusters of rocks settled on Ryugu’s surface. It is riddled with small depressions that might be craters from collisions with other space rocks. “Comets and asteroids are the dinosaur bones of the solar system. They were here first,” says Carey Lisse at Johns Hopkins University in Maryland. Asteroids splintered off larger rocks that were the building blocks of planets in the early solar system. Studying asteroids like Ryugu can tell us what those building blocks were made of, which may help us
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0 The enlarged view below shows the zigzagging path the probe has taken to ensure it reaches its tiny target 250
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200 Distance from asteroid (km)
AFTER a journey of three-and-aThe spacecraft will later drop off half years, Japan’s Hayabusa 2 one big lander and three smaller spacecraft is sidling up to its ones on the surface to study the destination, a small asteroid asteroid’s composition, geology called Ryugu. Its mission: to bring and temperature. some space dust back to Earth. Hayabusa 2 will make The approach is tricky, says numerous observations from Elizabeth Tasker of the Japan orbit. And, after deploying the Aerospace Exploration Agency. landers, it will itself touch down Ryugu is a relatively small on Ryugu three times to collect asteroid, less than a kilometre samples in 2018 and 2019. across, so it is hard to pin down It will also collect samples by its exact location at any one time. shooting a bullet at the surface “A tiny mistake can mean you miss the target entirely,” she says. “The distances are equivalent to trying to “The distances are equivalent to trying to hit a 6-centimetre target hit a 6-centimetre target in Brazil from Japan” in Brazil from Japan.” Because of that, Hayabusa 2 is zigzagging towards Ryugu instead and then collecting the dust thrown up afterwards. of heading straight for it. That To collect deeper samples, the allows the probe to repeatedly spacecraft will use an even more measure the asteroid’s position violent procedure. It is carrying with respect to background stars. a 2.5-kilogram projectile loaded Assuming everything goes to with high explosives that will plan, in August, Hayabusa 2 will blast into Ryugu at 2 kilometres descend to just 1 kilometre above per second. Hayabusa 2 will then Ryugu to measure its gravity. collect fresh dust, previously Ryugu, as pictured from unexposed to space, by the spacecraft on 24 June descending to the resulting crater.
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determine how certain materials – such as water, and the first ingredients for life – came to be on Earth and other planets. “This means that we are analysing a snapshot of our own past,” says Tasker. “If we find water and organics that are similar to those on Earth, it will be evidence that space rocks like Ryugu are how we all began.” ■
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Time to catch a space rock The Hayabusa 2 probe will reveal asteroid mysteries, says Leah Crane
JAXA,ET AL.
6 | NewScientist | 30 June 2018
Back and forth Hayabusa 2 is at the end of its journey to asteroid Ryugu 2000
Distance from asteroid (km)
“Using an impactor and observing the explosion as it strikes the asteroid is going to tell us a lot – way more than we currently know – about the internal structure of these objects,” says Daniella DellaGiustina at the University of Arizona. “It’s a little bit cowboy, but it’s really cool.” The spacecraft will start heading home at the end of 2019. Ryugu’s close orbit makes sample return particularly easy: it swings from just within Earth’s orbit to just beyond Mars’s orbit . The dust samples will be only the second lot retrieved from an asteroid. But the first Hayabusa mission, which returned in 2010, managed to grab only a few micrograms. NASA also has a sampling mission, OSIRIS-REx, which is due to arrive at asteroid Bennu in August. These efforts are the first baby steps in what could eventually become a full-blown asteroid-mining industry. Hayabusa 2’s first detailed pictures of Ryugu (left) showed an angular rock with a ridge circling its equator – an unusual shape that may make it harder to land. There is a large boulder or cliff about 150 metres across sitting at the top of the image, as well as other apparent clusters of rocks settled on Ryugu’s surface. It is riddled with small depressions that might be craters from collisions with other space rocks. “Comets and asteroids are the dinosaur bones of the solar system. They were here first,” says Carey Lisse at Johns Hopkins University in Maryland. Asteroids splintered off larger rocks that were the building blocks of planets in the early solar system. Studying asteroids like Ryugu can tell us what those building blocks were made of, which may help us
8 June
1500 11 June
1000 14 June
500
16 June
0 The enlarged view below shows the zigzagging path the probe has taken to ensure it reaches its tiny target 250
18 June
200 Distance from asteroid (km)
AFTER a journey of three-and-aThe spacecraft will later drop off half years, Japan’s Hayabusa 2 one big lander and three smaller spacecraft is sidling up to its ones on the surface to study the destination, a small asteroid asteroid’s composition, geology called Ryugu. Its mission: to bring and temperature. some space dust back to Earth. Hayabusa 2 will make The approach is tricky, says numerous observations from Elizabeth Tasker of the Japan orbit. And, after deploying the Aerospace Exploration Agency. landers, it will itself touch down Ryugu is a relatively small on Ryugu three times to collect asteroid, less than a kilometre samples in 2018 and 2019. across, so it is hard to pin down It will also collect samples by its exact location at any one time. shooting a bullet at the surface “A tiny mistake can mean you miss the target entirely,” she says. “The distances are equivalent to trying to “The distances are equivalent to trying to hit a 6-centimetre target hit a 6-centimetre target in Brazil from Japan” in Brazil from Japan.” Because of that, Hayabusa 2 is zigzagging towards Ryugu instead and then collecting the dust thrown up afterwards. of heading straight for it. That To collect deeper samples, the allows the probe to repeatedly spacecraft will use an even more measure the asteroid’s position violent procedure. It is carrying with respect to background stars. a 2.5-kilogram projectile loaded Assuming everything goes to with high explosives that will plan, in August, Hayabusa 2 will blast into Ryugu at 2 kilometres descend to just 1 kilometre above per second. Hayabusa 2 will then Ryugu to measure its gravity. collect fresh dust, previously Ryugu, as pictured from unexposed to space, by the spacecraft on 24 June descending to the resulting crater.
150
100
50
0
20 June
22 June 24 June 26 June 27 June
determine how certain materials – such as water, and the first ingredients for life – came to be on Earth and other planets. “This means that we are analysing a snapshot of our own past,” says Tasker. “If we find water and organics that are similar to those on Earth, it will be evidence that space rocks like Ryugu are how we all began.” ■
COPY SUB PAGE SUB