I amIn a few days, a capsule containing soil samples from a distant asteroid will be launched by a robotic spacecraft and fall into Earth’s upper atmosphere. If all goes well, the container will safely descend to the Woomera test range in South Australia on December 6, completing a mission that involved a three billion-mile journey across our solar system.
Scientists say the information being returned could help solve several major astronomical mysteries – including the riddle of how water first appeared on our planet.
“Asteroids are the remaining building blocks of the formation of our solar system 4.6 billion years ago, and that makes them very important to science,” said Martin Lee, professor of planetary science at the University of Glasgow. “If you want to know what a planet was made of in the beginning, you need to study asteroids.”
The Japanese probe Hayabusa 2 was launched six years ago and sent on a path to the Ryugu asteroid, which orbits the sun every 16 months at a distance of between 90 million and 131 million miles. For 18 months, she scanned this 1,100-yard nugget before It turns near its surface To collect a little soil. Then the probe released its ion thrusters and began returning to Earth for a year.
Lee and his colleagues will be among the first groups of scientists to study samples of Ryugu soil when they are delivered – although the team won’t have much to work on. “We expect to have a few grains of material, each a few millimeters in diameter,” said geologist Luke Daly, a member of the University of Glasgow team. “However, we won’t really know how much we’ll get until the Hayabusa capsule hits the surface: Quietly, hopefully.”
Analyzing the surface composition of an asteroid from a few patches of soil appears ambitious. Nevertheless, the Glasgow team is confident. They plan to use a device called an atom probe that would allow researchers to identify individual atoms in a sample. Given the sheer numbers of atoms that make up even the smallest samples, this would require counting and analyzing tens of millions of atoms of individuals.
“Basically, we’re going to take a piece of soil and remove its surface with a laser,” he told me. In other words, we’re going to explode their atoms one by one. Then each of these atoms will be measured to determine the identity of this element and its special counterpart.
“We will also be able to reconstruct exactly where the atom is placed in the sample, so we will get a 3D image of the atomic structure of our sample.”
Engineers at Japan’s space agency, Jaxa, are still not sure how much material Hayabusa 2. has collected. Its previous mission, Hayabusa 1 – Hayabusa is the Japanese word for peregrine falcon – in 2005, plagued with engine failure and other technical problems and returned very little material from Its target, Itokawa asteroid.
Hayabusa 2 should return more, although its specimens must survive first when returned to Earth. This will start when the probe launches a capsule carrying soil from Ryugu. Entering the atmosphere at a speed of 27,000 miles per hour, it would sink toward the Earth until, six miles above Australia, it would spread a parachute and slide down the ground.
The samples will then be distributed to scientists around the world. “ Aside from telling us what the early solar system was made of, they will also tell us what happens to rocks when they are bombarded by the solar winds for billions of years – and this has a critical effect in understanding the story Water in the solar system Most importantly, on the ground. “
The solar wind is a stream of protons and other subatomic particles emitted from the sun. Earth’s atmosphere protects us but in space particles fly mercilessly with surfaces that lack this protection. “This bombing may create water on asteroids,” Daly added. “Protons are mainly hydrogen ions and can interact with oxygen in rocks to form water molecules.”
Scientists are divided over the fundamental question of how water first appeared on our planet. Did it come with all the other materials that formed our planet 4.6 billion years ago, or did it come here much later by way of icy comets smashing onto our planet?
Modern space probes – such as the Rosetta mission that visited comet 67P / Churyumov-Gerasimenko between 2014 and 2016 – found water on these objects. However, it is not quite like water on Earth. These extraterrestrial samples contain higher levels of deuterium, an isotope of hydrogen, than is found in water from Earth, and this has led many scientists to conclude that our supplies have been around since the start.
He told me, “However, these ancient comets may not have been the only source of water from elsewhere in the solar system, and that modern reservoirs have been created by solar winds hitting rocks on asteroids.”
“The water created there may contain lower levels of deuterium, and this would explain how our oceans came to contain water with a different isotope signature. Of course, studying the rocks of the asteroid Ryugu, which has been struck by the solar wind for billions of years, may give us the answer.”