Space rocks could have made life on Earth possible, in line with a breakthrough latest study that checked out a near-Earth asteroid.
Asteroids and comets are time capsules, nuggets of materials saved within the deep freeze of distant space for the reason that earliest days of our Solar System, and so to planetary scientists, represent a precious and unique window to a past that eventually led to all life on Earth.
Scientists can learn quite a bit from these time capsules using telescopes and other instruments to check them from afar, but the true treasure can only be dug up through literal digging — sending a sample return mission to an asteroid, digging into it, and returning to Earth with the products. And that’s just what the Japanese Space Agency’s Hayabusa 2 mission achieved by returning 5.4 grams of the near Earth asteroid Ryugu to Earth in December.
In a paper published Thursday within the Proceedings of the Japan Academy, a world team led by researchers at Hokkaido University and the Tokyo Institute of Technology detail their findings from evaluation of the insides of the samples returned from asteroid Ryugu. They not only found evidence that Ryugu likely formed as a part of a much larger icy body at the sting of the infant Solar System, but that it incorporates water and amino acids, suggesting similar asteroids could have supplied the young Earth the materials essential for all times.
The Hayabusa 2 mission launched in 2014 and reached Ryugu in 2018, where it then sampled each surface and subsurface materials. Hayabusa 2 then swung by Earth and dropped the sampled materials to scientists waiting below. Early impressions confirmed what scientists largely already knew, that Ryugu was a C-type, or carbonaceous asteroid, very dark in color and thus difficult to check from afar.
Within the time sense the samples were first returned, researchers have cut into them using a diamond blade, and inside researchers found a group of minerals embedded in clay, suggesting the asteroid had undergone a period of freezing and thawing that peaked just 2.6 million years after the formation of the Solar System.
The researchers now imagine 1 kilometer-diameter Ryugu was once a part of a much larger planetesimal tens of kilometers in size. Large enough that radioactive elements would have melted ice inside the planetesimal, creating the matrix of minerals and clay observed within the samples, before the water refroze as a lot of the radioactive elements decayed over 5 million years.
It’s theorized that comets result from collisions between icy planetesimals on the outer reached of the Solar System, and that Ryugu experiences an analogous origin, eventually making its technique to the inner solar system, much of its surface ice sublimating — shifting from a solid phase to a gaseous phase in a single step — which could have set the asteroid spinning and given it the “spinning top” shape observed today.
Scientists imagine asteroids product of material much like Ryugu would have been common across the early Earth, which has profound implications for all times as we realize it.
The brand new research has confirmed the existence of amino acids on Ryugu, the organic constructing blocks of life forming entirely in space, a process scientists theorized took place, but could never confirm on the premise of meteorite samples since such space rocks had already passed through Earth’s atmosphere and may very well be contaminated.
Ryugu and particularly Ryugu like space rocks within the early Solar System would even have contained loads of water.
Getting those two ingredients, amino acids and water, to the surface of the Earth was an important step in life’s history, humanity’s history, and the Ryugu samples suggest theories that asteroids and comets provide each materials to the primitive Earth are on the best track.
Hayabusa 2 will not be the the primary time Jaxa has returned samples from an asteroid. The Hayabusa 1 mission returned samples from asteroid Itokawa in 2005, but those samples amounted to simply just a few micrograms of dust.
Hayabusa 2 can be not the last sample return mission.
Nasa’s Osiris-Rex mission will return samples from asteroid Bennu, a B-type asteroid with a composition very different to Ryugu’s, providing researchers with a beneficial contrast. Nasa also plans to return samples taken from the surface of Mars by the Perseverance rover to Earth sometime within the early 2030s.
Taken together, such sample return missions represent a latest phase in planetary science and astrobiology research, one where scientists are finally in a position to not only look, but to the touch.