Dust found on asteroid Ryugu is older than our solar system
The asteroid Ryugu is located about 300 million kilometers from Earth. It completes an orbit around the Sun every 16 months, and many believe an asteroid like this helped fuel the origin of water on Earth. Now, an international team of researchers studying dust particles collected at Ryugu believe they have discovered presolar stardust – space dust that existed before our solar system was formed.
Ryugu has dust older than our solar system
The evidence was collected by the Hayabusa-2 space probe during a mission that began in 2014. Now that Hayabusa-2 has brought the samples back to Earth, we are finally learning more about this asteroid and the presolar stardust. who inhabits it. Ryugu, like many other asteroids, is composed of gravel-like substances believed to come from other asteroids.
The asteroid itself is massive and scientists believe it originated beyond the limits of our solar system. Now, the presence of this dust that predates the formation of our solar system could yet extend to Ryugu’s origin – or at least when.
Ever since the asteroid probe sent its samples back to Earth, scientists around the world have been digging into the samples. A group of researchers wanted to determine the age of the samples. They published their findings in Letters from the Astrophysical Journal. They note that the samples seem to come from different stellar processes. However, this presolar stardust alone has attracted quite a bit of attention.
Ryugu isn’t the only celestial object we’ve found with substances that predate our solar system. About five percent of meteorites found on Earth harbor dust grains that predate it. We have dated some of them up to 7 billion years old. The grains of this dust from Ryugu contained the same identifiers as those of meteorites that predate our solar system.
As such, it seems likely that there are other particles on Ryugu that predate the solar system. It is possible that presolar stardust could make up much of the asteroid. Because it’s so far away and sample collection missions take so long, it’s hard to determine an exact composition. Researchers have also found evidence of a brittle silicate within Ryugu. Something must have shielded him from the sun’s harmful rays.
Perhaps future missions to Ryugu and other similar asteroids will provide more valuable information about presolar stardust. And, with a bit of luck and a ton of research, we might even learn more about the universe before our solar system was formed.