More than 75 percent of known asteroids are carbonaceous, or carbon-rich. Also known as C-type asteroids, these objects inhabit the outer regions of our solar system's main asteroid belt, located between the orbits of Mars and Jupiter.
Aside from being the most common asteroid type out there — another 17 percent of the bodies in the belt are silicaceous, or S-type asteroids, whereas most of the remaining space rocks are metallic, or M-type, according to NASA — C-type asteroids are relics of the early solar system.
These ancient bodies navigating the asteroid belt were forged about 4.5 billion years ago and are leftover material from when our planets were first churned out. This makes C-type asteroids particularly interesting to science, given that they hide a treasure-trove of information about the early solar system, notes CNN.
Two nations are currently going neck to neck in the race of landing on a near-Earth carbonaceous asteroid and retrieving samples for later studies.
On the one hand, the Japan Aerospace Exploration Agency (JAXA) has set its sights on a 3,000-foot-wide asteroid dubbed 162173 Ryugu, located about 180 million miles from Earth. As the Inquisitr recently reported, Japan's Hayabusa-2 mission has already reached the asteroid's orbit on June 27 and is gearing up to land a series of spacecraft on its surface starting next month.On the other hand, NASA is in the midst of its own sample-return mission, targeting a substantially smaller C-type asteroid — the 1,640-foot-wide space rock known as 101955 Bennu. Sitting three times as close to our planet as Ryugu, Bennu is found 54 million miles away and will soon be visited by NASA's OSIRIS-REx mission, due to rendezvous with the space rock on December 3, the Inquisitr previously reported.
JAXA And NASA Asteroid Landing Schedule
Since Japan's Hayabusa-2 mission has already completed its 3.5-year journey to asteroid Ryugu, the spacecraft will be spending the next 16 months studying the space rock from orbit. The mission will also be deploying on the asteroid's surface three MINERVA-II rovers on September 20 and 21, a German-French operated MASCOT lander on October 3, and the Hayabusa-2 spacecraft itself in late October.
The Japanese mission is scheduled to grab soil and rock samples by the end of 2019 and return with the precious cargo in December 2020.
Meanwhile, NASA's OSIRIS-REx spacecraft still has about 1.2 million miles to cover until reaching Bennu. The space probe has been chasing Bennu since 2016. Come December, OSIRIS-REx will begin its two-year study mission from the asteroid's orbit and eventually swoop down to snag an asteroid sample in early July 2020.
If successful, OSIRIS-REx will be heading back home in March 2021 and is slated to parachute down the sample in the Utah desert on September 24.If the current schedule stands true, Japan has a good chance of beating NASA to the punch and becoming the first one to retrieve a sample from a carbonaceous asteroid. Provided everything goes as planned, Hayabusa-2 will be the "world's first sample return mission to a C-type asteroid," JAXA noted in the mission description.
Ryugu And Bennu
In 2010, the Japanese space agency successfully retrieved a sample from an S-type asteroid called 25143 Itokawa, which was visited in 2005 by the current mission's precursor, Hayabusa, as reported by the Inquisitr.
"By exploring a C-type asteroid, which is rich in water and organic materials, we will clarify interactions between the building blocks of Earth and the evolution of its oceans and life, thereby developing solar system science," JAXA officials said in a statement.
At the same time, NASA is hoping that the OSIRIS-REx mission will help us learn more about asteroids in general and tell us how to keep them at bay. The U.S. space agency is particularly interested in Bennu's composition and is looking forward to finding out whether this asteroid contains water.Astronomers have long thought that the Earth's water may have come from carbon-rich asteroids, transferred though multiple collisions with carbonaceous space rocks. In fact, a recent experiment testing this theory proved that the scenario is by no means far-fetched, the Inquisitr reported earlier this year.
"Analyzing a sample from Bennu will help planetary scientists better understand the role asteroids may have played in delivering life-forming compounds to Earth," NASA stated last week.