April 8, 2019– Mary Greeley News – The Japanese Hayabusa-2 spacecraft is thought to have detonated an explosive charge on the asteroid it is exploring.
The idea was to create an artificial crater on the object known as Ryugu.
The Japan Aerospace Exploration Agency, or JAXA, said Hayabusa2 dropped a small explosive box which sent a copper ball the size of a baseball slamming into the asteroid, and that data confirmed the spacecraft had safely evacuated and remained intact.
JAXA later confirmed the impact from images transmitted from a camera left behind by the spacecraft which showed the Small Carry-on Impactor (SCI) being released and fine particles later spraying dozens of yards out from a spot on the asteroid.
Scientists believe these samples could help them better understand how Earth and the other planets were formed in the early Solar System.
The explosive device, called the Small Carry-on Impactor (SCI), was released from Hayabusa-2 on Friday. The SCI, a 14kg conical container, was packed with plastic explosive intended to punch a 10m-wide hole in the asteroid.
Because of the debris that would have been thrown up in this event, Hayabusa-2 maneuvered itself before the detonation to the far side of 800m-wide Ryugu – out of harm’s way and out of sight.
But the probe left a small camera behind called DCAM3 to observe the explosion. Images returned to Earth later Friday appeared to show a spray of debris emerging from the limb of the asteroid, indicating the experiment to excavate a crater very probably worked.
Hayabusa-2 will, in a few weeks, return to the crater to try to collect its pristine samples. Because they will come from within the asteroid, they will not have been exposed to the harsh environment of space.
Bombardment with cosmic radiation over the eons is thought to alter the surfaces of these planetary building blocks. So, scientists want to get at a fresh sample that hasn’t been changed by this process.
Ryugu belongs to a particularly primitive type of space rock known as a C-type asteroid. It’s a relic left over from the early days of our Solar System, and therefore records the conditions and chemistry of that time – some 4.5 billion years ago.
Launched on Dec. 3, 2014, Hayabusa2 arrived at Ryugu on June 27, 2018, when the asteroid was almost 170 million miles from Earth. The spacecraft traveled almost 2 billion miles to reach the space rock.
The asteroid, named Ryugu after an undersea palace in a Japanese folktale, is currently about 180 million miles from Earth.
162173 Ryugu, provisional designation 1999 JU3, is a near-Earth object and a potentially hazardous asteroid of the Apollo group. It measures approximately 1 kilometer (0.6 mi) in diameter and is a dark object of the rare spectral type Cg, with qualities of both a C-type asteroid and a G-type asteroid. In June 2018, a spacecraft, Hayabusa2, arrived at the asteroid.
Ryugu orbits the Sun at a distance of 0.96–1.41 au once every 16 months.
It has a minimum orbital intersection distance with Earth of 95,400 km (0.000638 au), which translates into 0.23 lunar distance.
The mass of Ryugu is estimated at about 450 million tons.
Stunning images taken by the rovers revealed the surface of the “dumpling-shaped” asteroid, which has a diameter of just 2,953 feet.
Hayabusa2 is expected to leave Ryugu at the end of 2019 and return to Earth around the end of 2020.
The spacecraft is the successor of JAXA’s Hayabusa, which landed on asteroid Itokawa in November 2005. Despite being dogged with problems, the mission collected a number of asteroid samples, which returned to Earth with Hayabusa in June 2010.
NASA is also conducting amazing asteroid research. The space agency’s OSIRIS-REx spacecraft reached asteroid Bennu on Dec. 3, 2018, after traveling more than 1 billion miles through space.
About a third of a mile, or half a kilometer, wide, Bennu is large enough to reach Earth’s surface; many smaller space objects, in contrast, burn up in our atmosphere.
If it impacted Earth, Bennu would cause widespread damage. Asteroid experts at the Center for Near-Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory in Pasadena, California, project that Bennu will come close enough to Earth over the next century to pose a 1 in 2,700 chance of impacting it between 2175 and 2196.
Given these parameters, astronomers can predict the next four exact dates (in September of 2054, 2060, 2080 and 2135) that Bennu will come within 5 million miles (7.5 million kilometers or .05 astronomical units) of Earth. That’s close enough that Earth’s gravity will slightly bend Bennu’s orbital path as it passes by. As a result, the uncertainty about where the asteroid will be each time it loops back around the Sun will grow, causing predictions about Bennu’s future orbit to become increasingly hazy after 2060.
The asteroid may provide answers to the origin of our solar system, according to NASA.
OSIRIS-REx, which stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, launched in September 2016 from Cape Canaveral Air Force Station.
The spacecraft is now surveying the space rock from orbit, recently helping scientists identify water locked inside the asteroid’s clay. The probe is scheduled to briefly touch the asteroid with a robotic arm in July 2020 and retrieve a sample that will be returned to Earth in September 2023.
credit: In part with https://www.bbc.com/news/science-environment-47818460