On the 24th of last month (local time), a small spacecraft capsule landed in the desert of Utah, USA via parachute. It was a capsule dropped to Earth by NASA’s (National Aeronautics and Space Administration) asteroid probe ‘Osiris-Rex’, which left Earth seven years ago. The surface of the capsule was charred black as it endured heat that was twice as hot as volcanic lava as it passed through the Earth’s atmosphere. The capsule contained rock samples collected from the asteroid Bennu, located about 320 million km away from Earth.
This is the third time that an asteroid sample has come to Earth, following the Japan Aerospace Exploration Agency’s (JAXA) probe ‘Hayabusa 1 and 2’ (2010 and 2020). The rock samples that arrived on Earth were immediately transferred to the Johnson Space Center in Houston, USA, and NASA is cataloging all the meteorites and dust in the samples and examining their chemical and mineralogical characteristics. Osiris-Rex principal investigator Dante Loretta said, “Through the 250-gram rock sample, we will find answers to how the Earth became a habitable world and where the organic molecules that make up life on Earth came from.”
◇Asteroid holds the key to the origin of life on Earth
Scientists believe that asteroid rock samples may be the key to unlocking the secrets of the origin of the Earth and the birth of life. This is because the history of planet formation is recorded in asteroid rocks that were formed billions of years ago when planets began to appear in the solar system.
Bennu is believed to have been created in Jupiter’s asteroid belt about 4.6 billion years ago, when the solar system was forming. About 1 billion years ago, when a large asteroid collided with another asteroid, Bennu, the size of the U.S. Empire State Building, was thrown out, and it has been wandering in space to this day. For this reason, scientists believe that rocks formed in the early days of the solar system will be preserved in Bennu like a time capsule. In 2019, a NASA research team predicted that Bennu’s surface rocks would be rich in carbonate through images taken by Osiris-Rex. Carbonates require the presence of liquid water to form. It is said that an asteroid collided with Bennu’s parent body, which was covered with high-temperature water. This supports the hypothesis that organic compounds, including water, were introduced to Earth as a result of an asteroid impact, which later became the source of the birth of life. Kim Joo-hyeon, a senior researcher at the Korea Aerospace Research Institute, said, “As the sun emits numerous hydrogen ions, the hydrogen hits the planet with strong energy, creating water molecules (H2O), or hydrogen is removed from hydrocarbons and they become carbonates, so carbonate minerals indicate the presence of water. “It can be used as evidence to suggest possibility,” he said.
In order to search for organic molecules associated with life in rock samples collected from Benue, it is also important to ensure that the samples are not exposed to the Earth’s environment. This is because when rocks are affected by exposure to the Earth’s environment, it is difficult to distinguish which molecules came from space. The capsule containing the rock samples was made with a special heat sink to withstand heat that is more than twice as hot as magma, and the air coming through the ventilation hole was filtered to prevent the inflow of water vapor and dust during the landing process. NASA said, “There will be no living organisms in the rock samples due to space radiation.”
Graphics = Jinyoung Lee
◇Continued ‘asteroid exploration’
NASA will launch the asteroid probe ‘Psyche’ with SpaceX’s Falcon Heavy rocket from Kennedy Space Center in Florida on October 12. The probe is heading to the asteroid ’16 Psyche’ with a diameter of 220 km in the asteroid belt between Mars and Jupiter. Scientists suspect that 16 Psyche may be part of the inner core of a giant planet. In the early days of the solar system’s formation, a violent collision caused the planet’s outer crust to peel off, leaving the exposed inner core floating around as an asteroid. For this reason, it is expected that 16 Psyche will provide an opportunity to observe the interior of a terrestrial planet.
On the 1st of next month, the asteroid probe ‘Lucy’ is scheduled to pass by the asteroid ‘Dinkinesi’ located between Mars and Jupiter. Launched in October 2021, this is the first asteroid encountered. Lucy plans to explore eight asteroids in the Trojan asteroid group, which orbit the sun near Jupiter. Lucy contains messages from 19 famous people, including Einstein and Carl Sagan, and is designed with the situation in mind that intelligent life forms discover Lucy in space. NASA said, “Because the Trojan asteroid group is the remnants of the early solar system, the asteroids here may hold important clues to decipher the history of the solar system.”
In addition, the United Arab Emirates is carrying out the ‘EMA Project’, which will send a lander to the asteroid ‘Justitia’ between Mars and Jupiter in 2028. After flying close to six asteroids in 2034, it plans to land on the seventh asteroid, Justitia, to study the origin and evolution of the asteroid, which appears to be rich in water.
