Asteroids, which threaten the Earth with the possibility of colliding, open new doors to the mysteries of space with the information they provide about the formation and structure of the planets and the Solar System.
“World Asteroid Day”, which is celebrated with events on June 30 every year in order to raise awareness of the asteroid danger to the Earth and to keep scientific interest alive in asteroids, focuses on asteroid research projects in addition to studies to develop planetary defense against asteroids in 2021.
This year, the events will celebrate the 25th anniversary of the US Aerospace Agency’s (NASA) Near-Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft, named after US planetary scientist Eugene Shoemaker, in 1996, sending it to the near-Earth asteroid Eros.
In addition, informative events will be held about the Trojan asteroids research mission Lucy and the Near Earth Asteroid Scan (NEA Scout) mission, which NASA will send into space this year, and the Asteroid Binary Redirect Test (DART), which will be a first in history.
“Rogue mines” thrown into space
Asteroids are defined as celestial bodies formed by the merging of materials left over from the formation of planets and moons into large clumps of smaller meteorites, but smaller than meteorites.
Most of the asteroids in the Solar System are located in the Asteroid Belt between Jupiter and Mars. However, some of them can leave the orbit and be thrown into the inner parts of the Solar System and even enter the Earth’s orbit.
Scientists draw attention to the importance of closely monitoring and understanding the near-Earth asteroids against the possibility of collision that could cause great damage to life on Earth and the natural environment, as in the event that led to the extinction of dinosaurs in the past.
How to deal with asteroids?
English astronomer Edmund Halley called an emergency meeting of the Royal Scientific Society in December 1694. In the secret meeting, the content of which was decided not to be made public, Halley shared his predictions that asteroids could hit the Earth for the first time with members of the society.
By studying the trajectories of comets, Halley noticed that some of them intersect with Earth’s orbit, making collisions likely.
Halley thought that the natural disasters mentioned in the Bible and the Torah may have been caused by asteroids hitting Earth in the past.
An asteroid incident at the beginning of the 20th century revealed what damage even a small-sized asteroid can cause if it hits the Earth.
On June 30, 1908, a small asteroid crashed into Siberia in Tsarist Russia, destroying forested areas equal to the area of a large city.
In the fires that broke out when the asteroid, which fell near the Stony Tuguska River in the Yenisei province, burned to pieces due to the friction in the atmosphere and the rocks that turned into fireballs were scattered, 2,000 kilometers of forested area in the East Siberian taiga was destroyed.
This event inspired the adoption of June 30 as “World Asteroid Day” aimed at raising awareness of the meteor threat.
Awareness of the meteorite threat
The idea of celebrating World Asteroid Day was first suggested by German filmmaker Gregory Richters in 2014.
In his fictional film “51 North Latitude”, Richters, who tells about the global disaster caused by an asteroid hitting the earth, pioneered this issue with astrophysicist Brian May, also known as the guitarist of the British music band Queen.
With the support of US Astronaut Rusty Schweickart, who took part in the Apollo 9 mission, and Danica Remy, the founder of the B612 non-governmental organization, which “aims to protect the future of the planet by using science and technology”, it was decided to celebrate one day a year for informative activities on this subject.
This special day aims to keep scientific interest in asteroids alive, as well as to raise a cool awareness of the asteroid danger to the earth.
This year’s events as part of World Asteroid Day will focus on space missions to probe asteroids, as well as work on developing planetary defenses against asteroids.
How to deal with asteroids: DART and Hera missions
Protecting against a space rock approaching the Earth requires meticulously monitoring the movements of meteorites and intervening when necessary.
As part of the space mission of the US Aerospace Agency (NASA), called the “Asteroid Binary Reorientation Test” (DART), it aims to measurably change its direction by hitting an asteroid with a spacecraft.
The 610-kilogram vehicle, which is planned to be launched on November 24 with a SpaceX production Falcon 9 rocket, is planned to crash into one of the twin Didymos asteroids between Earth and Mars.
The DART spacecraft will try to deflect it by colliding with the smaller asteroid, Didymos b, with a diameter of 170 meters.
A light cube satellite called “LICIACube”, developed by the Italian Space Agency (ISA) to photograph the collision, will accompany the DART spacecraft.
On the other hand, the European Space Agency (ESA) will conduct an impact assessment by sending Juventas and APEX cube satellites to the Didymos b asteroid in 2024 within the scope of its research mission called “Hera”.
Didymos asteroids are known as the closest meteorites to Earth.
Although meteorites are not expected to approach Earth before 100 years, the test will be useful in putting into practice the idea of reorienting asteroids for planetary defense.
What can be learned from asteroids: Hayabusa 2 and OSIRIS-REx missions
On the other hand, asteroids, which contain important clues about the formation of planets and other celestial bodies, are also of interest to science.
Japan is conducting space missions with the “Hayabusa 2” spacecraft to collect rock samples from the “Ryugu” asteroid, and the USA with the “OSIRIS-REx” spacecraft to collect rock samples from the “Bennu” asteroid.
Hayabusa 2 brought samples from the Ryugu asteroid to Earth on December 8, 2020.
Launched into space in 2016, OSIRIS-REx landed on the asteroid Bennu on October 20, 2020. The vehicle, which set off with the samples collected on May 11, is expected to return to Earth in 2023.
Ryugu and Bennu, which are among the Apollo group asteroids in the Asteroid Belt, may offer scientists new insights into the formation of the Solar System and Earth.
Ryugu’s journey, which left the Asteroid Belt and settled in an orbit close to the Sun, then came back to the Asteroid Belt with a centrifugal spin and settled in a near-Earth orbit, contains clues about the motion of asteroids.
Bennu, which is understood to have been shaped in the early formation phase of the Solar System, carries traces of abundant water and carbon molecules on its surface.
Traces pointing to components conducive to the emergence of life could provide scientists with new insights into how a planet like Earth formed.