Space is beautiful, fascinating, a treasure of information and infinite imaginations. Recall as a young kid, looking at the sky, counting the stars and occasionally if you are lucky to get to witness the falling star (meteor falling), gaze at the starts and get drowned in infinite imaginations. The thought would pass our minds, can we understand the secrets of Space better?
Space is home to millions of galaxies inhabited by countless celestial objects with only a few of these have been discovered. Many questions, how the universe is formed, how did earth and other planets have its origin in.
Astronomers still have different opinions about the origin of the universe. Asteroids are small, rocky objects and leftover from the formation of our solar system. Although asteroids orbit the sun like planets, they are much smaller than planets. Researchers believe that celestial objects like as asteroids, meteoroids, comets have hidden secrets which can help to solve the mysteries of the universe. Most asteroids are made of different kinds of rocks, but some have clays or metals, such as nickel and iron.
In 1801, while making a star map, Italian priest and astronomer Giuseppe Piazzi accidentally discovered the first and largest asteroid, Ceres, orbiting between Mars and Jupiter. With the diameter of 940 kilometres, Ceres is believed to be the largest object in the main asteroid belt.
Some of these objects come close to Earth’s orbit, which makes them prone to the collision, such objects are called Near-Earth Objects. The Earth’s largest asteroid incident known as “Tunguska asteroid event in Siberia” on 30 June 1908 lead the UN General Assembly in adopting the resolution on making, 30 June as International Asteroid Day with the aims to raise public awareness about the asteroid and its impacts.
There are lots of asteroids in the solar system and positioned in the main asteroid belt – a region between the orbits of Mars and Jupiter. Our solar system has millions of asteroids present and the vast majority (1.1 and 1.9 million asteroids larger than one kilometer in diameter and millions of smaller ones) found in the main asteroid belt – a region between the orbits of Mars and Jupiter. Due to the powerful gravity of the Jupiter, some small asteroids move out from the orbit and move towards other planets in which some of the asteroids collide with each other or with other planets and make the new form of a celestial object. Some asteroids are also found in the orbital path of planets and follow the same path around the sun and Earth too has some asteroids like this. Because asteroids formed in different locations at different distances from the sun, no two asteroids are alike.
Most asteroids are normally at least 1.8 million miles away from Earth when they pass. Asteroids whiz through space and past the Earth regularly. In a rare instance, in 2019, two asteroids (asteroid2019 QS, 2019 OU1) passed by Earth at unusually close distances and only hours apart. Astronomers keep an eye on anything that comes within 4.6 million miles of Earth and could be “potentially hazardous.”
When space objects fly this close to our planet, even the smallest external or internal factors could change their trajectory, potentially leading to a collision with our planet. Due to the Yarkovsky effect, makes the sunlight pushing an asteroid in a different direction and changing the way it rotates. A gravitational keyhole, gravity from other objects or planets in space, is another factor that could cause asteroids to change direction. Astronomers are discovering new NEOs at a rate of about 30 each week.
Asteroids can be one of the objects which can help to unlock the mystery of the universe since asteroids were formed at the same time as other objects in our solar system. Researchers also learn about asteroids by studying meteorites.
Japan Aerospace Exploration Agency (JAXA) has landed two hopping robots onto asteroid Ryugu, making Japan the first country in the world to land rovers on an asteroid. Japan’s space agency also conducted experiments by successfully dropped an explosive to create a crater on the asteroid. Hope to gather the samples to bring back to earth. Several NASA Space missions have flown by and observed asteroids. Asteroid Bennu discovered in 1999 is a small near-earth asteroid that passes close to the earth about every six years. OSIRIS-REx spacecraft studied Bennu and collect a sample of the asteroid.
Research work of scientists from India pointed out the possibility of southern peninsular India hit by an asteroid larger than the one that wiped out dinosaurs (some 65 million years ago) an asteroid struck 800-550 million years ago.
SPACE group is providing an opportunity to astronomy enthusiasts (including school children) from across India. Through the training provided by SPACE to Indian students led to the discovery of two Asteroids, many Provisional Discoveries of Asteroids and Near-Earth Object Observations.
In April 2020, Asteroid (52768) 1998 OR2, passed relatively close to Earth though at a safe distance at some 6 million kilometres.
Let us celebrate “World Asteroid Day”…
And Continue research and observations to unravel the mysteries of the universe.
Toons: Reema Jaiswal
Logs: Kartikay Shukla and Sai Baba