Comet 3I/ATLAS To Brush Past Earth Soon: How Was It Discovered And Is It A Threat?
Comet 3I/ATLAS: While the comet poses no threat to the Earth, its uniquely positioned trajectory and origin have caught the attention of scientists.
US space agency NASA is studying a rare comet known as 3I/ATLAS, as it passes through our solar system. It is only the third known object from beyond our solar system to visit us.
Astronomers call it interstellar because its orbit is hyperbolic, which means it does not orbit the Sun in a closed path. While the comet poses no threat to Earth, its uniquely positioned trajectory and origin have caught the attention of scientists.
Discovered on July 1, this comet "won’t come closer than 1.8 astronomical units (about 170 million miles, or 270 million kilometres) to our planet," according to NASA. The US space agency added that on Oct. 30, it will be closest to the Sun at about 1.4 astronomical units, or 130 million miles (210 million kilometres), just inside Mars' orbit. As per multiple media reports, the comet will make its closest approch to Earth on Oct. 29.
How Was Comet 3I/ATLAS Discovered?
According to NASA, Comet 3I/ATLAS formed in another star system and was ejected into interstellar space, the region between stars. It drifted for millions or even billions of years before arriving in our solar system.
The comet has been approaching from the direction of the constellation Sagittarius, near the Milky Way’s centre. When discovered, 3I/ATLAS was about 410 million miles (670 million km) from the Sun, within Jupiter’s orbit.
"The NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile, first reported observations to the Minor Planet Center of comet 3I/ATLAS on July 1. Since the first report, observations made before the discovery were gathered from the archives of three different ATLAS telescopes around the world and Caltech’s Zwicky Transient Facility at the Palomar Observatory in San Diego County, California," the US space agency said.
How Comet 3I/ATLAS Got Its Name?
According to NASA, the comet 3I/ATLAS is named after its discoverers, the ATLAS survey team. The "I" stands for “interstellar,” showing it came from outside our solar system. It is the third known interstellar object, which is why the number "3" appears in its name.
Comet 3I/ATLAS Features
Astronomers around the world are studying the size and properties of 3I/ATLAS. According to NASA, existing observations show that the nucleus of the comet is no bigger than 5.6 km. The comet is active and has an icy nucleus. It also has a coma, a bright cloud of gas and dust that forms as it nears the Sun. This is why astronomers classify it as a comet rather than an asteroid.
When discovered, 3I/ATLAS was travelling about 137,000 miles per hour (221,000 km per hour or 61 km per second). NASA said its speed will continue to increase as it approaches the Sun.
