A comet known as 3I/Atlas, an interstellar object speeding through our solar system, has sparked significant excitement among scientists. First detected in July 2023, this celestial body is currently traveling at an impressive speed of approximately 61 km (38 miles) per second towards the sun. It is only the third confirmed interstellar object observed, following ‘Oumuamua in 2017 and 2I/Borisov in 2019.
What Is 3I/Atlas?
The name 3I/Atlas reflects its classification as the third interstellar object discovered, with the “i” denoting its interstellar origin. The object was identified by the Asteroid Terrestrial-impact Last Alert System (ATLAS) network of telescopes. Despite some speculation regarding its nature, experts believe that 3I/Atlas is most likely a comet.
“We’ve never had an object like this to study before,” said Dr. Rebecca Allen, co-director of Swinburne’s Space Technology and Industry Institute. Dr. Laura Driessen, a radio astronomer at the University of Sydney, confirmed that while the exact origins of the object remain unknown, it indisputably comes from outside our solar system.
Dr. Driessen dismissed concerns about extraterrestrial life, stating, “There’s no evidence to point towards [3I/Atlas] being anything other than a really fun space rock that came from outside the solar system.”
Scientific Significance and Observations
The Hubble Space Telescope recently captured images of 3I/Atlas, revealing a hazy, snowball-like appearance attributed to its coma. As the comet approaches the sun, its surface heats up, releasing dust and gas, which contribute to its distinctive look. Scientists anticipate that its chemical composition will become clearer as it draws nearer to our star.
“We can use a tool called spectroscopy, and we can use light to actually understand exactly what that material is,” said Allen. She noted that this could help determine whether the comet originated in a solar system with conditions similar to our own or if it is entirely unique. Current estimates suggest that the diameter of 3I/Atlas is less than 5.6 km, possibly as small as 320 metres.
In terms of trajectory, 3I/Atlas is traveling at speeds exceeding 200,000 km/h. Following its passage through the inner solar system, it is expected to make its closest approach to the sun between October and December 2023, coming within approximately 210 million kilometres of the sun. After this close encounter, it will continue on its hyperbolic path, not bound by the sun’s gravity.
Future Visibility and Impact
As 3I/Atlas draws closer to the sun, it is predicted to brighten, potentially becoming visible to large amateur telescopes. However, astronomer Con Stoitsis from the Astronomical Society of Victoria cautioned that even then, it may only appear as a smudge in the sky. He indicated that while bright comets are seen several times a year, 3I/Atlas is unlikely to be among them without a substantial telescope.
The closest approach to Earth will be about 270 million kilometres, with its exact future path remaining uncertain until it moves around the sun and out towards the outer solar system.
In summary, the study of 3I/Atlas presents an invaluable opportunity for scientists to learn more about interstellar objects and the conditions from which they originate. As it speeds through our solar system, researchers eagerly await its upcoming encounters and the insights they may gain from this extraordinary visitor.
