Scientists Excited as Comet 3I/Atlas Approaches the Sun

A comet from beyond our solar system, known as 3I/Atlas, is making its way toward the sun at a staggering speed of approximately 61 kilometers (38 miles) per second. First detected in July 2023, this celestial visitor is only the third confirmed interstellar object observed, following ‘Oumuamua in 2017 and 2I/Borisov in 2019. The excitement among scientists has surged since the Hubble Space Telescope captured a detailed image of the comet, providing a unique opportunity to analyze its composition and characteristics.

Understanding 3I/Atlas’s Origins

Researchers are eager to uncover the mysteries surrounding 3I/Atlas. According to Dr. Laura Driessen, a radio astronomer at the University of Sydney, while the exact origin of the comet remains unknown, it is confirmed to have come from outside the solar system. The name 3I/Atlas signifies its interstellar nature, with “i” standing for interstellar, “3” indicating it is the third such object detected, and Atlas referring to the network of telescopes that identified it, known as the Asteroid Terrestrial-impact Last Alert System.

Some speculation has arisen regarding potential extraterrestrial origins, similar to discussions surrounding ‘Oumuamua. However, scientific consensus leans towards the idea that 3I/Atlas is likely a comet rather than an alien artifact. “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,” Driessen stated. “Which, to be honest, is cool enough.”

Scientific Opportunities with 3I/Atlas

The image captured by Hubble reveals that 3I/Atlas resembles a “fuzzy snowball,” according to Dr. Rebecca Allen, co-director of the Swinburne Space Technology and Industry Institute. This hazy appearance is attributed to its “coma,” formed as the comet’s surface heats up from the sun, releasing dust and gas. There are also indications of a comet tail, which will become more pronounced as it approaches the sun.

The chemical signatures released by 3I/Atlas will provide key insights into its composition. “We can use a tool called spectroscopy, and we can use light to actually understand exactly what that material is,” Allen explained. “Does this comet represent a solar system that had conditions similar to our own, or is it something completely different?” Researchers have estimated the diameter of 3I/Atlas to be less than 5.6 kilometers, potentially as small as 320 meters.

As the comet speeds through space, it is expected to travel at over 200,000 kilometers per hour. Allen noted that 3I/Atlas is on a hyperbolic orbit, meaning it is not gravitationally bound to the sun. It will traverse the inner solar system, passing between the orbits of Mars and Earth before continuing its journey out of the solar system.

The closest approach to the sun is anticipated to occur between October and December 2023, when 3I/Atlas will come within approximately 210 million kilometers of the sun. NASA reports that its closest point to Earth will be about 270 million kilometers. “We’re not really sure where it’s going to end up until it comes around from the other side of the sun and starts heading out to the outer solar system again,” Stoitsis remarked.

While visibility of 3I/Atlas is currently limited, it is expected to brighten as it nears the sun, potentially becoming observable through larger amateur telescopes. Nevertheless, the comet may still appear as a faint smudge. “We get bright-ish comets three or four times a year that are visible with small telescopes and binoculars. This is definitely not one of those,” Stoitsis cautioned. “Unless you’ve got a decent-sized telescope, you won’t see it.”

The journey of 3I/Atlas presents an exciting opportunity for astronomers and enthusiasts alike, as it offers a glimpse into the characteristics of celestial bodies from beyond our solar system.