CAPE CANAVERAL, Fla. (AP) – A comet that passed by Earth from another star system last year is believed to have come from a remote, frigid region of the galaxy, which had not yet formed its own solar system, astronomers reported on Thursday.
Comet 3I/ATLAS is only the third interstellar object to be confirmed and may be the oldest known.
Scientists estimate its age at up to 11 billion years, more than twice the age of the Sun.
frameborder=”0″ allow=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen>A team from the University of Michigan utilized the ALMA observatory in Chile’s Atacama Desert to study the comet last fall.
This stray but harmless icy body was identified last summer, allowing NASA and the European Space Agency ample time to target it with various space telescopes as it passed by Mars in October, making its nearest approach to Earth in December.
It is now beyond Jupiter, leaving our Solar System for good, and remains visible only to professionals.
The study revealed that scientists found unusually high levels of deuterium, or heavy hydrogen, in the water of comet 3I/ATLAS.
This suggests the comet originated in a much colder environment than our own cosmic neighborhood, before the star of this solar system even formed, according to Teresa Paneque-Carreno from the University of Michigan.
She explained that while our Sun may have developed alongside other newborn stars, this comet’s originating star might have been more isolated, resulting in cooler conditions.
The exact origin of the comet remains unknown.
Hubble Space Telescope observations estimate the size of its nucleus to be between a quarter-mile and 3.5 miles (440 meters and 5.6 kilometers).
Comet 3I/ATLAS is moving away at a speed of 137,000 mph (220,000 kph).
Paneque-Carreno noted in an email that piecing together these findings could provide insights into the conditions for planet formation in the early universe.
Related: A Giant Telescope Searched 3I/ATLAS For Signs of Aliens. Here’s Why.
The first interstellar object detected in our vicinity, Oumuamua, was discovered by a Hawaiian telescope in 2017.
Comet 2I/Borisov followed in 2019, named after the Crimean amateur astronomer who discovered it.
The research findings were published in Nature Astronomy.
