The interstellar comet 3I/ATLAS recently made headlines as it passed by Earth, revealing some exciting secrets about the origins of life. Observations from NASA’s SPHEREx space telescope showed that this comet, one of the very few from another star system, released important organic molecules like methanol, cyanide, and methane during its close swing around the sun in December 2025.
These molecules are essential for life as we know it, but they can also occur through non-biological means. So, while the presence of these molecules might spark thoughts of alien life, most scientists believe 3I/ATLAS is just a typical comet, not a spaceship from another world.
In this latest study published in the Research Notes of the AAS, researchers explored specific gases emitted by the comet. As the comet draws near to the sun, its ice heats up, turning into gas and creating bright jets of material. This process allowed scientists to glimpse what’s inside a comet, like the carbon-rich materials hidden in its icy layers.
Carey Lisse, an astronomer at Johns Hopkins Applied Physics Laboratory, noted, “3I/ATLAS was erupting into space in December 2025, causing it to brighten significantly.” The comet, rich in water ice, was shedding materials that had been trapped for billions of years. According to research published in 2022, comets may play a role in spreading life’s building blocks across planets, suggesting they could have delivered organic materials to Earth as well.
Astronomers first spotted 3I/ATLAS in July 2025, traveling at an astonishing speed of about 137,000 mph (221,000 km/h). It’s believed this comet has been journeying through space for eons, gaining speed as it passed other stars. After its closest approach to the sun, the comet flew by Earth, coming within 168 million miles (270 million kilometers) of us.
SPHEREx, which launched in March 2025, just happened to be in the right place at the right time to observe the comet. This space telescope is designed to scan the night sky with high precision, gathering data essential for understanding the universe and the building blocks for life. Yoonsoo Bach, a researcher at the Korea Astronomy and Space Science Institute, remarked on this lucky timing: “Our galaxy delivered a piece of a faraway star system to us only a few months after launch.”
As 3I/ATLAS continues on its trajectory, it is set for a close pass by Jupiter soon, where NASA’s Juno spacecraft will make one last attempt to study it before it exits our solar system forever.
