Uploaded September 2025 | Updated September 2026, 1 week ago
In late October 2025, a rare astronomical moment will unfold. On the 29th, an object called 3I Atlas will swing past the Sun at its closest approach, known as perihelion. What makes this moment so unusual is that the Sun, Earth, and 3I Atlas will line up perfectly in a straight line. That alignment means the Sun will block our view just when scientists are most eager to study it.
3I Atlas is not an ordinary comet or asteroid. Its path through our solar system has been puzzling astronomers since its discovery. Unlike most objects that come from the outer regions of our solar system, this one appears to be from interstellar space. Questions about its origin and purpose have been growing, especially since its movement is unlike anything seen before.
Between August 8th and 12th, 2025, NASA's SPHEREx observatory captured detailed infrared images of 3I Atlas when it was about 3.2 astronomical units from the Sun. The observatory looked for emissions of water vapor, carbon dioxide, and carbon monoxide. Surprisingly, no signs of water or carbon monoxide were found. Instead, a huge cloud of carbon dioxide surrounded the object, stretching roughly 348,000 kilometers. The data showed 3I Atlas was losing about 70 kilograms of CO2 every second, but its water loss was almost zero, which is unusual because it is already inside the region where water ice should easily turn into gas.
In late October 2025, a rare astronomical moment will unfold. On the 29th, an object called 3I Atlas will swing past the Sun at its closest approach, known as perihelion. What makes this moment so unusual is that the Sun, Earth, and 3I Atlas will line up perfectly in a straight line. That alignment means the Sun will block our view just when scientists are most eager to study it.
3I Atlas is not an ordinary comet or asteroid. Its path through our solar system has been puzzling astronomers since its discovery. Unlike most objects that come from the outer regions of our solar system, this one appears to be from interstellar space. Questions about its origin and purpose have been growing, especially since its movement is unlike anything seen before.
Between August 8th and 12th, 2025, NASA's SPHEREx observatory captured detailed infrared images of 3I Atlas when it was about 3.2 astronomical units from the Sun. The observatory looked for emissions of water vapor, carbon dioxide, and carbon monoxide. Surprisingly, no signs of water or carbon monoxide were found. Instead, a huge cloud of carbon dioxide surrounded the object, stretching roughly 348,000 kilometers. The data showed 3I Atlas was losing about 70 kilograms of CO2 every second, but its water loss was almost zero, which is unusual because it is already inside the region where water ice should easily turn into gas.
