NASA’s SPHEREx space telescope is making waves by observing interstellar comet 3I/ATLAS, which recently flared up months after its closest approach to the Sun. This comet, only the third confirmed interstellar object in our solar system, gives scientists a unique glimpse of materials from another star system.
Launched on March 11, 2025, SPHEREx, or the Spectro-Photometer for the History of the Universe, aims to scan the entire sky in 102 infrared wavelengths. Its main goals are to understand galaxy evolution and search for the building blocks of life.
### What’s Behind the Comet’s Brightness?
As comets get closer to the Sun, they heat up. This warms their icy surfaces, causing the ice to turn into gas and form a surrounding coma. Interestingly, the peak brightness doesn’t always happen right after the closest approach; sometimes, it takes a little while for the effects to show up.
For 3I/ATLAS, this delay is notable. Recent observations show the comet erupting with gas and organic material, as noted by Carey Lisse from the Johns Hopkins Applied Physics Laboratory. Lisse shared that water ice quickly sublimated into gas, releasing carbon-rich substances long trapped beneath the surface.
### A Chemical Treasure Trove in Space
SPHEREx first detected the comet’s coma in August 2025. The initial data showed significant amounts of carbon dioxide and smaller quantities of carbon monoxide and water. By December, the findings revealed a richer chemical profile. Organic compounds like methanol, cyanide, and methane were found, which are crucial for life on Earth but can also form through non-biological means.
Phil Korngut from Caltech added that the comet likely developed a crust from radiation exposure while in interstellar space. As solar energy penetrated this layer, previously hidden ices began releasing a mix of chemicals that hadn’t been exposed to space for billions of years.
### Comet’s Unique Ejection Patterns
3I/ATLAS appears to be ejecting larger chunks of material rather than fine dust. This results in its distinctive pear-shaped dust tail. Larger particles are more resistant to being pushed away by solar radiation pressure, which explains why the comet’s tail looks the way it does.
Discovered on July 1, 2025, by the ATLAS telescope in Chile, 3I/ATLAS was quickly determined to be an interstellar object due to its high velocity. SPHEREx has now completed its first all-sky infrared map, part of a broader mission to analyze the cosmos.
As insights from 3I/ATLAS continue to unfold, they may hold clues about the origins of organic molecules in our own solar system. The exploration of such interstellar bodies can deepen our understanding of life’s building blocks, showcasing the intricate connections between celestial events and potential life beyond Earth.
Source link
