Comet 3I/ATLAS: NASA Telescope Reveals Unusual Activity
Hear’s a breakdown of the key information from the provided text, focusing on how the TESS telescope was used to study interstellar comet 3I/ATLAS:
TESS’s Primary Function: The Transiting Exoplanet Survey Satellite (TESS) is designed to detect exoplanets by observing stars for dips in brightness as planets pass in front of them.
Unexpected Data Source: researchers realized TESS had data on interstellar comet 3I/ATLAS as the telescope was pointed in that direction around the time the comet was predicted to be ther. They went back through TESS’s archives.
Data collection Period: They found data from May 7th, 2025, to June 2nd, 2025.
“Shift-Stacking” Technique: As 3I/ATLAS moves faster than the stars TESS usually observes, a special technique called “shift-stacking” was needed. This involved:
Predicting the comet’s position in each image.
Shifting the images to align the comet.
stacking the images together to create a clearer signal.
Comet’s movement & Brightness: The comet moved from about 6.35 AU to 5.47 AU during the observation period. Its brightness increased by a factor of 5, more than expected based on distance alone. Clarification for Brightness Increase: Researchers believe the increased brightness is due to the comet releasing “hypervolatile” materials (like carbon dioxide and carbon monoxide) - substances that sublimate (turn into gas) at higher temperatures than water ice. This is unusual because comets in our solar system have largely depleted these materials.
Speculation & Option Theories: There was initial speculation about the comet’s behavior, including the possibility of it being alien technology, but the researchers favor the outgassing explanation.