Interstellar Comet 3I/ATLAS: NASA Captures New Images and Data

Early Observations of Comet 3I/ATLAS

• 🔭 The Transiting Exoplanet Survey Satellite (TESS) data was used to identify comet 3I/ATLAS prior to its official discovery, by stacking frames to reduce noise.
• 💧 Near-infrared telescopes like Gemini South and NASA's Infrared Telescope Facility detected water ice in the comet's surrounding cloud.
• 💨 Hubble Space Telescope observations confirmed a dust coma, limiting the nucleus size to an upper limit of 2.8 km and estimating material loss at tens to hundreds of kg per second.

James Webb Space Telescope and Spectroscopic Analysis

• ⚛️ The James Webb Space Telescope (JWST) performed spectroscopy, identifying water and carbon dioxide.
• 🤯 A surprising discovery was that the comet emitted 8 times more carbon dioxide than water, a ratio only exceeded by one other solar system comet (2016 R2).
• 🌌 This high CO2 ratio sparked discussions about the comet's formation environment, potentially in a carbon dioxide-rich region or due to cosmic ray bombardment in deep space.
• 🔗 The comet also appeared carbon chain depleted, suggesting simpler carbon molecules, possibly due to its formation location or extended time in interstellar space.
• ⚛️ Near-ultraviolet spectroscopy revealed a significant amount of nickel, unusual as nickel and iron typically form together; this is hypothesized to be from volatile nickel carbonyls.

Observations from Mars and Solar-Studying Spacecraft

• 🛰️ The European Space Agency's ExoMars Trace Gas Orbiter provided improved astrometry by observing the comet from two angles, enhancing orbital accuracy.
• 📸 NASA's Mars Reconnaissance Orbiter captured a smeared image of the comet, demonstrating its ability to detect objects millions of miles away, though resolution was limited.
• ⚡ Maven's ultraviolet spectrograph analyzed hydrogen emissions, differentiating between hydrogen from the comet, deep space, interplanetary space, and near Mars.
• 🦘 Perseverance's Mastcam on the surface of Mars detected a tiny smear of the comet, though with limited scientific value.
• ☀️ Spacecraft studying the sun, including SOHO, PUNCH, and STEREO, were able to capture images of the comet on the opposite side of the sun by stacking multiple images.

Deep Space and Future Observations

• 🪐 The Psyche and Lucy asteroid missions, while in deep space, used their onboard imagers to track the comet, contributing to orbital refinement by stacking images.
• 🔭 Lucy provided a unique view from nearly a 90-degree angle, showing the comet's tail formation.
• 🚀 Future observations are expected from the JUICE mission, and ground-based observatories as the comet departs the solar system.
• 🔭 While Juno is in orbit around Jupiter, its operational status is uncertain due to a government shutdown, limiting potential observations of the comet's final flyby.