ESA’s JUICE used five instruments to study 3I/ATLAS, including NavCam imagery during approach to perihelion and closest Earth approach.

The imagery network for 3I/ATLAS includes contributions from PUNCH, SOHO, MAVEN, Perseverance, and non-U.S. cameras from ESA and ExoMars Trace Gas Orbiter.

3I/ATLAS is currently not visible from ground-based telescopes due to solar proximity, but will become observable as it passes Earth on December 19, with JWST and observatories like Keck ready to observe.

Perihelion brought increased activity as solar heating sublimated ices, producing visible tails.

Hubble’s late-November image constrains the nucleus size to roughly 1,400 feet to 3.5 miles across, with the comet traveling about 130,000 mph.

Ongoing observations, including Hubble’s, refine estimates of size and activity as 3I/ATLAS moves through the inner solar system.

3I/ATLAS, an interstellar comet, has been imaged by both NASA’s Hubble Space Telescope and ESA’s JUICE spacecraft after its close solar approach and as it heads toward an Earth encounter on December 19.

A JUICE image from early November shows the comet with a visible coma and hints of two tails — a plasma tail and a possible dust tail.

ESA’s JUICE image taken closer to the comet than Hubble reveals a coma and potential dual tails, including a plasma tail stretching toward the top of the frame and a faint dust tail to the lower left.

NASA officials say there are no detectable techno-signatures; observations aim to study 3I/ATLAS’s composition, appearance, velocity, and possible origin as it approaches Earth.

Ground- and space-based observations continue to determine the object’s composition, size, and origin, with JUICE expected to provide more detailed data soon.

Additional observations are planned from other observatories, including the James Webb Space Telescope, as 3I/ATLAS moves through the inner solar system.

The effort to study 3I/ATLAS involves multiple spacecraft and ground observers, highlighting the collaborative nature of modern space science.

JUICE data will reach Earth in February 2026, delayed because the spacecraft uses a high-gain antenna as a heat shield and relies on a slower secondary antenna for transmission.

Complete scientific data from JUICE will be available in late February 2026 due to the same transmission constraints while approaching the Sun.

Preliminary analyses suggest the comet’s acceleration may not be gravity-driven and that 3I/ATLAS is rich in carbon dioxide, with more data anticipated as it nears perihelion in mid-December.

Current estimates place 3I/ATLAS about 170 million miles from Earth at its closest approach, posing no threat to our planet.

3I/ATLAS is the third confirmed interstellar object to pass through our solar system, following 1I/’Oumuamua and 2I/Borisov.