NASA will publish a large set of images and observations of the interstellar comet 3I/ATLAS during a live event on , at 3:00 p.m. EST (8:00 p.m. UT). The collection draws on data gathered by both space missions and ground telescopes while the object moved through the inner Solar System. Scientists expect the release to illuminate activity that occurred around the comet’s perihelion on , a period that was largely unobservable from Earth because 3I/ATLAS passed behind the Sun. The images and accompanying analysis will be streamed on NASA platforms and partner outlets.
Key Takeaways
- Event timing: NASA’s public release is scheduled for at 3:00 p.m. EST (8:00 p.m. UT), streamed via NASA channels.
- Object identity: 3I/ATLAS is the third confirmed interstellar object known to visit the Solar System, first detected in July 2025.
- Perihelion and solar concealment: The comet moved behind the Sun from Earth’s view on and reached perihelion on .
- Mars proximity: Around perihelion 3I/ATLAS was close enough to Mars that orbiting instruments may have recorded its activity; some Mars-based observations have already been reported by ESA.
- Upcoming closest approach to Earth: The comet will be nearest Earth on , at roughly 270 million kilometers (170 million miles), offering the best ground-based viewing opportunity.
- Participation: NASA has indicated multiple assets were used; Hubble, JWST, Mars orbiters, ATLAS survey telescopes and facilities like Gemini are plausible contributors, though not all instrument lists are confirmed.
Background
Interstellar visitors are exceedingly rare. Before 3I/ATLAS, the community cataloged two confirmed interstellar objects: 1I/’Oumuamua in 2017 and 2I/Borisov in 2019. Each arrival has prompted intense, short-lived observation campaigns because their trajectories and compositions can differ markedly from native Solar System bodies. That rarity makes every new dataset valuable for understanding the diversity of small bodies that form around other stars.
Comets are often described as “dirty snowballs”—agglomerates of rock, dust and volatile ices. As a comet approaches the Sun, solar heating drives sublimation of ices, producing a coma and one or more tails of gas and dust. Perihelion—when the object is closest to the Sun—is typically when this activity peaks and when dramatic changes (brightening, fragmentation, jets) can occur. In the case of 3I/ATLAS, the critical perihelion window was partially obscured from Earth, increasing the importance of space-based and Mars-orbiter observations.
Main Event
3I/ATLAS was first detected in July 2025 and quickly attracted global attention because its incoming trajectory and speed indicate an origin beyond the Solar System. Observers tracked it through the following months until it moved behind the Sun on , preventing direct Earth-based monitoring of its closest solar passage. The comet reached perihelion on , a likely period for peak outgassing and structural change.
Because the object passed near Mars around perihelion, operators of Mars orbiters and rovers had a window to image or otherwise measure the comet from a vantage point not blocked by the Sun. The European Space Agency has already reported some observations from Mars-orbiting assets. NASA has said multiple mission assets contributed data; the agency has not yet published a definitive list of instruments.
Ground-based observatories will have an improved view as 3I/ATLAS emerges and approaches Earth. The ATLAS survey telescope that originally found the object and large facilities such as the Gemini Observatory are expected to provide higher-resolution follow-up as the comet brightens toward its nearest approach on . That approaching date will be the prime time for spectroscopy and detailed morphological imaging from Earth.
Analysis & Implications
High-quality images and spectra around perihelion can reveal the comet’s volatile inventory and nucleus behavior—key clues to its formation environment. If 3I/ATLAS shows a composition similar to Solar System comets, that would point to convergent chemistry in planetesimal formation across systems. If its volatiles or dust-to-gas ratio differ substantially, models of protoplanetary disk diversity will need revision.
Perihelion-driven activity can also expose internal layers through jets or fragmentation, offering a rare look at an interstellar object’s structure. Because 3I/ATLAS passed behind the Sun from Earth’s perspective, Mars-based and spaceborne vantage points might capture outbursts or morphological changes that ground telescopes missed. Those observations will help constrain mass loss rates, nucleus size estimates, and the physics of hyperbolic passages through a star’s near environment.
On an operational level, coordinating instruments across Earth, Mars, and space telescopes demonstrates the growing ability of the planetary community to respond to transient interstellar visitors. The dataset from 3I/ATLAS will inform observing strategies for future objects and may influence decisions about which facilities receive priority when rare targets appear. For planetary science and astrophysics alike, these data will be mined for months to come.
Comparison & Data
| Event | Date (2025) | Distance / Note |
|---|---|---|
| Discovery | July | First detection by survey telescopes |
| Became sun-blocked from Earth | Oct 21 | Behind Sun from Earth’s viewpoint |
| Perihelion (closest to Sun) | Oct 29 | Peak activity expected |
| Re-emergence | Early November | Visible again from some Earth-based sites |
| Closest approach to Earth | Dec 19 | ~270 million km (170 million miles) |
The table summarizes the key milestones of 3I/ATLAS’s 2025 passage. The most scientifically consequential interval was perihelion on , when peak sublimation and possible fragmentation could have occurred. Because Earth-based line-of-sight was blocked during that window, complementary observations from Mars orbit and space telescopes are especially valuable to reconstruct the event timeline and quantify mass loss and composition.
Reactions & Quotes
“Assets within NASA’s science missions give the United States the unique capability to observe 3I/ATLAS almost the entire time it passes through our celestial neighborhood, and study — with complementary scientific instruments and from different directions — how the comet behaves.”
NASA (official statement)
“Observations from Mars-orbiting platforms have already contributed views of the comet near perihelion, offering angles unavailable from Earth during solar occultation.”
European Space Agency (official note)
Scientists and mission teams are framing the Nov. 19 release as the first consolidated look at multi-instrument, multi-location data from the passage. Public engagement is expected to be high, since interstellar visitors attract broad interest beyond the specialist community.
Unconfirmed
- Which specific space telescopes (for example Hubble or JWST) captured perihelion activity has not been confirmed by NASA at the time of the Nov. 19 event announcement.
- Details on whether 3I/ATLAS experienced fragmentation or major outbursts at perihelion remain preliminary until teams release analyzed imaging and light curves.
- The full list of Mars-orbiting instruments and the extent of their datasets are still being compiled and publicly verified.
Bottom Line
The Nov. 19 NASA release will be the first consolidated presentation of space- and ground-based views of 3I/ATLAS gathered as the object traversed the inner Solar System. Because perihelion occurred while the comet was hidden from Earth’s line of sight, the new imagery could show phenomena that were otherwise missed and will be crucial for compositional and structural interpretation.
For researchers, the dataset will inform models of interstellar small bodies and offer comparative material against 1I/’Oumuamua (2017) and 2I/Borisov (2019). For the public, the coming weeks—especially the approach on —will provide the best opportunities for telescopes on Earth to study this rare visitor in detail.
Sources
- ScienceAlert — media reporting on the NASA announcement and collected observations.
- NASA Television / YouTube — official live-stream channel for NASA events (official/agency broadcast).
- European Space Agency (ESA) — official agency notices regarding Mars-orbiter observations (official/agency).