3I/ATLAS Interstellar Comet Live Tracker: When and how to watch ATLAS? When does it peak?

The closest it will approach Earth is about 1.8 astronomical units (about 170 million miles, or 270 million kilometers). It will reach its closest point to the Sun around October 30.

NASA stated that Comet 3I/ATLAS poses no threat to Earth and will remain at a safe distance.

Every planet, moon, asteroid, comet and lifeform in our Solar System share a common origin. But interstellar comets are “true outsiders”, carrying clues about the formation of worlds far beyond our own, the ESA said.

Every planet, moon, asteroid, comet and lifeform in our Solar System share a common origin. But interstellar comets are “true outsiders”, carrying clues about the formation of worlds far beyond our own, the ESA said.

According to NASA, astronomers categorised Comet 3I/ATLAS as an interstellar object because of the hyperbolic shape of its orbital path. It does not follow a closed orbital path about the Sun.

The European Space Agency (ESA) confirmed that two Mars missions, the ExoMars Trace Gas Orbiter (TGO) and Mars Express, turned their cameras toward the comet between October 1 and 7.

TGO’s CaSSIS instrument captured several images on October 3 even though it could only capture 3I/ATLAS as a faint, blurry white spot moving among streaked stars.

Space enthusiasts may follow the journey of interstellar object 3I/ATLAS using NASA’s interactive tool, Eyes on the Solar System.

The comet created excitement when it passed close to Mars between October 2-3, at a distance of about 29 million kilometers. This was its closest approach to any planet during its one-time passage through our solar system.

Harvard astrophysicist Dr Avi Loeb earlier shared a provocative theory about the interstellar Comet 3I/ATLAS. The cosmic visitor from another world will come closest to Earth on October 29.

Dr Loeb speculated that the object could even be a “mothership” releasing small probes towards Earth.

“If you want to take a vacation, take it before that date because who knows what will happen now,” Dr Avi Loeb said in an earlier interaction with Dr Mayim Bialik and Jonathan Cohen.

Comets are generally named after their discoverer(s). In this case, it was the ATLAS survey team. The letter “I” is for “interstellar,” indicating that this object came from outside our solar system.

It’s the third known interstellar object – following 1I/ʻOumuamua in 2017 and 2I/Borisov in 2019 – hence the “3” in the name.

Perihelion is the point in an object’s orbit closest to the Sun. For comets, which often have highly elongated orbits, perihelion can have a significant impact, unlike planets, which follow nearly circular paths.

Comet 3I/ATLAS was discovered on July 1, 2025, and since then, astronomers have been working tirelessly to study it. Unlike regular comets that orbit the Sun, 3I/ATLAS is an interstellar comet, making it one of only three ever observed. This means it originated from outside our Solar System and is only passing through, eventually leaving forever as it continues its journey through the galaxy, according to the BBC.

Comets and meteorites are often confused, but they’re quite distinct. A comet is a massive icy object that travels around the Sun, developing a bright, glowing tail as it nears it. In contrast, a meteorite is a tiny fragment of rock or metal that enters Earth’s atmosphere, appearing as a “shooting star” prior to eventually landing on the surface.

As interstellar comet 3I/ATLAS moves closer to the Sun and heats up, astronomers have detected it releasing a jet of material. According to Space.com, the jet is directed toward the Sun, a common behaviour observed in comets as solar heat causes their icy surfaces to vaporise. Images of the event reveal the comet’s glowing atmosphere, or coma, along with the jet highlighted in purple.

The European Space Agency (ESA) has decided not to send a spacecraft to study the interstellar comet 3I/ATLAS, which will make its closest approach to the Sun on October 30. According to ESA, the comet’s high speed and the limited time before its flyby make a direct mission impossible. Instead, scientists will observe it from afar using powerful telescopes such as Hubble and the James Webb Space Telescope to analyse its dust and gas composition.

The ESA said its Jupiter Icy Moons Explorer (Juice) will have the best view of interstellar comet 3I/ATLAS when it becomes most active.

Juice will attempt to observe the comet in November 2025.

The spacecraft will employ cameras, spectrometers, and a particle sensor to study the comet.

ESA is considering coordinating with NASA’s Europa Clipper mission, especially to use the twin ultraviolet spectrographs aboard both spacecraft.

Current position: Juice is close to the Sun, using its high-gain antenna as a heat shield to protect its instruments.

Expected data return: ESA expects to receive data from Juice’s 3I/ATLAS observations by February 2026.

According to NASA website, 3I/ATLAS originated in another star system outside our Solar System.

-It was ejected into interstellar space, drifting between stars for millions or even billions of years.

-The comet has been approaching from the direction of the constellation Sagittarius, home to the Milky Way’s central region.

-When astronomers discovered it, 3I/ATLAS was about 410 million miles (670 million km) from the Sun, located within Jupiter’s orbit.

-Its long journey makes it one of the few interstellar visitors ever observed entering our Solar System.

After its discovery, 3I/ATLAS was observed by the NASA/ESA Hubble Space Telescope and the NASA/ESA/CSA James Webb Space Telescope, both located near Earth.

ESA is expanding its observation campaign by directing several interplanetary spacecraft toward the comet.

Missions involved:

Mars Express – will help observe the comet from Mars’ orbit.

ExoMars Trace Gas Orbiter (TGO) – will collect additional data on the comet’s composition and activity.

Jupiter Icy Moons Explorer (JUICE) – will turn its instruments toward 3I/ATLAS for remote observation.

The European Space Agency (ESA) has confirmed that it has no plans to send a spacecraft to visit interstellar comet 3I/ATLAS, which will make its closest approach to the Sun on October 30, 2025.

According to ESA, the comet will pass just inside the orbit of Mars before speeding away from the centre of the Solar System — making any mission to intercept or land on it impossible within the available timeframe.

“This is far too soon, and the comet is moving far too quickly, to contemplate sending a spacecraft to visit or land on it,” ESA said in an update.

Instead, astronomers are focusing on remote observations using advanced space telescopes and planetary missions. Instruments such as the NASA/ESA Hubble Space Telescope and the James Webb Space Telescope are already tracking the comet’s activity, capturing images of its dust plume and analysing gases released as it nears the Sun.

NASA/ESA Hubble Space Telescope captured a dust plume from the comet’s Sun-facing side and a dust tail trailing behind its nucleus.

As it approaches the Sun, the comet will lose mass as frozen gases vaporize, releasing dust and ice into space.

James Webb Space Telescope (NASA/ESA/CSA) detected carbon dioxide, water, carbon monoxide, carbonyl sulphide, and water ice in the comet’s coma (halo).

These substances are released as the comet heats up during its solar approach.

The European Space Agency’s (ESA) Planetary Defence Office is closely tracking the recently discovered interstellar comet 3I/ATLAS, coordinating with global observatories to better understand its path and composition.

ESA astronomers are contributing to the worldwide tracking effort using telescopes located in Hawaii, Chile, and Australia. They are also conducting a “precovery” search — examining archival telescope data to find earlier, unrecognized images of the comet to refine its trajectory.

“These observations help us improve our understanding of 3I/ATLAS’s orbit and characteristics,” ESA said, noting that while the comet will pass through the inner solar system, it is not classified as a near-Earth object due to its distance from our planet.

The agency added that by the time 3I/ATLAS reaches its closest point to Earth, it will be obscured by the Sun, making direct observation impossible. However, the comet is expected to reappear in late November, giving astronomers another opportunity to study this rare interstellar visitor.

NASA has confirmed that the interstellar object 3I/ATLAS is a comet, not an asteroid, based on recent telescope observations. Astronomers have detected signs of activity — a key characteristic that distinguishes comets from asteroids.

According to NASA, 3I/ATLAS displays an icy nucleus surrounded by a coma, a bright cloud of gas and dust that forms as sunlight warms the comet during its approach to the Sun. This visible outgassing and dust activity indicate that the object is made largely of volatile materials, typical of comets.

NASA has confirmed that the interstellar comet 3I/ATLAS poses no danger to Earth despite its approach through the inner solar system. According to NASA, the comet will make its closest pass to our planet on December 19, 2025, maintaining a safe distance of about 1.8 astronomical units — roughly 170 million miles (270 million kilometers) from Earth.

Astronomers emphasize that while 3I/ATLAS is traveling on a trajectory that takes it near the Sun’s orbit, its path does not intersect with Earth’s orbit, ruling out any risk of impact.

Astronomers are closing in on the size of the interstellar comet 3I/ATLAS, a rare visitor from beyond our Solar System. Based on recent observations from NASA’s Hubble Space Telescope as of August 20, 2025, scientists estimate that the comet’s nucleus — the solid core at its center — measures between 1,444 feet (440 meters) and 3.5 miles (5.6 kilometers) in diameter.

Size: Likely between a few hundred meters and a few kilometers across

Speed: ~210,000 km/h — fastest ever recorded for a Solar System visitor

Age: Billions of years — its extreme speed suggests a long journey through interstellar space

Closest approach to Mars: ~30 million km — 3 October 2025

Closest approach to the Sun: ~210 million km — 30 October 2025

Closest approach to Earth: ~270 million km — 19 December 2025

(ESA)

Interstellar comet 3I/ATLAS — currently located in the constellation of Virgo — is expected to make its closest approach to Earth later next year, marking its nearest flyby this century, as per The Sky.

According to observational data compiled for the period between January 1, 2000 and December 31, 2099, the comet will pass closest to Earth on December 19, 2025, at a distance of 1.797478 Astronomical Units — approximately 268.9 million kilometers.

Interstellar comet 3I/ATLAS is currently passing through the constellation Virgo, continuing to draw scientific attention as it travels through the inner Solar System.

According to data from The Sky, the comet is located roughly 344.8 million kilometers from Earth — a distance equal to 2.30 Astronomical Units (AU). At that range, light takes approximately 19 minutes and 10 seconds to reach Earth from the comet.

Astronomers tracking its position report apparent coordinates of:

The latest brightness estimate, calculated using NASA’s JPL Horizons data, places the comet’s magnitude at 14.71 — making it too faint for the unaided eye, and visible only through advanced telescopes.

ESA said its astronomers immediately began tracking the comet using ground-based telescopes in Chile, Hawaii and Australia, after it was first detected on July 1, 2025, by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope.

Observations have since expanded to space observatories, including the NASA/ESA Hubble Space Telescope and the NASA/ESA/CSA James Webb Space Telescope.

In the coming months, ESA plans to turn several deep-space spacecraft toward the object — including Mars Express, the ExoMars Trace Gas Orbiter, and Jupiter Icy Moons Explorer (Juice) — to capture additional data from multiple vantage points in the Solar System.

ESA explained that the designation follows an international naming system:

• “3” marks it as the third confirmed interstellar object

• “I” stands for “interstellar”

• “ATLAS” credits the survey project that spotted it

3I/ATLAS was first detected on July 1, 2025, by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile. Its unusual, hyperbolic trajectory — not bound to the Sun — quickly signaled an origin from interstellar space. Astronomers worldwide later confirmed the finding.

Comet 3I/ATLAS, a newly identified visitor from outside our Solar System, is giving scientists a rare opportunity to study material formed around a distant star system, according to the European Space Agency (ESA).

The comet is only the third confirmed interstellar object ever observed, following 1I/ʻOumuamua in 2017 and 2I/Borisov in 2019.

NASA said numerous assets are scheduled to gather data on the rare visitor, including Hubble, Webb, TESS, Swift, SPHEREx, Perseverance and Curiosity rovers, Mars Reconnaissance Orbiter, Europa Clipper, Lucy, Psyche, Parker Solar Probe, PUNCH, and ESA/NASA’s SOHO and Juice missions.

The object 3I/ATLAS was first reported to the Minor Planet Center on July 1, 2025, by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile.

Following its discovery, astronomers identified earlier, archived observations stretching back to June 14 from ATLAS telescopes and Caltech’s Zwicky Transient Facility in California, NASA noted.

As with other comets, its name honors the survey team that detected it. The designation “3I” indicates it is the third confirmed interstellar object.

NASA emphasized that 3I/ATLAS poses no danger to our planet. Its closest approach to Earth will be about 1.8 astronomical units away — roughly 170 million miles (270 million kilometers).

The US space agency said the comet will swing just inside Mars’ orbit when it reaches perihelion — its closest point to the Sun — around October 30, 2025, at a distance of about 1.4 au (130 million miles, or 210 million kilometers).

Comet 3I/ATLAS, the third interstellar object ever detected passing through our solar system, is on course for its nearest approach to the Sun on October 30, according to NASA.

The comet has been confirmed as interstellar based on its hyperbolic trajectory — a path that shows it does not orbit the Sun and instead originates from beyond the solar system.

“When the orbit of 3I/ATLAS is traced into the past, the comet clearly originates from outside our solar system,” NASA said in its overview.