Don’t Miss It: Interstellar Comet’s Closest Earth Pass, New Images

New images of the interstellar comet 3I/ATLAS nearing Earth have been captured by astronomers

Fresh observations of comet 3I/ATLAS reveal its unusual structure and dynamic tails as it nears its closest approach to Earth later this month. The interstellar visitor, which originated beyond our solar system, has sparked intense interest among scientists since its discovery in July 2025.

Comet 3I/ATLAS is only the third interstellar object ever detected traveling through our solar system, making every observation crucial for understanding its trajectory, composition, and behavior. Both the Hubble Space Telescope and the European Space Agency’s Jupiter Icy Moons Explorer (Juice) mission have captured detailed images of the comet, offering unprecedented insight into this rare cosmic phenomenon.

The comet’s teardrop-shaped coma is unveiled by Hubble

Hubble initially captured images of 3I/ATLAS soon after it was identified in July 2025, at a distance of approximately 277 million miles from Earth. Employing its Wide Field Camera 3, Hubble recorded a unique teardrop-shaped dust halo emanating from the comet’s frozen core. This luminous envelope of material emphasizes the continuous sublimation of gases and particles as the comet heated up while nearing the sun.

Observations continued on November 30, when the comet was 178 million miles (286 million kilometers) from Earth. Hubble captured even sharper images, allowing astronomers to study the comet’s evolving shape and gas emissions in greater detail. These images are vital for tracking the comet’s path and understanding how interstellar bodies behave when exposed to the sun’s energy.

The Juice spacecraft records two tails

While Juice’s main goal is to examine Jupiter and its largest moons—Ganymede, Callisto, and Europa, which might harbor subsurface oceans that could sustain life—it utilized its path to observe comet 3I/ATLAS in early November. From approximately 41 million miles (66 million kilometers) away, the spacecraft employed five scientific instruments and its onboard Navigation Camera (NavCam) to document the comet’s activity.

The spacecraft transmitted a portion of the NavCam data ahead of the full download schedule. The images reveal a bright coma enveloping the comet, along with two distinct tails: a plasma tail consisting of electrically charged gases and a fainter dust tail of solid particles. This dual-tail structure is characteristic of comets within our solar system, but observing it on an interstellar object provides valuable clues about its physical and chemical properties.

Juice’s full dataset, expected to arrive on Earth between February 18 and 20, will include high-resolution images, composition analysis, and particle measurements. These data could shed light on the comet’s origin and the environment it traveled through before entering our solar system.

Proximity to Earth and Observability

Comet 3I/ATLAS is projected to pass within 167 million miles (270 million kilometers) of Earth on December 19, positioning it on the opposite side of the sun and posing no threat to our planet. For context, the Earth orbits roughly 93 million miles (150 million kilometers) from the sun, highlighting that the comet will remain safely distant while still observable by telescopes and space missions.

Even after its closest approach, the comet is expected to remain visible for several months as it continues its journey out of the solar system. Observations during this period will allow scientists to monitor how the comet interacts with solar radiation and the solar wind, further contributing to our understanding of interstellar bodies.

Insights into interstellar origins

Studying 3I/ATLAS provides a rare window into material formed outside our solar system. The comet’s icy core, enveloped in a halo of dust and gas, may contain clues about the chemical makeup of distant star systems. The tails, driven by heat and solar radiation, allow researchers to examine how volatile compounds react when exposed to the sun.

Every interstellar visitor brings unique opportunities to compare our own solar system’s formation with that of other star systems. By analyzing the composition of 3I/ATLAS, scientists hope to uncover information about the types of materials that exist in other parts of the galaxy and how they evolve over time.

Prospects for future studies and research opportunities

The information gathered by Hubble and Juice constitutes just a fraction of the possible insights this comet might offer. Future observations from both terrestrial and space telescopes will assist in monitoring the comet’s path, assessing its changes in brightness, and enhancing models of its course.

As more data arrive from Juice, researchers anticipate learning more about the distribution of dust and gas in the coma and tails, the size and rotation of the comet’s nucleus, and potential isotopic signatures that could reveal the interstellar environment from which it originated. Such findings could enhance our understanding of planetary formation, interstellar chemistry, and the prevalence of comets traveling between star systems.

The singular chance offered by 3I/ATLAS highlights the significance of synchronized observations from various space missions. By merging high-resolution imaging from Hubble with in-situ data from Juice, researchers are able to construct a detailed depiction of an object that has journeyed through the galaxy to arrive at our solar system.

In conclusion, comet 3I/ATLAS offers an extraordinary glimpse into the wider universe beyond our solar system. Its teardrop-shaped coma, dual tails, and interstellar origins provide invaluable data for astronomers, while its safe approach allows continued observation from Earth. The ongoing analysis of images and measurements from Hubble and the Juice spacecraft promises to deepen our understanding of how interstellar objects behave, paving the way for future discoveries about the cosmos.