Astronomers capture new images of interstellar comet 3I/ATLAS approaching Earth
New insights into comet 3I/ATLAS highlight its distinctive composition and active tails as it approaches its nearest point to Earth this month. The interstellar traveler, hailing from outside our solar system, has captivated scientists’ attention since it was first identified in July 2025.
Comet 3I/ATLAS represents just the third interstellar object identified as it journeys through our solar system, rendering each observation vital for comprehending its path, makeup, and actions. Detailed images of the comet have been captured by both the Hubble Space Telescope and the European Space Agency’s Jupiter Icy Moons Explorer (Juice) mission, providing unparalleled insight into this extraordinary cosmic event.
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.
Juice spacecraft captures dual 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 sent a segment of the NavCam data prior to the complete download timeline. The images display a luminous coma surrounding the comet, accompanied by two separate tails: a plasma tail made up of electrically charged gases and a more subtle dust tail composed of solid particles. This dual-tail formation is typical of comets in our solar system; however, witnessing it on an interstellar object offers valuable insights into its physical and chemical characteristics.
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.
Close approach to Earth and visibility
Comet 3I/ATLAS is anticipated to come within 167 million miles (270 million kilometers) of Earth on December 19, situating it on the far side of the sun and presenting no danger to our planet. To put this in perspective, Earth orbits at approximately 93 million miles (150 million kilometers) from the sun, underscoring that the comet will stay safely remote while remaining visible to telescopes and space missions.
Even after its nearest pass, the comet is anticipated to stay visible for numerous months as it proceeds on its path out of the solar system. During this time, observations will enable scientists to examine how the comet engages with solar radiation and the solar wind, further enhancing our comprehension of interstellar bodies.
Insights into interstellar origins
Studying 3I/ATLAS offers a unique glimpse into material that originated beyond our solar system. The comet’s icy nucleus, surrounded by a cloud of dust and gas, might hold insights into the chemical composition of remote star systems. The tails, influenced by heat and solar radiation, enable scientists to explore how volatile compounds behave when subjected to the sun.
Every interstellar traveler offers distinct chances to contrast the formation of our solar system with that of other stellar systems. By examining the composition of 3I/ATLAS, researchers aim to reveal insights into the kinds of materials present in different regions of the galaxy and their evolution over time.
Prospects for future studies and research opportunities
The data collected by Hubble and Juice represent only a portion of the potential insights this comet can provide. Upcoming observations from both ground-based and space-based telescopes will help track the comet’s motion, measure its brightness variations, and refine models of its trajectory.
As additional data are received from Juice, scientists expect to gain insights into the dispersion of dust and gas within the coma and tails, the dimensions and spin of the comet’s nucleus, and possible isotopic markers that might unveil the interstellar environment it emerged from. These discoveries could broaden our comprehension of planetary formation, interstellar chemistry, and the frequency of comets moving between star systems.
The unique opportunity presented by 3I/ATLAS underscores the importance of coordinated observations from multiple space missions. By combining high-resolution imaging from Hubble with in-situ measurements from Juice, scientists can create a comprehensive picture of an object that has traveled across the galaxy to reach our solar system.
Comet 3I/ATLAS provides an exceptional view into the vast universe beyond our solar system. Its teardrop-shaped coma, twin tails, and interstellar origins offer invaluable insights for astronomers, while its safe proximity permits ongoing observation from Earth. The continuous analysis of images and data from Hubble and the Juice spacecraft is expected to enhance our comprehension of interstellar objects’ behavior, paving the way for future revelations about the cosmos.
