Astronomers and space enthusiasts across the world are gearing up for an extraordinary celestial encounter as interstellar comet 3I/ATLAS makes its reappearance in the eastern sky before dawn on 11 November 2025, as reported by EarthSky.com. This rare interstellar visitor, which has captivated scientists and the public alike with its mysterious origins, recently completed its closest approach to the Sun or perihelion on 30 October, passing within 130 million miles (1.36 astronomical units) of our star.Experts from NASA and the European Space Agency (ESA) are tracking its trajectory closely using advanced space instruments and live observation missions, hoping to uncover more about this fascinating traveller from beyond our solar system.
3I/ATLAS visibility and skywatching guide for November 2025
Currently, 3I/ATLAS is positioned behind the Sun from Earth’s perspective, hidden from view due to the intense solar glare. However, astronomers predict that the comet will reappear in the eastern pre-dawn sky on 11 November 2025.Viewing conditions will be challenging, as reported, the comet will not be visible to the naked eye. Astronomers recommend using a large telescope of at least 8 inches (20 cm) in diameter to glimpse this faint interstellar visitor. The comet is expected to appear low on the horizon before sunrise, near the constellation Sagittarius, in the same direction from which it entered our solar system.For those unable to view the event directly, live tracking and streaming are available through NASA, ESA, and several university-led observatories. Real-time sky maps and high-resolution imaging feeds are helping enthusiasts follow 3I/ATLAS as it continues its cosmic passage.
Discovery and orbit of interstellar comet 3I/ATLAS
Discovered on 1 July 2025 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile, 3I/ATLAS is only the third confirmed interstellar object to pass through our solar system following ‘Oumuamua in 2017 and 2I/Borisov in 2019.NASA scientists have confirmed that the comet follows a hyperbolic orbit, meaning it is not gravitationally bound to the Sun. Once it departs, it will continue its eternal journey into deep space, never to return, making this a once-in-a-lifetime astronomical event for observers.At the time of its discovery, the comet was travelling at around 130,000 mph, accelerating to nearly 152,000 mph as it approached the Sun. ESA’s Jupiter Icy Moons Explorer (JUICE) spacecraft currently has one of the best vantage points for monitoring the comet as it becomes more active. Preliminary data from JUICE’s instruments are expected to arrive by February 2026, providing valuable insights into the comet’s structure and composition.
3I/ATLAS composition and mysterious interstellar origin
As 3I/ATLAS approached the Sun, NASA’s Planetary Science Division observed that its frozen gases began to sublimate turning directly from solid to gas and releasing clouds of dust and ice. This activity created a faint, shimmering tail, which continues to change as the comet moves away from the Sun.The European Space Agency has deployed instruments aboard the JUICE spacecraft including spectrometers, cameras, and particle sensors to analyse these ejected materials. Early results suggest the comet is composed primarily of frozen water, carbon compounds, and dust, similar to comets native to our solar system. However, scientists have not ruled out the presence of more exotic materials formed in distant interstellar environments.The origins of 3I/ATLAS remain an area of active research. It is believed to have originated from a star system beyond the Milky Way’s central region, possibly ejected billions of years ago. Harvard astrophysicist Avi Loeb, who previously proposed unconventional ideas about interstellar objects, suggested an artificial origin in early analyses. He has since clarified that 3I/ATLAS is “most likely natural”, though he acknowledges that alternative explanations cannot be completely dismissed.
3I/ATLAS best viewing tips
- Look east before sunrise:
The comet will appear low in the eastern sky about an hour before sunrise, near the constellation Sagittarius.Go somewhere away from city lights to get a clearer view of the faint comet.3I/ATLAS will not be visible to the naked eye. You’ll need a telescope with at least an 8-inch (20 cm) aperture to spot it.
3I/ATLAS set to reappear: Related FAQs
What makes 3I/ATLAS special?3I/ATLAS is only the third known interstellar object to pass through our solar system, after ‘Oumuamua (2017) and 2I/Borisov (2019). Unlike typical comets, it originated beyond our solar system, likely from a distant star system.Why can’t we see it with the naked eye?Despite being an interstellar object, 3I/ATLAS is too faint and distant for naked-eye viewing. Its brightness is limited due to its small size and the vast distance from Earth. Specialized telescopes are required to detect it.Where did 3I/ATLAS come from?Astronomers believe it may have been ejected from a stellar nursery or planetary system near the Milky Way’s core billions of years ago. It has been traveling through interstellar space ever since.Could it be artificial, as some scientists once speculated?Early theories by Harvard astrophysicist Avi Loeb proposed that interstellar objects like 3I/ATLAS could be artificial. However, based on recent observations, he and other experts now agree it is most likely a natural comet, though its origin remains a subject of study.When will we get new data about it?The European Space Agency’s JUICE spacecraft is monitoring 3I/ATLAS from an advantageous position near Jupiter. Early scientific data about its structure and composition is expected by February 2026.
