On the 92nd night of In These Nights, we shared the story of a traveller from a distant star coming to visit us.

On a quiet night, beneath a star-filled sky, a new story began in our solar system. On July 2, 2025, news of a strange and wondrous object reached scientists, like a breeze from the cosmos. This object, discovered by the ATLAS system, was neither an ordinary asteroid nor a comet from the familiar corners of our solar system. This guest was a traveller from a far-off star, embarking on a long journey through interstellar space to visit our Sun.

The ATLAS system, a network of powerful telescopes located in Hawaii, Chile, and South Africa, operated by NASA and the University of Hawaii, continually scans the sky to track moving objects, such as asteroids and comets. This time, ATLAS found something unexpected: an object whose orbit and speed suggested it did not originate from the Oort Cloud or the Kuiper Belt, the two vast reservoirs of comets in our solar system. The Oort Cloud, an imaginary shell about one light-year from the Sun, and the Kuiper Belt, a region beyond Pluto, are the birthplaces of most of our solar system’s comets. But this object, with its peculiar entry angle and astonishing speed of 68 kilometres per second, told a different story. It seemed to have been flung toward us from another star system, perhaps from the vicinity of an unknown star.

This is not the first time such a guest has visited our solar system, but such encounters are rare. In 2017, a peculiar object named ʻOumuamua was discovered. Its elongated shape and unusual behaviour sparked countless rumours, marking it as the first known interstellar visitor. Then, in 2019, Comet Borisov, with its classic comet halo and tail, became the second confirmed guest.

Now, this new object is the third member of this rare group. Currently, it is about 670 million kilometres from Earth—roughly in Jupiter’s orbit—and is racing toward the Sun. Scientists predict it will reach its closest point to the Sun (perihelion) on November 8, 2025, somewhere closer than Mars’ orbit.

This cosmic visitor poses no danger to Earth. Contrary to science fiction tales, it is neither a spaceship nor a messenger from alien civilizations. And despite the claims of sensationalists—like Mr. Raefipour—who see it as a cosmic omen or a sign of ancient apocalyptic prophecies, it is simply a natural object visiting us.

Yet, for scientists, this object is a priceless treasure. It is a fragment of another world that could reveal secrets of a distant star. We usually study other stars through their light or spectroscopy, but now a tangible piece of that world has come to us. If we could design a mission to sample it, the data would revolutionize our understanding of exoplanetary systems. Such missions, however, require years of planning, so for now, we must rely on remote observations.

This object, currently shining at an apparent magnitude of about 17, grows brighter each day. But predicting its behaviour is challenging. As astronomers say, “The only certain thing about comets is their unpredictability!” Depending on its structure, it might become bright enough near the Sun to be visible with amateur telescopes. By early 2026, better observation opportunities may arise. However, its proximity to the Sun will make it difficult to observe with large telescopes, as the Sun’s light may obscure it.

This discovery is a rare opportunity. Data from this object could reveal the chemical composition and structure of other star systems. Every speck of dust, every molecule of ice on it, could be a clue to its birthplace. The Minor Planet Center maintains updated information on this object, and enthusiasts can track its journey through the center’s website.

This story reminds us of the wonders of the cosmos. We live in a small corner of the galaxy, but every so often, a visitor from afar reminds us how vast and mysterious the universe is. This object, coming from an unknown star, not only enriches our knowledge but teaches us to remain humble before the grandeur of the cosmos. So, tonight, as you gaze at the sky, perhaps somewhere in that darkness, your eyes will catch a faint glimmer of a traveller bringing us a tale from distant stars.

Suggested Resources for Further Reading

1. NASA Science – Comet 3I/ATLAS
   NASA’s official source for up-to-date information on the position, trajectory, and characteristics of the comet:
   https://science.nasa.gov/solar-system/comets/3i-atlas
2. NASA Planetary Defense Blog – Interstellar Comet Discovery
   Detailed report on the discovery and characteristics of this interstellar object by the ATLAS project:
   https://science.nasa.gov/blogs/planetary-defense/2025/07/02/nasa-discovers-interstellar-comet-moving-through-solar-system
3. Scientific American – “New Interstellar Object: 3I/ATLAS”
   Initial analysis of the object’s interstellar origin and comparison with ʻOumuamua and Borisov:
   https://www.scientificamerican.com/article/new-interstellar-object-comet-3i-atlas-what-we-know-so-far-as-it-zips
4. NASDAQ Science – Kuiper Belt
   Comprehensive introduction to the Kuiper Belt, its structure, key objects, and related missions (e.g., New Horizons):
   https://science.nasa.gov/solar-system/kuiper-belt
5. NASA Science – Oort Cloud
   Detailed information about the Oort Cloud as the source of long-period comets in our solar system:
   https://science.nasa.gov/solar-system/oort-cloud
6. Morbidelli et al. (2005) – “Origin and Dynamical Evolution of Comets and their Reservoirs”
   Scientific analysis of the origin and dynamical paths of comets related to the Oort Cloud and Kuiper Belt:
   https://arxiv.org/abs/astro-ph/0512256
7. Rickman et al. (2008) – “Injection of Oort Cloud Comets”
   Modelling and simulation of external forces (e.g., galactic tides) in activating Oort Cloud objects:
   https://arxiv.org/abs/0804.2560
8. Shannon et al. (2019) – “Oort Cloud Asteroids: Nice Model”
   Examination of planetary migration models in the formation of the Oort Cloud and object transfers to current orbits:
   https://arxiv.org/abs/1903.03199
9. Dobson et al. (2023) – “Phase Curves of KBOs and JFCs from ATLAS”
   The role of the ATLAS project in analyzing the optical and phase properties of Kuiper Belt objects and Jupiter-family comets:
   https://arxiv.org/abs/2303.08643