- 3I/ATLAS is one of only three known interstellar objects ever detected.
- The comet will reach its closest approach to Earth on December 19, at about 168 million miles away.
- To observe the comet, a telescope or skywatching app can be used as it won’t be visible to the naked eye or weaker binoculars.
- Experts believe that 3I/ATLAS may not be visible in the night sky at the exact time of its closest approach due to location and weather conditions.
A Rare Visitor from Outside Our Solar System
The cosmos has a new, rare visitor as interstellar comet 3I/ATLAS makes a brief appearance in our solar system. This event is significant because only three known interstellar objects have ever been detected before, making this an exciting opportunity for scientists and astronomy enthusiasts alike.
Understanding Comet 3I/ATLAS
Comet 3I/ATLAS, discovered on July 1, 2025, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey telescope in Chile, is a “cosmic snowball” as NASA refers to comets. It originates from outside our solar system and will pass through briefly before continuing its journey into deep space. At closest approach on December 19 at around 1:00 AM EST or 6:00 GMT, the comet will be approximately 168 million miles away from Earth—nearly twice the average distance between Earth and the sun.
Observing Comet 3I/ATLAS
While 3I/ATLAS will not be visible to the naked eye or weaker binoculars, a telescope is your best bet for observing this cosmic phenomenon. The comet can currently be found in the constellation Leo, near its brightest star, Regulus. However, due to Earth’s position and potential weather conditions, the exact visibility may vary depending on where you are located.
For those unable to observe from home, a live stream by The Virtual Telescope Project, featuring views from Italy, will be available starting at 11:00 PM EST or 4:00 GMT on December 18. This broadcast is subject to weather conditions and may not provide the best view of the comet.
Scientific Significance
The study of comets like 3I/ATLAS provides valuable insights into planetary formation around other stars. Scientists are using this rare opportunity to examine material from outside our solar system, which has never before been possible on such a scale. Observations indicate that the comet has a diameter between 1,000 feet (320 meters) and 3.5 miles (5.6 kilometers), traveling at an incredible speed of 130,000 miles per hour.
While 3I/ATLAS will not return to our solar system after its brief pass, it offers a unique glimpse into the mysteries of interstellar space and the formation of planets beyond our own star.
The comet’s journey through our skies is both an astronomical event and a moment in time that will be remembered for years to come.
Stay tuned as we continue to observe and learn from this rare cosmic visitor. Who knows what other secrets the universe holds, waiting to be discovered by future generations of astronomers?
