Astronomers all over the world are closely watching a rare cosmic event as the interstellar comet 3I Atlas will be making its closest approach to Earth on December 19. The object is the third confirmed interstellar visitor ever observed passing through our solar system after the discoveries of ‘Oumuamua in 2017 and comet Borisov in 2019. For the unversed, it was discovered in July and will flyby Earth, offering the scientists a unique opportunity to study material formed around the space. But the question is how close it will flyby and are we safe?
Comet 3I/ATLAS was discovered on July 1 by NASA-funded ATLAS telescopes in Chile. Scientists quickly determined that the comet formed outside of the Sun’s gravitational influence, confirming its interstellar nature. According to trajectory data, 3I/ATLAS entered the solar system from deep space and will exit after completing its flyby, never returning.
As per the European Space Agency, the comet will pass Earth at a distance of around 1.8 astronomical units, or roughly 270 million kilometres. This distance can be contemplated as twice the distance between Earth and the Sun. This means we are completely safe from the comet.
Even if it passes from a massive distance, the flyby will offer astronomers a rare opportunity to study the material formed around another star. As the comet approaches the Sun, heat triggers the release of gas and dust from its icy nucleus. Analysing this material can help scientists better understand how comets and planetary systems form beyond our solar system.
In recent weeks, several space agencies and observatories have focused their instruments on the interstellar comet. New images from the Hubble Space Telescope and the European Space Agency’s JUICE spacecraft show the object as it moves through the inner solar system.
If you are a skywatcher, you can follow the comet’s close approach through a free livestream hosted by astronomer Gianluca Masi via the Virtual Telescope Project. It will start at 11 PM EST on December 18 or 9:30 AM IST on Friday, December 19, 2025.