Interstellar Comet 3I Atlas: What Will Happen When It Passes Earth?

Interstellar Comet 3I Atlas is the third confirmed object from outside our solar system to pass through it. Astronomers say the comet will make its closest approach to Earth on December 19, 2025, without posing any danger.

The object was first confirmed in July 2025 after scientists tracked its speed and trajectory. Data showed it was not bound by the Sun’s gravity, proving it originated beyond our solar system.

Interstellar Comet 3I Atlas flyby details and confirmed observations

Interstellar Comet 3I Atlas was detected traveling at about 137,000 miles per hour, according to NASA. Its extreme speed and hyperbolic orbit confirmed it formed in another star system and was later ejected into interstellar space.

NASA said the comet entered our solar system from the general direction of the constellation Sagittarius. It has likely been traveling through the Milky Way for millions or even billions of years before this encounter.

The Hubble Space Telescope captured images of Interstellar Comet 3I Atlas in July and again on November 30, 2025. Those observations helped scientists estimate the size of its icy nucleus.

Current estimates suggest the solid core is between about 1,400 feet and 3.5 miles wide. The European Space Agency notes the uncertainty comes from how much dust and gas surrounds the nucleus.

NASA confirmed the comet will pass within roughly 170 million miles of Earth on December 19. That distance is about twice the average distance between Earth and the Sun.

Officials stress that Interstellar Comet 3I Atlas is not a threat. Its path keeps it far outside Earth’s orbital zone, and no interaction with our planet is expected.

While it will not be visible to the naked eye, the comet can be observed with small telescopes. NASA says it should be visible in the pre-dawn sky through early 2026.

Why scientists are watching Interstellar Comet 3I Atlas closely

Researchers see Interstellar Comet 3I Atlas as a rare scientific opportunity. Only two other interstellar visitors have ever been confirmed before it.

Studying its composition may reveal how other star systems form planets. Scientists are particularly interested in its ice, dust, and chemical makeup.

The comet’s hyperbolic orbit means it will never return. After passing through the inner solar system, it will continue back into interstellar space.

Public interest has grown rapidly, fueled by telescope images and social media attention. NASA officials have repeatedly dismissed speculation about artificial origins.

Interstellar Comet 3I Atlas will pass Earth quietly and safely. Its value lies in the data it provides, not any visible spectacle or risk.

FYI (keeping you in the loop)-

Q1: What is Interstellar Comet 3I Atlas?

It is a comet confirmed to have originated outside our solar system. Scientists identified it in July 2025 based on its speed and trajectory.

Q2: When will Interstellar Comet 3I Atlas pass Earth?

NASA says the closest approach will occur on December 19, 2025. It will remain about 170 million miles away.

Q3: Can Interstellar Comet 3I Atlas be seen without a telescope?

No. The comet is too faint for naked-eye viewing. Small telescopes can detect it in the early morning sky.

Q4: Is Interstellar Comet 3I Atlas dangerous to Earth?

No risk has been identified. Scientists confirm it will pass at a safe distance and will not affect Earth.

Q5: Why is Interstellar Comet 3I Atlas important to science?

It offers rare insight into material formed around another star. Researchers can study its composition and motion.