Astronomers have made a rare observation. They have seen jets spinning on a comet from another star system. The comet is named 3I/ATLAS. It is traveling out of our solar system now. The discovery was reported in early 2025.
Scientists studied the comet for over two months. They used telescopes in the Canary Islands. They saw repeating patterns in its tail. The tail was pointing toward the sun. This type of tail is called an “anti-tail.” It is not common.
The jets in the tail moved in a cycle. The cycle repeated every 7 hours and 45 minutes. This movement allowed scientists to estimate the comet’s spin. They believe the comet’s core rotates once every 15.5 hours.
This comet is a special visitor. It is only the third object known to come from outside our solar system. The first was ‘Oumuamua in 2017. The second was 2I/Borisov in 2019.
Why This Discovery is Important
This is the first time such jets have been seen on an interstellar comet. The process is called “outgassing.” It happens when sunlight warms the comet. Frozen material turns to gas and escapes. This gas carries dust away, forming jets.
Scientists understand this process in our own solar system’s comets. Seeing it on a visitor from another star is new. It helps us learn about how comets behave everywhere in the galaxy.
One researcher explained the significance. They said studying these jets is a rare chance. It lets us examine a pure object formed in another star system.
The Comet’s Journey Past the Sun and Earth
The comet’s path was tracked for 37 nights. Observations ran from July to September 2025. The team used a powerful twin telescope in Tenerife.
They watched the comet’s dust and gas change. The sun-facing tail grew very long. At one point, it stretched about 1 million kilometers.
The comet came closest to the sun on October 30, 2025. It swung within 130 million miles. Later, it passed closest to Earth on December 19, 2025. It was about 168 million miles away.
Now, the comet is moving away. It will leave our solar system completely. Like the two interstellar visitors before it, it will not return.
These short visits are very valuable. They give scientists a brief chance to study material from another star. The data collected will be analyzed for years to come.