Sky Matters: rogue star wandering the galaxy since before the earth or sun was born gets a temporary comet tail

For most of its journey 3I/ATLAS has been frozen solid, but the warming rays of our Sun are enough to unfreeze some of its gases such as carbon dioxide, generating a faint cometary tail. For a period of a few weeks 3I/ATLAS comes alive, only to pass out of the solar system and spend perhaps the next billion years or more back in its frozen state

Comet C/2025 A6 (Lemmon) — pictured from Blackrock Castle Observatory. Unlike the interstellar wanderers referred to in the article, this comet is bound to the Sun and takes about 1,300 years to complete one orbit.

We are all familiar with the idea of a solar system... a gathering of planets and smaller objects (comets, asteroids and moons) orbiting a parent star again and again over periods of billions of years.

Solar systems provide a high degree of stability — a place in the vast cosmos that one can feel comfortable when referring to it as 'home'.