Comets are mysterious travelers through our night skies. To those living in ancient times, the unpredictable appearance of comets meant the heralds of horror and the death of kings. Scientists often think of them as ancient messengers, artifacts from our youngest times as a solar system. With compositions from those early beginnings, 4.6 billion years ago, the belief is that comets carry clues to building blocks that formed the planets.

The next comet that may be visible is C/2025 K1 (ATLAS). It was discovered on May 25, 2025, in Chile. When it has its close passage to the sun, what is called perihelion, astronomers can’t be sure it will survive. Comets have a nucleus that is made of water, ice, and frozen gasses. Mixed with dust, rocky debris, and dark organic compounds loosely held together they’ve earned the nickname, dirty snowballs. This structure leaves them vulnerable to the intense gravity of the sun, the heat of which vaporizes the gases and forms the long tail that stirs our imaginations.

C/2025 K1 (ATLAS) has a relatively small nucleus and will pass close to the sun in early October. Though it will brighten a bit, it will be more visible early mornings in the northern latitudes during late October and into November when it heads past Earth. These prehistoric time machines provoke curiosity and wonder. If the expectation holds, we may have a ghostly visitor for Halloween.