The two newly discovered comets - Lemmon (C/2025 A6) and Swan (C/2025 R2) - are moving across the sky in a spectacular performance as they approach the Earth's orbit closest at the end of October, according to astronomers at the Lowell Observatory (USA).
Brooms are a collection of ice, thick deposits of freezing gas and rock. As they approach the Sun, the heat causes them to release gas and dust, creating a characteristic bright tail, creating a rare scene that restaurant lovers are unlikely to miss.
The Lemmon broom was discovered on January 3, while Swan was only identified on September 10, when it approached the Sun. Both have a trajectory of hundreds of years, meaning that after leaving the field of view, they will not return for many generations. Swan will not return until about 700 years, while Lemmon will not return until 1,300 years.
According to Quanzhi Ye, a researcher at the University of Maryland, Swan Broken Star is only observed in the early evening, right after dark, while Lemmon can now be seen before dawn, and will appear more clearly in the evening. Both only appear in a short period of time each day, due to their position near the Sun in the sky.
Astronomers predict that Swan will approach the Earth closest on October 20 at a distance of 38.6 million km, while Lemmon will reach its closest point on October 21 at about 88.5 million km. Both of them issued a brilliant green light, accompanied by hundreds of thousands of kilometers of dusttails.
Comets like Lemon and Swan are the time capsules of the Sun System they preserve primitive matter that formed billions of years ago, according to Carrie Holt, an economist at the Las Cumbres Observatory. When the ice layer evaporates, scientists have a rare opportunity to study the origin of the planets.
Lemmon is more noticeable in the Northern Hemisphere, while Swan shines brilliantly in the Southern Hemisphere, but it will soon be possible to observe it from the Northern Hemisphere. Lemon is expected to be bright in the next few weeks, and can even be seen with the naked eye if conditions are ideal.
Experts recommend using conveyor tubes or small constellations, observing in places with little light pollution. The Stellarium, KStars applications or livestreams from virtual Telescope Project (Italy) will help locate comets more easily.
