Science & Tech · Space · 10 hrs ago
Euclid telescope discovers previously unknown comet
Euclid spotted a comet astronomers had not known about in September 2026, even though the European Space Agency telescope was built to study distant galaxies.
The discovery was made in images taken from September 16 to 24, when the comet appeared in five patches of sky.
Software written by University of Helsinki student Mikko Pöntinen flagged the moving object as a streak, and a fuzzy cloud around it suggested it was shedding dust and gas.
Pöntinen found no match in lists of known comets and reported the object to the International Astronomical Union’s Minor Planet Center.
The center confirmed it on October 8 as C/2026 S1 (Euclid) after astronomers on the ground added observations.
The comet is about 1.3 billion kilometres from Earth and follows a path high above the plane where the planets orbit the Sun.
The chance discovery shows Euclid can also capture Solar System objects, although its main mission is to map billions of galaxies and study dark matter and dark energy.
ESA’s Euclid telescope discovered comet C/2026 S1, the first comet it has found that was not already known.
Euclid captured the comet in images taken between September 16 and 24, 2026.
Software written by University of Helsinki Ph.D. student Mikko Pöntinen flagged the comet’s streak across the images.
The International Astronomical Union’s Minor Planet Center confirmed the comet on October 8.
The comet is about 800 million miles (1.3 billion kilometers) from Earth and follows a path high above the Solar System’s planetary plane.
- Who
- ESA’s Euclid telescope discovered the comet. Mikko Pöntinen’s software flagged it.
- What
- Euclid discovered a previously unknown comet, officially named C/2026 S1 (Euclid).
- When
- Euclid photographed it between September 16 and 24, 2026. The Minor Planet Center confirmed it on October 8.
- Where
- In images of five patches of sky captured by Euclid. The comet is about 800 million miles (1.3 billion kilometers) from Earth.
- Why
- Not stated
This story does not have two clearly opposing sides.
Euclid captured images showing the comet in five patches of sky.
Pöntinen compared the object with lists of known comets and asteroids, found no match, and reported it to the Minor Planet Center.
The Minor Planet Center confirmed the comet.
- Official name
- C/2026 S1 (Euclid)
- Image dates
- September 16–24, 2026
- Number of image sets
- Five
- Number of exposures
- 16
- Distance from Earth
- About 800 million miles (1.3 billion kilometers)
What people are saying
I was excited to see my software flag a ‘streak’ smeared across several images – the result of a fast-moving object
Very few comets are expected to be discovered by Euclid so it was a happy coincidence that the combination of the comet’s orbit and Euclid’s scanning over those days captured the object in multiple images