Astronomers have found a tailless comet that seems to be made of inner solar system material from the time of Earth’s formation, which offers clues to the solar system’s beginnings. Named C/2014 S3, the comet is more of an ancient body rock that could have been one of the building blocks of rocky planets like the Earth but was expelled from the inner solar system billions of years ago.

The comet was detected back in 2014 by the Pan-STARRS1 telescope, also known as the Panoramic Survey Telescope and Rapid Response System telescope. The findings were published on April 29 in the journal Science Advances, stating that the object came from the Oort cloud located beyond the dwarf planet Pluto and the Kuiper Belt, with an orbital period of around 860 years.

Interestingly, the comet bears a resemblance to the S-type asteroids found in the inner asteroid main belt. However, unlike a typical comet, C/2014 S3 is rocky rather than icy.

ESO/L. Calçada

Artist’s impression of the unique rocky comet C/2014 S3. Credit: ESO/M. Kornmesser

Moreover, C/2014 S3 does not come with a characteristic tail like other comets, which appears when the ice vaporises as they approach near the Sun, prompting the team to nickname the comet as the Manx comet after the tailless cat. The scientists explain that the tailless comet contains about 100,000 to one million times less water than other comets.

The research team hopes to find other Manx comets waiting to be discovered out there. A discovery of more Manx comets could help restructure and improve current models that seek to explain how the solar system formed and settled to its present configuration.

“We’ve found the first rocky comet, and we are looking for others,” adds co-author Olivier Hainaut, an astronomer with the European Southern Observatory in Garching, Germany. “Depending how many we find, we will know whether the giant planets danced across the Solar System when they were young, or if they grew up quietly without moving much.”