An article published in the journal “Science Advances” describes a research about comet C/2014 S3 (PANSTARRS), which was preserved in the Oort cloud for billions of years while maintaining almost the same features it had at the time of its formation. Its peculiarity is that it seems to be composed of the same materials of the inner areas of the solar system so it’s a kind of fossil of the times of the Earth’s formation.
C/2014 S3 was identified originally by the Pan-STARSS1 telescope as a weakly active comet. It has an orbital period of 860 years and this suggests that it came from the Oort cloud, the outermost area of the solar system. Recently, it ended up in an orbit that brought it closer to the Sun. However, the team led by Karen Meech of the University of Hawai`i’s Institute for Astronomy realized very quickly that it’s an out of the ordinary comet.
The tail is one of the characteristics of comets that approach the Sun, instead C/2014 S3 practically doesn’t have one. For this reason, it’s been nichnamed Manx like the race of cats with no tail. Karen Meech’s team studied this strange comet with the Very Large Telescope and the Canada France Hawaii Telescope noting that has characteristics typical of S-type asteroid, composed mainly of silicates.
This type of asteroid, which have a rocky composition, is generally found in the belt between Mars and Jupiter while usually comets come from the Oort cloud and contain a lot of water ice and that’s why Manx was identified as a comet. Examining the amount of ice that determines its weak activity, it was found that the Manx’s is about a million times lower than that of a typical active long period comet.
According to the researchers, the oddities of the C/2014 S3 comet are probably due to the fact that it was born in the inner solar system from the materials present at the time, a few billion years ago. It seems to have suffered very few collisions because on its surface there are very few or even no craters.
Probably the comet C/2014 S3 was pushed into the Oort cloud shortly after its formation and there spent a few billion years. In relatively recent times some new gravitational pull altered its orbit pushing it back towards the inner area of the solar system.
For the moment it’s impossible to say whether the comet C/2014 S3 is a rare object or there are many other similar objects because we can’t detect asteroids or comets in the Oort cloud. This humble celestial body may offer important clues about the formation of the inner solar system because it remained almost unchanged for billions of years so the research on S3 will continue along with that of similar objects.
