An icy belt of comets orbiting a nearby young, sun-like star has been recently discovered, potentially giving scientists a peek into the evolution of our solar system.
The star, called HD 181327, is estimated to be 23 million years old, while our solar system's age is about 4.6 billion years. It is situated in the Painter constellation some 160 light-years away.
"Young systems such as this one are very active, with comets and asteroids slamming into each other and into planets," said Sebastián Marino, lead author and a Cambridge Ph.D. student. He added that the discovery of a system that has ice composition similar to ours can enrich information on the early days of the solar system.
A dust ring thought to be debris, emerging from comets and other cosmic bodies surrounds the star, which may have planets in its orbit as well. Since current technology could not determine this, the team used data from the Atacama Large Millimeter Array (ALMA) telescopes in Chile to look for gas signatures, since the same collisions causing the dust ring formation around HD 181327 should also lead to the release of gas.
They found low concentrations of carbon monoxide in the dust ring – similar to the amount of gas found in our own comets. Usually, carbon monoxide is detected only around stars that are much bigger. However, HD 181327 is only around 30 percent more massive than the sun.
Comets are considered “dirty snowballs” of rock and ice, accompanied sometimes by a tail of dust and trailing evaporating ice. Formed early during the birth of star systems, they are usually located in the outer solar system, but are most visible once they visit the inner regions.
Halley’s Comet, for instance, drops by the inner solar system every quarter of a century, while others take their sweet time and reach 100,000 years before visiting again.
It is believed that during the formation of the solar system, Earth was a rocky terrain that approximates Mars’ current conditions. As comets collided with the planet, they brought a number of compounds and elements, such as water, with them.
The findings will be published in the journal Monthly Notices of the Royal Astronomical Society.
A tailless comet called Manx discussed earlier in May may also hold clues on the solar system’s evolution, as it appeared to feature materials from Earth’s own beginnings. The said materials hailed and were preserved from the Oort Cloud far from our sun for billions of years.
