Scientists found a Tiny Fragment of a Comet inside a Meteorite

A recent study, published in the journal ‘Nature Astronomy’, announced that a team of researchers has identified a tiny fragment of a comet inside LaPaz Icefield 02342.

Science has yet again found something that may hold clues to the origin of our solar system. Researchers from the Carnegie Institution of Science have found a speck of a comet inside LaPaz Icefield 02342, a meteorite which was collected in 2002 from Antarctica. According to a popular belief, this meteorite was formed beyond Jupiter about 4.5 billion years ago.

Difference between Meteorite and Comet

The debris from space that survives an atmospheric entry and lands on a planet is called a meteorite. While in space, the very same body is known as an asteroid. As the body enters the atmosphere, friction, pressure, and atmospheric chemicals cause the foreign body to heat up to a point that it turns into a fireball, commonly known as a shooting star. A comet is an icy body that warms up and releases gases as it passes near the Sun (Outgassing). These gases are responsible for the glowing ‘tail’ of the comet. While asteroids and comets both are formed from space debris, they coalesce at different distances and have different chemical composition.

The Findings of Meteorite

So how did a part of a comet end up inside a meteorite?  Researchers believe that during its formation, the meteorite picked up a tiny bit of a presolar comet, only about a tenth of a millimeter across. Then with the comet part embedded inside it, the meteorite crashed into our planet. Jemma Davidson, a Meteorite Expert at the Arizona State University, referred to her experience of examining the body and said,

“When Larry [Nittler] and Carles [Moyano-Cambero] showed me the first electron images of the carbon-rich material, I knew we were looking at something very rare. This meteorite belongs to a class of primitive carbonaceous chondrite meteorites that have undergone minimal changes since they formed more than 4.5 billion years ago, likely beyond the orbit of Jupiter.”

Although the comet fragment is quite small, it helps us better understand how the material came together to form planets. Larry Nittler, the Lead Author of the paper from the Carnegie Institution of Science explained that as carbon-rich icy bodies were forming in the far outer reaches of the disk, some of their building blocks moved closer to the Sun and got trapped in asteroids. He elaborated the findings in the following words:

“Because this sample of cometary building block material was swallowed by an asteroid and preserved inside this meteorite, it was protected from the ravages of entering Earth’s atmosphere. It gave us a peek at material that would not have survived to reach our planet’s surface on its own, helping us to understand the early solar system’s chemistry.”

Link with the Formation of Earth

The tiny part of the comet is also important for understanding the formation of Earth. Matthew Genge, a Meteorite Researcher at Imperial College London who was not a part of the researching team, mentioned that most of the water on our planet was deposited by comets and asteroids. He further elaborated that the building material of comets was formed outside our solar system and was later pulled inwards. This provides a possible explanation for how water was transported to Earth, billions of years ago.

The carbon-rich primitive material of the comet is strikingly similar to the extraterrestrial dust particles that are believed to have originated from the outer edges of our solar system. It is just a tenth of a millimeter across, which is roughly the same as the thickness of a human hair. The existence of this material inside the meteorite suggests that particles like it migrated from the outer edges of the solar system due to the drag caused by the surrounding gas. Ultimately, it gave birth to comets and other Kuiper belt objects. This information reveals the details about how our solar system took shape during the early stages of planet formation. Davidson described the significance of this discovery by saying,

“Discoveries like this demonstrate how important it is to retrieve precious meteorites like LaPaz from Antarctica. We never know what secrets they’ll reveal.”