A Meteorite That Asks Questions

^{Meteorite captured by a Global Fireball Observatory camera.}

The fall of a meteorite is not an extraordinary event. Scientists believe that an average of 17 meteorites enter the Earth's atmosphere every day. But the meteorite that fell last year in Canada turned out to be very interesting, although no one realized it immediately.

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An Ordinary Meteorite

In February 2021, a completely familiar meteorite fell to the Earth's surface in Canada. Its mass was about 2 kg, and it was the size of a grapefruit. Any cosmic body is interesting to study, this meteorite is no exception. The standard scheme for studying a meteorite involves analyzing its composition, after which scientists try to calculate its trajectory in order to find out where the alien came to us from.

Analysis of the composition of the Canadian meteorite did not show anything unexpected - it consisted of stone. Therefore, very quickly everyone forgot about this small meteorite. However, science does not allow us to be guided solely by assumptions or feelings. Everything must be checked exactly according to the standard scheme. Despite everything, scientists spent more than a year to find out where this cosmic body came to us from. This became possible thanks to the fact that the fall of this meteorite caught some of the cameras that are part of the Global Fireball Observatory (GFO) network.

The determination of the place from where the meteorite came to us contained the biggest surprise. It turned out that it had flown in from the distant Oort cloud.

Oort Сloud

The Oort cloud is a very distant hypothetical region of the Solar System. The existence of the Oort cloud has not yet been confirmed by direct observations, but numerous indirect facts indicate its existence.

^Source.

The expected distance from the Sun to the outer boundary of the Oort cloud is 50,000 to 100,000 astronomical units, i.e. approximately one light year. The outer boundary of the Oort cloud defines the gravitational boundary of the Solar System.

The Oort cloud is thought to be divided into two separate regions: an outer spherical and an inner disc-shaped one. Objects in the Oort cloud are largely composed of water, ammonia, and methane ices.

Questions

Meteorites like the Canadian one come from the asteroid belt that lies between Mars and Jupiter, or from places even closer to Earth. It is here that the rocky bodies are located. However, calculations show that it came from the Oort cloud. Normally this should not be possible. All known objects that have flown in from the Oort cloud, usually comets such as Gale-Bopp's Comet, are composed of ice of various origins. According to modern ideas, rocky bodies do not exist there. Moreover, according to modern ideas about the formation of the universe, they should not be there.

“This discovery supports an entirely different model of the formation of the solar system, one which backs the idea that significant amounts of rocky material co-exist with icy objects within the Oort cloud,” said Denis Vida, an author of the study. “This result is not explained by the currently favored solar system formation models. It’s a complete game changer.”

Sources:

• New Atlas
• Nature Astronomy