So many valuable historical things are hidden beneath the Earth’s surface.
According to scientists, the oldest material on Earth is stardust. It is about 7 billion years old and found hidden away in a huge meteorite that hit the Earth’s surface 50 years ago.
Stardust is considered the oldest solid material ever to be discovered. They indicate how stars came into being in our galaxy. These presolar grain-minerals were formed before the sun came into existence. Stardust is a solid sample of stars.
They remained the same for 7 billion years because they were trapped inside meteorites. Quite like time capsules, don’t you think?
Presolar grains are scarce and tiny and found in only 5% of meteorites that fall onto Earth. Phillip Heck, a professor from the University of Chicago, is currently researching these presolar grains.
This particular meteorite was found in Australia.
This ancient interstellar dust, which made of presolar grains, which is dust grains that predate our sun, was ejected into the universe by dying stars. Some of that dust ultimately hitched a ride to Earth on an asteroid that produced the Murchison meteorite, a vast, 100 kilograms of rock that fell near Murchison, Victoria, in Australia.
Just like humans, stars too have a lifecycle. They come into existence when bits of dust and gas floating in space come together and heat up. Stars live for about billions of years and then die. The particles that form the star then float in space.
These particles of stardust end up creating new stars, new planets, moons, and meteorites. The Murchison meteorite now resides in the Field Museum of Murchison, Victoria. The presolar grains were extracted from the meteorite for further studies 30 years ago and are currently at The University of Chicago.
Based on the cosmic rays absorbed, researchers found out that the presolar grains were older than the Sun and Earth. According to their studies, the grains are created in an enhanced star formation episode and is not constant.
Researchers also discovered that presolar grains waft in space in large clusters that are stuck together. Since the lifetime of stardust has been figured out, we can’t wait to discover more about the galaxy.
Heck and his colleagues are working day and night to uncover the hidden truths of the galaxy, which sounds very exciting.
The word galaxy is originated from the Greek “γαλαξίας” translated Galaxies or galaktikos. The galaxy is a gravitationally bound arrangement of stars, interstellar gas, stellar remnants, dark matter, and dust.
The ‘Milky Way’ is the galaxy that includes our Solar System, describing the galaxy’s appearance from Earth. It is a hazy band of light seen in the night sky formed from stars, yet the naked eye cannot distinguish it.