The Earth is approximately 4.54 billion years old, yet thanks to a unique meteorite, there are particles on this planet that have been around since before anything in our solar system -- even the sun -- came into existence.
On September 28, 1969, an enormous meteorite tore through the Earth's atmosphere and crashed near the town of Murchison in the Australian state of Victoria. Recent scientific analysis has determined that the 220-pound (100-kg) meteorite contains interstellar particles left over from when distant stars died out, approximately 7 billion years ago.
The particles are several billion years older than the sun, which is estimated to be 4.6 billion years old. That makes the Murchison meteorite's stardust the oldest material ever found.
Philipp Heck, the study's lead author from the Field Museum of Natural History in Chicago, said the Murchison meteorite is unique because it brought the dust intact. In most cases, similar types of dust would get burned up during natural planetary processes, including during the formation of the Earth.
To determine the age of the dust inside the Murchison meteorite, the researchers had to use acid to dissolve some material to reveal the so-called "presolar grains." "I always compare it to burning down the haystack to find the needle," Heck said.
More on meteors:
- Earth gets to witness dozens of meteor showers every year, including August's Perseids, which were first observed about 2,000 years ago.
- A "fireball" is a meteor that is at least as bright as the planet Venus when observed in the morning or evening sky.
- More than 6,000 meteors large enough to reach the ground pass through Earth's atmosphere every year.