Don't expect it to own up to it in public, but it would appear that the oldest rock fragment that scientists have until now discovered on our planet is about 4.4 billion years old. More precisely, it has been around for 4.375 billion years, give or take 6 million years.
In a paper published in the journal Nature Geoscience this past February 23, an international team of scientists details that the rock fragment now said to be billions of years old is a fairly small zircon crystal.
The crystal in question, along with several others of its kind, was found on a sheep ranch in Western Australia's Jack Hills region back in 2001.
As surprising as this may sound, it would appear that, despite its importance, the crystal is fairly small. Thus, it measures just 200 by 400 micromicrons, information made available to the public says.
Eurek Alert tells us that, according to researcher John Valley with the University of Wisconsin-Madison, the age of this zircon crystal indicates that our planet's crust first came into being at least 4.4 billion years ago.
Otherwise put, it formed a mere 160 million years after our solar system was born, specialist John Valley goes on to detail.
The researcher also says that, all things considered, the age of this zircon crystal suggests that our planet was home to liquid water quite early in its life.
“The study reinforces our conclusion that Earth had a hydrosphere before 4.3 billion years ago, and possibly life not long after,” John Valley reportedly said in a statement.
In order to determine the age of the zircon crystal, now referred to as the oldest known material of any kind acknowledged to have formed on our planet, the researchers who worked on this project resorted to two different techniques.
These techniques are known to the scientific community as atom-probe tomography and ion mass spectrometry, and allowed specialists to establish the age of the crystal and its thermal history by analyzing individual atoms of lead contained in it.