We know that Earth is about 4.54 billion year old , but essay to piece together the very earliest stage of its evolution is easy said than done . Luckily , science has had some assistance from a first-rate depressed speck of zircon dated to around 4.4 billion year honest-to-god , making it the old chunk of Earth to ever have been discovered – though it ’s not the oldest affair we ’ve ever found on the planet .
The ancient vitreous silica was found in the sticks of Western Australia at a outside rock ‘n’ roll outcrop ring Jack Hills . Ina 2014 study , scientists dated the uncovering to 4.39 billion years old , give or take a few million long time . In other word , they ’d confirmed the oldest known geological cloth .
Even before this enquiry , zircons were known to be some of the oldest fabric on Earth , though finding any previous than 4.3 billion years old is extremely rare , making the Jack Hills find all the more significant .
zircon form as a mineral within sure magma as they cool . They ’re tough as nail and up to of survive for billions of class , even when subject to intense heat or pressure . This make them perfect time capsules from Earth ’s former history .
Bear in mind , this particular zircon crystal is perfectly petite , barely visible to the naked optic . Despite its microscopical sizing , however , it obligate some Brobdingnagian implications .
Its date of lineage was a mere 160 million age after the organisation of our Solar System . This means it was produce just tens of millions of age after an former proto - Earth collide with a giant Mars - sizing object , creating our Moonin the process and turning our planet into a glowing red glob of molten rock .
However , this jot of zircon suggested that this impassioned hellhole did n’t last for too long . If zircon was around 4.4 billion year ago , then Earth must have cooled and congealed by then , forming a incrustation . Working within this time flesh , the prehistoric zircon serves as grounds that Earth developed liquid water environments around 4.3 billion year ago andpossibly lifeshortly after .
“ This reassert our view of how the Earth cooled and became inhabitable . This may also help us interpret how other habitable planet would form , " Professor John Valley , a geochemist at the University of Wisconsin - Madison , said in astatementmade in 2014 .
" The Earth was assembled from a lot of heterogeneous material from the solar system of rules , ” tot Valley . “ Our samples form after the magma oceans cooled and prove that these event were very other . "
However , while the Jack Hills zircon might be the onetime patch of Earth we ’ve ever found , it ’s not theoldest material to ever have been discoveredon the major planet . That title goes to some tiny grains of interstellar rubble .
These miniscule fragment of the Murchison meteorite that fall in Victoria , Australia back in 1969 have been date at a whopping 5 to 7 billion years old . According to the scientist who examine them , the grains are grounds that the Milky Way went through “ a period of enhancedstar geological formation ” during this time .
An earlier edition of this clause was published inApril 2023 .
