Approximately 14 million years after the start of the Solar System, Earth and the rest of the inner planets were supposedly inundated with water, setting back the clock for when life could have evolved, according to a new study. The study headed by Adam Sarafian of the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Massachusetts, found that our seas may have arrived much earlier on our planet than previously thought.
Because the environmental conditions in Earth’s early years made it impossible for water to remain on the planet’s surface, scientists have found evidence that the ingredients for water were protectively stored inside rocky bodies near our planet — and maybe inside Earth itself. The new findings suggest that there was water in the inner solar system 135 million years earlier than previous evidence had shown.
The new analysis pushes water’s first appearance in Vesta and presumably on other rocky, planet-like bodies including Earth to just 14 million years after the start of the solar system. While the Earth grew and changed over the next 4 billion years or so, Vesta remained frozen in time, according to Sarafian.
“Our findings show the earliest evidence of water in the inner solar system,” said Adam Sarafian, a Ph.D. student at the Woods Hole Research Center in Massachusetts. Water in rocks left over from the earliest formation of Earth’s solar system neighborhood, studied at UNM and Woods Hole in Massachusetts, bears the same chemical fingerprint as the water that dominates Earth’s surface today, according to the new research.
Our solar system formed more than 4 billion years ago when a cloud of dust and gas coalesced, with a star – our sun – in the center. Smaller bits clumped together under the growing tug of their own gravitational attraction to form the orbiting planets. Scientists had long suspected that the inner part of the solar system, nearer to the sun, was too hot for water during this early part of formation. Under that theory, the inner solar system was dry. Water lurked in the outer reaches of the solar system, locked up in icy comets. Only later, once Earth had finished forming, that theory went, was the water added through cometary bombardment.
Geologic activity on Earth has destroyed the earliest records of the planet’s formation, with its oldest rocks dating back to about 200 million years after the formation of the solar system some 4.6 billion years ago. But the Vesta meteorites, known as eukrites, date back to 14 million years after the start of the solar system. Sarafian and collegues measured a mineral called apatite in the samples to determine their water content.
“This is the oldest water that anyone has measured that has accreted to something that resembles a planet,” Sarafian said.