The young sun's outbursts were trapped in blue crystals from outer space

Astronomers believed the sun went through something like the “terrible twos” based on observations of young stars far away in space. But they lacked physical clues of what our star was like in the early years after it formed some 4.6 billion years ago.

Now, by studying blue crystals trapped inside a meteorite that predates the planets, researchers have collected what they say is the first direct evidence of the sun’s activity during its fiery start. The findings were published Monday in the journal Nature Astronomy.

“This is essentially a real record of the early active sun,” said Philipp Heck, a cosmochemist at the Field Museum in Chicago and the University of Chicago, and an author of the paper.

The researchers studied the Murchison meteorite, which had crashed in Australia in 1969. Embedded inside it were microscopic blue space crystals, called hibonites, which are thought to be among the first minerals that formed in the solar system.

“Since its fall, it has been a treasure trove for science because it contains so much unaltered material from the very early solar system, like these hibonites,” Heck said.

The sun during that period was surrounded by a rotating disc of dust and gas that would eventually birth the planets. The center region of the disk was very hot, about 2,700 degrees Fahrenheit, making that area about three times as hot as Venus, the hottest planet in the solar system. The hibonites formed in space rocks as the disc cooled. And these rocks were located farther from the sun than Earth is today, according to Heck.

Although the age of the blue hibonites in the Murchison meteorite has not been directly determined, their composition suggests they may have been present during a period that stretches from when the sun was as young as a few hundreds of thousands of years old to as old as about 50 million years, when Earth formed.

Levke Kööp, a cosmochemist at the University of Chicago and lead author of the paper, took samples from the meteorite to a mass spectrometer at the Institute of Geochemistry and Petrology, at ETH Zurich, a university in Switzerland. Using an infrared laser, scientists melted the hibonites to release the gases trapped inside. The team found that the cerulean time capsules contained isotopes of neon and helium. These noble gases, trapped inside the hibonites for more than 4.5 billion years, provide clues to the young sun’s violent behavior.

“By finding helium and neon we can say that the mineral itself was irradiated,” Kööp said. “The sun was actually much more active in the early days than it was today.”

Hibonite crystals are rich in calcium and aluminum. As the young sun spewed bursts of radiation into space, the protons collided with these elements in the crystal, splitting them into neon and helium.

“It would be like watching cosmic fireworks,” Heck said. “These eruptions resulted in a stream of charged particles going into different directions irradiating anything in its way.”

Heck said that this phase of irradiation has not been seen in younger meteorites that have fallen to Earth, or on Earth rocks or moon rocks, further indicating the sun’s activity slowed down at some point.

The sun is now about halfway through its life cycle. That means that humanity can look forward to another 4 billion years of relative calm as long as we stick around this solar system.

“Afterward, it becomes a red giant and is much less pleasant,” Heck said.

This article originally appeared in The New York Times.