The solar system may be almost 2 million years older than previously thought, a new study shows. Data from a newly studied meteorite recovered from the Saharan Desert show that the solar system formed 4,568.2 million years ago, 0.3 million to 1.9 million years earlier than other estimates. The results were published online August 22 in Nature Geoscience.
“All the interesting things we want to understand about the chemistry of our solar system happened within the first five to 10 million years,” says study coauthor Meenakshi Wadhwa, a cosmochemist from Arizona State University in Tempe. “When you push it back by 2 million years, that’s a substantial proportion of that 5 to 10 million years.”
The meteorite contains millimeter- and centimeter-sized bits of calcium- and aluminum-rich substances, some of the oldest material ever found in primordial rocks. These pockets in the rock, called inclusions, are believed to be among the first solids that condensed from gas at the beginning of the solar system’s formation. Along with other materials in the presolar cloud, the inclusions snowballed into larger objects, eventually forming asteroids and planets.
Study coauthor Audrey Bouvier of Arizona State measured the ratios of variants of lead atoms produced by the radioactive decay of uranium present when the inclusions formed. Since uranium decays at a known rate, current amounts of lead forms, or isotopes, allow scientists to calculate how long ago the space dust formed………….
read more here Solar System Older Than Estimated – Science News.