Scientists later used radioactive dating
to determine the ages of layers of the lava and ash that have repeatedly blanketed the area.
The researchers relied on radioactive dating
to determine the ages of tiny glass beads in the soil samples.
Finally, radioactive dating
revealed that the salt crystals were 4.6 billion years old.
A highly accurate method for radioactive dating
of meteorites underlies the findings.
Both the total abundance of carbon-14 and its age, estimated from radioactive dating
at between 5,200 and 11,900 years old, demonstrate that it originated on Earth, Jull says.
Analyzing 10 samples of the meteorite by radioactive dating
, the team found that the iddingsite formed between 274 and 655 million years ago.
of certain isotopes in the rock indicates that it formed beneath the Martian crust some 4.5 billion years ago.
The new finding, based on a highly accurate method for the radioactive dating
of primitive meteorites, pinpoints one of the earliest and most important events in the solar system-the time at which frozen water became liquid.