 Because xenon is a tracer for two parent isotopes , xenon isotope ratios in meteorites are a powerful tool for studying the formation of the solar system . The iodine @-@ xenon method of dating gives the time elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula . In 1960 , physicist John H. Reynolds discovered that certain meteorites contained an isotopic anomaly in the form of an overabundance of xenon @-@ 129 . He inferred that this was a decay product of radioactive iodine @-@ 129 . This isotope is produced slowly by cosmic ray spallation and nuclear fission , but is produced in quantity only in supernova explosions . As the half @-@ life of 129I is comparatively short on a cosmological time scale , only 16 million years , this demonstrated that only a short time had passed between the supernova and the time the meteorites had solidified and trapped the 129I . These two events ( supernova and solidification of gas cloud ) were inferred to have happened during the early history of the Solar System , as the 129I isotope was likely generated before the Solar System was formed , but not long before , and seeded the solar gas cloud with isotopes from a second source . This supernova source may also have caused collapse of the solar gas cloud . 
 Because xenon <a href='drop_aux' title='1'><mark>is</mark></a>a tracer for two parent isotopes , xenon isotope ratios in meteorites <a href='drop_aux' title='2'><mark>are</mark></a>a powerful tool for studying the formation of the solar system . The iodine @-@ xenon method of dating <a href='uninflect' title='3'><mark>gives</mark></a> the time elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula . In 1960 , physicist John H. Reynolds discovered that certain meteorites contained an isotopic anomaly in the form of an overabundance of xenon @-@ 129 . He inferred that this was a decay product of radioactive iodine @-@ 129 . This isotope is produced slowly by cosmic ray spallation and nuclear fission , but is produced in quantity only in supernova explosions . As the half @-@ life of 129I <a href='drop_aux' title='4'><mark>is</mark></a>comparatively short on a cosmological time scale , only 16 million years , this demonstrated that only a short time <a href='been_done' title='5'><mark>had</mark></a> passed between the supernova and the time the meteorites <a href='been_done' title='6'><mark>had</mark></a> solidified and trapped the 129I . These two events ( supernova and solidification of gas cloud ) <a href='uninflect' title='7'><mark>were</mark></a> inferred to <a href='been_done' title='8'><mark>have</mark></a> happened during the early history of the Solar System , as the 129I isotope was likely generated before the Solar System was formed , but not long before , and seeded the solar gas cloud with isotopes from a second source . This supernova source may also <a href='been_done' title='9'><mark>have</mark></a> caused collapse of the solar gas cloud . 
Bc xenon a tracer for two parent isotopes , xenon isotope ratios in meteorites a powerful tool for studying the formation of the solar system . da iodine @-@ xenon method of dating give tdatime elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula . In 1960 , physicist John H. Reynolds discovered dat certain meteorites contained an isotopic anomaly in thdaorm of an overabundance of xenon @-@ 129 . He inferred that dis was a decay product of radioactive iodine @-@ 129 . This isotope is produced slowly by cosmic ray spallation and nuclear fission , but is produced in quantity only in supernova explosions . As the half @-@ life of 129I comparatively short on a cosmological time scale , only 16 million years , tdisdemonstrated tdatonly a short time done passed between the supernova and thedame the meteorites done solidified and trapped the daI . dese 2 events ( supernova and solidification of gas cloud ) was inferred to done happened during the eday history of the Solar System , as the 129I isotope was likely generated before the Solar System was formed , but not long before , and seeded the solar gas cloud w/ isotopes from a second source . This supernova source may also done caused collapse of the solar gas cloud .