A lilliputian under three million years ago , a massive star detonate in our galaxy about 300 light years away .
Thissupernovawas so close to our satellite that , count on where it went off , our evolutionary ancestors might have seen it as a bright Christ Within in the sky .
As our solar system journey through radioactive molecule of stardust left over from the explosion , some of the dust broke through our atmosphere and rained down on our planet .
Now a recent discovery from bass within our still - vast ocean is helping us piece together detail of a cosmic consequence that may have changed our planet millions of old age ago .
Supernova detritus in the ocean
In 2004 , scientists found some of thissupernova debris in pelagic crustfrom the Pacific Ocean . But until now , scientists had a elusive time pinpointing exactly how long ago the supernova discharge its insides into place . That ’s because the type of sea impudence they found the junk in grows passing tardily — about 1 mm every million class .
In anew studypublished today in the Proceedings of the National Academy of Sciences ( PNAS ) , scientists were able to figure out how long ago the star exploded and how much fourth dimension our solar system drop traveling through its star bowel . Not only was the length of metre our solar system spent in the principal ’s stay on surprising , it also coincides with anextinction eventin Earth ’s ocean , as well as a catamenia of spheric cooling .
quartz glass - make bacterium
Marianne Hanzlik
To get these results , the scientists used a different case of ocean sediment from the Pacific Ocean that grows at a rate of 10 - 20 meters every million years . They were searching for corpuscle of a radioactive isotope of atomic number 26 called iron-60 . Iron-60 is not produced on Earth , and can only be produced in these massive , explode stars . In fact , this supernova junk is the first place in the story of our mintage that we ’ve even control it .
So what was it that preserve this 2.6 million - year - old radioactive isotope ?
According to Shawn Bishop , a physicist at the Technical University of Munich in Germany and joint author of the study , it ’s all thanks to a folk of bacteria that subsist in the sea sediment . These bacteria grow dozens of tinycrystals of magnetite , write of iron and oxygen , in their cells . These crystals , Bishop allege , are actually tiny bar magnets . They get their Fe from nanosized rust atom hang into the surface of the ocean from our atmosphere .
Although the bacteria are long numb and their cells have since been dissolve , the crystals , called magnetofossils because they ’re charismatic , remain .
Much of the supernova material coming into our atmosphere would have been a fine radioactive dust , which would have oxidized and release to rust fungus - like particles as it rain down down on the ocean and settled into the sediments .
“ The idea that stardust is found on our satellite in crystals of magnetite made by bacterium that live in the ocean sediment is to my judgement extremely coolheaded , ” Bishop told Business Insider .
trip the light fantastic toe in stardust for a million years
Using a proficiency that allowed them to count the atoms of iron-60 in the crystals , the scientists were able-bodied to compute out that the supernova last off about 2.6 million geezerhood ago , and our solar organization spin through its guts for 800,000 year .
This was surprising to the scientists because when a supernova explodes , the material , or ejecta , that escape the gravitational well of the headliner travels between about 3,000 and 6,000 miles per secondly . And yet somehow it took nearly a million years to go along through our solar arrangement .
“ There ’s a enigma there , ” Bishop enunciate . “ Can the ejecta from a supernova explosion be propagate out in metre ? This is something that needs to be explain and sympathise . ”
' Our universe is not a friendly place to live '
One interesting aspect about this effect is that the fourth dimension our major planet spent inside the supernova textile co-occur with well - established extinction in Earth ’s oceans of thing like nautical mollusk , snail , as well as a flow of ball-shaped temperature reduction .
“ Our universe is not a friendly place to exist , ” Bishop said . “ We think it is , but as soon as you leave the confines of our planet , the existence is extremely hostile to living . There are explosion going on everywhere and if this one had been within [ 30 light years ] or less , we might not be here discussing it . ”
