If you were to watch Earth from space , you might notice sudden flashes of light . This has been known for decennary , but now scientists have found out what ’s causing them : ice crystallization .
The flashes were first key out in the other 1990s by Carl Sagan and fellow . Now , NASA ’s DSCOVR ( Deep Space Climate Observatory ) has provided enough data to understand them – the spark are because of horizontal , high - altitude ice crystals . So far , DSCOVR ’s Earth Polychromatic Imaging Camera ( EPIC ) has observed 866 of them .
Sagan ’s team used the Galileo investigation , which launch in 1989 , as it passed near Earth in 1990 . The team wanted to feel out ifthey could tell somethingabout life on Earth by seem at scene of our planet . They thought the ostentation were reflections on the sea , but afterwards scientists realise that the glints appeared over state too .
“ We found quite a few very bright photoflash over land as well , " Alexander Marshak , DSCOVR deputy project scientist at NASA ’s Goddard Space Flight Center , said in astatement . " When I first meet it I suppose maybe there was some weewee there , or a lake the sun reflects off of . But the glint is pretty big , so it was n’t that . "
Another initial explanation was light . Electrical spark in the atmosphere could be burnished enough to be see by DSCOVR , which is located 1,500,000 kilometers ( 930,000 miles ) from Earth . However , when the team considered the stead of the Sun and the craftiness when the image were take , the flashes only appeared when the angle between the EPIC , Earth , and our Sun matched .
“ Lightning does n’t care about the sun and EPIC ’s localization , ” Marshak add . " The source of the flashes is definitely not on the ground . It ’s emphatically water ice , and most potential solar reflection off of horizontally oriented particle . "
The EPIC legal instrument can measure how high clouds are , and in this case they were able to estimate that the flashes originate in high cirrus cloud clouds 5 to 8 kilometers ( 3 to 5 geographical mile ) over the surface of the Earth .
This ice crystal discovery has import both near and far . terrestrial scientists will for certain be rum to translate how much sunlight is reflected into outer space by these atmospherical formation . It ’s unclear at the moment if there ’s enough of them to make a goodish donation to the vim budget of the atmosphere .
The other consequence is instead relate to exoplanets . Similar to what Sagan had envisioned , these flashes might be visible using advanced instruments ( like the upcoming James Webb Space Telescope ) and might tell us a fate about a remote major planet ’s atm .
