A bizarre green 'fireball ' left residents in Colorado baffled after appearing in the sky for more than ten seconds . The bright light , which was seen by dozens of early morning commuters on Wednesday , lingered over a highway before disappearing behind mountains . Residents took to social media to share their theories , which ranged from an unusually bright aircraft to an alien invasion . A bizarre green 'fireball ' left residents in Colorado baffled on Wednesday after appearing in the sky for more than ten seconds . Erica Hopkins wrote on Twitter : 'Ummmmmm the green fireball in Colorado sky this morning ... what DE heck was that and why nobody seem to care ? ' ( sic ) And Greg Moore , an analyst and contributor at Weather5280 , said : 'Huge fireball north to south west of vail pass this morning . Bright green flaming tail . Across full sky . # fireball # meteor # cowx ' But NASA has now confirmed the unusual sight was just a meteor . Bill Cooke , lead for the meteoroid environments office at NASA , said that the meteor moved from east to west around 45,000 miles per hour . NASA has now confirmed the unusual sight was just a meteor . Bill Cooke , lead for the meteoroid environments office at NASA , said that the meteor moved from east to west around 45,000 miles per hour . Residents took to social media to discuss what they had seen and share their theories , which ranged from an unusually bright aircraft to an alien invasion . 'The fireball belongs to a class of meteors called Earthgrazers , which hit the Earth 's atmosphere at a very shallow angle , ' he told the Denver Post . Earthgrazers are bright stars that often display colourful halos and long-lasting trails . The American Meteor Society wrote on Facebook that 150 witnesses had filed sightings spanning from southern Wyoming and northern Colorado . It added on its website : 'This is an atypical meteor event because most fireball meteors last only three to five seconds . ' It said it did not know whether it was a fireball meteor or space trash .
Fireball was seen by this morning commuters in Colorado on Wednesday . Theories shared on social media ranged from bright aircraft to aliens . But glow came from meteor hitting the Earth 's atmosphere , NASA said .