In this clip from his radio show “Star Talk,” astrophysicist Neil deGrasse Tyson explains that while there are white stars, blue stars and red stars, there are no green stars.
“There’s green in space,” Tyson said, “there’s just no green stars.”
“There’s actually green emissions from gas clouds in space,” he continued, which for centuries scientists observed but did not understand. The clouds came to be called nebulae.
Nebulae are made up of “oxygen behaving in ways that we have never been able to reproduce in the laboratory,” said Tyson.
“Stars,” on the other hand, he said, “are giving off this whole spectrum of light. Green is this very narrow part of the middle of the spectrum.”
Spectrums, Tyson explained, can “lean to the blue side or lean to the red side or about the same of each,” which results in blue stars, red stars or stars, like Earth’s sun, that appear white.
“You’re not going to get a green star,” he concluded, “and that’s why.”
Watch the video, embedded below via YouTube and Star Talk Radio: