A Dark Earth with a Red Sprite
			
		
		
			Image Credit:  
ISS Expedition 31 Crew, 
NASA
		
		
			There is something very unusual in this picture of the Earth -- can you find it?
A fleeting phenomenon once thought to be only a legend has been newly caught if you know just where to look.
The above image 
was taken from the orbiting 
International Space Station (ISS) 
in late April and shows familiar ISS solar panels on the far left and part of a robotic arm to the far right.
The rarely imaged phenomenon is known as a 
red sprite and it 
can be seen, 
albeit faintly, just over the bright area on the image right.
This bright area and the red sprite 
are different types of lightning, 
with the white flash the more typical type.
Although sprites have been reported 
anecdotally for as long as 300 years, they were first caught on film in 1989 -- by accident.
Much remains unknown about 
sprites including how they occur, their effect on the atmospheric 
global electric circuit, 
and if they are somehow related to other 
upper atmospheric lightning 
phenomena such as 
blue jets or 
terrestrial gamma flashes.