Inside the space bubble
© NASA Goddard
Around 7,100 light years from Earth is the Bubble Nebula. It spans seven light years across and at its centre is a star 45 times more massive than our Sun. The central star has lost most of its outer hydrogen and is emitting gas rapidly – at over 4 million miles per hour. These stellar winds of gas create the outer shell of the bubble. The gases are seen in blue for oxygen, green for hydrogen and red for nitrogen.