Explanation: What happens if you ascend this stairway to the Milky Way? Before answering that, let's understand the beautiful sky you will see. Most eye-catching is the grand arch of the Milky Way Galaxy , the band that is the central disk of our galaxy which is straight but distorted by the wide-angle nature of this composite image . Many stars well in front of the Milk Way will be visible, with the bright white star just below the stellar arch being Altair , and the bright blue star above it being Vega . The air glows green on the left, just above the yellow cloud deck. The featured image was taken last month on Portugal 's Madeira Island in the North Atlantic Ocean . Oh, and what happens after you reach the top of these stairs and admire the amazing sky is, quite probably, that you then descend down the stairs on the other side.

Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)