"ABC it's easy as 1 2 3," or so the 'Jackson Five' song goes.
For one NASA expert however, spelling out the alphabet took a little longer.
Science writer, Adam Voiland, began collecting satellite images and photos from astronauts, representing all 26 letters.
After two years, he achieved his goal. Writing on the NASA Earth Observatory website, he stated:
"Some letters, like O and C, were easy to find. Others—A, B, and R—were maddeningly difficult. Note that the A below is cursive."
His captions for each of the images stem from a character familiar to most of us - Dr. Seuss.
"When I finally tracked down all the letters... I happened to be a new dad and deep into a Dr. Seuss reading phase with my son," he said.
Here is his entire collection: