Alongside the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory this #imageoftheweek lies two celestial landmarks of the northern hemisphere: the Big Dipper asterism on the right, and the North Star Polaris on the left. Often used for celestial navigation from as early as the 5th century, spotting the Big Dipper’s bright stars implies that the North Star must be nearby. This is especially the case with the stars Merak (blue) and Dubhe (white) that form the front of the Big Dipper’s cup — by extending an imaginary line between the two across the sky, Polaris can easily be located.
Credit: KPNO/NOIRLab/NSF/AURA/T. Slovinský