Across Arizona, landmarks of the state's earliest days and greatest moments still stand today. Here are seven landmarks and ...

Add Yahoo as a preferred source to see more of our stories on Google. Guests visting the Lowell Observatory in Flagstaff, Arizona during the I Heart Pluto Festival gaze at celestial objects from the ...

Lowell Observatory comes out on top, claiming the Best Northern Arizona Attraction status in this year's Best of Flag. Sitting on Mars Hill, Lowell Observatory looks over downtown Flagstaff and is ...

From 1905 until his death in 1916, Percival Lowell searched for a ninth planet, which he called Planet X. Lowell had predicted the planet based on irregularities in the orbit of Uranus. In 1929, ...