Alaska's state flag features the Big Dipper (Ursa major or Great Bear constellation) as a symbol of strength, and Polaris (the North Star ) as a symbol of Alaska's northern location and "the ever constant star for the mariner, the explorer, hunter, trapper, prospector, woodsman, and the surveyor..." (quote from legislation). The blue background represents the sky, sea, lakes, and wildflowers of Alaska (the blue alpine forget-me-not is the state flower of Alaska).

The Alaska state flag (selected for its simplicity, its originality, and its symbolism) was created by Benny Benson (John Bell Bensona), a 13 year old 7th grader from an orphanage in Seward, Alaska. Seward honors him with a monument on 3rd Avenue. Alaska's state song is titled "Alaska's Flag" (hear MP3 clips of state song).

Notes: The North star is also found on the state flag of Maine. The Big Dipper constellation also contains "The Delaware Diamond" (the state star of Delaware).

Source:

Alaska's Flag & Song: SLED Alaska (statewide library)
Alaska State Flag & Song Intertwined: U of Alaska
The Kids Hall of fame: 13 year old inductees
Finding the Pole Star: From Stargazers to Starships
Alaska state flag illustration by Erin - public domain image

Links:

How far is the Big Dipper from the sun? - Straight Answers
Ursa Major - Big Dipper: Dept. of Astronomy / U Wisconsin
Ursa Major - Constellation Report: Utah Skies Astronomy
State Flags - 50 states List
National Flag
State Stars - 50 States