Officials say the Powerball jackpot has risen to an estimated $500 million, which would make it the fifth largest lottery prize in U.S. history.

The lottery raised its jackpot estimate hours before Wednesday night's drawing and has raised it twice since Saturday's drawing by a total of about $105 million.

No one has won the Powerball jackpot for more than two months, so the prize has been growing gradually from its $40 million starting point.

It's been nearly a year since a Powerball prize topped $400 million

Powerball is sold in 44 states as well as Washington, D.C., the U.S. Virgin Islands and Puerto Rico.

The chance of winning a Powerball jackpot is about 1 in 175 million.