GRAND RAPIDS, Mich. - To celebrate the 50th anniversary of the Apollo 11 moon landing, the Grand Rapids Public Museum is holding a special scavenger hunt.

Starting Monday, July 15, four painted "moon" rocks will be hidden throughout downtown Grand Rapids for people to find with a chance to win a space-themed prize.

To get the latest riddles, follow the Facebook event page about where the rocks are hidden. GRPM asks that people leave the rocks at their locations so everyone can play along.

To be entered to win, you must find three of the four hidden "moon" rocks, post a picture of each rock to Facebook and tag GRPM while using the hashtag #GRPMMoonWeek.

The first riddle is:

  • The first animal was sent to space in 1949. He was a monkey named Albert. You will find a "moon rock" near where a similar monkey in a spacesuit is drooling over burgers that were named "Best in America" by GQ and Best in Grand Rapids by Grand Rapids Magazine and On the Town.

►Make it easy to keep up to date with more stories like this. Download the 13 ON YOUR SIDE app now.

Have a news tip? Email, visit our Facebook page or Twitter.