United Mileage Plus is marking 25 years with 25 sweepstakes prizes of 1 million miles each. Entries for the sweepstakes are earned by flying on United, United Express or Ted flights before June 16 (one entry per qualifying segment).

One million miles might be redeemed for 40 domestic Saver Award coach tickets, or 10 first-class Saver Award trips to Paris. To rack up that kind of mileage on your own, you’d need to fly the roundtrip distance to the moon…twice.

Visit http://www.united.com/25million to register.