Thank you to everyone who entered, and congrats to L.M. Preston on her debut! Without further ado, the winner of a copy of Explorer X-Alpha and a poster is...
(#25 on random.org)
Congrats, Sarah! I've emailed you and you have 48 hours to respond with your mailing address. If you didn't win, feel free to check out the other contests I have going on right now, and maybe you'll be luckier! :)