Moon, who will graduate from high school in Seoul in February, is an infielder who can play third base, shortstop and second base. He's a left-handed contact hitter who has no shortage of energy. He possesses above-average speed.
Moon arrived in the U.S. for the first time Wednesday night with his parents and passed a physical Thursday. He will report to the Astros' instructional league in Kissimmee, Fla., on Saturday.
He is the second player the Astros have signed out of the Pacific Rim, joining Taiwanese right-hander Chia-Jen Lo, who went 1-2 with a 2.10 ERA in 42 relief appearances this year between Double-A Corpus Christi and Class A Lancaster.
"I'm really excited with this signing," Barker said. "It's the first high school guy we actually had a chance to sign out of Asia. Last year, Lo was in college and was a little more advanced and had a little more experience. Moon is a high-energy player who has a lot of potential, is fundamentally solid, and I could see him making a quick move through the organization. I think he's going to be an asset to us."
Barker first saw Moon in March and watched him a few more times before convincing him to sign with the Astros over a few other teams. Barker projects Moon as a second baseman in the Major Leagues, though he currently plays shortstop.
"With Asia, the talent pool is a little different than the U.S.," Barker said. "We have so many kids here, but each time you go to a different country there are a certain amount of teams after a few players. You really have to get in there and work hard to get your kid signed. A lot of times it's difficult to sign players from Korea or Japan because Japanese teams put pressure on them not to sign with U.S. teams."
Wade said the Astros are far from done in signing players from the Pacific Rim.
"As we indicated two years ago, we were going to do everything we could to go out there and find players wherever they were," he said. "At that time, we armed Glen with a radar gun and a road atlas and he went over to the Pacific Rim and has done a terrific job for us in establishing a presence over there and being able to sign some very good players."
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.