In medium bowl, drizzle lemon juice over scallops; set aside.
Cook pasta to desired doneness as directed on package.
Meanwhile, heat large nonstick skillet or wok over medium-high heat until hot. Add oil; heat until hot. Add carrots and asparagus; cook and stir 2 minutes. Add scallops with lemon juice; cook and stir 3 to 5 minutes or until scallops turn opaque. Add onions; cook and stir 1 minute.
Drain pasta; add to skillet. Stir in sauce; cook until thoroughly heated.