Bring 8 cups of salted water to a rolling boil in a large pot. Cook the pasta following package directions. Add the asparagus to the pot during the last minute of cooking. Drain the pasta and asparagus, and set aside.

Warm a large skillet over medium heat, and add 1 tablespoon of the oil. Add the scallops, and cook 3 minutes. Turn the scallops, and cook 3 minutes more, or until seared. Remove the scallops from the pan, and set aside.

In the same skillet over low heat, combine lemon zest and juice and the remaining oil. Add the pasta, asparagus and scallops, and toss well. Season with salt and pepper to taste. Garnish with basil. Serve immediately.