The NASA Goddard Visitor Center offers a family-friendly experience, open Wednesday to Sunday with varying hours. Visitors can explore the center's exhibits, including real rockets in the garden, science displays, and interactive educational experiences. Admission is free, but if you don't have time to go inside, swing by and check out the Moon Tree out front, which is open to the public. The moon tree was grown from a seed that orbited the moon during Apollo 14, from the entryway without entering the center.