In the morning, explore the various exhibits on astronomy, paleontology, and more at the Houston Museum of Natural Sciences. Take a break for lunch at the museum's restaurant, which offers a mix of international cuisines. Spend the afternoon at the Cockrell Butterfly Center, where you can observe hundreds of live butterflies. For the evening, check the museum's schedule for any special exhibits or events.
Start the day off by touring the Space Center Houston, the official visitor center for NASA's Johnson Space Center. Explore the exhibits on space exploration and technology, and take a tram tour of the Johnson Space Center to see the historic mission control center and astronaut training facilities. For lunch, grab some food at the Space Center's Zero-G Diner, and then spend the afternoon at the center's interactive exhibits. For the evening, check out the center's cinema and shows for a cosmic experience.
In the morning, head over to the Houston Zoo and explore the various animal exhibits, including the African Forest and Kipp Aquarium. Take a break for lunch at the zoo's restaurant, or pack a picnic to enjoy in the park. Spend the afternoon strolling through the Museum District, home to several museums including the Museum of Fine Arts, the Children's Museum of Houston, and the Houston Museum of African American Culture. For the evening, choose from the various restaurants and bars in the area.
End the trip with a day of shopping at The Galleria, one of the largest malls in the United States. Browse through the various high-end stores and boutiques, such as Louis Vuitton and Chanel, and grab some lunch at one of the many restaurants in the mall. Spend the afternoon at the mall's ice rink or take a break at the spa. For the evening, head to one of the several bars or nightclubs in the area.
If you have more time, consider visiting the Buffalo Bayou Park, which offers various outdoor activities such as kayaking and hiking. For a side trip, visit the nearby city of Galveston, which offers a beach and several historic attractions. To maximize your fun, consider using the Houston CityPASS, which offers discounts to several attractions including the Space Center Houston and the Houston Zoo. Lastly, don't forget to enjoy some of Houston's famous barbecue and Tex-Mex cuisine while you're in town.