Joseph Gordon-Levitt began his acting career at the age of six, appearing in some made-for-television films and two episodes of Family Ties. He made his feature-film debut with a background role in 1992's Beethoven. Later that same year, he played a young version of Craig Sheffer's character in A River Runs Through It. He also appeared in the lead role of the successful Disney film Angels in the Outfield.
In 1996, he began playing Tommy Solomon, the oldest alien trapped in the body of an adolescent on the sitcom 3rd Rock from the Sun. In 1998, he was a guest star in the first season of That '70s Show. During the late 1990s, he also appeared in several films including The Juror, Halloween H20: 20 Years Later, Sweet Jane and 10 Things I Hate About You. He performed the voice of the main character Jim Hawkins in the Disney animated feature Treasure Planet.
For two years following the end of 3rd Rock, Gordon-Levitt quit acting and attended Columbia University. He studied history, literature and French poetry, dropping out in 2004 to return to acting. Gordon-Levitt went on to appear in a number of independent films such as Manic, Mysterious Skin, Brick, The Lookout, Killshot and Stop-Loss.
Tommy is the oldest member of the crew; however, he is trapped in the body of a teenager. His role on the mission is that of Information Officer, and thus he is the most intelligent. Tommy tries to maintain a low profile but often has difficulty explaining his family's bizarre behavior - as well as difficulty maintaining relationships with humans.