Discoveries both dramatic and scientific underlie several programs tonight.
* "Beverly Hills, 90210" (8 p.m.-9 p.m., WBFF, Channel 45) -- When Donna (Tori Spelling) travels to Oregon to visit Ray (Jamie Walters), David (Brian Green) tags along to see his mother (Caroline Lagerfelt). She turns out to be broke, homeless and suffering from mental illness. Fox.
* "The New Explorers: The Sounds of Discovery" (8 p.m.-9 p.m., MPT, Channels 22, 67) -- The science/adventure series documents how acoustic technology has become a key tool beneath the waves, in both nature study and defense. PBS.
* "The Lady Killer" -- (9 p.m.-11 p.m., WJZ, Channel 13) -- In a gender reversal of "Fatal Attraction" (cable item below), this TV movie features Judith Light ("Who's the Boss?"), who learns the peril of an affair when her lover (Jack Wagner, of "General Hospital") does not want to go away. CBS.
* "Coach" (9:30 p.m.-10 p.m., WMAR, Channel 2) -- Luther refuses to pay his agent a commission but may suffer a painful retaliation. His rep -- durable guest star Tom Poston -- is also his dentist. ABC.
* "PrimeTime Live" (10 p.m.-11 p.m., WMAR, Channel 2) -- Almost 12 percent of America's high school students carry a weapon to school, contends a report by Diane Sawyer exploring violence in the hallways. ABC.
* "Late Show With David Letterman" (11:35 p.m.-12:35 a.m., WJZ, Channel 13) -- A guest on Dave's final NBC show in June 1993, rocker Bruce Springsteen is the scheduled musical guest tonight. CBS.
* "Fatal Attraction" (8 p.m.-10 p.m., HBO) -- The 1987 suspense thriller with Glenn Close and Michael Douglas offers a sobering lesson on marital fidelity.
* "Cowboy Jubilee: Celebrating the National Cowboy Hall of Fame" (8 p.m.-9 p.m., The Nashville Network) -- Guest star Reba McEntire includes a salute to cowgirls, too, in this special from the National Cowboy Hall of Fame in Oklahoma City. Cowboy singers Riders in the Sky are the hosts.
* "CyberSpace" (8 p.m.-9 p.m., Discovery Channel) -- If it doesn't occupy physical space, how can anyone go there? That's just one of the obvious questions about the computer-accessed world explored in this documentary, produced with Time magazine.