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What: Killer whale vs. great white shark.

Where: Cabrillo Marine Aquarium, San Pedro

Time: 7 p.m.

If you happened to miss footage of last week’s violent confrontation between a killer whale and great white shark off the Farallon Islands west of San Francisco--it was shown at various lengths on every Los Angeles news station--you can still witness this unusual natural spectacle tonight at the Cabrillo Marine Aquarium in San Pedro.

Alisa Schulman-Janiger, a whale researcher with the American Cetacean Society, obtained footage--shot by naturalist Peter Pyle--and will show about 10 minutes worth beginning at about 7, then discuss the event with those in attendance.

It was believed to be the first time an orca, or killer whale, has been witnessed doing battle with a great white. The fact that the incident, a one-sided affair favoring the 20-foot orca over the 10-foot shark, was videotaped is even more exciting for scientists and researchers, who had previously believed that the two species, at the very top of the marine world’s food chain, pretty much left each other alone.

The underwater and above-water footage is at times shaky but often clear, showing the shark and one or two killer whales before the attack, then the whales disappearing immediately below the attack and one emerging moments later with the shark in its mouth. It then shows at least one killer whale feeding on the great white.

Why the attack occurred remains a subject of debate. Also, it was reported by witnesses aboard a boat on a nature cruise to the Farallones that the smaller of the two orcas was a calf, possibly explaining the aggressive behavior of the larger orca. But after studying footage, Schulman-Janiger and others tend to believe there wasn’t a calf, merely two adult orcas of different size.

Schulman-Janiger will also point out wounds to the face and back of the killer whale, possibly indicating that the shark got in a few licks before it was killed.

The two-hour program, which is primarily the first of a series of orientation classes for those interested in being docents aboard whale-watch vessels this winter, is open to the public and free of charge. Details: (310) 548-7563.