From the award-winning producers of NOVA, NOVA scienceNOW brings its fast-paced, magazine-style approach to investigate what's happening on the very front lines of science. Go behind the scenes of today's most exciting science research with host Neil deGrasse Tyson, renowned astrophysicist and Director of the American Museum of Natural History's Hayden Planetarium.

This episode of NOVA scienceNOW covers:

Dark Matter: Neil deGrasse Tyson reports from a half-mile underground, where scientists are using special detectors to look for evidence of a ghostly substance that they believe makes up most of the matter of the universe--a hypothetical entity that no one has seen yet called dark matter.

Of Mice and Memory: Researchers have found that mice with induced memory loss are able to retrieve memories by either being put into an enriched environment or by being given a drug that promotes beneficial gene activity in their brains. Such new insights may lead to a better understanding of dementia and other memory-impairment disorders in humans.

Profile--Hany Farid: Is seeing believing? In this age of easy photo manipulation, sometimes it's hard to know. Enter Hany Farid, professor of computer science at Dartmouth College. Farid got the idea for software that detects doctored photos after seeing a faked celebrity shot that showed Angelina Jolie and Brad Pitt strolling on the beach. He went on to develop a program that can unmask photo tampering by analyzing light sources and other subtle features in an image--a service that turns out to be in high demand.

Wisdom of the Crowds: The famed British scientist Sir Francis Galton thought he was proving the ignorance of the masses in his observation about a country-fair competition in which entrants were asked to guess the exact weight of an ox. The correct answer was 1,198 pounds, and, understandably, none of the 800 contestants got it exactly. However, Sir Francis failed to realize that graphing all the guesses and determining their average produced very close to the right answer.

Special DVD features include: materials and activities for educators; a link to the NOVA scienceNOW Web site; segment selection; closed captions; and described video for the visually impaired. On one DVD5 disc. Region coding: Region 1. Audio: Dolby stereo. Screen format: 16:9 Anamorphic.