Are all invasive species as bad as the Asian carp? The discovery of Asian carp DNA near Lake Michigan has ecologists and officials from Great Lakes states concerned that efforts to prevent the voracious fish from entering the lakes have failed. The Asian carp is one example of an invasive species that can have a devastating impact on the environment, but one biologist says not all invasive species need to be eradicated.9:06 a.m.
Joel Brammeier: Acting president of the Alliance for the Great Lakes.
Mark Davis: Chair of the Biology department at Macalester College in St. Paul and author of "Invasion Biology."
Dan Simberloff: Professor of environmental science, ecology and evolutionary biology at the University of Tennessee-Knoxville and director of the Institute for Biological Invasions.
Meteor showers and 'The Lives of Stars' Stargazers mark your calendars: the most reliably showy meteor shower of the year comes around on Sunday (Dec. 13) and Monday (Dec. 14). The Geminid meteor shower usually displays 100 meteors per hour. Astronomer Ken Croswell talks about meteor showers and the continuing controversy over Pluto, which was declassified as a planet in 2006.10:06 a.m.
Ken Croswell: Astronomer and author of many books on space. His latest is "Lives of the Stars."