PBS NewsHour - Science

According to new research published in the journal Science this week, plant and animal extinctions are happening at a rate one thousand times greater than before humans walked the Earth. Stuart Pimm of Duke University joins Hari Sreenivasan to discuss how extinction rates are determined and what can be done to help set conservation priorities.

What causes a seemingly happy, non-violent teenager to open fire on classmates? Science correspondent Miles O'Brien reports on the minds of rampage killers by profiling Andy Williams, who killed two students in a school shooting in California.

The National Institutes of Health announced that it will require scientists to test new drugs on both male and female animals. Until now, most early trials have been conducted on males. Judy Woodruff joins Dr. Janine Clayton of National Institutes of Health and Phyllis Greenberger of Society for Women's Health Research to discuss the past problems driving the decision.

A study released by NASA and others offers the most definitive evidence that parts of the ice sheet in West Antarctica are melting and the damage is irreversible. The collapse will take more than a century, and the melting will lead to rising sea levels. Judy Woodruff talks to Thomas Wagner of NASA, one of the team’s lead members, about the larger consequences of these projections.

In its most comprehensive report on climate change yet, the White House forecasts the likely, negative effects facing each of the eight regions in the U.S., from drought in the Southwest, to stronger storms in the Northeast. The administration is expected to cite the warnings when it lays out new regulations this summer. John Holdren, science advisor to the president, talks to Gwen Ifill.

Researchers are working to bring back extinct animals like the woolly mammoth and passenger pigeon, operating under the belief that reviving such species could restore vanishing habitats. But many biologists suggest these efforts should focus on endangered, rather than extinct, species. Gabriela Quiros and Thuy Vu of KQED have the story.

NASA scientists say the Kepler space telescope may have discovered the most “Earth-like” planet yet. Circling a star about 500 light-years away, planet Kepler 186-F may be the right temperature to allow liquid water to flow on its surface. Hari Sreenivasan talks to Tom Barclay of NASA Ames Research Center about why this discovery is exciting to astronomers.

The latest U.N. report on climate change suggests ways to potentially ward off the worst impacts of rising emissions. But these scenarios come with real costs, and have faced political opposition as well as reluctance from the American public. Judy Woodruff learns more from Robert Stavins of the Harvard Kennedy School of Government and Maura Cowley of the Energy Action Coalition.

Following 12 years of research and testing, designers and pilots Bertrand Piccard and Andre Borschberg debuted a huge solar-powered plane in Switzerland this week. The plane, which boasts a wingspan wider than a 747's, is covered in more than 17,000 solar cells. Hari Sreenivasan reports.

In some regions of northern New England, the moose population is down as much 40 percent in the last three years. The cause of this iconic animal’s dramatic die-off is not yet known, but researchers’ main theory is centered on the parasitic winter tick, and warmer winters may be partly to blame. Hari Sreenivasan reports from New Hampshire.

A report published this week in Science magazine gave new details about the presence of water on Saturn’s moon Enceladus. Is it a sign of the possibility of life elsewhere in our solar system? One of the article’s authors, David Stevenson of the California Institute of Technology, speaks with Hari Sreenivasan about the implications of the findings.

The overflow of information generated during a crisis like the Malaysian airliner gone missing can be just as paralyzing as the absence of information for those officials charged with searching. A crowdsourced search for Flight 370 harnesses the energy and time of the more than 3 million people who have volunteered to scour satellite imagery. Science correspondent Miles O’Brien reports.

Scientists say they have found evidence confirming a theory that our cosmos expanded from almost nothing to its first huge growth spurt in just fractions of a second after the Big Bang. A telescope at the South Pole revealed patterns and skewed light waves created by gravitational ripples from the incredible expansion. Gwen Ifill interviews Sean Carroll of the California Institute of Technology.

A disaster at the Fukushima Daiichi nuclear power plant on March 11, 2011, has greatly affected how Japanese citizens feel about that energy source. Polls suggest that 80 percent of voters now oppose nuclear power in Japan. But walking away from nuclear power is a tricky proposition for a country that has not invested much in renewable alternatives. Science correspondent Miles O'Brien reports.

In an unlikely alliance, natural gas companies and environmentalists have decided to work together to make fracking safer. Rick Karr travels to Pennsylvania to explore the tensions this has created among environmental groups.