Joe Palca

This just in: After 15 years of deliberation, the U.S. Food and Drug Administration has yet to decide whether it will approve a genetically modified salmon for human consumption.

Now there's a catchy lead. But the truth is, the long-running regulatory saga of AquaBounty's application to sell salmon with a growth hormone gene from one fish plus a promoter of an antifreeze gene from another — which help it grow twice as fast as typical farmed salmon — does not seem headed toward a conclusion.

It's time to go back to Mars. Once every two years, the orbits of Earth and Mars are aligned just right, so it's possible to send a spacecraft from here to there. That special time is now.

Scientists in California think they've figure out why flies like beer. That may sound a bit trivial, but in fact it could lead to new ways of combating plant and animal pests.

That flies like beer is well known. "The attraction of flies to beer was first reported in the early 1920s," says Anupama Dahanukar. She's part of an inter-disciplinary program involving neuroscience and entomology at the University of California, Riverside. She's been studying how flies recognize chemicals, so answering the question of why flies like beer is actually quite relevant to her research.

People get very riled up about foie gras, the fatty liver of ducks and geese.

Some are bothered by the force feedings the ducks and geese undergo to produce those fatty livers, which are 6 to 10 times the normal size. Others fear the fat itself – although foie gras enthusiasts insist that the delicacy is "surprising low in bad fats, and high in good fats."

A controversy erupted earlier this year over who deserved credit for what many say is the most important astronomical discovery of the 20th century: the realization that the universe was expanding.

In 1929, American astronomer Edwin Hubble proposed that the more distant a galaxy is, the faster it appears to be receding from us, a concept that is known as Hubble's law.

Astronomer Mario Livio has worked with the Hubble Space Telescope for more than 20 years. "So clearly, anything Hubble is of interest to me," he says.

It doesn't happen often, but there are times when a single book turns the world on its head. Isaac Newton's Principia unraveled the mystery of gravity. Charles Darwin's On the Origin of Species explained how evolution worked.

But before either of these, there was On the Revolutions of the Heavenly Spheres by Nicolaus Copernicus. It was published in 1543. In it, Copernicus made the astounding claim that Earth revolves around the sun, not the other way around.

It's a huckster's dream: "Try the new Burmese Python Diet. No calorie counting or special foods. Eat whatever comes along, up to a quarter of your body weight. Not only is it good for your waistline; it's good for your heart."

Trouble is, what works in pythons probably won't work for humans.

Pythons employ what scientists call a "sit and wait foraging tactic." In other words, they lie around in a jungle and wait for the food to come to them. And of course, this can mean months between meals.

Richard Larrick has been bothered by something for two decades.

"Twenty years ago, I'd done a paper with some graduate students just showing that in hotter temperatures, pitchers are more likely to hit batters with pitches," says Larrick, a professor at the Fuqua School of Business at Duke University.

Was it because they would sweat more, and the ball might get slippery and hard to control? Or was it something intentional?

Researchers in New York are reporting an advance in creating cloned human embryos. The embryos would not be used for reproduction, but rather for the creation of embryonic stem cells. Many scientists believe that human embryonic stem cells made this way could revolutionize medicine.

The advantage of stem cells made this way is that they could be personalized to an individual.

Astronomers are lining up to use a powerful new NASA telescope called SOFIA. The telescope has unique capabilities for studying things like how stars form and what's in the atmospheres of planets.

But unlike most of the space agency's telescopes, SOFIA isn't in space — it flies around mounted in a Boeing 747 jet with a large door cut on the side so the telescope can see out. Putting a telescope in space makes sense: There's no pesky atmosphere to make stars twinkle. But why put one on a plane?

Weird things jump out at me in press releases.

Take the press kit NASA prepared for the GRAIL mission. GRAIL consists of two nearly identical spacecraft that are on their way to the moon. Once there, they will make a precise map of the moon's gravitational field. Such a map will help scientists refine their theories about how the moon formed and what the interior is made of.

Migratory songbirds like Swainson's thrushes spend their winters in South and Central America. But as spring approaches, they fly thousands of miles north to Canada.

Along the way, these little birds show endurance that would shame even the toughest athletes. They can fly for up to eight hours straight without stopping for food or water.

Scientists know how birds cope without food during the flights: They burn fat. But until now, they haven't figured out the water question. How do migrating birds avoid dehydration after all that flying?

In 1969, astronaut Alan Bean went to the moon as the lunar module pilot on Apollo 12. Although the trip going to the moon covered the same distance as the trip back, "returning from the moon seemed much shorter," Bean says.

People will often feel a return trip took less time than the same outbound journey, even though it didn't. In the case of Apollo 12, the trip back from the moon really did take somewhat less time. But the point remains that this so-called "return trip effect" is a very real psychological phenomenon, and now a new scientific study provides an explanation.

Scientists may have found a critical weakness in Plasmodium falciparum, the parasite that causes malaria. Researchers say the discovery provides a promising target for new malaria therapies.

Scientists in Australia are using a bacterium to try to stop a deadly virus in its tracks.

There's a revolution under way in biology. Scientists are coming to understand that genetics isn't just about genes. Just as important are smaller sequences of DNA that control genes.

These so-called regulatory elements tell genes when to turn on and off, and when to stop functioning altogether. A new study suggests that changes in these non-gene sequences of DNA may hold the key to explaining how all species evolved.

A lot of simple things in science turn out to be quite complicated. Take, for example, coffee: You may have noticed that a spilled drop of coffee doesn't dry as a brown blob, but rather as a clear blob with a dark ring around the edge.

It's taken physicists more than a decade to figure out why this effect, known technically as "the coffee ring effect," happens. But now they think they have an answer.

Any time you report on promising but preliminary results about a new therapy for a lethal disease, you worry that you might be raising false hopes. So be warned: Although this is a "good news" story, it's preliminary. Don't expect to find it at a hospital near you any time soon.

Can the most modern of technologies help solve the health woes in the poorest countries in the world? Some biomedical engineers say yes. They are designing diagnostic laboratories that fit on something as small as a credit card, and give results in minutes instead of hours or days.

These devices are sometimes referred to as a "lab on a chip." To use them, all you need to do is obtain a drop of someone's blood.

NASA's space shuttle may be down for the count, but robotic planetary missions are up, up and away. Before the end of this year, three new solar system probes are due to launch.

Juno To Jupiter

First up is the Juno spacecraft, which blasted off from Cape Canaveral, Fla., Friday on a mission to Jupiter.

Let's say you're a vampire bat, and you are trying to decide where to bite your victim. You want a spot rich in blood, right? But how do you find such a spot?

Turns out, vampire bats have a kind of remote sensing ability that can tell them where there is a warm patch of skin on a nearby animal. A warm patch of skin means there are blood vessels just below the skin surface. And now scientists have identified the molecular basis for this remote sensing ability.

Scientists would like to know more about how cells work. But seeing what's happening inside a cell isn't easy. It's dark in there, and even if you shine a light, many of the critical chemical reactions are invisible.

Now, a team of researchers has found a way to reveal the invisible by attaching what amounts to a reflective tag to a chemical called RNA, a close relative of DNA. Molecules made of RNA have a variety of important jobs inside cells and frequently, doing those jobs requires the RNA to shuttle from one part of the cell to another.