Joe Palca

A scientist walks up to a cottonwood tree, sticks a hollow tube in the middle and then takes a lighter and flicks it. A jet of flame shoots out from the tube.

It seems like a magician's trick. Turns out, there's methane trapped in certain cottonwood trees. Methane is the gas in natural gas. It's also a powerful greenhouse gas.

So how does it get inside towering trees like the ones on the campus of the Oak Ridge National Laboratory in Tennessee?

It's easy to take corned beef sandwiches for granted. There's no mystery about them. They simply exist.

But corned beef sandwiches, along with everything else in the universe, raise a critical question in the minds of physicists: Why do they exist?

In the earliest moments of the universe, energy turned into matter. But matter comes in two forms, matter and antimatter. And when a particle of matter encounters a particle of antimatter, they annihilate each other — and all you're left with is light.

Small drones can do big jobs: Firefighters can use them to find hot spots in blazes, environmental monitors can find the source of hazardous chemical leaks. One just delivered a human kidney for transplant surgery.

But it takes lots of power to spin four helicopter blades fast enough to keep a quadcopter-type drone in the air. Most can only stay aloft for about 30 minutes.

George Berzsenyi is a retired math professor living in Milwaukee County. Most people have never heard of him.

But Berzsenyi has had a remarkable impact on American science and mathematics. He has mentored thousands of high school students, including some who became among the best mathematicians and scientists in the country.

I learned about Berzsenyi from a chance conversation with a scientist named Vamsi Mootha.

A team of astronomers led by an undergraduate student in Texas has discovered two planets orbiting stars more than 1,200 light-years from Earth.

Astronomers already knew of about 4,000 exoplanets, so finding two more might not seem like huge news. But it's who found them and how that's getting attention.

Is there an efficient way to tinker with the genes of plants? Being able to do that would make breeding new varieties of crop plants faster and easier, but figuring out exactly how to do it has stumped plant scientists for decades.

Now researchers may have cracked it.

Modifying the genetics of a plant requires getting DNA into its cells. That's fairly easy to do with animal cells, but with plants it's a different matter.

Opportunity lost.

NASA has officially declared an end to the mission of the six-wheeled rover on Mars. Opportunity lost power in a dust storm last June, and all efforts to make contact have failed.

"Our beloved Opportunity remained silent," Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate, said Wednesday at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "With a sense of deep appreciation and gratitude," he added, "I declare the Opportunity mission as complete."

Many vaccines and some medicines, such as insulin, have to be delivered by injection. That's a pain, both for patients and for health care providers. But two groups of researchers are trying to put some of these medications in pill form to avoid the needle.

Scientists have evidence that a mountain 3 miles tall, in the middle of a crater on Mars, may be made largely from dust and sand.

To get the data for that surprising conclusion, the researchers MacGyvered a navigation instrument on the NASA rover Curiosity, and turned it into a scientific instrument.

Big, important scientific breakthroughs are built of small, incremental experiments. And the partial government shutdown is already interfering with some of that research.

Scientists often depend on the government for grant funding, expertise and — in some cases — even regulatory approval. With the shutdown, some researchers are missing those key elements of scientific collaboration. Here's how some scientists say the shutdown is affecting their work.

Sometime early in 2019, the Chinese civilian space program plans to land a six-wheeled rover on the moon's far side — the side we never see from Earth.

The Chinese haven't released the exact date the landing is to occur, but they have announced the location. The probe, known as Chang'e 4, is targeted for Aitkin Basin, a giant impact crater near the Moon's south pole.

In addition to a variety of cameras, the rover carries ground-penetrating radar that can peer beneath the lunar surface.

NASA tried a communications experiment with its latest mission to Mars, and it turned out spectacularly well.

On Nov. 26, as the probe known as InSight plummeted through the Martian atmosphere on its way to the planet's surface, two miniature spacecraft — known collectively as MarCO — relayed telemetry from InSight to Earth, assuring all those watching that the landing of the probe was proceeding successfully and was soft.

In 2003, Jay Siegel was up for a new challenge. Siegel was a tenured professor of chemistry at the University of California, San Diego, but he took a job at the University of Zurich.

"When I first moved, people said, 'Oh, you're crazy to leave San Diego; it's a paradise. Why would you go to Europe? Blah, blah blah,' "recalls Siegel. "And after 10 years people were saying, 'Oh, man, that was the smartest thing you ever did. Zurich is wonderful.' "

Copyright 2018 NPR. To see more, visit https://www.npr.org.

DAVID GREENE, HOST:

Updated Nov. 26 at 3:12 p.m. ET

NASA's InSight probe landed successfully on Mars Monday shortly before 3 p.m. ET.

Two tiny spacecraft that flew with the lander to Mars were able to relay telemetry from the probe as it descended to the surface. As a result, mission managers knew immediately that the landing had worked. Unsurprisingly, the control room at the Jet Propulsion Laboratory in Pasadena, Calif., erupted in cheers.

If you hold your nose and take a sip of coffee, mostly what you'll taste is a bitter liquid. Much of the gustatory pleasure we take from coffee comes from its aroma.

But a new study suggests people's sensitivity to that bitter taste plays a role in how much coffee they drink. And though it seems counterintuitive, the study shows that the more sensitive you are to the bitter taste of coffee, the more of it you tend to drink.

The European Space Agency is sending a mission to explore the mysteries of Mercury.

BepiColombo, named after the Italian mathematician and engineer Giuseppe "Bepi" Colombo, launched at 9:45 p.m. ET Friday aboard an Ariane 5 rocket from a spaceport in French Guiana.

Astronomers have found — way beyond the orbit of Pluto — an intriguing distant object orbiting the sun.

It's just a dwarf planet, about 200 miles across, but some researchers think finding it increases the likelihood that there is a heretofore undiscovered giant planet lurking in the outer reaches of our solar system. That would bring the number of true planets in our solar system back to nine, replacing Pluto which was demoted in 2006.

The explosion of deaths related to opioid misuse has underscored a pressing need for better ways of treating pain, especially chronic pain.

Duquesne University pharmacology associate professor Jelena Janjic thinks she's on to one. It involves using a patient's own immune system to deliver non-opioid pain medication to places in the body where there's pain.

Using lessons learned from harbor seals and artificial intelligence, engineers in California may be on to a new way to track enemy submarines.

The idea started with research published in 2001 on the seals.

Scientists at the University of Bonn in Germany showed that blindfolded seals could still track a robotic fish. The researchers concluded that the seals did this by detecting the strength and direction of the whirling vortex the robot created as it swam through the water.

An Italian team of scientists says it has strong evidence of a subsurface lake of liquid water on Mars. It's a discovery that adds to the speculation that there could once have been life on Mars — and raises the possibility that it might be there still today, since liquid water is an essential ingredient for life.

When people think of particle accelerators, they tend to think of giant structures: tunnels many miles long that electrons and protons race through at tremendous speeds, packing enormous energy.

But scientists in California think small is beautiful. They want to build an accelerator on semiconductor chips. An accelerator built that way won't achieve the energy of its much larger cousins, but it could accelerate material research and revolutionize medical therapy.

First of all, what is an accelerator?

More than 400 years after Galileo Galilei discovered the first of Jupiter's moons, astronomers have found a dozen more — including one they've dubbed "oddball" — orbiting the planet. That brings the total number of Jovian moons to 79.

Scientists for the first time have been able to pinpoint the source of an extremely powerful version of a neutrino, a ghostly particle that can travel virtually unimpeded through space.

It's an achievement that opens a whole new way of looking at the universe.

The neutrino was detected by a South Pole observatory called IceCube that was specifically designed to catch the particles. It consists of a cubic kilometer of ice festooned with more than 5,000 detectors.

Copyright 2018 NPR. To see more, visit http://www.npr.org/.

ARI SHAPIRO, HOST:

A giant dust storm on Mars is threatening to end the mission of a NASA rover. The rover called Opportunity depends on solar panels to charge its batteries. Right now, the storm has practically blotted out the sun. NPR's Joe Palca has more.

For the first time, scientists say they have clear evidence that the chemical building blocks of life exist on Mars.

What they can't say yet is whether there is, or ever was, life on the Red Planet.

NPR / YouTube

Editor's note: This post was updated at 9:55 a.m. on Jan.

Scientists have new evidence that there are plumes of water erupting from the surface of Jupiter's icy moon Europa — plumes that could, maybe, possibly contain signs of life.

The evidence comes from data collected by the now-defunct Galileo spacecraft. Although the data has been available since it was collected in 1997, it's only now that an analysis confirms the existence of water plumes.

NASA is heading back to Mars. If all goes well, a two-stage Atlas V 401 will lift off from California's Vandenberg Air Force Base on Saturday morning. Onboard will be a lander named InSight, an $813.8 million mission to study the interior of the Red Planet.

Recent Mars missions have snapped pictures of the surface, studied rocks, dug in the dirt and looked for signs that water once flowed on Mars. But as Insight's principal investigator William "Bruce" Banerdt sees it, that's just scratching the surface.

Pages