Heavenly research

Most science fair projects are pretty down to Earth. Competing in the Intel Science Talent Search (STS) requires going further. It is America’s oldest and most prestigious science and math competition for high school seniors. This year, four teens landed in the Intel STS finals on the basis of their truly-out-of-this-world research.

Each probed some facet of astronomy. And all but one finished within the top 10 spots in this competition.

Intel Foundation sponsors the contest. Society for Science & the Public, publisher of Science News for Students, which created the competition in 1942 and still runs it.

Two of the teens studied objects familiar to anyone who has gazed at the night sky: the moon and Jupiter. The other two studied features of two types of extremely dense objects found nowhere near Earth. Neutron stars are one kind. “Primordial” black holes are the other.

Research done by these teens sheds light on mysteries being tackled by older experts working across multiple scientific fields.

Hint: It’s not green cheese

At first glance, the Earth and moon seem to have little in common. Our planet has a substantial atmosphere, loads of liquid water and surface temperatures just right for a huge variety of living things. The moon has none of the above.

Still, both share a lot of chemistry — and history. Research suggests the moon formed when a Mars-sized object slammed into Earth a few million years after it formed. That massive collision blasted material into space. Some of Earth’s cast-offs later coalesced, creating our closest celestial companion.

Plagioclase (PLAY gee oh klayz) minerals form a major part of Earth’s crust. Minerals in this family typically contain aluminum, silicon and oxygen. Some of these minerals are rich in sodium, others contain calcium instead. Not surprisingly, Apollo astronauts returned from their moon walks lugging rocks rich in these minerals.

But a mystery surrounds plagioclase on the moon, says Aron Coraor. He’s a 17-year-old senior at Huntington High School in Huntington, N.Y. Lunar samples contain two distinctly different types. Until now, most scientists have proposed that they formed at different times in the moon’s history. No one, however, was really certain. Now, Aron’s research posits another idea. His lab studies hint that the two types formed at roughly the same time, just at different depths in the moon’s crust.

The moon has always fascinated Aron. He’s been told that “moon” was the first word he uttered. In high school, Aron began meeting with a mentor at Stony Brook University in New York. It was that scientist who first told Aron about the moon’s unsolved plagioclase mystery. That turned on the teen’s quest for answers. The project also allowed Aron to use chemistry, a favorite subject, to tackle a real-world problem.

Aron started out trying to make his own “moon rocks” in the lab. Scientists have chemically analyzed plagioclase samples from the moon. So Aron thought recreating their recipe would be relatively easy. It wasn’t.

He mixed what he thought were the right proportions of calcium oxides, aluminum oxides and silicon oxides. Then he heated them under high pressure inside a laboratory furnace. This created molten rock. But those lab-made plagioclase minerals didn’t match the moon’s.

Sometimes in science, failure can lead to success. Here, Aron’s work suggested that maybe the moon rocks hadn’t formed the way that scientists had presumed. “No one had had the idea,” Aron says, to look at the rocks this way.

So, the teen tweaked his recipe. Then he cooked up more batches. He heated each mix of ingredients to 1,500° Celsius (2,732° Fahrenheit). Afterward, he allowed each batch to slowly cool. This allowed plagioclase crystals to form, just as they might have on the moon billions of years ago.

Some of the rocks that cooled at high pressure resembled one of the types of lunar plagioclase. Other lab-made rocks, which had cooled at lower pressures, resembled the other type of moon rock. The teen’s results suggest that some plagioclases formed near the moon’s surface. Others likely formed at a depth of a few kilometers (miles), his findings suggest. More importantly, he notes, both types could have formed at nearly the same time.

“This is in a completely different way than expected,” Aron says. His research, if accepted, will completely change how people think these rocks formed, he says.

At last month’s finals in Washington, D.C., Aron’s project won him sixth-place and $25,000.

When the atmosphere glows

People who live at high latitudes, either far north or south of the equator, may sometimes see a stunning and shimmering phenomenon in the night sky. In the Northern Hemisphere, this spectacle is called the aurora borealis, or northern lights. The Southern Hemisphere has its own version: the aurora australis, or southern lights.

Auroras typically occur about 80 kilometers (50 miles) or more above Earth’s surface. Electrons and other charged particles streaming from the sun create these light shows as they slam into Earth’s atmosphere at high speeds. Auroras are usually seen only at high latitudes. (That’s because charged particles are accelerated and steered by magnetic fields. Because Earth’s magnetic field enters the atmosphere near the poles, that’s where auroras usually occur.)

Similar light displays dance above the surface of other planets too. Jupiter’s aurora is particularly prominent because its magnetic field is about 14 times stronger than Earth’s, notes John Anthony Clarke. He goes to Regis High School in Syosset, N.Y. Scientists have called the giant gas planet’s magnetic field “the solar system’s largest natural particle accelerator,” John Anthony notes. A particle accelerator uses magnetic fields to make charged particles go faster, either for physics experiments or for medical imaging. (The stronger the magnetic field and the longer its field lines are, the faster the charged particles will move.)

Auroras most often appear green. They can shine in other colors too, as well as in wavelengths that people can’t see, notes John Anthony. On Jupiter, the incoming charged solar particles slam into atoms in the planet’s atmosphere so forcefully that they produce auroras featuring X-ray light.

For his project, John Anthony used a computer program to estimate the full range of X-ray wavelengths that Jupiter’s auroras would emit. That simulation took into account the specific gases found in Jupiter’s atmosphere and the strength of the planet’s magnetic field. It also accounted for how strongly solar flares might interact with Jupiter’s magnetic field to boost that field’s strength. (That, in turn, would make the sun’s incoming particles accelerate even faster than they otherwise would, he explains.)

The teen’s project isn’t just a math exercise. It also suggests that a NASA space telescope launched in 2012 — the Nuclear Spectroscopic Telescope Array — should be able to see all of the X-ray wavelengths produced by Jupiter’s auroras. That includes wavelengths beyond low-energy X rays. Previously, the teen contends, it wasn’t certain that this spacecraft could do that.

Thanks to his research, John Anthony says, scientists no longer need worry they might be missing some information when they analyze data gathered by the new telescope.

His new calculations earned the teen ninth place in the Intel STS competition and a cash award of $20,000.

Astronomy has interested John Anthony since junior high school. “I was arrested by images taken by the Voyager probes [in the late 1970s],” he recalls, “which opened up the exploration of Jupiter.”

In the heart of a star

Stars come in all sizes and types. Neutron stars are among the weirdest. These dense, tiny objects are leftovers from supernova explosions. They form when stars that are mid-size — only slightly larger than our sun — collapse at the ends of their lives. A neutron star might have a mass between 1.4 and 3.2 times that of our sun. But all that mass is crammed into an object only about 10 kilometers (6 miles) across. That is about the size of a small city.

“Neutron stars” are aptly named. They aren’t made of atoms, where electrons circle a nucleus (and therefore contain a lot of empty space). Instead, a neutron star starts out so massive that its immense gravitational force causes all of its atoms to collapse into one glob of neutrons. (As a result of the collapse, the particles all come into contact. Here, the positive charges of the protons cancel out the negative charges of the electrons.) In a sense, a neutron star becomes like one big atomic nucleus.

The physics of an atom — and in particular, how its subatomic particles interact with each other — is pretty complicated. And those physics are weird, especially when compared to the phenomena we see and experience under normal circumstances, notes Shaun Datta. This 18-year-old attends Montgomery Blair High School in Silver Spring, Md.

A type of physics called quantum mechanics helps explain interactions between subatomic particles. In particular, Shaun notes, it explains how protons can stick together inside a nucleus, when they’d normally repel each other very strongly. “Without these interactions, an atom’s nucleus would fly apart,” he says.

Quantum physics is surprising in many ways. In particular, says Shaun, even groups of particles that are mostly made of electrically-neutral neutrons have a tendency to fly apart — whether they make up an exceptionally large atomic nucleus or a neutron star. The same processes inside the nuclei of large atoms are probably happening inside neutron stars too, he adds. They’re just happening on a much larger scale. But such interactions aren’t fully understood.

That is one reason why Shaun chose to study how large groups of subatomic particles stick together, without flying apart. “My mentor told me this is a problem that has been formulated but not yet addressed,” he explains.

Shaun’s research used a computer to simulate how subatomic particles inside atomic nuclei and neutron stars interact. The results aren’t easy to explain, he admits. But in simple terms, his simulations suggest that in some situations, small groups of particles within a larger mass stick together (just as they do in atoms) and then act as “glue balls.” They help bind the entire collection of particles together.

Shaun’s project earned him 10th place in the competition and $20,000.

Black holes forever!

Black holes can be weirder than neutron stars. Neutron stars pack together subatomic particles into one city-sized object. In black holes, the gravitational forces are so strong that even tiny-but-tough subatomic particles can’t take the pressure. Instead, all of the mass in the object collapses down to a very small point. According to the simplest theory, a black hole’s gravity is so strong that nothing, not even light, can escape it. Processes inside a black hole — inside what’s called its event horizon — are forever hidden.

Well not totally. According to quantum mechanics (those weird rules of physics at the atomic level, again!), some things might be able to escape a black hole, says Kaitlyn Shin. This 17-year-old attends Jericho Senior High School in Jericho, N.Y.

Under certain situations, even in empty space, energy can be converted into a pair of particles, she explains. If that happens very close to the event horizon of a black hole, one of those particles can tunnel through the event horizon and reach the outside. There, in theory, such newly escaped particles could be detected. (These emissions are called Hawking radiation. The phenomenon is named after Stephen Hawking, a famous British physicist. He came up with the idea that black holes could emit particles after all.)

For a long time, most astronomers thought black holes could only be large. These objects start out as stars much larger than our sun. They form when the stars collapse at the end of their lifetimes. (Scientists suggest that any star larger than a neutron star will eventually collapse into a black hole.)

Recently, researchers have theorized that many small black holes formed just after the Big Bang that created our universe. As the universe expanded from one very small point, they suggest, massive chunks of matter somehow remained locked in very small pieces. So they failed to spread into large clusters of atoms. These primordial black holes still exist throughout the universe, some scientists believe. (“Primordial” means existing at or from the beginning of time.)

Using complicated math, scientists have estimated the probability of detecting Hawking radiation emitted by primordial black holes. According to Kaitlyn’s calculations, the actual chances are only one-thousandth as high as previous studies suggested. Kaitlyn says that her mentor, a professor at Columbia University in New York City, has reviewed her work. He thinks she’s right. So if primordial black holes do exist, her work suggests, finding them may be tougher than expected.

Kaitlyn first got interested in science at age 8 or 9, she says. “When my dad would tuck me in at night, he’d tell me all about stars like red giants and white dwarfs,” she says. He told her that black holes were like taking a planet the size of Earth, and squashing it down to the size of a peanut. “There’s a magic called physics, and I’ve been sold on it ever since,” says Kaitlyn, one of this year’s teen research leaders.