Brilliant 10: Sun Diver

Flying a heat-resistant probe near the sun will reveal the physics of solar plasma

By Lauren Aaronson

Justin Kasper Courtesy Justin Kasper

In July 2010, a colleague rushed into Justin Kasper’s office at the Harvard-Smithsonian Center for Astrophysics, in Cambridge, Massachusetts. He showed Kasper a telescope video of something they had never seen before: a comet crashing into the sun. The sight was amazing. But what grabbed Kasper’s attention was the moment before impact, when a surprising cloud puff indicated that the comet had hit unobserved material.

To answer, among other questions, what caused the cloud puff, Kasper is designing an instrument that will get closer to the sun than ever before. The Solar Probe Cup will scoop up bits of the sun’s corona and solar wind to continuously measure its speed, temperature and density. That information will help astrophysicists investigate why the corona’s plasma gets so hot—it can reach a million degrees—and how the plasma turns into a millionmile-per-hour solar wind, and what that mysterious puff might be. “Who knows what we can’t make out because we’re just too far away?” Kasper says.

The Solar Probe Cup will ride on NASA’s first solar mission, called Solar Probe Plus, in 2018. When it reaches the sun, it will have to withstand temperatures of up to 2,550°F. Kasper and his team have begun upgrading a conventional ion detector by shrinking the plasma-collection cup (so that it will absorb less heat) and etching sturdier grids out of melt-resistant tungsten and sapphire.

Once the Cup takes off, the data-crunching begins. Kasper has several theories about the plasma movements his detector could uncover, but sometimes even the best theories can’t anticipate what the actual conditions in the plasma will be. “We’re trying to build instruments as capable as we can,” Kasper says, “because very rarely do we find what we were expecting. That’s part of the fun.”

Brilliant 10: Molecular Filmmaker

Capturing the motion of macromolecules will help researchers make better HIV drugs

By Mara Grunbaum

Hashim M. Al-Hashmi Courtesy Hashim M. Al-Hashmi

Early every morning, before dawn if he can, Hashim Al-Hashimi goes running. Six miles, rain or shine, summer heat or bitter Michigan cold (Al-Hashimi works at the University of Michigan). His chosen route is hilly for a reason. Just at the uphill crests—when the muscle pain is sharpest and the body most wants to quit—that’s when his mind is sharpest. “Most of my thinking is at the top of a hill,” he says.

It was one such push that led to his biggest innovation in molecular visualization. Using a computer algorithm he developed and nuclear magnetic resonance imaging, Al-Hashimi recorded the atomic-scale contortions of RNA and DNA, long thought of in biology as relatively inflexible structures. Instead of holding one predominant form, Al-Hashimi found, RNA bends and wiggles into a predictable series of shapes as its atoms rotate around their bonds. Each shape is a potential target for RNA-attacking drugs. Using this new method, Al-Hashimi has already identified one molecule, called netilmicin, that can stop HIV replication by latching onto RNA where one of the virus’s essential proteins otherwise would.

Al-Hashimi himself has always been in motion. He was born in Lebanon just before its civil war, and his family escaped to Greece soon thereafter. They then lived in Italy, Jordan, Wales and England. Soon after he started his Ph.D. at Yale, a labmate visualized a protein called myoglobin and couldn’t fit it to any single 3-D configuration. To Al-Hashimi, it seemed obvious that the protein was moving—everything in biology moves—but at the time, most biologists did not realize the extent to which biological macromolecules were moving. He realized then that revealing molecular motion would be his focus.

He’s now lived in Ann Arbor for nine years, longer than anywhere else, advising the scientists at his biotech start-up, Nymirum, and trying to view larger areas of DNA molecules. He says that being settled is somewhat strange, but he still runs every morning. It’s best if it’s still dark out. “Then there’s nothing to look at,” he says. “It’s just you and your brain.”

Brilliant 10: Sludge Miner

Scanning the genomes of an entire ecosystem will help scientists understand carbon sequestration

By Elizabeth Svoboda

Marsh Dwellers Susannah Tringe studies the genomic fingerprints of ecosystems to understand how microbial species work together John B. Carnett

Susannah Tringe spends a fair bit of her work time, currently for the U.S. Department of Energy Joint Genome Institute, in the fragrant, murky wetlands of California’s Sacramento–San Joaquin Delta. Thriving microbial communities there could be the key to understanding how wetlands mitigate or exacerbate greenhouse-gas levels in our atmosphere. Tringe is cataloging the genetic fingerprints of the entire microbial ecosystem to determine how these wetlands work and if we can tailor them while restoring drained wetlands to absorb more greenhouse gas than they emit.

A biophysicist by training and a crossword-puzzle fiend in her spare time, Tringe is focused most closely on wetland microbes and the soil and plants they live in and on. Studying the ecosystem’s collective biology, she says, will help her figure out whether the wetlands are pulling carbon dioxide out of the atmosphere—or whether, in some cases, they’re net producers of methane and other greenhouse gases. But this practice poses logistical problems: a single cup of swamp sludge can contain many thousands of microbe species, and it’s very difficult to isolate each one and catalog its genes individually.

Instead, Tringe extracts the Dna from all the microbes in an entire sample to determine which genes are present. “If a lot of organisms in an environment have a gene, it’s probably pretty important,” she says. When she finds many genes in a microbe sample that code for processes guiding carbon storage, for example, that is a good indication that microbes, not just vegetation, are important for sequestering carbon dioxide.

The Department of Energy recently awarded Tringe a $2.5-million research grant to continue her study of wetland ecosystems, with the goal of finding the best way to restore them. Tule, a plant commonly used to restore wetlands, harbors methane-producing microbes in its roots, tringe found. Replacing the tule with a different plant might cut down on greenhouse-gas seepage. If we restored all the drained wetlands in the Sacramento delta, she says, “it would be like converting all the SUVs in the state into hybrids."