The search for life beyond our solar system tends to focus on finding familiar ground — a rocky, Earth-like world that sits in its star’s habitable sweet spot, where water is liquid and life could thrive.
But as the hunt for habitable worlds has gotten closer to successfully detecting planets that are the right size and distance from their stars to meet that criteria, some scientists have begun looking elsewhere: to those planet’s moons.
So far, efforts to detect those faraway moons, called exomoons, have not been successful. David Kipping, an astronomer at the Harvard-Smithsonian Center for Astrophysics who is leading the year-old Hunt for Exomoons with Kepler, recently reported that his team had been unable to detect moons circling their first seven candidate planets, using data from the NASA Kepler space telescope.
A paper to be published this month in the journal Astrobiology describes the factors that would determine whether moons in other solar systems could support life.
In that work, Rene Heller of the Leibniz Institute for Astrophysics Potsdam and Rory Barnes of the University of Washington introduced the concept of a “habitable edge” that could be used as a tool to estimate whether moons might provide a welcoming environment for life.
They detail ways in which moons could expand astronomers’ notions of habitable worlds. For example, planets that are too cold and far from their suns to support life may have moons that are perfectly suited. Imagine a giant planet with a moon that’s quite close, such as Jupiter’s volcanic moon, Io. Jupiter is far from the sun’s warmth, but Io has what’s called tidal heating, due to the gravitational pull that the massive planet exerts on its moon. This is what fuels its volcanic activity, with lava temperatures above 2,000 degrees. “In that case it’s too extreme, too hot,” Kipping said. “But you can imagine a bit cooler moon, way outside of the traditional ‘habitable zone’ that we think of.”
Burrowing mice help team find genetic link to a simple behavior
A team of Harvard University biologists has untangled a connection between genes and a simple behavior using a most unlikely set of tools: a large box filled with a ton-and-a-half of soil and sand, two closely related species of mice, and a polyurethane foam that can expand to fill crevices.
The researchers, led by zoology professor Hopi Hoekstra, had initially been focused on more straightforward questions, such as trying to understand the genetic basis of color variation and physical differences in mice. Then, Hoekstra’s interest was piqued by a distinctive behavior first described in a 1929 scientific paper: the tendency of oldfield mice to dig complex burrows.
Hoekstra was not so much interested in the burrows as she was in the consistency of oldfield mice, which followed the same basic blueprint again and again: a long entrance tunnel leading to a nest, with a second escape tunnel that tilted upward, without quite breaching the surface.
Hoekstra and her team decided to check whether they could discern how genes contributed to this characteristic behavior. In a paper published Wednesday in the journal Nature, the researchers mated the oldfield mice with a closely related species that dug less impressive burrows and saw what kinds of architects their offspring were. Left alone in the big box of soil, the offspring built burrows that resembled their big-burrowing parent. The complex home-making tendencies appeared to be a genetically dominant behavior.
The researchers were able to locate three regions of the genome that seemed to contribute to the length of the entrance tunnel, and a single swath of genetic material that appeared to determine whether the mice would build the escape tunnel.
“The ultimate goal, now that we’ve found these regions, is to find genes in those regions,” Hoekstra said. The researchers can see what happens to mouse tunnel-making tendencies if they knock out those genes, or even see what happens if they insert a key gene from a big-burrowing mouse into one that digs a more modest home.
Expert group aims to keep biology safe for amateurs
When some people hear the word “hacker,” they think of the garage hobbyists who laid the foundation for the personal computer industry. Others envision a shadowy world in which programmers build computer viruses or break into websites. A third category of hacker is motivated not by evil, but by the desire to spark larger conversations about how technology and information are used — perhaps best represented by Aaron Swartz, who committed suicide earlier this month. These sometimes conflicting visions are part of the mythology of the computer hacker, which has for years been creeping into a very different field: biology.
As equipment has gotten cheaper and techniques have become more accessible, biology has been embraced by a growing number of amateurs. To many, that seems like an extraordinary opportunity: Bringing biology, and specifically the ability to analyze and manipulate DNA, out of the specialized and intimidating confines of the laboratory could drive science education forward and bring in a surge of creative ideas from people with other expertise and interests.
The flipside is that amateurs could — accidentally or purposefully — do science that could harm others, such as release a specially engineered pathogen into the environment or, more likely, pour the wrong substance down the drain.
Now, in an effort to make sure the DNA hackers know what they’re doing, Boston-based DIYbio.org (short for Do-it-Yourself Biology) and the Synthetic Biology project at the Woodrow Wilson International Center for Scholars , a nonpartisan research organization, have created a new resource: “Ask a Biosafety Expert.”
The website, staffed by three experienced professionals, will post answers to questions submitted by users about how to do science safely.
“It’s the regular, old-fashioned biosafety issues that we need to address,” said Jason Bobe, a cofounder of DIYbio.org, a nonprofit that aims to support and foster the community of amateur biologists.
Ted Myatt, one of the three experts who will field questions from amateurs, is director of research compliance at the University of Rhode Island. He said that, based on his own experience with amateur biologists, the idea that people will intentionally do something to harm others has been overhyped. Most are happy to have the safety service available, he said.