A breadloaf-sized satellite could find the next Earth

By Laura Shin


If you’re searching for another Earth-like planet out in space, you’d think you’d need something fairly big for your search. After all, the Kepler space telescope, which last year found many planets orbiting other stars, including two Earth-sized ones, is 15 feet tall and 9 feet in diameter.
But even something small can do the trick: Case in point, the satellite ExoplanetSat, which could easily fit in a backpack.
About 4″ x 4″ x 12″, roughly the size of a loaf of bread, ExoplanetSat isn’t only unusual for its size. Once it launches (which NASA originally scheduled for fall though the project may be delayed), it will also look for stars differently from Kepler, which monitors 150,000 stars at once. ExoplanetSat will look at one star at a time, detecting the faint dimming of a star that occurs when an otherwise invisible planet crosses in front of it.
ExoplanetSat is also different from other satellites in that it’s not a product of NASA, but was born out of a class project at MIT led by astrophysicist Sara Seager, known for her research on what the atmospheres of planets orbiting distant stars might look like through telescopes on Earth.
The challenge for the student scientists and engineers was to figure out how to find planets using CubeSat, a literal cube (about four inches on each side) that was created at California Polytechnic State University in San Luis Obispo about a decade ago.
The MIT students put three together to form ExoplanetSat, which has all the elements of a telescope — lenses, detectors, power supply and more — plus packages together two elements that are separate on traditional telescopes: Space telescopes usually have a second small scope on the outside of the big telescope. It’s used to spot the objects that the big scope should zoom in on. The ExoplanetSat, however, has both the star finder and the star gazer in one unit.
When in orbit, it will complement the work of Kepler, which searches for distant planets that are too far to check out for signs of life. ExoplanetSat, meanwhile, will search for Earth-like planets orbiting relatively close sun-like stars.

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Sperm swimmers could use lessons

By Rose Eveleth

Sperm aren’t the graceful swimmers you think they are, according to new research. Instead of gracefully waving their flagella and swimming through the vaginal tract, most sperm actually bump along the walls and crash into each other on the way.

The research, published in the Proceedings of the National Academy of Sciences, explains that sperm don’t really “swim” per say - instead they cling to the sides of the reproductive tract and bump their way along. Imagine a crowded ice skating rink for novices. Most people cling to the wall, slipping and sliding and half-dragging themselves along. That’s essentially what sperm are doing inside the female reproductive tract.

In fact, sperm almost never swim, the researchers say. The only time they leave the walls is when the tract makes a sharp corner. At that point, the sperm wind up swimming along until they crash into the other wall, and continue their unsteady journey onwards.

If this sounds ridiculous looking, you’re right, says Dr. Denissenko at the University of Warwick who did the study. ““I couldn’t resist a laugh the first time I saw sperm cells persistently swerving on tight turns and crashing head-on into the opposite wall of a micro-channel,” she said.

Figuring out how sperm swim is important for couples who have to turn to fertility treatments for help conceiving. ““In basic terms – how do we find the ‘Usain Bolt’ among the millions of sperm in an ejaculate,” explained Dr. Kir,man Brown, at the University of Warwick. “Through research like this we are learning how the good sperm navigate by sending them through mini-mazes.” If you can figure out which characteristics make the most successful sperm, you can pick the strongest ones to use during fertility treatments.

Bonus: there’s a movie to go along with the paper.

Via: Eurekalert

Photo: Wikimedia Commons

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What is your dog thinking?

By Rose Eveleth |

In movies, talking dogs are one of our favorite tropes. From Homeward Bound to the army of evil dogs in Up, we seem to think we’ve got a pretty good handle on what’s going on in fido’s brain. It probably involves toys, and chasing squirrels, and wanting belly rubs.

But, what are dogs really thinking? Are they secretly judging us and our poor wardrobe choices? Are they plotting to overthrow humanity? Or are they not thinking anything at all? Where Hollywood fails, science has the answer! Well, sort of.

Researchers at Emory University put a bunch of dogs in a functional Magnetic Resonance Imaging (fMRI) machine. That’s the same machine that reads human brains for all sorts of studies. The dogs owners then gave them hand signals, and the machine picked up what was going on in their brains.

The dogs had to be trained over several months to walk into the scanner and hold still - any movement could mess up the reading. One hand signal meant that the dog would get a treat, while the other meant no treat. When the dog saw the hand signal for treat, the area of the brain associated with rewards in humans was activated. So, the dog was paying attention to the treat signal and has a similar brain structure to humans.

But what does this really mean? We love our dogs, we think that they think about us all the time, is this just another search for something that’s not really there. Carl Zimmer’s piece in Time recently saying (unpopularity, as you might imagine) that dogs aren’t really truly our friends the way we might think.

Even the way the researchers describe the dogs in the study suggests that they might have some opinions about doggy brains. ““The dog’s brain represents something special about how humans and animals came together. It’s possible that dogs have even affected human evolution. People who took dogs into their homes and villages may have had certain advantages. As much as we made dogs, I think dogs probably made some part of us, too,” Gregory Berns, the direct of the Emory Center for Neuropolicy said in the press release. More brain scanning will be required to really understand what our dogs think about us, if they do at all.

Bonus: the study comes with adorable pictures of the two dogs involved: Callie and MCKenzie. And a video!

Via: Eurekalert

Photo: Emory University

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How to fall from 120,000 feet

By Rose Eveleth |

Do you ever wish you could fall from 120,000 feet safely? No? Huh, you must not be Felix Baumgartner.

Baumgartner is planning on falling from 120,000 feet in the air. That’s 23 miles up. To put that into context, a typical sky diving jump is somewhere between 3,000 and 13,000 feet. It would be the longest fall in history, and he’ll be falling through air that could be -70ºF at around 700 miles an hour.

So, obviously, Baumgartner isn’t heading up there in his swim trunks. In fact, he’s got a special suit designed just for him by the same engineers who build NASA’s pressure suits, to help him withstand the fall. PopSci broke down the futuristic space digs into six parts (along with some cool pictures).

The suit itself will pressurize and become rigid, helping him maintain the right position while he falls (called “delta position”). When he hits 35,000 feet (still way higher than any standard skydiving) the suit will soften, so he can move again. Since he’s falling from so high up, the suit also pumps oxygen to Baumgartner, and keeps an internal pressure of 3.5psi.

The suit will also keep track of how fast Baumgartner is falling and what the G-forces are on him. If things go wrong, he could lose consciousness. If the G-force meter sensors unsafe conditions it will deploy a parachute that will stabilize his spinning.

Speaking of parachutes, Baumgartner’s got a bunch. Three, in fact. The stabilizing one we just mentioned, the main chute, and a backup in case the main one fails. That main parachute have nine cells, which is standard for him, but this time they’re two and a half times bigger.

And, for those of you who want to live vicariously through Baumgartner, the suit includes a voice transmitter, a high-def video camera, and an accelerometer. It will be like you’re there, except without the freezing cold and the insane amounts of danger.

Baumgartner has jumped from crazy heights before. In March he jumped from a balloon capsule from 71,500 feet above New Mexico. If he manages to jump from 120,000 feet, he’ll break the world record set by Joe Kittinger, a US Air Force Colonel in 1960.

Via: Popular Science

Image: Dr. Michel Royon

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Aliens among us

By Rose Eveleth

When you think about aliens, you probably imagine a benevolent, ET style friend, or a gruesome, abdomen ripping monster. Or maybe you just imagine a small green man, or a blob of a space tyrant like Jabba the Hutt. But according to a new essay and podcast in PLoS ONE Biology, we should care less about what these potential aliens look like, and more about what they’re made of.

Gerald F. Joyce, a researcher at the Scripps Research Institute in La Jolla, California, has his own ideas about what we should be looking for when we search for life beyond our own.

In his essay, Joyce asks the question: “Why are we so confused (or so lonely) that we have such trouble distinguishing life from non-life and distinguishing our biology from another?” He’s referring to the many times we’ve “discovered” new forms of life. Like when bacteria was supposed to be using arsenic to build life, or when researchers built a synthetic cell. None of these are new life, or different from the biology we know.

His answer is that it’s hard to discover something we don’t know how to look for. We only know our own biology. Which makes looking for things that are not like us very difficult. Even if we were to have something in our hands that was alien, how would we know it?

“A genetic system that contains more bits than the number that were required to initiate its operation might reasonably be considered a new form of life.” If you’re scratching you’re head, it’s okay, me too. Here’s the breakdown.

Let’s use life we know it as an example. Humans have a genetic system made up of four bits: the four base pairs, A, T (or U), G and C. Using those four base pairs there can be all sorts of combinations, and that’s how evolution works. New life would have different bits, bits totally removed from our base pairs.

Joyce proposes two ways of new life forming. The first way is through chemistry. For that new life to form with its new bits, it would require what he calls a “bit generating system.” So, for us, that was the primordial soup of chemicals around when the Earth was young. From there we got self-replicating molecules, and from that we could get evolution.

But the second way is through biology. What if a few chunks of Earthly life found their way to a distant planet? At what point does that life become alien? That’s where the “more bits than the number that were required to initiate it” comes in. If the life on these distant planets still has four bits, let’s say A, T (or U), G and C, it’s not alien. If it has more, then it’s biology is fundamentally different, and it is.

Okay, but Joyce isn’t the first person to have an idea for what alien life is or isn’t. Smart Planet’s own John Rennie has a great, extended discussion of how we might find aliens. The SETI institute has been searching for over 25 years, and NASA has flip flopped on findings from several missions.

Other people argue that we’re looking in the wrong place for extraterrestrials, or at least evidence of them. Rather than pointing our instruments towards the sky, Paul Davies at Arizona State University thinks we should be looking for footprints of those aliens here on earth, according to Space.com. What he’s looking for is far from Joyce’s bit-based system of evolution, but rather messages from those aliens or evidence of a Dyson sphere they might be using to trap the energy of stars.

And all this talk of aliens is also, apparently, quite telling about ourselves. Anthropologist Kathryn Denning studies how we look up, and down, and around, for aliens, and what that really means. She told Wired,

“ I think one good example is the variable of L, the lifetime of civilizations, which dominates the Drake equation. [An estimate of the number of intelligent extraterrestrials that could exist in our galaxy.]

The speculation on this has been frankly goofy sometimes. I mean you can make up basically any value of L that you like and justify it in some way. So people say we should try to use Earth’s data to look at it. We should ask what really does cause civilizations to collapse or revert to a lower order of complexity or technological regime.”

But Joyce, for one, recognizes that often the search for alien life is odd and troubled, and hopes humans can do it better. “I think humans are lonely and long for another form of life in the universe,” he said in the press release, “preferably one that is intelligent and benevolent. But wishing upon a star does not make it so. We must either discover alternative life or construct it in the laboratory. Someday it may be discovered by a Columbus who travels to a distant world or, more likely in my opinion, invented by a Geppetto who toils at the workbench.”

Via: Eurekalert

Image: C G-K, Flickr

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