According to New Scientist:

Kathleen Benison, a geologist at Central Michigan University, Mount Pleasant, led a team that studied the sediments formed by acidic and very salty lakes in modern day Western Australia, and those deposited around 250 million years ago in North Dakota. It is very difficult to survive in such a tough environments and few signs of life have ever been found in these sorts of lakes.

Inside the halite and gypsum "evaporate" minerals, which form as the lake waters dry up, Benison and colleagues found previously unknown fossilised blobs at both the modern and ancient sites, ranging in size from 0.05 to 1.5 millimetres. They were made up of a mix of inorganic crystals and "hairs" stuck together in a mass (pictured). They named them hairy blobs.

The team argues that each hair was in fact a separate microorganism because the hair fossils are made of disordered graphite which, unlike inorganic graphite, has irregular layers that suggest it was once a live organism..

Many of the hairs are coated with crystals of gypsum, a calcium sulphate mineral. This link with gypsum suggests that the microorganisms were fuelled by chemical interactions with sulphur in the acidic water - which helped the gypsum to form.

Scientists are still divided on whether these crystal-hair creatures actually count as "life." As they run further tests on the fossils, the mere existence of such creatures fuels hope among astrobiologists that life could indeed have evolved on Mars and we might get a chance to meet it — or at least, to find its fossilized remains. Images from Benison's published paper in Astrobiology.

Hairy Blobs Found in Acidic Hell [via Eurekalert and New Scientist]

See full text of Benison's article here (just scroll down).

Lineweaver's idea kind of rocks SETI scientists' mission statement to the core. Ever since Carl Sagan's famously framed the ET question "are we alone?" as "Are there functionally equivalent humans elsewhere in the universe?" SETI folks have been trying to answer it. It's a gargantuan task, and one that that Lineweaver argues we're making worse by assuming that there is something about humans that is unique or special, or that life on Earth "wants" to be human.

If there is any tendency for life to evolve to get as functionally human-like as possible, then Lineweaver asks why haven't isolated part of Earth evolved human-like intelligence? Madagascar has been separated from Africa for millions of years, and should therefore be full of high-level primates instead of lemurs — apes' distant cousins. New Zealand (which because of its isolation Jared Diamond said was "the best opportunity we'll ever have to study life on another planet") should be filled with super-intelligent giant birds.

Lineweaver thinks that big brains aren't the be-all and end all of evolution. In fact, he argues that the answer to Sagan's question is "no" — functionally equivalent humans don't exist elsewhere in the universe. Instead, life elsewhere might be so weird as to be unrecognizable. "Intelligence" could easily take the form of some kind of system at profound disequilibrium with its environment — something like a hurricane or a star could be intelligent.

It's sounds like he's begging to get the SETI Institute's funding pulled, and to declare the entire SETI operation utterly useless, and in a sense he is. But he also thinks it's worth continuing the search because there's a lot of unexplored universe still out there to look at. And he admits he could be wrong — there could be a Planet of the Apes out there, too.

Lineweaver presented his theories at the Astrobiology Science Conference 2008.

SETI scientists have been looking for alien lasers for years now — part of the Optical SETI programs several universities and observatories across the country.

Those projects are still going full-bore, but scientists are hoping to increase their chances of success by building a detector that will look for near-infrared lasers, too. Just on the lower edge of the optical range of electromagnetic wavelengths, Andrew Howard and colleagues from UC Berkeley figure there's no good reason aliens wouldn't build a near-IR laser. And if they did, they'd obviously use it to broadcast complex signals to Earth containing detailed plans on how to build a device for interstellar travel.

Maybe that's getting a bit ahead of ourselves, but just in case, we'd better look for intelligent signals broadcast through gravity waves, too. These still-theoretical ripples in space-time are being tested for by the LiGO (Laser interferometry Gravitational wave Observatory) detector, mostly as a way to test astronomical theories. At least one researcher, Peter Hahn believes we should start analyzing the data for signs of ET, too.

In his simulations, Rasio assumed that the Earth-like planet was orbiting at the same distance we orbit our Sun (1Astronomical Unit, or AU, or around 93 million miles), and he calculated orbital eccentricities in cases where the second star was orbiting at distances of 250, 500, and 1000 AU.

Left by itself the lonely Earth-twin would probably oscillate between a highly elliptical orbit, and a fairly circular one. If it's too oval (an eccentricity greater around 0.7 say) the planet's climate goes haywire and turns into a runaway greenhouse, superheating the surface. At around an eccentricity of 0.4, most of the water would evaporate, but would hover in the atmosphere...and Vaporators would sell like hotcakes.

Things got a little better when Kita added a Jupiter-mass planet to the system. When placed just a few AU from the Earth-like planet, the eccentric orbit stabilized. In that case, the rocky planet's climate would be much like ours.

So far there are two systems that are our best bets for finding the real Mos Eisley — 55 Cancri and Epsilon Andromeda. Both have multiple planets, though Kita says we're not sure yet whether any are rocky or if they're all gas giants.

The Earthrise photo (and check out the video if you really want to feel tiny) taken from Apollo 8 is one of the most famous space pics ever taken. Along with a few other nearly identical images, the shots are the only space-borne perspective that feature our pale blue dot from anything like a wide-angle view. This sort of thing is exactly what we need more of, Wolfe said. Imaging all of the phases of Earth (crescent, half, gibbous, full, etc.) from at least one lunar distance away would give us tons of info for what a world with continents, a dynamic atmosphere and water looks like.

The grand prize would be taking an image of the Sun's reflection on our oceans in polarized light. "That would give us a measurement of what the glint of sunlight on water looks like," Wolfe said, which could be used to determine whether planets are other stars have liquid water on their surfaces too.

Image: NASA

Lineweaver's four main preconditions for a piece of galactic real estate being hospitable to intelligent life are:

- Distance from galactic center. Our sun is about 8.5 kiloparsecs from the center of the Milky Way which is about right. The further you go out from the center of a galaxy, the fewer stars there are. The further you go in, the more likely a nearby star will go supernova, and wipe out life in your start system. LIneweaver figures between 7 and 9 kpc is about right.

- Age. Life takes time to evolve into something resembling intelligent. This takes a few billion years.

- Metallicity. This is Lineweaver's way of measuring how much of the supernova leftovers are accumulated in a given region of space. If there's less than 1% of the metals found in our solar system, there's probably not enough to build a rocky planet (in astronomers' parlance, 'metals' includes everything that's not hydrogen and helium, so stuff, like water, too).

- The likelihood of forming a gas giant. Like supernovas, Jupiters, Saturns and other giant planets make bad neighbors for harboring life. During the early stages of star system formation, they have a tendency to come crashing through planetary habitable zones, annihilating rocky planets that may one day harbor life.

In short, it's a galactic jungle out there, and in 2004 Lineweaver's beginning to get his head around narrowing down the best places we may find our interstellar neighbors, whether in this galaxy or the next. All that said, though, he's careful to point out that we don't even really know what a good definition of life is, so instead of "habitable zone" maybe the name should be changed to the more sensible (and way less-exciting) "pre-habitable zone."

Image: NASA

Chart: Science

Here is our Martian woman's spec:

First, our woman is tall, a little pear-shaped, with really thick legs. This shape compensates for the reduced gravity.

She has a very lightweight exoskeleton covering her whole body. The exoskeleton has to keep her warm, keep her pressurized, shield her from solar wind, and absorb lots of sunlight. So it can be thin, but laced with heated mesh. It should have a nanofabric outer shell laced with lead to repel x-rays and other cosmic rays. And the upper half should have super bendy, ultra-thin solar cells that are constantly sucking up solar energy.

In her boots and strapped to her thighs, she has water drilling/processing packs. A cannulated drill can extend out of it, go deep under martian crust, suck up water, run it through a filter to get the salt and acid out, and then store it close to her body to keep it liquid so she can sip from it.

She also has a photosynthesis rig on her back. This is a light, thin backpack that converts the C02 from the atmosphere and some of the water from her leg pack into sugars and oxygen for our Martian. So it's a combination breathing apparatus and feeder.

Image by Stephanie Fox. Additional reporting by Nivair Gabriel.