Web Concepts

Posts Tagged ‘life on mars?’

Scientists have found several meteorites that originated on Mars or the moon, after being ejected in asteroid collisions, forcefully thrown into space and finally arriving on Earth. It makes sense that the opposite could be true, and that after mega-collisions, some pieces of Earth could be thrown toward Mars or Venus.

But most simulations suggest very few Earth pieces would reach the fourth planet, because they would have a hard time overcoming the gravitational pull of both Earth and the sun. Lots of the ejected particles would actually wind up back on Earth, according to previous studies. Some scientists have even suggested these refugee particles would “re-seed” their home planet.

Now researchers in Mexico have a new simulation, and they say plenty of Earth bits would indeed make it to Mars — and beyond, all the way to the Jovian system. Mauricio Reyes-Ruiz and colleagues at the Universidad Nacional Autonoma de Mexico ran computer simulations of 10,242 test particles, following their predicted paths for 30,000 years. That’s about as long as scientists think life could survive in space, the authors note.

They ran simulations at five different ejection velocities, from 6.97 miles per second to 10.2 miles per second. They found that at faster velocities, particles are more likely to reach Jupiter than Mars, because of their great speed relative to Mars’ low gravitational pull. The particles also reach Jupiter more quickly, with half making the trip in 10,000 years, the authors write. In one simulation, just one particle reaches Mars, and it takes between 25,000 and 30,000 years to get there.

Even more bizarre, many particles end up traveling past 40 AU, which the authors describe as leaving the solar system.

This is all theoretical, of course — the ejection velocity and the particles’ trajectory would be determined by variables like the size and velocity of the incoming object, not to mention the collision location relative to the spin of the Earth. But it’s an interesting concept — as KFC points out over at Technology Review, if life persists in space longer than astrobiologists think, life from Earth could still be speeding toward distant worlds.

[Technology Review]

Maybe it's not so dry over there after all

There are huge implications in that of course, provided the hypothesis turns out to be true. It underscores the idea that Mars could indeed be capable of harboring some kind of life. And it whets (wets?) the appetite for future Mars exploration, both robotic and--eventually--manned.

The evidence comes to us in the form of the finger-like features you see running down the slope of the crater in the pic above (and in the animation below). Regular observation shows that they appear during the warm months, extend themselves down sloping terrain, then fade away when temperatures drop in the fall. During the next Martian spring they return again. And while there are a few hypotheses floating around out there as to what might cause these features to appear, retreat, and appear again as the seasons change, the general consensus seems to be that briny water is the culprit.

Don’t get the wrong idea--these features are far from being fully explained. But a briny water would fit the aforementioned characteristics nicely. The saltiness would lower the water’s freezing point such that it could flow even during the cold (relative to Earth) Martian spring and summer. And we already know that brines were abundant in Mars’ past, making them a much more likely candidate to make these dark features rather than something wholly new.

But mysteries still abound. For one, the markings aren’t dark because they are wet, but because of something else at play here that is currently unexplained. Equally inexplicable: why the features brighten again when the temperatures decline in fall and winter.

But the finding is no less significant for the questions it raises. Liquid water on mars, salty though it may be, is a huge finding for those holding out hope that Mars might yet yield some kind of evidence of life. And even if it doesn’t, perhaps it could help sustain life--perhaps life forms visiting from another nearby planet--at some point in the future.

NASA/JPL-Caltech/Univ. of Arizona

H. mephisto was found thriving in three different gold mines in South Africa, where they’ve apparently been living in water and feeding off bacteria for thousands of years (carbon dating shows that they’ve been living at this depth for between 3000 and 12,000 years). Just how deep are they dwelling? H. mephisto was found as far down as 2.2 miles down, impressive considering that almost all multicellular life is found either on the surface or in the first 30 feet of the crust.

That’s because the conditions down there aren’t ideal for larger, complex organisms. It’s hot (H. mephisto can survive in temperatures up to 109 degrees), there’s no sunlight, little oxygen, and no food. Life down there is tough enough for single-celled organisms. Introduce the more complex energy needs of multicellular creatures to those environs, and very quickly the math doesn’t add up.

But the finding of these multicellular, complex life forms at such depths has major implications for life in the universe. It proves that multi-celled organisms can subsist completely isolated form other complex ecosystems, existing on the energy scavenged from single-celled, microbial communities. That means that any planet where surface life spawned at some point in history could still harbor complex life deep beneath the surface, even if surface life there had been extinguished.

[New Scientist]

To make Mars more Earthlike, or “terraform” it, we just need to increase the greenhouse effect by adding fluorocarbons to the atmosphere, absorbing and trapping the sun’s rays. Tetrafluoromethane, or CF4, is a simple refrigerant that could work without destroying the ozone, as other fluorocarbons do.

As Mars warms, its frozen soil would thaw enough to release carbon dioxide, and more carbon in the atmosphere would further accelerate the greenhouse effect, bringing the average temperature up to 32°. Mars’s frozen underground water supply would melt and flow back into ancient riverbeds. And when the water reaches Martian soil, it would break down latent peroxides, releasing oxygen into the atmosphere—not yet enough to sustain human life, but enough to grow plants—which would further increase the supply.

Once the plants took root, we could just wait for oxygen to accumulate. At this point, Mars colonizers, who Zubrin imagines would work out of a research base camp and wear something akin to scuba gear to supplement their oxygen intake, would also grow algae and seaweed in ponds, which could anchor a growing food chain. “You could have fish farms on Mars,” he says. “Water would become the first environment that would be habitable by higher animals without any kind of artificial assistance.”

After bringing in fish, we could begin introducing land-dwellers to Mars, starting with insects and, as more and more oxygen became available, progressing to warm-blooded creatures. Using this process, Zubrin says, humans could walk around without supplemental oxygen within 1,000 years. But he also predicts that we’ll come up with other ways to speed up our settlement of Mars, such as genetically engineered plants that photosynthesize faster. “We can grapple with it and come up with a way to do it using 20th-century technology,” he says. “Yet these are solutions that people in the future will consider prophetic but quaint.”

Have a science question you've always wondered about? Email fyi@popsci.com

Check out this amazing new animation of NASA’s new Mars rover, the car-sized Mars Science Laboratory, on its harrowing journey to the red planet.

The rover, also called Curiosity, is too big to land bouncing along airbags a la its predecessors, Spirit and Opportunity. And Mars doesn’t have enough atmosphere for a parachute to slow it sufficiently. So engineers at the Jet Propulsion Laboratory came up with this hybrid approach, involving a rocket-slowed descent and a “sky crane.”

Curiosity will launch this fall and spend the next eight months traveling to Mars. It will enter the Martian atmosphere careening at 13,000 miles per hour, where its Apollo-esque heat shield will protect it from burning up. A parachute slows it down a bit before the rocket-powered descent stage. Then the sky crane lowers the rover, something that has never been done before .... just watch the super-realistic animation below.

Spirit and Opportunity were bouncing around like glorified beach balls when they landed, which was somewhat terrifying for any Mars enthusiast, let alone the rover teams at NASA and affiliated institutions. But a sky crane? It's hard to imagine the tension. Here's hoping it all goes as smoothly as the video.

[via IEEE]

The premise of their reasoning is this: It’s estimated that Mars and Earth have swapped a billion tons of rock over the course of their lifetimes. And some of the stowaway microbes aboard those rocks could be quite hardy, surviving the trip. DNA is pretty durable as well. On the surface of Mars it wouldn’t last too long, but shielded from UV radiation DNA could lie dormant on Mars for a million years or so.

So MIT’s DNA decoder will be designed to dig. If there ever was life on Mars, or if there are organics buried there from other origins – be they Earth or elsewhere – the Search for Extraterrestrial Genomes (SETG) should be able to isolate, amplify, and identify nucleic acids right there on the Mars, no return trip necessary.

The technology is still a couple of years away from field tests in Chile’s Atacama Desert or in Antarctica, two of Earth’s analogs for the arid, cold deserts of Mars. If it passes muster there, it could be hunting the building blocks of life on the Red Planet by the dawn of the next decade.

[Discovery News]

Spirit is not exactly parked in a puddle yet, but the pattern of the ferric sulfates in the red soil look like it was caused by seeping of liquid -- recently, perhaps seasonally, perhaps continually.

If Spirit survives the coming Martian winter, during which the rover will be placed in a hibernation state, she will continue to do valuable science when she wakes up.

[NASA]