Cuplikan dari website TIME - Mars researchers revealed the strongest evidence yet that liquid water is flowing on the Red Planet. That prospect can help sustain humanity’s presence there and establish a growing settlement on that world.

Water is the elixir of life. And using this vital resource further bolsters my plan to establish Cycling Pathways to Occupy Mars.
So the good news is that there’s water.

But the bad news is that it’s poisonous water.

The running water on Mars is briny, rather than pure, and loaded with deadly perchlorates. Nevertheless, the treatment and processing of that water—as well as making use of subsurface reservoirs of ice and tapping possible underground aquifers—that all adds up to the ability of humans to live off the land: Marsland.

A water supply on Mars could enable the growing of vegetation and edible foods, and perhaps the cultivation of protein-rich fish.

So this revelation about water and the Red Planet makes a lot of things possible. Furthermore, I’m positive that other exciting findings about Mars are in the offing. One of which is that, perhaps, the planet is today an extraterrestrial address for microbial life.

The evidence of water on the surface of Mars has many implications. In fact, the finding is a wellspring, a gusher of good news to make possible the creation of a permanent settlement outpost on the Red Planet.

Still, back here on Earth, we need to face the ebb and flow of politics and budgets. It’s time to rebuild and sustain America’s space program that makes the vision of our future on Mars valid.

No dream is too high for those with their eyes in the sky!

Buzz Aldrin, best known for his Apollo 11 moonwalk, holds a doctoral degree in astronautics and continues to wield influence as an international advocate of space science and planetary exploration. Aldrin and co-author, Leonard David, wrote Mission to Mars – My Vision for Space Exploration, published in 2013 by the National Geographic Society. Aldrin’s new children’s book, Welcome to Mars: Making a Home on the Red Planet, co-authored with Marianne Dyson, was published in this month.

Cuplikan dari national geographic- It’s tempting to say that the announcement of liquid water on the surface of Mars heralds a new era in Martian exploration.
You might think that the first human explorers on Mars will park next to a salty stream and use it to manufacture fresh drinking water. Maybe they could even find life in damp Martian nooks and crannies, areas where the dusty red planet can still fuel microbes.

Reality is much more subtle. Finding evidence for flowing water is not the same as finding life. Right now, scientists don’t know where this water is coming from, or if the chemistry in these Martian seeps is even life-friendly. And unfortunately, chances are it will be a long time before we can get there to find out.
Water on Mars: What Does It Really Mean?

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Water on Mars: What Does It Really Mean?
A new find of liquid water fuels hopes that life may yet exist on the red planet.
Picture of an impact crater on Mars
Traces of salty water have been detected in in gullies and craters on Mars, such as this impact crater with dark streaks along its inner edge.
PHOTOGRAPH BY NASA/JPL-CALTECH/UNIV. OF ARIZONA
By Nadia Drake, for National Geographic
PUBLISHED SEPTEMBER 29, 2015







It’s tempting to say that the announcement of liquid water on the surface of Mars heralds a new era in Martian exploration.


You might think that the first human explorers on Mars will park next to a salty stream and use it to manufacture fresh drinking water. Maybe they could even find life in damp Martian nooks and crannies, areas where the dusty red planet can still fuel microbes.

Reality is much more subtle. Finding evidence for flowing water is not the same as finding life. Right now, scientists don’t know where this water is coming from, or if the chemistry in these Martian seeps is even life-friendly. And unfortunately, chances are it will be a long time before we can get there to find out.

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“It’s hard to get a spacecraft clean enough to send a lander or rover there right now,” says Bethany Ehlmann, a planetary geologist at Caltech, referring to concerns about hitchhiking Earth microbes contaminating the Martian surface.

But there's still reason for excitement. These seasonal seeps, which scientists call recurring slope lineae, “are probably the best place to look for modern life,” she says.

Odds of Life
Here's what scientists know. Analyses have confirmed that enigmatic streaks that appear in summertime on the planet's slopes are produced by liquid water—salty water, perhaps capable of sustaining chemical reactions and even life.

Like Mars itself, the dark watery streaks are ruggedly beautiful, as seen in photographs taken by the HiRISE camera aboard the Mars Reconnaissance Orbiter. But for all their picturesque drama, these dark marks represent more of a trickle than a flow.

It’s possible they’re fed by some kind of underground aquifer, or a buried icefield that thaws in warmer weather and sends melted Mars water sliding downhill.

While not outside the realm of possibility—we do know there’s ice buried beneath the Martian surface—such scenarios aren’t as likely as the one scientists favor: The water comes from the atmosphere. If that's true, it’ll be a much tougher resource to tap into.

But how could water from the atmosphere form these dark streaks? On Mars, as on Earth, salts on the surface can absorb atmospheric water vapor and trap it in their crystal structures. Then, when the soggy crystals warm up, they dissolve. The whole liquidy mix surrenders to the tug of gravity, and off it goes, tumbling downhill.

In Chile’s super-dry Atacama desert, this exact type of system—called deliquescence—is the key to supporting some rather extreme life, says NASA astrobiologist Chris McKay.

But there’s no guarantee this is happening on Mars. McKay notes that the type of salts near the Martian streaks, called perchlorates, form different watery mixtures than the salts we’re most used to on Earth. In fact, it’s possible the perchlorate streaks could behave similarly to Antarctica’s Don Juan Pond, which is the saltiest liquid water body on Earth—and totally dead.

“Such a brine is not suitable for life and is of no interest biologically,” McKay says. “Nothing can live in the brine of Don Juan Pond.”

Follow the Water
So, seeps fueled by atmospheric humidity might not make the most convenient water well for human colonists, and they might not even be ideal habitats for Martian microbes—but wouldn’t it be worth finding out?

Of course. What we know so far, based on the single example of Earth, is that life tends to show up wherever there’s water. That’s why NASA’s search for life beyond Earth has been driven by the mantra, “Follow the water.”

The frustrating irony here is that NASA can’t follow this particular water. Not yet.
Sending a spacecraft to an area where liquid water flows is much too risky, cautions NASA’s Office of Planetary Protection. Finding water in the streaks will brand them as a "special region," an area where spacecraft can land only after thorough cleaning or sterilization, says Ernst Hauber of the German Aerospace Center.

If hitchhiking microbes were to somehow survive the journey to Mars and find themselves in a briny bath, it’s possible they could gain a foothold and contaminate the red planet. Such a scenario would not only complicate any future detection of life on Mars, but also introduce a potential disaster: Think about how great we are at hastening the spread of invasive species on Earth.

It’s certainly worth the caution, though humans walking on Mars (which some say is the next goal in solar system exploration) are much more likely to shed microbes than a sterilized robot is, and Earth microbes aren't necessarily likely to thrive in Mars brines.

If there’s one big story from the past decade of planetary exploration, it’s that water is everywhere. It’s tucked into moon dust, frozen in Mercury’s shadowed craters, streaming off the backs of comets, and sequestered inside the shells of icy moons. Mars, finally, has joined the population of bodies where we know water flows—and that’s interesting enough on its own, without the breathless speculation.

“Modern Mars is right ‘on the edge,' ” Ehlmann says, as an active world where liquid water exists even today. “Just a slight tweak in climate could make waters even more widespread.”

Follow Nadia Drake on Twitter and on her blog at National Geographic's Phenomena.