NASA confirms evidence of ‘flowing liquid water’ on Mars 28-09-2015
Cape Canaveral:
After days of speculation, NASA, for the first time, has confirmed the existence
of liquid water on the surface of Mars, according to new research announced on
Monday. The finding stems from data and analysis by NASA’s Mars Reconnaissance
Orbiter.
The Mars Reconnaissance
Orbiter (MRO) has verified that dark, seasonal streaks that have appeared on
Mars’ surface come from briny water flows.
Scientists found the
first evidence that briny water may flow on the surface of Mars during the
planet’s summer months, a paper published on Monday showed.
Although the source and
the chemistry of the water is unknown, the discovery could affect thinking
about whether the planet that is most like Earth in the solar system could
support present day microbial life.
Scientists developed a
new technique to analyze chemical maps of the Martian surface obtained by
NASA's Mars Reconnaissance Orbiter spacecraft. They found telltale fingerprints
of salts that form only in the presence of water in narrow channels cut into cliff
walls throughout the planet's equatorial region.
The slopes, first
reported in 2011, appear during the warm summer months on Mars, then vanish
when the temperatures drop. Scientists suspected the streaks, known as
recurring slope lineae, or RSL, were cut by flowing water, but had previously
been unable to make the measurements.
“I thought there was no
hope,” Lujendra Ojha, a graduate student at Georgia Institute of Technology and
lead author of a paper in this week's issue of the journal Nature Geoscience,
told Reuters.
Mars Reconnaissance
Orbiter makes its measurements during the hottest part of the Martian day, so
scientists believed any traces of water, or fingerprints from hydrated
minerals, would have evaporated.
Also, the
chemical-sensing instrument on the orbiting spacecraft cannot home in on
details as small as the narrow streaks, which typically are less than 16 feet
(5 meters) wide.
But Ojha and colleagues
created a computer program that could scrutinize individual pixels. That data
was then correlated with high-resolution images of the streaks. Scientists
concentrated on the widest streaks and came up with a 100 percent match between
their locations and detections of hydrated salts.
“We’re not claiming
that we found... evidence of liquid water. We found hydrated salts,” Ojha said.
Still, that was enough for NASA, which declared a "Mars mystery
solved," in a press advisory. A press conference on it was planned for
11:30 a.m. EDT/1530 GMT on Monday.
“It’s a little bit
over-the-top announcement by NASA,” Ojha said. “There’s so many mysteries to be
solved about RSL.”
The discovery “confirms
that water is playing a role in these features,” added Alfred McEwen, a
planetary scientist with Arizona State University. “We don’t know that it’s coming
from the subsurface. It could come from the atmosphere.”
Whatever the water's
source, the prospect of liquid water, even seasonally, raises the intriguing
prospect that Mars, which is presumed to be a cold and dead planet, could
support life today. Much more information about the water's chemistry, however,
would be needed before scientists could make that assessment, McEwen added.
“It's not necessarily
habitable just because it's water – at least to terrestrial organisms,” he
said.
NASA’s ongoing Mars
rover Curiosity has found evidence that Mars had all the ingredients and
suitable habitats for microbial life to exist at some point in its past.
Scientists have been
trying to figure out how it transformed from a warm, wet and likely Earth-like
planet early in its history into the cold, dry desert that exists today.
Billions of years ago,
Mars, which lacks a protective, global magnetic field, lost much of its
atmosphere. Several initiatives are under way to determine how much of the
planet’s water. (With inputs from agencies) |