The results of Earth-bound lab experiments appear to back up the theory that dark lines on Martian slopes are created by water — though in an otherworldly manner, scientists said Monday.
A team from France, Britain and the United States constructed models and simulated Mars conditions to follow up on a 2015 study which proffered “the strongest evidence yet” for liquid water — a prerequisite for life — on the Red Planet.
That finding had left many scientists scratching their heads as the low pressure of Mars’ atmosphere means that water does not survive long in liquid form. It either boils or freezes.
Identifying water on the Red Planet is complicated by our limited understanding of natural processes under conditions so different to those on Earth.
In September last year, a team reported in the journal Nature Geoscience that curious lines running down slopes on the Martian surface in “summer” may be streaks of super-salty brine.
They said they had found evidence in the lines of “hydrated” salt minerals, which require water for their creation.
The lines, up to a few hundred metres in length and typically under five metres (16 feet) wide, appear on slopes during warm seasons, lengthen, then fade as they cool.
“Under certain circumstances, liquid water has been found on Mars,” NASA concluded at the time.
For the latest study, also published in Nature Geoscience, researchers took to the lab to try and explain how water could have made the lines.
– ‘Remarkably similar –
The team, led by Marion Masse of the University of Nantes in France, included several of the authors of last year’s headline-making study.
They placed a block of ice on a 30-degree plastic slope covered with loose fine-grained sand, and allowed it to melt in a chamber in which Martian pressure and summer temperature was recreated.
They repeated the experiment under Earth conditions to compare the processes.
Under Martian pressure, they found, melting ice produced a liquid which boiled vigorously as it flowed downslope and filtered into the sand.
The evaporating water vapour blasted grains upward, creating ridges which collapse onto themselves when they become too steep, forming channels.
“The morphologies produced on the sandy slopes in these experiments are remarkably similar to the streaks observed on Mars,” Wouter Marra of the geosciences faculty of the University of Utrecht in the Netherlands commented on the study.
“This process in which unstable boiling water causes grains to hop and trigger slope failures may underlie some of the active landforms observed on the Martian surface.”
A video of the experiment can be seen below:
Fifty years after Moon mission, Apollo astronauts meet at historic launchpad
Fifty years ago on Tuesday, three American astronauts set off from Florida for the Moon on a mission that would change the way we see humanity's place in the universe.
The crew's surviving members, Buzz Aldrin and Michael Collins, are set to reunite at the same launchpad on Tuesday, the start of a week-long series of events commemorating Apollo 11.
Their commander and the first man on the Moon, Neil Armstrong, passed away in 2012.
But Aldrin and Collins, 89 and 88 respectively, will meet Tuesday at precisely 9:32 am (1332 GMT) at the Kennedy Space Center's pad 39A to kick off the festivities.
Training journalists in the era of fake news
As uncannily realistic "deep fake" videos proliferate online, including one recently retweeted by Donald Trump, journalism schools are scrambling to adapt to an era of misinformation -- or fake news.
Experts discussed how to train tomorrow's reporters for these new challenges at the World Journalism Education Congress in Paris last week.
The three-day event -- "Teaching Journalism During a Disruptive Age" -- was attended by 600 educators and researchers from 70 countries.
"We have journalism educators from places as different as Bangladesh and Uganda, but essentially we all face the same challenges," congress organizer Pascal Guenee, head of IPJ Dauphine journalism school in Paris, told AFP.
Amazon workers strike as ‘Prime’ shopping frenzy hits
Amazon workers walked out of a main distribution center in Minnesota on Monday, protesting for improved working conditions during the e-commerce titan's major "Prime" shopping event.
Amazon workers picketed outside the facility, briefly delaying a few trucks and waving signs with messages along the lines of "We're human, not robots."
"We know Prime Day is a big day for Amazon, so we hope this strike will help executives understand how serious we are about wanting real change that will uplift the workers in Amazon's warehouses," striker Safiyo Mohamed said in a release.