Scientists find likely source of methane on Mars

This NASA photo released June 7, 2018 shows a low-angle self-portrait of NASA's Curiosity Mars rover vehicle at the site from which it reached down to drill into a rock target called "Buckskin" on lower Mount Sharp. (AFP)
Updated 02 April 2019

Scientists find likely source of methane on Mars

  • The presence of methane in the vicinity was confirmed by readings taken 24 hours earlier by NASA’s Curiosity rover

PARIS: The mystery of methane on Mars may finally be solved as scientists Monday confirmed the presence of the life-indicating gas on the Red Planet as well as where it might have come from.
In the 15 years since a European probe reported traces of the gas in the Martian atmosphere, debate has raged over the accuracy of the readings showing methane, which on Earth is produced by simple lifeforms.
Because methane gas dissipates relatively quickly — within around 12 years on Earth — and due to the difficulty of observing Mars’ atmosphere, many scientists questioned previous studies that relied on a single data set.
Now an international team of experts have compared observations from two separate spacecraft, taken just one day apart in 2013, to find independent proof of methane on our neighboring planet.
Furthermore, they conducted two parallel experiments to determine the most likely source of methane on Mars to be an ice sheet east of Gale Crater — itself long assumed to be a dried up lake.
“This is very exciting and largely unexpected,” Marco Giuranna, from Rome’s National Astrophysics Institute, told AFP.
“Two completely independent lines of investigation pointed to the same general area of the most likely source for the methane.”
Europe’s Mars Express probe measured 15.5 parts per billion in the atmosphere above the Gale Crater on June 16, 2013. The presence of methane in the vicinity was confirmed by readings taken 24 hours earlier by NASA’s Curiosity rover.
Using the data, Giuranna and the team divided the region around the crater into grids of 250 by 250 square kilometers.
One study then ran a million computer-modelled emissions scenarios for each section while another team studied images of the planet surface for features associated on Earth with the release of methane.

The most likely source was a sheet of frozen methane beneath a rock formation, which the team believes periodically ejects the gas into the atmosphere.
Giuranna said that while methane is a sign of life on Earth, its presence on Mars doesn’t necessarily constitute evidence of something similar on the Red Planet.
“Methane is important because it could be an indicator of microbial life,” he said. “But life is not required to explain these detections because methane can be produced by abiotic processes.”
“Though not a direct biosignature of life, methane can add to the habitability of martian settings, as certain types of microbes can use methane as a source of carbon and energy,” he added.
Though there is no liquid water on Mars, the European Space Agency said in February its imaging equipment had shown further evidence of dried up river beds, suggesting the Red Planet may once have been home to simple organisms.
Giuranna said that further research was needed to determine the extent of the methane ice sheet near Gale Crater.
If founded to be extensive, the methane it contains “could support a sustained human presence” on Mars as a possible source of fuel for industrial processes and a propellant for returning manned missions to Earth, he said.


“Punch in the gut” as scientists find micro plastic in Arctic ice

Chief Scientist for the Northwest Passage Project Dr. Brice Loose drills an ice core in the Arctic as part of an 18-day icebreaker expedition that took place in July and August 2019 in the Northwest Passage, in a still image taken from a handout video obtained by REUTERS on August 14, 2019. (REUTERS)
Updated 15 August 2019

“Punch in the gut” as scientists find micro plastic in Arctic ice

  • The researchers said the ice they sampled appeared to be at least a year old and had probably drifted into Lancaster Sound from more central regions of the Arctic

LONDON: Tiny pieces of plastic have been found in ice cores drilled in the Arctic by a US-led team of scientists, underscoring the threat the growing form of pollution now poses to marine life in even the remotest waters on the planet.
The researchers used a helicopter to land on ice floes and retrieve the samples during an 18-day icebreaker expedition through the Northwest Passage, the hazardous route linking the Pacific and Atlantic Oceans.
“We had spent weeks looking out at what looks so much like pristine white sea ice floating out on the ocean,” said Jacob Strock, a graduate student researcher at the University of Rhode Island, who conducted an initial onboard analysis of the cores.
“When we look at it up close and we see that it’s all very, very visibly contaminated when you look at it with the right tools — it felt a little bit like a punch in the gut,” Strock told Reuters by telephone.
Strock and his colleagues found the material trapped in ice taken from Lancaster Sound, an isolated stretch of water in the Canadian Arctic, which they had assumed might be relatively sheltered from drifting plastic pollution
The team drew 18 ice cores of up to two meters in length from four locations, and saw visible plastic beads and filaments of various shapes and sizes. The scientists said the findings reinforce the observation that micro plastic pollution appears to concentrate in ice relative to seawater.
“The plastic just jumped out in both its abundance and its scale,” said Brice Loose, an oceanographer at the University of Rhode Island and chief scientist of the expedition, known as the Northwest Passage Project.
The scientists’ dismay is reminiscent of the consternation felt by explorers who found plastic waste in the Pacific Ocean’s Marianas Trench, the deepest place on Earth, during submarine dives earlier this year.
The Northwest Passage Project is primarily focused on investigating the impact of manmade climate change on the Arctic, whose role as the planet’s cooling system is being compromised by the rapid vanishing of summer sea ice.
But the plastic fragments — known as micro plastic — also served to highlight how the waste problem has reached epidemic proportions. The United Nations estimates that 100 million tons of plastic have been dumped in the oceans to date.
The researchers said the ice they sampled appeared to be at least a year old and had probably drifted into Lancaster Sound from more central regions of the Arctic.
The team plans to subject the plastic they retrieved to further analysis to support a broader research effort to understand the damage plastic is doing to fish, seabirds and large ocean mammals such as whales.
Funded by the National Science Foundation and the Heising-Simons Foundation in the United States, the expedition in the Swedish icebreaker The Oden ran from July 18 to Aug. 4 and covered some 2,000 nautical miles.