Alien life in our Solar System? Study hints at Saturn’s moon

Enceladus, one of Saturn's many moons. (NASA/AFP)
Updated 27 February 2018
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Alien life in our Solar System? Study hints at Saturn’s moon

PARIS: Humanity may need look no further than our own Solar System in the search for alien life, researchers probing one of Saturn’s moons said Tuesday.
The icy orb known as Enceladus may boast ideal living conditions for single-celled microorganisms known as archaeans found in some of the most extreme environments on Earth, they reported in the science journal Nature Communications.
A methanogenic (methane-producing) archaean called Methanothermococcus okinawensis thrived in laboratory conditions mimicking those thought to exist on Saturn’s satellite, the team said.
On Earth, this type of archaean is found at very hot temperatures near deep-sea hydrothermal vents, and converts carbon dioxide and hydrogen gas into methane.
Traces of methane were previously detected in vapor emanating from cracks in Enceladus’ surface.
“We conclude that some of the CH4 (methane) detected in the plume of Enceladus might, in principle, be produced by methanogens,” the researchers in Germany and Austria wrote.
They also calculated that sufficient hydrogen to support such microbes could be produced by geochemical processes in Enceladus’ rocky core.
The authors had set out to test the hypothesis that conditions on the satellite may be good for hosting methanogenic archaea.
The data, based purely on laboratory study, showed this “could be” so, said Simon Rittmann of the University of Vienna who co-authored the scientific paper.
But the results provide “no evidence for possible extraterrestrial life,” he underlined to AFP.
“Our study only concerns microorganisms. I would like to avoid any speculation about intelligent life,” he said.
Saturn is the sixth planet from the Sun, separated from Earth only by Mars and Jupiter.
It has dozens of moons.
Previous research suggested that Enceladus sports an ocean of liquid water — a key ingredient for life — beneath its icy surface.
The moon is also thought to contain compounds such as methane, carbon dioxide, and ammonia, and its south pole sports hydrothermal activity — a combination of traits that makes it a key target in the search for extra-terrestrial life.
Further research is needed to exclude the possibility that Enceladus’ methane may come from non-biological, geochemical processes, the authors said.


YouTube, under pressure for problem content, takes down 58 mln videos in quarter

Updated 14 December 2018
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YouTube, under pressure for problem content, takes down 58 mln videos in quarter

  • Google added thousands of moderators this year, expanding to more than 10,000, in hopes of reviewing user reports faster

WASHINGTON: YouTube took down more than 58 million videos and 224 million comments during the third quarter based on violations of its policies, the unit of Alphabet Inc’s Google said on Thursday in an effort to demonstrate progress in suppressing problem content.
Government officials and interest groups in the United States, Europe and Asia have been pressuring YouTube, Facebook Inc. and other social media services to quickly identify and remove extremist and hateful content that critics have said incite violence.
The European Union has proposed online services should face steep fines unless they remove extremist material within one hour of a government order to do so.
An official at India’s Ministry of Home Affairs speaking on the condition of anonymity on Thursday said social media firms had agreed to tackle authorities’ requests to remove objectionable content within 36 hours.
This year, YouTube began issuing quarterly reports about its enforcement efforts.
As with past quarters, most of the removed content was spam, YouTube said.
Automated detection tools help YouTube quickly identify spam, extremist content and nudity. During September, 90 percent of the nearly 10,400 videos removed for violent extremism or 279,600 videos removed for child safety issues received fewer than 10 views, according to YouTube.
But YouTube faces a bigger challenge with material promoting hateful rhetoric and dangerous behavior.
Automated detection technologies for those policies are relatively new and less efficient, so YouTube relies on users to report potentially problematic videos or comments. This means that the content may be viewed widely before being removed.
Google added thousands of moderators this year, expanding to more than 10,000, in hopes of reviewing user reports faster. YouTube declined to comment on growth plans for 2019.
It has described pre-screening every video as unfeasible.
The third-quarter removal data for the first time revealed the number of YouTube accounts Google disabled for either having three policy violations in 90 days or committing what the company found to be an egregious violation, such as uploading child pornography.
YouTube removed about 1.67 million channels and all of the 50.2 million videos that were available from them.
Nearly 80 percent of the channel takedowns related to spam uploads, YouTube said. About 13 percent concerned nudity, and 4.5 percent child safety.
YouTube said users post billions of comments each quarter. It declined to disclose the overall number of accounts that have uploaded videos, but said removals were also a small fraction.
In addition, about 7.8 million videos were removed individually for policy violations, in line with the previous quarter.