European space mission takes search for alien life to Jupiter's icy moons
Could vast, long-hidden oceans be teeming with alien life in our very own Solar System?
A new chapter in humanity's search for extraterrestrial life opens on Thursday as Europe's JUICE spacecraft blasts off on a mission to investigate the icy moons of Jupiter.
First discovered by Italian astronomer Galileo Galilei more than 400 years ago, these ice-covered moons are so far from the Sun that they were long dismissed as possible candidates to host life in our backyard.
Until recently, the Solar System's habitable zone was thought to "end at Mars", French astrophysicist Athena Coustenis, one of the scientific leads of the European Space Agency (ESA)'s JUICE mission, told AFP.
But NASA's Galileo probe to Jupiter in 1995 and the more recent Cassini spacecraft's trip to Saturn caused scientists to broaden their horizons.
The gas giant planets themselves were correctly ruled out, but their icy moons – particularly Jupiter's Europa and Ganymede, and Saturn's Enceladus and Titan – offered fresh hope of nearby life.
Under their icy surfaces are thought to be huge oceans of liquid water – a crucial ingredient for life as we know it.
Nicolas Altobelli, a JUICE project scientist at ESA, said it would be "the first time that we explore habitats beyond the frost line" between Mars and Jupiter.
Beyond that line, temperatures plummet and "liquid water can no longer exist on the surface", Altobelli told AFP earlier this year.
'Gigantic' oceanThe Jupiter Icy Moons Explorer (JUICE) mission launches from Europe's spaceport in Kourou, French Guiana on Thursday on an eight-year odyssey through space.
By July 2031 it will have entered Jupiter's orbit, from which it will probe Ganymede, Europa and fellow icy moon Callisto.
Then, in 2034, JUICE will enter the orbit of Ganymede, the first time a spacecraft has done so around a moon other than our own.
As well as being the largest moon in the Solar System, Ganymede is also the only one that has its own magnetic field, which protects it from dangerous radiation.
This is just one of several signs that Ganymede's hidden ocean could provide a stable environment for life.
Unlike similar missions to Mars, which focus on finding signs of ancient life long since extinguished, scientists hope Jupiter's icy moons will still be home to living organisms, even if only tiny or single-celled.
Such habitability requires a power source. Lacking energy from the Sun, the moons could instead take advantage of the gravity that Jupiter exerts on its satellites.
The force creates a process called tidal heating, which warms the interior of the moons and keeps their water liquid.
Ganymede's "gigantic" liquid ocean is trapped between two thick layers of ice dozens of kilometers beneath the surface, said Carole Larigauderie, JUICE project head at French space agency CNES.
"On Earth, we still find life forms at the bottom of the abyss," she added.
Tiny microbes such as bacteria and archaea have been found to be able to survive on Earth without sunlight, raising hopes that life elsewhere will be able to do the same.
As well as water and energy, life needs nutrients.
"The big question is therefore whether Ganymede's ocean contains" the necessary chemical elements, Coustenis said.
The ocean would need to be able to absorb the nutrients from anything that fell on the moon's surface, for example, which would eventually dissolve into the water, she added.
Not aloneJUICE's array of instruments will probe Ganymede's ocean to determine its depth, distance from the surface and – hopefully – its composition.
The ESA's 1.6 billion euro ($1.7 billion) probe will spend eight months orbiting Ganymede, getting as close as 200 kilometers (125 miles) from the moon, all while sheltered from radiation.
It will not be the only spacecraft lurking around Jupiter.
NASA's Europa Clipper mission is scheduled to launch in October next year. It will take a quicker path to Jupiter, arriving at Europa in 2030.
If one – or more – of Jupiter's moons ticks all the boxes to host life, the "logical next step" would be to send a mission to land on the surface, said Cyril Cavel, JUICE project manager at manufacturer Airbus.
Although there are no plans for such a mission, which could definitively prove the existence of life outside of Earth, "that's part of the dream," he said.
© 2023 AFP One in five Americans have a family member killed by guns: survey
One in five American adults have a family member who was killed by a gun -- including by suicide -- and a similar percentage said they've been threatened with one, according to a survey released Tuesday.
Gun-related violence -- including mass shootings, suicides and accidents -- has become so common in the United States that 84 percent of US adults say they have taken precautions to protect themselves and their families from the danger of being shot, according to health research group KFF, which released the survey.
More than one third of those surveyed said they have avoided large crowds due to the possibility of gun violence. Some 29 percent have bought firearms to protect themselves and their families.
The data was released one day after the latest mass shooting to hit the country, at a bank in Louisville, Kentucky, left five dead. Governor Andy Beshear said one of the victims was "an incredible friend" of his.
Louisville Mayor Craig Greenberg detailed how he was shot at during his election campaign last year.
On March 27, three children and three adults were shot dead at a primary school in Nashville, Tennessee.
According to the Gun Violence Archive, 11,631 people have been killed by guns so far in 2023, including 4,965 by homicide, accidents and incidents of defensive gun use, and 6,666 by suicide.
In 2022, the organization said, 20,249 people died in homicidal, accidental or defensive shootings. More than 24,000 used guns to kill themselves.
KFF said 41 percent of American adults live in households where there is a gun present -- and in 44 percent of those homes, the weapon is kept in an unlocked location.
Black and Hispanic Americans reported far more experiences knowing someone who was shot, and generally feeling threatened by gun violence, than white Americans did.
Three out of 10 Black adults had personally seen someone being shot, the survey said, more than twice the rate for white adults.
KFF's data was based on a survey of 1,271 adults taken during mid-March.
© Agence France-PresseU.S. ski season extended as record snowpack dents Western drought
Record snowfall across much of the western United States has not only helped to alleviate drought -- it has also brought a massive boon for the region's ski resorts, with many hoping to keep their lifts running deep into summer.
Sitting more than 10,500 feet (3,200 meters) above sea level, Colorado's Arapahoe Basin has long been famous for its long seasons. The resort's frozen pistes were the state's first to open last fall, and typically don't close until June.
"I bet you, here, we might make it into July. I hope so," said local ski enthusiast Ian Burkle, 52.
"We always aim for July 4. If you can ski up here on the fourth, it's always great. It's been a couple years since that."
But this year, with mountains across California, Utah and Colorado reporting staggering snowfall, "A-Basin" has plenty of competition for spring skiing, in what is shaping up to be a bumper-sized season across the West.
While Colorado can thank consistent, steady snowfall and low temperatures for its positive ski and snowboard outlook, California's Mammoth Mountain has recorded its snowiest ever winter, with 704 inches (nearly 18 meters) and counting.
That shatters the previous record of 668 inches.
"It's going to be a legendary spring up here and we'll be open daily through at least July!" the resort wrote on Instagram.
Utah passed its statewide record for snowpack on March 24, according to the federal government's Natural Resources Conservation Service, with a number of ski resorts there pushing back their closing dates too.
One Utah resort, Little Cottonwood Canyon, even had to close for a day because of too much snow, which posed an avalanche risk.
It is all a stark contrast with Europe's Alps, where "extreme" warm winter weather left many hopeful skiers frustrated by the sight of brown hillsides with just slivers of snow in January.
Katherine Fuller, spokeswoman for Arapahoe, said the resort has received heightened interest from overseas travel agencies "reaching out and seeing how to put together that last-minute US ski trip."
Of course, the wild swings and variations point to worrying long-term trends.
Human-caused global warming exacerbates existing weather patterns, making the wet spells wetter and the dry spells drier.
And for many skiers interviewed by AFP, the excitement over snow conditions pales in comparison to the implications for the US West's decades-long drought.
"Having quality water and making sure it gets to the right spot, and there's enough for crops and everything is pretty important," said Jared Brower, from Denver.
"Skiing is a nice thing to do, but being able to eat is kinda more important in the long term, probably!"
But still, the chance to keep skiing is "awesome," said Fuller.
"It's kind of a party scene. The weather's beautiful. There's nothing like skiing in a t-shirt from the top of the mountain in late spring, even early summer."
© 2023 AFP
