Ever since the Galileo spacecraft flew by Jupiter’s icy moons in 1989, scientists interested in life beyond our planet have been desperate to go back.
Europa Clipper, which blasted off from Kennedy Space Center at Cape Canaveral, is doing just that.
Galileo found clear evidence that while Ganymede, Calisto and Europa have barren frozen surfaces, beneath them likely lie vast oceans of water.
And, as far as any astrobiologist knows, where there’s water there’s a chance of life.
Kept liquid by Jupiter’s huge tidal forces, Europa’s ocean may be the Solar System’s largest.
Image: Artist’s illustration of the Europa Clipper spacecraft over the Europa moon, with Jupiter in the background. Pic: NASA/JPL-Caltech via AP
Up to 100 miles deep, containing twice the volume of water in all Earth’s oceans, this ocean makes it a prime candidate for exploration.
After a six-year, 1.8 billion-mile journey, Europa Clipper – the largest planetary science mission ever launched by NASA – will spend four years orbiting Jupiter making flybys of its icy moon.
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It will use nine instruments to image the surface of the moon to study its atmosphere, measure the thickness of the icy crust, confirm the presence of the ocean and attempt to measure its depth and saltiness.
But before we get too excited, if there’s life on Europa, Europa Clipper won’t “see” it squirming around beneath the ice.
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First, the crust is thought to be at least 10 miles thick, too deep for the weak Sun at Jupiter to penetrate.
Image: The Europa Clipper spacecraft being tested in April. Pic: Reuters
Without photosynthesis, if life exists, it is expected to be more akin to the bacteria that lurk in the blackness around hydrothermal vents deep on the sea floor here on Earth.
On Europa, it may live off geothermal heat, or even Jupiter’s radiation fields for energy, and simple organic molecules for food.
But we’re getting beyond Europa Clipper’s remit, which is to confirm whether the environment on the moon is compatible with these theories.
A major bonus would be whether Europa Clipper spots a plume of water erupting from the surface of the moon, which it is known to do on other icy moons. That would mean the chemicals present in the water below can be analysed directly.
“If there are life-forming conditions we expect they’re deep down in the dark,” said Dr Adam Masters, a space scientist at Imperial College London.
Image: Europa Clipper blasted off under sunny skies
“So when the water comes to you, that saves a lot of hassle,” he said.
The chances of getting answers are doubled however. Dr Masters works on another mission, the European Space Agency’s Jupiter Icy Moons Explorer (JUICE).
It arrives at Jupiter shortly after Europa Clipper and will study Europa as well as another prime candidate for life, Jupiter’s moon Ganymede.
But even if these missions find tantalising chemical evidence of life, confirming its existence, let alone understanding its alien biology, would be decades away.
For that reason, one of the probes’ other objectives is to look for potential landing sites on one of these icy moons.
If Europa Clipper and JUICE finds evidence that Jupiter’s moons have the right conditions for life, the challenge for future space scientists will be figuring out how to get through miles of ice to see it.
In Minneapolis, the spot where George Floyd was murdered has been turned into a mural.
His face is depicted in street art on a pavement covered in flowers, rosaries, and other trinkets left by people who have come to pay their respects in the last five years.
His final moments, struggling for breath with white police officer Derek Chauvin’s knee on his neck, were captured in a viral video that provoked anger, upset, and outrage.
Image: Derek Chauvin kneeling on George Floyd’s neck
In Minneapolis and other parts of America, there were protests that at points boiled over into unrest.
The events to mark the fifth anniversary of his death took on a very different tone – one of celebration and joy.
Behind a wooden statue of a clenched fist on one end of a junction now renamed George Perry Floyd Square, people gathered in the morning.
There was a moment of prayer before a brass band began to play and the group marched, while singing and chanting.
Image: George Perry Floyd Square, a makeshift memorial area
‘It made us want to fight harder’
Among those gathered in front of a makeshift stage built in the square were two of Floyd’s family members – his cousin Paris and aunt Mahalia.
To them, the man whose death sparked a racial reckoning in America and further afield, was simply “Perry,” a larger-than-life figure whose presence is missed at family gatherings.
Speaking to me while the speakers behind them thumped and people danced, they didn’t just reflect with sadness though.
There was also pride at a legacy they felt has led to change.
“It made us want to fight harder,” said Mahalia, “and it’s a feeling you cannot explain. When the whole world just stood up.”
Image: George Floyd’s aunt Mahalia and cousin Paris
Referring to Chauvin’s eventual murder charge, Paris added: “I think that from here on out, at least officers know that you’re not going to slide through the cracks. Our voices are heard more.”
The tapestry of items outside the Cup Foods convenience store, now renamed Unity Foods, is not the only makeshift memorial in the area.
A short walk away is the “Say Their Names” cemetery, an art installation honouring black people killed by the police.
Meeting me there later in the day, activist Nikema Levy says the installation and George Floyd Square are called “sacred spaces” in the community.
As someone who took to the streets at the time of Floyd’s death and a community organiser for years before that, she’s constantly stopped by people who want to speak to her.
Image: Activist Nikema Levy speaking to Sky News
‘White supremacy on steroids’
Once we do manage to speak, Levy reminds me of a wider political picture. One that goes beyond Minneapolis and is a fraught one.
In the week of the anniversary, the US Department of Justice rolled back investigations into some of the largest police forces in the country, including in Minneapolis – a move she calls “diabolical.”
“That type of cruelty is what we have seen since Donald Trump took office on January 20th of this year,” she continued.
“From my perspective, that is white supremacy on steroids. And it should come as no surprise that he would take these types of steps, because these are the things that he talked about on the campaign trail.”
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3:23
Has US changed five years after George Floyd’s death?
‘True healing has never taken place’
Trump has argued his policing reforms will help make America’s communities safer.
Even on a day of optimism, with a community coming together, Levy’s words in front of headstones bearing the names of black people who have died at the hands of the police are a reminder of how deep the racial divides in America still are – a sentiment she leaves me with.
“From the days of slavery and Jim Crow in this country, we’ve just had the perception of healing, but true healing has never taken place,” she says.
“So the aftermath of George Floyd is yet another example of what we already know.”
On Friday, after a period of relative calm which has included striking a deal with the UK, he threatened to impose a 50% tariff on the EU after claiming trade talks with Brussels were “going nowhere”.
The US president has repeatedly taken issue with the EU, going as far as to claim it was created to rip the US off.
However, in the face of the latest hostile rhetoric from Mr Trump’s social media account, the European Commission – which oversees trade for the 27-country bloc – has refused to back down.
EU trade chief Maros Sefcovic said: “EU-US trade is unmatched and must be guided by mutual respect, not threats.
“We stand ready to defend our interests.”
Image: Donald Trump speaks to reporters in the Oval Office on Friday
Fellow EU leaders and ministers have also held the line after Mr Trump’s comments.
Polish deputy economy minister Michal Baranowski said the tariffs appeared to be a negotiating ploy, with Dutch deputy prime minister Dick Schoof said tariffs “can go up and down”.
French trade minister Laurent Saint-Martin said the latest threats did nothing to help trade talks.
He stressed “de-escalation” was one of the EU’s main aims but warned: “We are ready to respond.”
Mr Sefcovic spoke with US trade representative Jamieson Greer and commerce secretary Howard Lutnick after Mr Trump’s comments.
Mr Trump has previously backed down on a tit-for-tat trade war with China, which saw tariffs soar above 100%.
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US and China end trade war
Sticking points
Talks between the US and EU have stumbled.
In the past week, Washington sent a list of demands to Brussels – including adopting US food safety standards and removing national digital services taxes, people familiar with the talks told Reuters news agency.
In response, the EU reportedly offered a mutually beneficial deal that could include the bloc potentially buying more liquefied natural gas and soybeans from the US, as well as cooperation on issues such as steel overcapacity, which both sides blame on China.
Stocks tumble as Trump grumbles
Major stock indices tumbled after Mr Trump’s comments, which came as he also threatened to slap US tech giant Apple with a 25% tariff.
The president is adamant that he wants the company’s iPhones to be built in America.
The vast majority of its phones are made in China, and the company has also shifted some production to India.
Shares of Apple ended 3% lower and the dollar sank 1% versus the Japanese yen and the euro rose 0.8% against the dollar.
In the dozens of framed images and newspaper clippings covering the walls of his office in downtown New York City, Al Sharpton is pictured alongside presidents and leading protests.
He has spent decades campaigning and is perhaps the most famous civil rights activist in the US today.
Many of those clippings on the wall relate to one moment in May 2020 – the murder of George Floyd.
Image: George Floyd was killed while under arrest in Minneapolis in May 2020
Speaking to Sky News ahead of the five-year anniversary of that moment, Mr Sharpton remembered the combination of “humiliation and deep anger” he felt seeing the footage of Mr Floyd’s death that swept the world.
“The more I watched, the more angry I felt,” he said.
Mr Floyd was murdered in Minneapolis by Derek Chauvin, a 44-year-old white police officer.
Mr Floyd had been arrested after a store clerk reported he had made a purchase using counterfeit money.
Chauvin knelt on Mr Floyd’s neck for over nine minutes, while he was handcuffed and lying face down in the street.
Image: Chauvin pressed his knee on Mr Floyd’s neck for more than nine minutes, as the victim repeatedly said ‘I can’t breathe’. Pic: AP
‘A seismic moment’
For Mr Sharpton, who has marched with countless other families, this felt different because it was “graphic and unnecessary”.
“What kind of person would hear somebody begging for their life and ignore them?” he said.
“I had no idea this would become a seismic moment,” he continued.
“I think people would accuse civil rights leaders, activists like me of being opportunistic, but we don’t know if one call from the next one is going to be big, all we know is we have to answer to the call.”
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3:23
Has US changed five years after George Floyd’s death?
Trump ‘pouring salt on the wounds’
Mr Floyd’s death took place during Donald Trump’s first term in the White House.
During Trump’s second term, his administration has moved to repeal federal oversight plans for the Minneapolis Police Department – a move originally supported by Joe Biden’s administration.
Mr Sharpton believes Mr Trump and the Department of Justice have purposely timed this for the 5th Anniversary of Mr Floyd’s Death.
“It’s pouring salt on the wounds of those that were killed, and those that fought,” he said.
“I think Donald Trump and his administration is actively trying to reverse and revoke changes and progress made with policing based on the movement we created after George Floyd’s death, worldwide.”
Image: The murder of George Floyd sparked Black Lives Matter protests around the world
Mr Sharpton still supports George Floyd’s family and will be with them this weekend in Houston, Texas, where many of them will mark the anniversary.
He said the legacy of Mr Floyd’s death is still being written.
Evoking the civil rights movement of the 1960s he said: “The challenge is we must turn those moments into permanent movements, it took nine years from 1955 to 1964 for Dr [Martin Luther] King in that movement to get a Civil Rights Act after Rosa Parks sat in the front of a bus in Montgomery.
“We’re five years out of George Floyd, we’ve got to change the laws.
“We can do it in under nine years, but we can’t do it if we take our eye off the prize.”