Countdown to a mission to hunt for alien life on a mysterious icy moon

In a few hours, the spacecraft should blast off from Florida hunting for signs of extraterrestrial life.

The destination is Europa, a mysterious moon orbiting the distant planet Jupiter.

Trapped under the ice would be a vast ocean with twice the volume of water on Earth.

The Europa Clipper spacecraft will chase the Europa mission that left last year, but using cosmic piggyback, it will pass and arrive first.

That won’t be until 2030 but what it finds could change what we know about life in our solar system.

Years in the making, the Europa Clipper launch was delayed at the last minute after Hurricane Milton battered Florida this week.

The spacecraft was taken indoors for shelter, but after inspecting the launch pad at Cape Canaveral for damage, engineers have now given the go-ahead for liftoff at 1206 local time (1706 BST) on 14 October.

“If we find life this far from the Sun, it could mean a different origin of life to Earth,” said Mark Fox-Powell, a biologist and planetary scientist at the Open University.

“That is very important, because if that happens twice in our solar system, it would mean that life is really normal,” he said.

Located 628 million km from Earth, Europa is slightly larger than our moon, but that’s where the similarities end.

If it were in our sky, it would be five times brighter because the water ice would reflect more sunlight.

Its icy crust is up to 25km thick, and if it sinks, there may be a large ocean of salt water. There may also be chemicals that are ingredients for simple living.

Scientists first realized that Europa might support life in the 1970s when, peering through a telescope in Arizona, they spotted water ice.

Voyager 1 and 2 spacecraft captured the first close-up images, and then in 1995 Nasa’s Galileo spacecraft flew past Europa taking deeply puzzling images. They show an area full of dark, crimson cracks, cracks that may contain salt and sulfur compounds that could support life.

The Hubble space telescope has since taken pictures of what may be layers of water ejected 100 miles (160 kilometers) above the moon’s surface.

But none of those missions got close enough to Europa long enough to really understand it.

Now scientists hope that instruments on Nasa’s Clipper spacecraft will map almost the entire moon, and collect dust particles and fly over the water.

Britney Schmidt, a professor of earth and atmospheric sciences at Cornell University in the US, helped design the onboard laser that will be able to see through the snow.

“I am very happy to understand the Europa pipelines. Where is the water? “Europa has an ice version of the subsurface, magma chambers and tectonics – we will try to see those regions and map them,” he said.

His instrument, called Reason, was tested in Antarctica.

But unlike on Earth, all the instruments on Clipper will be exposed to a lot of radiation which Prof Schmidt says is “a big problem.”

The spacecraft must fly past Europa about 50 times, and each time, it will be bombarded with the equivalent of a million X-rays.

“Most electronics are in a radiation shielded environment,” explains Prof Schmidt.

The spacecraft is the largest ever built to visit the planet and has a long way to go. Traveling 1.8 billion miles, it will orbit both Earth and Mars to propel itself toward Jupiter in the so-called sling-shot effect.

It can’t carry enough fuel to propel itself, so it will fall back from Earth’s orbit and Mars’ gravity.

It will pass by JUICE, the European Space Agency’s spacecraft that will revisit Europa on its way to one of Jupiter’s moons called Ganymede.

When Clipper approaches Europa in 2030, it will turn on its engines again to carefully guide itself into the right orbit.

Astronomers are very cautious when talking about the possibility of finding life – there is no expectation that they will find human-like creatures or animals.

“We want energy to stay and you need four things – liquid water, a heat source, and living things. Ultimately those three ingredients need to stabilize over a long enough period of time for something to happen,” explains Michelle Dougherty, professor of atmospheric science at Imperial College London.

And they hope that if they can better understand the ice surface, they will know where to base the ship on future voyages.

An international team of scientists with Nasa, the Jet Propulsion Lab and the Johns Hopkins Applied Physics Lab will oversee the odyssey.

In an age where there is a space launch almost every week, these missions promise something different, suggests Professor Fox-Powell.

“No profit is made. This is about exploration and curiosity, and pushing back the boundaries of our knowledge of our place in the universe,” he said.