Europa, Jupiter’s fourth largest moon, has been hailed as one of the most likely places for aliens to exist in our solar system.
Now, NASA may have the chance to find out, as its ambitious Europa Clipper mission launches on an ambitious five-and-a-half-year journey to investigate.
After a delay caused by Hurricane Milton, Clipper will launch from NASA’s Kennedy Space Center in Florida at 12:06 ET (17:06 BST) today.
After a journey of about 1.8 billion miles, the $5.2 billion spacecraft will finally begin orbiting Jupiter in April 2030.
Over more than 40 flybys, Clipper will conduct a detailed study of Europa to determine whether the frozen world “could have conditions suitable for life.”
Beyond Earth, Jupiter’s moon Europa is considered one of the most promising potentially habitable environments in the solar system. Clipper will enter orbit around Jupiter in 2030 to explore Europa, the fourth largest of Jupiter’s 95 moons.
Europa is made up of an ice sheet, whose thickness is estimated at about 24 kilometers and a very thin atmosphere. Shown here, imaged by the Juno spacecraft, September 2022.
Slightly smaller than Earth’s moon, Jupiter’s moon Europa is considered one of the most promising potentially habitable environments in the solar system.
Along with Earth and Saturn’s moon Enceladus, Europa is one of the few places in our solar system with liquid water.
Live coverage of today’s launch will be broadcast on NASA+ and NASA YouTube Channel.
“There is very strong evidence that the ingredients for life exist on Europa, but we have to go there to find out,” said Dr. Bonnie Buratti of NASA’s Jet Propulsion Laboratory, deputy project scientist for the mission.
Dr. Buratti said exploratory missions like this always discover something “we couldn’t have imagined.”
“There will be something there, the unknown, that will be so wonderful that we cannot conceive of it now,” he said.
“That’s what excites me the most.”
Europa, one of Jupiter’s 95 known moons, is encased in a shell of ice estimated to be 10 to 15 miles or more (15 to 24 kilometers) thick.
Scientists believe this frozen outer crust hides a liquid ocean of salt water that could be 80 miles (120 kilometers) or more deep.
Scientists believe Europa’s ocean could contain about twice as much water as Earth’s global ocean, and could possibly support life.
Clipper is the largest spacecraft NASA has ever built for a planetary mission, measuring about 100 feet (30.5 meters) with its solar panels deployed, larger than a basketball court.
Clipper’s considerable solar panels will collect sunlight to power scientific instruments, electronics and other systems, about 500 million kilometers from the sun, where sunlight is weaker compared to that on Earth.
Key objectives of the Clipper mission are to produce high-resolution images of Europa’s surface, determine its composition, and search for signs of recent or ongoing geological activity.
The mission will also measure the thickness of the moon’s icy shell, search for underground lakes, and determine the depth and salinity of Europa’s ocean.
Scientists are almost certain that hidden beneath Europa’s icy surface is a saltwater ocean with about twice as much water as Earth’s global ocean. The illustration shows a possible model of Europe.
The mission aims to find out if Europa (pictured) contains the ingredients that would allow life to exist.
Clipper is as big as an SUV with solar panels long enough to span a basketball court. Here it is seen being built and tested at the Jet Propulsion Laboratory during a press tour, in Pasadena, California, on April 11, 2024.
Elon Musk’s SpaceX firm will launch its Falcon Heavy rocket carrying Europa Clipper from LC-39A, at the Kennedy Space Center, Florida. Pictured before the launch on Sunday, October 13.
In this animation, Clipper (pink) leaves Earth (blue). He It will pass Mars (brown) early next year and then Earth in late 2026. Finally, after a journey of about 1.8 billion miles, Europa Clipper will enter orbit around Jupiter (green) in April 2030.
Dr. Buratti points out that there are three main requirements for life to form in our solar system: liquid water, some chemistry (that is, organic compounds that could serve as food for any primitive organism), and a source of energy.
In the case of Europa, one energy source could be thermal vents at the bottom of the ocean.
Experts believe there could be microbes deep in this potentially nutrient-rich liquid ocean, which could be much warmer than the outer layer thanks to thermal vents.
Alternatively, life forms can adapt to survive in extremely frigid temperatures.
These life forms could be tiny, like “extremophile” microbes that would be invisible to the human eye.
An enormously promising finding made last year by the James Webb Space Telescope was the presence of carbon dioxide (CO2) in Europa.
The “biologically essential” compound could be produced by life forms much like humans produce CO2 on Earth.
Last year, scientists discovered that there is less oxygen on Europa’s surface than previously thought, which is crucial for cells to function.
While not completely ruling out the possibility of life in Europe, the study said there is a “narrower range to support habitability” than we thought.
Clipper will not enter orbit around Europa, but will instead orbit Jupiter. This illustration provided by NASA shows the Europa Clipper spacecraft on the surface of the moon Europa, in the foreground, and Jupiter behind.
The main body of the spacecraft is a giant 10-foot-tall propulsion module, designed and built by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland.
Dr. Buratti believes that any life on Europa would be primitive, like the bacterial life that originated in Earth’s deep ocean vents.
However, he emphasizes that Clipper will not directly search for signs of life, but rather determine whether the moon contains the “ingredients” that would allow life to be present.
If it does, another mission would have to make the trip to try to detect it, for example by drilling into the ice sheet.
“We won’t know from this mission because we can’t see as deeply,” Dr. Buratti said.
This look at the complex, ice-covered surface of Jupiter’s moon Europa came from NASA’s Juno mission during a close pass on September 29, 2022.
When it completes its journey more than five years from now, Clipper will not enter orbit around Europa, but will instead orbit Jupiter.
While orbiting Jupiter, it will conduct 44 flybys of Europa, each at altitudes ranging from 16 to 1,678 miles (25 km to 2,700 km) during its 3.5-year mission.
In September 2022, another NASA probe called Juno 355 kilometers (220 miles) from the moon’s icy surface.
But Clipper will come within 25 kilometers (16 miles) of Europa’s surface, closer than any other spacecraft.
When its work is completed in 2034, the mission will end with a planned crash against Ganymede, Jupiter, the largest moon in the solar system.
