NASA Prepares Europa Clipper Launch to Study an Ocean Moon’s Habitability

The spacecraft will lift off Monday on a SpaceX Falcon Heavy rocket on a nearly six-year journey to Jupiter.

by · NY Times

NASA’s first mission to Jupiter in more than a decade is scheduled to launch on Monday.

This time, the object of investigation is not the giant planet itself, but one of its moons: Europa. This Jovian satellite possesses an ocean of liquid water beneath its icy shell, and many scientists think it is the most promising place to look for life elsewhere in the solar system.

What is Europa Clipper?

The $5.2 billion NASA mission will study whether Europa, Jupiter’s fourth-largest moon, possesses ingredients and conditions favorable for life.

Europa Clipper is the biggest interplanetary spacecraft that NASA has ever built. At launch, it will weigh about 12,500 pounds — nearly half of that is propellant. When unfurled, its solar panels will span more than 100 feet — a bit longer than a basketball court.

The spacecraft is carrying a suite of nine scientific instruments, including cameras, spectrometers, a magnetometer and radar. Researchers on Earth will use that tool kit to study the moon’s surface and interior in more detail than earlier missions to Jupiter could.

When is the launch and how can I watch it?

Europa Clipper will launch on top of a SpaceX Falcon Heavy rocket from NASA’s Kennedy Space Center in Florida.

Liftoff is scheduled for Monday at 12:06 p.m. Eastern time. Forecasts give a 95 percent chance of favorable weather. NASA will broadcast coverage of the launch on its website beginning at 11 a.m., or you can watch it in the video player embedded above.

If the flight cannot launch on Monday, backup opportunities are available on Tuesday and Wednesday.

NASA and SpaceX still have several weeks to get it off the ground. The spacecraft has to launch by Nov. 6. After that, it would not be able to enter orbit around Jupiter in 2030.

After a journey of five and a half years and 1.8 billion miles, Europa Clipper will enter orbit around Jupiter on April 11, 2030. It will then make 49 flybys of Europa over four years.

The Jupiter moon Europa captured by the Juno spacecraft during a flyby in 2022. Oceans of water slosh beneath Europa’s surface under a shell of ice that could be more than 10 miles thick.
Credit...Kevin M. Gill/NASA/JPL-Caltech/SwRI, via Associated Press

Why study Europa?

Europa is a bit smaller than the Earth’s moon. Its surface is bright and smooth, covered with ice with few craters. The smoothness suggested the possibility of an ocean below, that water periodically broke through the ice, spilled onto the surface and froze, filling in the geological scars.

Measurements of Europa’s magnetic field by NASA’s Galileo spacecraft a couple of decades ago provided even more compelling evidence. The easiest and best explanation for that field is a salty ocean.

Indeed, planetary scientists now think Europa could have twice as much water as all of Earth’s oceans combined.

With water there, the next question is: Could something alive be swimming in the water?

The other essential ingredients of life are thought to be energy and carbon-based molecules. Europa Clipper’s mission is to look for signs of those.

“I think Europa is certainly the most likely place for life beyond Earth in our solar system,” said Robert Pappalardo, the project scientist for Europa Clipper. “And that’s because it is the most likely to have the ingredients for life in abundance and for there to be enough time for life to get going.”

How will the spacecraft study Europa?

Using the spacecraft’s nine instruments, scientists expect to measure the depth of Europa’s ocean, identify some of the compounds at its icy surface and precisely map the magnetic field, which will give additional clues about what lies within.

A thermal imager will look for warm spots, which could indicate places where the ice is thinner and the ocean is closer to the surface.

That instrument, along with the radar, could spot lakes embedded within the ice and cryovolcanoes that erupt water, not molten rock. The Hubble Space Telescope has spotted what could be plumes of water vapor sporadically erupting from Europa’s surface.

During flybys of the moon, a tube-shaped instrument about the size of a baguette will scoop up and identify molecules from the thin atmosphere, including carbon-based molecules that could serve as the building blocks for life. With luck, Europa Clipper could fly through one of the erupting plumes, which could be material from the under-ice ocean.

Another instrument, an ultraviolet spectrometer, could also identify molecules within a plume when a distant star passes behind Europa. Stars are expected to be eclipsed by Europa in this way about 100 times during the mission. Looking at how the colors of ultraviolet light from the star dim will tell scientists the density of the gases and what they are made of.

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