NASA is doubling down on its efforts to find alien life at Jupiter’s moons

When a spacecraft completes its mission, it is typically consigned to one of two possible fates: Either it wanders aimlessly through the cosmic void, becoming yet another piece of space junk, or it is directed to its death, burning up in the atmosphere of a planet, as Cassini so famously did in 2017.

Saying farewell to a spacecraft is a hard and emotional thing to do — Cassini's engineers, some of whom had worked on the mission for decades, were caught on camera crying as she plunged to her demise. For the engineers who have worked on the Juno and InSight missions, the former a mission to Jupiter to scope out the planet's moons, and the latter a mission to Mars to chart the planet's geology and climate, the hard goodbyes have been delayed.

This week, NASA announced the extension of both Juno and InSight. In doing so, NASA is also extending its efforts to discover one thing: Whether there are potentially habitable — or indeed, inhabited — worlds beyond Earth in the Solar System.

Why it matters — Juno, the agency's mission to Jupiter, will now be dedicated to studying the planet's moons, including Europa. This moon is one of the best candidates for life existing in the Solar System beyond our own planet. InSight, meanwhile, furthers the commitment to bring humans to Mars, and perhaps further afield.

What's new — Based on the recommendations of an independent review panel, this week NASA decided to extend the lifeline of the Juno mission, which has been exploring Jupiter for the past ten years, for four years, until 2025, as well as the InSight mission, a robotic lander that has been studying Mars since 2018, for an additional two years, until 2023.

Here's the background — Juno launched on August 5, 2011, headed towards the largest planet in the Solar System. The spacecraft has been instrumental in the search for life among the other 8 planets that make up our cosmic neighborhood.

The spacecraft completes one orbit around Jupiter every 53 days, collecting data on the gas giant in order to determine how the planet formed and evolved over time.

The main objective of the mission so far has been to measure the composition of Jupiter’s atmosphere, determine how much water is in the atmosphere, map the planet’s magnetic field and how its magnetic force affects its atmosphere.

Aside from beaming down stunning images of Jupiter, Juno has taught us much of what we know about the planet.

• Data collected by Juno revealed the most-accurate measurements of the water in Jupiter's atmosphere ever taken.
• Juno revealed that Jupiter’s infamous winds might plunge 1,900 miles deep into the planet’s depths.
• Juno’s very first flyby over the Great Red Spot in July 2017 showed that the storm’s roots go 50 to 100 times deeper than Earth’s oceans, and are warmer at the base than they are at the top.

Juno was initially meant to hang up its scientific instruments in July 2021. But NASA has extended the mission to September 2025, or until the spacecraft breaks down.

What's next for Juno — Juno's mission is going to change slightly, taking our exploration of Jupiter and its moons to new heights. Now, Juno will explore Jupiter’s rings and larger moons, and there are flybys planned for the moons Ganymede, Europa, and Io.

Jupiter has 79 confirmed moons, but those three are by far the most special. Io is the most volcanically active body in the Solar System, while Ganymede is the largest planetary satellite yet discovered in the Solar System, with its massive size making it larger than the planet Mercury and about three quarters the size of Mars.

Europa however, may be the most intriguing. Scientists suspect the moon may be habitable. From previous observations suggesting water vapor plumes erupting from Europa, they believe the moon may have a saltwater ocean that holds twice as much water as all of Earth’s oceans combined beneath its icy surface. If this theory is borne out in future research, then that would mean Europa has one of the key ingredients for life as we know it.

That’s why astronomers have looked to Jupiter’s moon as a promising world beyond our own to host life. There is a planned mission to Europa, the Europa Clipper, which will specifically look for signs of life on the moon, but it is not set to launch until at earliest 2025. Keeping Juno on the go will help scientists bridge the gap between the two missions, and may even help direct the Clipper's future work.

What's next for InSight — NASA’s InSight mission, or Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, launched on May 5, 2018 and landed on Mars in November, 2018.

The lander is designed to study the interior structure of Mars to look for the fingerprints of the ancient processes that formed the planet, and the Solar System.

InSight landed at the planet’s Elysium Planitia, a crater, in November, 2018. Elysium Planitia is just north of Mars’ equator, and has a flat surface, allowing the lander to conduct its measurements by probing deep into Mars’ interior.

Through the mission, scientists were able to confirm that Mars is a seismically active planet with signs of tectonic plate activity. Now dubbed a "Marsquake," InSight confirmed not only does the Red Planet have seismic activity, its quakes can also closely resemble those recorded here on Earth.

During the mission’s first 10 months on Mars, it detected 174 confirmed seismic events, including 20 that were of magnitude 3 to 4, scientists report.

For its two year extension, the InSight lander will continue to investigate Marsquakes, and produce a long-duration, high quality, seismic dataset.

In so doing, InSight helps further a different ambition of NASA and other space agencies, as well as private space companies like SpaceX — to get humans on the surface of Mars. If we understand the processes underlying the Red Planet's activity and geology, then we can better plan out how humans might exist on Mars, either as part of scientific missions, or as part of a longer-term Martian colony.