At some point in their lives, everyone looks up at the night sky and wonders what is really out there and what is still waiting to be discovered. Thanks to the NASA scientists and engineers, the public has access to scientific data of the planets in our solar system that may not be reached by humans in our lifetime. Their exploratory missions utilizing satellites and probes seek to learn about the planets and other phenomena in our solar system and beyond. One such satellite is known as Juno, and it is part of the Juno Mission to orbit Jupiter and collect data and samples to learn more about our solar system’s largest planet.

Launched on August 5th, 2011, the Juno probe is currently orbiting Jupiter after reaching the planet in July of 2016. Juno is the second spacecraft created as a part of NASA’s New Frontiers Program and it is set to study Jupiter for 2 years. Juno’s primary goals are to determine the composition of Jupiter’s atmosphere, search for the presence of water, and study the magnetic and gravitational fields of the planet.

This color view from NASA’s Juno spacecraft is made from some of the first images taken by JunoCam after the spacecraft entered orbit around Jupiter on July 5th (UTC). Credits: NASA/JPL-Caltech/SwRI/MSSS

After its launch, the Juno probe traveled 365 million miles over the course of 5 years to reach Jupiter. Despite this great distance, Jupiter can actually be seen from Earth. On nights when the sky is clear, Jupiter is visible as a bright dot even without a telescope. However, if you are using one affordable telescope for beginners, you can even see a few of the moons of Jupiter including Io, Europa, Ganymede, and Callisto. With a more advanced telescope, the moving clouds and gases of Jupiter can be seen as well.

While watching Jupiter from Earth can be a fun and entertaining past time, the goals of the Juno probe are far more research-oriented. For the past 10 months, Juno has been orbiting Jupiter and collecting data on the planet. All of this time that Juno has spent in close proximity to Jupiter begs the question: what has Juno actually found?

One of the major discoveries so far is the fact that Jupiter’s visible stripes are much deeper than initially thought. These stripes are consisted of clouds and swirling gases and cannot be penetrated by visible light. However, Juno is equipped with microwave instrumentation that allows it to probe the layers of clouds to whatever depth it chooses and study the formations at these particular depths. The farthest these instruments have been able to reach is 250 miles below the surface of the initial cloud layer, and the slight pattern differences in the lower layers suggest that the stripes are dynamic and constantly evolving.

Another crucial part of Juno’s mission is to study the magnetic fields of Jupiter, particularly around the north and south poles. One natural phenomenon of note occurring near the poles of Jupiter is the auroras, which are influenced by the magnetic field of the planet. Similar in appearance to Earth’s own auroras, the auroras on Jupiter were first seen by the Hubble Space Telescope and became an important part of Juno’s exploratory mission.

Interestingly, Juno’s measurements revealed that the auroras were not consistent with what NASA expected. The initial findings showed that certain aspects of the auroras that were expected to be seen were not actually found, and that other aspect that was not expected to be there were indeed present.

During the same flyby in which Juno observed Jupiter’s auroras, the probe found some interesting results regarding the planet’s magnetic field. When Juno reached its closest position to the planet, the magnetic data it received began to differ greatly from what was predicted. The probe found that the magnetic field was much stronger suggesting that Jupiter’s internal magnetic field is much more complex than had been previously assumed in the planetary model.

Before Juno’s 2 years mission comes to a dramatic close with the probe intentionally crashing itself into the planet, scientists at NASA hope to determine how much water is present in Jupiter’s atmosphere, if any. This information will help in choosing which planet formation theory is correct in regards to Jupiter’s formation or if any new theories.

Additionally (as of May 25, 2017), we’ve learned that clouds in Jupiter’s atmosphere grow to astonishingly high altitudes.  There are massive “cloud towers” that stretch up 30 miles and cast shadows on the clouds below, according to NASA.  The swirls that dot Jupiter’s South Pole are actually massive cyclones 600 miles (965 KM) across.  Indeed, it’s a perpetually stormy day on Jupiter.

Closeup of Jupiter's clouds.

The Juno Mission goal is to learn as much as possible about the atmosphere and the magnetic and gravitational fields of Jupiter. The Juno probe has traveled closer to Jupiter than any other spacecraft before it and still has much data to gather before its mission ends in January of 2018.



Images of Jupiter:  NASA