With thunderheads that tower forty miles high and stretch half the width of a continent, hurricane-force winds in enormous storms that rage for centuries, and lightning three times as powerful as Earth’s strongest superbolts, Jupiter—king of the planets—has proven itself a more-than-worthy namesake to the supreme Roman god of sky and thunder.
In spite of more than 400 years of scientific observations, many details of the gas giant’s turbulent and ever-changing atmosphere have remained elusive. Now, thanks to the teamwork of the Hubble Space Telescope, the Gemini Observatory, and the Juno spacecraft, scientists are able to probe deep into storm systems, investigating sources of lightning outbursts, mapping cyclonic vortices, and unravelling the nature of enigmatic features within the Great Red Spot.
This unique collaboration is allowing researchers to monitor Jupiter’s weather and estimate the amount of water in the atmosphere, providing insight into how Jupiter operates today as well as how it and the other planets in our solar system formed more than four-and-a-half billion years ago.
NASA’s Hubble Space Telescope and the ground-based Gemini Observatory in Hawaii have teamed up with the Juno spacecraft to probe the mightiest storms in the solar system, taking place more than 500 million miles away on the giant planet Jupiter.
A team of researchers led by Michael Wong at the University of California, Berkeley, and including Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and Imke de Pater also of UC Berkeley, are combining multiwavelength observations from Hubble and Gemini with close-up views from Juno’s orbit about the monster planet, gaining new insights into turbulent weather on this distant world.
“We want to know how Jupiter’s atmosphere works,” said Wong. This is where the teamwork of Juno, Hubble and Gemini comes into play.
Radio ‘Light Show’
Jupiter’s constant storms are gigantic compared to those on Earth, with thunderheads reaching 40 miles from base to top — five times taller than typical thunderheads on Earth — and powerful lightning flashes up to three times more energetic than Earth’s largest “superbolts.”
Like lightning on Earth, Jupiter’s lightning bolts act like radio transmitters, sending out radio waves as well as visible light when they flash across the sky.
Every 53 days, Juno races low over the storm systems detecting radio signals known as “sferics” and “whistlers,” which can then be used to map lightning even on the day side of the planet or from deep clouds where flashes are not otherwise visible.
Probing Storm Systems on Jupiter Graphic
This graphic shows observations and interpretations of cloud structures and atmospheric circulation on Jupiter from the Juno spacecraft, the Hubble Space Telescope and the Gemini Observatory. By combining the Juno, Hubble and Gemini data, researchers are able to see that lightning flashes are clustered in turbulent regions where there are deep water clouds and where moist air is rising to form tall convective towers similar to cumulonimbus clouds (thunderheads) on Earth. The bottom illustration of lightning, convective towers, deep water clouds and clearings in Jupiter’s atmosphere is based on data from Juno, Hubble and Gemini, and corresponds to the transect (angled white line) indicated on the Hubble and Gemini map details. The combination of observations can be used to map the cloud structure in three dimensions and infer details of atmospheric circulation. Thick, towering clouds form where moist air is rising (upwelling and active convection). Clearings form where drier air sinks (downwelling). The clouds shown rise five times higher than similar convective towers in the relatively shallow atmosphere of Earth. The region illustrated covers a horizontal span one-third greater than that of the continental United States. Credit: NASA, ESA, M.H. Wong (UC Berkeley), A. James and M.W. Carruthers (STScI), and S. Brown (JPL)
Coinciding with each pass, Hubble and Gemini watch from afar, capturing high-resolution global views of the planet that are key to interpreting Juno’s close-up observations. “Juno’s microwave radiometer probes deep into the planet’s atmosphere by detecting high-frequency radio waves that can penetrate through the thick cloud layers. The data from Hubble and Gemini can tell us how thick the clouds are and how deep we are seeing into the clouds,” Simon explained.
By mapping lightning flashes detected by Juno onto optical images captured of the planet by Hubble and thermal infrared images captured at the same time by Gemini, the research team has been able to show that lightning outbreaks are associated with a three-way combination of cloud structures: deep clouds made of water, large convective towers caused by upwelling of moist air — essentially Jovian thunderheads — and clear regions presumably caused by downwelling of drier air outside the convective towers.
The Hubble data show the height of the thick clouds in the convective towers, as well as the depth of deep water clouds. The Gemini data clearly reveal the clearings in the high-level clouds where it is possible to get a glimpse down to the deep water clouds.
Wong thinks that lightning is common in a type of turbulent area known as folded filamentary regions, which suggests that moist convection is occurring in them. “These cyclonic vortices could be internal energy smokestacks, helping release internal energy through convection,” he said. “It doesn’t happen everywhere, but something about these cyclones seems to facilitate convection.”
The ability to correlate lightning with deep water clouds also gives researchers another tool for estimating the amount of water in Jupiter’s atmosphere, which is important for understanding how Jupiter and the other gas and ice giants formed, and therefore how the solar system as a whole formed.
While much has been gleaned about Jupiter from previous space missions, many of the details — including how much water is in the deep atmosphere, exactly how heat flows from the interior and what causes certain colors and patterns in the clouds — remain a mystery. The combined result provides insight into the dynamics and three-dimensional structure of the atmosphere.