The power to combine three different ways of observing Jupiter – even a terrestrial telescope on Earth millions of miles away – resides in different wavelengths.
Hubble can observe Jupiter in visible and ultraviolet light while Gemini can capture observations in thermal infrared. Juno is ready to capture the radio signals emitted by lightning in Jupiter storms. Radio signals are called “spherical” and “whistles” which can be used to map lightning even under the heavy clouds of Jupiter.
Sferics is the abbreviation for atmosphere, while the whistles are named after the hissing tone they made.
Hubble and Gemini provide remote high-resolution observations, which can be used to interpret Juno’s close-up views on Jupiter.
Jupiter storms are monsters. Their storm clouds can span 40 miles from base to top, which is five times the height of Earth’s storm heads. Even the lightning of Jupiter punches, up to three times the energy in the so-called “superbolts”, the most powerful lightnings on Earth.
“Juno’s microwave radiometer investigates deep into the planet’s atmosphere by detecting high frequency radio waves that can penetrate through the thick layers of clouds. The Hubble and Gemini data can tell us how thick the clouds are and how deep we are seeing in the clouds, “said Amy Simon, senior scientist for research on planetary atmospheres in the Solar System Exploration Division at NASA’s Goddard Space Flight Center in Maryland, in a statement.
The combined data reveal three types of clouds coming together in storms. These include clouds of deep water vapor, large convective towers made of humid air similar to storm clouds on Earth and underlying clear areas caused by dry air.
Lightning strikes probably occur in deep-water clouds, caused by wet convection. The lightning of Jupiter and the great storms form both inside and around the large convective cells positioned above deep and humid clouds.
“Scientists track lightning because it is a convection marker, the turbulent mixing process that transports Jupiter’s internal heat to the tops of visible clouds,” said Michael Wong, planetary scientist at the University of California, Berkeley, in a note. “The ongoing studies on lightning sources will help us understand how the convection on Jupiter is different or similar to the convection in the Earth’s atmosphere.”
Detecting lightning in these clouds can help researchers better know how much water there is in Jupiter’s atmosphere. Understanding Jupiter’s atmosphere and water content can shed light on how the planet was formed.
While multiple unmanned space missions have visited Jupiter, researchers still have many questions about how this gas giant formed and the processes occurring on the planet.
The support of Hubble and Gemini during Juno’s mission also offers researchers a window on Jupiter’s climate in general, such as wind patterns, atmospheric waves and cyclones, as well as its gases and heat.
“This is our equivalent of a weather satellite,” said Simon. “We can finally start looking at the weather cycles.”
This observation team work was also used to analyze Jupiter’s best-known storm: the Great Red Spot, an ongoing storm. The images returned by Juno and other missions have revealed dark features that evolve over time during the storm. But the researchers weren’t sure if the characteristics were caused by the actual dark material in the clouds or by the holes in the clouds showing the underlying layers.
The combination of the visible light images of the Hubble storm with Gemini’s infrared observations revealed that the dark features are holes in the cloud level. In visible light, these appear dark. But in thermal infrared, researchers could see that the holes reveal the brightness of Jupiter’s heat escaping into space. Normally, this process is blocked by Jupiter’s huge clouds.
Infrared, the warm layers of Jupiter deep under the clouds seem to shine through the voids of the clouds.
“It’s a bit like a jack-o-lantern,” said Wong. “See the bright infrared light from cloud-free areas, but where there are clouds, it’s really dark in the infrared.”
The observations were obtained using “lucky imaging”, in which many sharp and short-exposure images are taken when Earth’s normally dark atmosphere is momentarily stable.
This technique created the sharpest images of Jupiter ever taken from Earth.
“These images compete with the view from space,” said Wong.
For example, Gemini was able to achieve 300 miles resolution on Jupiter.
“At this resolution, the telescope could resolve the two headlights of a car in Miami, viewed from New York City,” said Andrew Stephens, Gemini astronomer who led the observations, in a statement.