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The James Webb Space Telescope has imaged clouds over one of the solar system’s most intriguing moons.
In November, the space observatory turned its infrared gaze to Saturn’s largest moon, Titan. It is the only moon in our solar system to have a dense atmosphere – four times denser than Earth’s.
Titan’s atmosphere is made of nitrogen and methane, giving it a cloudy, orange appearance. This thick haze blocks visible light from reflecting off the moon’s surface, making features difficult to distinguish.
The Webb telescope observes the universe in infrared light, invisible to the human eye – on November 5, the telescope detected a bright cloud in Titan’s northern hemisphere and soon detected a second cloud in the atmosphere.
The larger cloud was located over Titan’s north polar region near Kraken Mare, the largest known sea of liquid methane on the lunar surface.
Titan has Earth-like liquid bodies on its surface, but its rivers, lakes and seas are made of liquid ethane and methane that form clouds and cause rain to fall from the sky. Researchers also believe that Titan has an internal ocean of liquid water.
“Detecting clouds is exciting because it confirms long-held predictions about Titan’s climate from computer models that clouds will easily form in the mid-northern hemisphere in late summer, when the surface is heated by the Sun.” Scientist at NASA Goddard Space Flight Center in Greenbelt, Maryland, NASA’s Webb blog.
Nixon is also the principal investigator. In the Webb observation program for Titan.
The team of astronomers studying the Webb observations reached out to their colleagues at the WM Keck Observatory. He’s in Hawaii to see if follow-up observations can reveal whether the clouds are moving or changing shape.
“When Keck and I looked at Titan two days later, we were worried that the clouds would be gone, but it was our pleasure to have clouds that seemed to have changed shape in the same locations,” said Emeritus professor Imke de Pater. The leader of astronomy and the Keck Titan Observation Team at the University of California, Berkeley, said in a statement.
Atmospheric modeling experts helped the team determine that the two telescopes were capturing observations of seasonal weather on Titan.
Webb’s Near Infrared Spectrograph instrument was also able to collect data on Titan’s lower atmosphere, which cannot be seen by ground-based observatories. Like Keck due to interference from Earth’s atmosphere at different wavelengths of infrared light.
The data currently being analyzed was able to see Titan’s atmosphere and surface deeper than the Cassini spacecraft, which orbited Saturn and its moons for 13 years. Webb’s observations may also reveal the cause of a bright feature on Titan’s south pole.
Cloud observations were a long time ago.
“We’ve waited years to use Webb’s infrared vision to see beyond the haze to study Titan’s atmosphere, including its fascinating weather patterns and gas composition, as well as to study albedo features on the surface,” Nixon said, referring to the bright and dark patches. Said. .
“Titan’s atmosphere is incredibly interesting, not only because of its methane clouds and storms, but also what it can tell us about Titan’s past and future – including whether it has always had an atmosphere. We were absolutely delighted with the initial results.”
The team is planning more Titan observations in June that could provide additional information about the gases in its atmosphere.
