Titan, as seen by the keck ii telescope on maunakea, hawai'i, is the only moon in the solar system with a dense atmosphere and the only world besides earth that has standing bodies of liquid rivers, lakes, and seas. Credit: W. M. Keck Observatory/Judy Schmidt
Maunakea, Hawaiʻi – From space with NASA’s James Webb Space Telescope (JWST) and on the ground with the W. M. Keck Observatory on Maunakea, Hawaiʻi Island, astronomers have tag-teamed to capture a set of extraordinary images revealing large clouds in the northern hemisphere of Saturn’s largest moon, Titan.
“Detecting clouds is exciting because it validates long-held predictions from computer models about Titan’s climate, that clouds would form readily in the mid-northern hemisphere during its late summertime when the surface is warmed by the Sun,” said Conor Nixon, Principal Investigator of the Guaranteed Time Observation (GTO) program 1251 team at NASA’s Goddard Space Flight Center.
As part of their investigation of Titan’s atmosphere and climate, Nixon’s team used JWST’s Near-Infrared Camera (NIRCam) to observe the moon during the first week of November. After seeing the clouds near Kraken Mare, the largest known liquid sea of methane on the surface of Titan, they immediately contacted the Keck Titan Observing Team to request follow-up observations.
Near-infrared Images of Saturn’s moon Titan, as seen by JWST on November 4, 2022 (left), followed by Keck Observatory’s NIRC2 instrument paired with adaptive optics on November 6, 2022 (middle) and November 7, 2022 (right). Credit: NASA/STScI/W. M. Keck Observatory/Judy Schmidt
“We were concerned that the clouds would be gone when we looked at Titan a day later with Keck, but to our delight there were clouds at the same positions on subsequent observing nights, looking like they had changed in shape,” said Imke de Pater, emeritus professor of astronomy at the University of California, Berkeley, who leads the Keck Titan Observing Team. Using Keck Observatory’s second generation Near-Infrared Camera (NIRC2) in combination with the Keck II Telescope’s adaptive optics system, de Pater and her team observed one of Titan’s clouds rotating into and another cloud either dissipating or moving out of Earth’s field of view due to Titan’s rotation. Tracking the clouds’ motions are important because they give insight into how air is flowing within Titan’s atmosphere.
Evolution of clouds on Titan over 30 hours between Nov. 4 and Nov. 6 captured by JWST (top) and Keck Observatory (bottom). Titan’s trailing hemisphere seen here is rotating from left (dawn) to right (evening) as seen from Earth and the Sun. Cloud A appears to be rotating into view while Cloud B appears to be either dissipating or moving behind Titan’s limb. Clouds are not long-lasting on Titan or Earth, so those seen on November 4 may not be the same as those seen on November 6. Credit: NASA/STScI/Keck Observatory/Judy Schmidt Nixon and de Pater’s teams will continue to analyze the fresh data, with more JWST observations planned.
As the only moon in the solar system with a dense atmosphere, as well as the only place besides Earth to have present-day liquid rivers, lakes, and oceans, astronomers hope to deepen their understanding of Titan’s spectacular environment.
Read more:
- “Webb, Keck Telescopes Team Up to Track Clouds on Saturn’s Moon Titan” – NASA Webb Blog by Principal Investigator Conor Nixon
- “Webb Space Telescope, Keck Team Up to Study Saturn’s Moon Titan” – UC Berkeley
Source: W.M. Keck Observatory
About NIRC2
The Near-Infrared Camera, second generation (NIRC2) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.
About Adaptive Optics
W. M. Keck Observatory is a distinguished leader in the field of adaptive optics (AO), a breakthrough technology that removes the distortions caused by the turbulence in the Earth’s atmosphere. Keck Observatory pioneered the astronomical use of both natural guide star (NGS) and laser guide star adaptive optics (LGS AO) and current systems now deliver images three to four times sharper than the Hubble Space Telescope at near-infrared wavelengths. AO has imaged the four massive planets orbiting the star HR8799, measured the mass of the giant black hole at the center of our Milky Way Galaxy, discovered new supernovae in distant galaxies, and identified the specific stars that were their progenitors. Support for this technology was generously provided by the Bob and Renee Parsons Foundation, Change Happens Foundation, Gordon and Betty Moore Foundation, Mt. Cuba Astronomical Foundation, NASA, NSF, and W. M. Keck Foundation.
About W. M. Keck Observatory
The W. M. Keck Observatory telescopes are among the most scientifically productive on Earth. The two 10-meter optical/infrared telescopes atop Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometers, and world-leading laser guide star adaptive optics systems. Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c) 3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.
