Titan's river maps may advise Dragonfly's 'sedimental' journey

Date:
October 18, 2021
Source:
Cornell University
Summary:
With future space exploration in mind, a team of astronomers has
published the final maps of Titan's liquid methane rivers and
tributaries -- as seen by NASA's late Cassini mission -- so that
may help provide context for Dragonfly's upcoming 2030s expedition.



FULL STORY ==========================================================================
With future space exploration in mind, a Cornell-led team of astronomers
has published the final maps of Titan's liquid methane rivers and
tributaries -- as seen by NASA's late Cassini mission -- so that may
help provide context for Dragonfly's upcoming 2030s expedition.


==========================================================================
The fluvial maps and details of their accuracy were published in the
Planetary Science Journal (August 2021.) In addition to the maps, the
work examined what could be learned by analyzing Earth's rivers by using degraded radar data - - similar to what Cassini saw.

Like water on Earth, liquid methane and ethane fill Titan's lakes, rivers
and streams. But understanding those channels -- including their twists
and branch- like turns -- is key to knowing how that moon's sediment
transport system works and the underlying geology.

"The channel systems are the heart of Titan's sediment transport
pathways," said Alex Hayes, associate professor of astronomy in the
College of Arts and Sciences. "They tell you how organic material is
routed around Titan's surface, and identifies locations where the material might be concentrated near tectonic or perhaps even cryovolcanic features.

"Further, those materials either can be sent down into Titan's liquid
water interior ocean, or alternatively, mixed with liquid water that
gets transported up to the surface," Hayes said.

Larger than the planet Mercury and fully shrouded in a dense nitrogen and methane atmosphere, Titan is the only other place in the solar system
with an active hydrologic system, which includes rain, channels, lakes
and seas.



========================================================================== "Unlike Mars, it's not 3.6 billion years ago when you would have seen
lakes and channels on Titan. It's today," Hayes said. "Examining Titan's hydrologic system represents an extreme example comparable to Earth's hydrologic system - - and it's the only instance where we can actively
see how a planetary landscape evolves in the absence of vegetation."
Julia Miller '20 led the detailed work of examining Cassini's Synthetic Aperture Radar (SAR) images of Titan's surface, looking for fluvial characteristics and then comparing those images to those available
on Earth.

On Earth, fluvial geomorphology is typically studied with topographic
data and high-resolution visible images, but that was not available for
Titan. Instead, Miller used Earth-based radar images and degraded them
to match the Cassini radar images of Titan.

This way, Miller could understand the limits of the Cassini dataset and
know which results are robust for analysis using low, roughly 1-kilometer resolution data.

"Although the quality and quantity of Cassini SAR images put significant
limits on their utility for investigating river networks," Miller said,
"they can still be used to understand Titan's landscape at a fundamental level." River shapes say a lot. "You can use sort of what the river
looks like to try to say some things about the type of material that
it's flowing through, or like how steep the surfaces, or just what went
on in that region," Miller said.

"This is using the rivers as a starting point, to then, ideally, learn
more about the planet." The Dragonfly mission to Titan is slated to
launch in 2027 and is scheduled to arrive at Titan in 2034.

Said Hayes: "These maps will provide context for understanding things
that Dragonfly finds locally and regionally, and will help to place
Dragonfly's result into global context." This project was funded by
NASA and the European Space Agency.

========================================================================== Story Source: Materials provided by Cornell_University. Original written
by Blaine Friedlander, courtesy of the Cornell Chronicle. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. J. W. Miller, S. P. D. Birch, A. G. Hayes, M. J. Malaska,
R. M. C. Lopes,
A. M. Schoenfeld, P. M. Corlies, D. M. Burr, T. G. Farr, JT Perron.

Fluvial Features on Titan and Earth: Lessons from Planform Images
in Low- resolution SAR. The Planetary Science Journal, 2021; 2
(4): 142 DOI: 10.3847/PSJ/ac0245 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/10/211018130346.htm

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