6. The images above are from two different worlds. The image at left shows a lak
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6. The images above are from two different worlds. The image at left shows a lake (at different resolutions) located in the polar region on Titan, while the image at right shows Lake Superior on Earth. For the pair of images shown, list a few things that look very similar and a few that are quite different.
Saturn's Satellite with Liquid on its Surface: Titan Even though Titan is a satellite and is about 1.5 times the diameter of the Moon, it is more interesting and relevant as you've learned, to compare Titan's surface features with those of Earth. Earth's average surface temperature is about 290 K; Titan's is about 94 K! The Cassini spacecraft, which orbits Saturn and passes by its satellites, used infrared and radar instruments to map most of Titan's surface. You were introduced to a large number of features that have analogie:s on Earth. Lets take a look at the most interesting - lakes and tributary networksExplanation / Answer
Saturn’s moon Titan may be worlds away from Earth, but the two bodies have some characteristics in common: Wind, rain, volcanoes, tectonics and other Earth-like processes all sculpt features on Titan, but act in an environment more freezed than Antarctica.
"It is really surprising how closely Titan's surface resembles Earth's "a planetary geologist who is presenting the results of two new studies at the annual meeting of the of the International Astronomical Union (IAU) in Rio de Janeiro, Brazil "In fact, Titan looks more like the Earth than any other body in the solar system, despite the huge differences in temperature and other environmental conditions." This view of Titan comes from observations made by the Cassini-Huygens mission, which has revealed details of Titan's geologically young surface, showing few impact craters, and featuring mountain chains, dunes and even "lakes."
The RADAR instrument on the Cassini orbiter has now allowed scientists to image a third of Titan's surface using radar beams that pierce the giant moon's thick, smoggy atmosphere. As its name implies, Titan is no small moon, with a size approaching that of Mars.
Titan gets about 1 percent the amount of sunlight Earth receives.
Titan is the only moon in the solar system known to possess a thick atmosphere, and it is the only celestial body other than Earth to have stable pools of liquid on its surface. Lakes that pool on Titan's surface are thought to be filled not with water, but with liquid hydrocarbons, such as methane and ethane.
"With an average surface temperature hovering around -180 C [-292 degrees Fahrenheit], water cannot exist on Titan except as deep-frozen ice as strong as rock”.
On Titan, methane takes water's place in the hydrological cycle of evaporation and precipitation (rain or snow) and can appear as a gas, a liquid and a solid. Methane rain cuts channels and forms lakes on the surface and causes erosion, helping to erase the meteorite impact craters that pockmark most other rocky worlds, such as our own moon and the planet Mercury.
Other new research presented at the IAU General Assembly points to current volcanic activity on Titan, but instead of scorching hot magma, scientists think these "cryovolcanoes" eject cold slurries of water-ice and ammonia.
The ammonia signature seems to vary, which suggests that ammonia frosts are ejected and then subsequently dissipate or are covered over. Although the ammonia does not stay exposed for long, models show that it exists in Titan's interior, indicating that a process is at work delivering ammonia to the surface. RADAR imaging has indeed found structures that resemble terrestrial volcanoes near the site of suspected ammonia deposition.
New infrared images of this region, with ten times the resolution of prior mappings, will be unveiled at the IAU meeting.
"The images provide further evidence suggesting that cryo-volcanism has deposited ammonia onto Titan's surface," said Robert M. Nelson, a senior research scientist, also at JPL, who presented results on Wednesday.
The presence of ammonia and hydrocarbons could have interesting implications for the possibility of life existing on Titan.
"It has not escaped our attention that ammonia, in association with methane and nitrogen, the principal species of Titan's atmosphere, closely replicates the environment at the time that life first emerged on Earth," Nelson said. "One exciting question is whether Titan's chemical processes today support a pre-biotic chemistry similar to that under which life evolved on Earth?"
Yet more terrestrial-type features on Titan include dunes formed by cold winds, and mountain ranges. These mountains might have formed tectonically when Titan's crust compressed as it went into a deep freeze, in contrast to the Earth's crust, which continues to move today, producing earthquakes and rift valleys on our planet.
Titan is largest moon, and is the only moon known to have a dense atmosphere. A better understanding of how its hazy, soupy atmosphere works could shed light on similar ones scientists might find on alien planets and moons. However, conflicting details about how Titan's atmosphere is structured have emerged over the years.
The lowest layer of any atmosphere, known as its boundary layer, is most influenced by a planet or moon's surface. It in turn most influences the surface with clouds and winds, as well as by sculpting dunes. This layer is very important for the climate and weather — we live in the terrestrial boundary layer," said study lead author Benjamin Charnay, a planetary scientist at France's National Center of Scientific Research. Earth's boundary layer, which is between 1,650 feet and 1.8 miles (500 meters and 3 kilometers) thick, is controlled largely by solar heat warming the planet's surface. Since Titan is much further away from the sun, its boundary layer might behave quite differently, but much remains uncertain about it — Titan's atmosphere is thick and opaque, confusing what we know about its lower layers. [Amazing Photos of Titan]
For instance, while the Voyager 1 spacecraft suggested Titan's boundary layer was about 2 miles (3.5 km) thick, the Huygens probe that plunged through Titan's atmosphere saw it as only about 1,000 feet (300 m) thick.
To help solve these mysteries about Titan's atmosphere, scientists developed a 3D climate model of how it might respond to solar heat over time.
"The most important implication of these findings is that Titan appears closer to an Earth-like world than once believed,"
Their simulations revealed the lower atmosphere of Titan appears separated into two layers that are both distinct from the upper atmosphere in terms of temperature. The lowermost boundary layer is shallow, only about 2,600 feet (800 meters) deep and, like Earth's, changes on a daily basis. The layer above, which is 1.2 miles (2 kilometers) deep, changes seasonally.
The existence of two lower atmospheric layers that both respond to changes in temperature help reconcile the formerly disparate findings regarding Titan's boundary layer, "so there are no more conflicting observations,".
This new work help explains the winds on Titan measured by the Huygens probe, as well as the spacing seen between the giant dunes on Titan's equator. Also, "it could imply the formation of boundary layer clouds of methane on Titan." Such clouds were apparently seen before but not explained.
"3D models will be very useful in the future to explain the data about the atmospheres of exoplanets," .
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