Scientists unravel the chemistry of Titan's hazy atmosphere
September 15, 2009
Titan, seen during Cassini's Mar. 31, 2005, flyby
A team of University of Hawai'i at Mānoa researchers led by Ralf Kaiser, physical chemist at UH Mānoa, unraveled the chemical evolution of the orange-brownish colored atmosphere of Saturn's moon Titan, the only solar system body besides Venus and Earth with a solid surface and thick atmosphere. The UH Mānoa team, including Xibin Gu and Seol Kim, conducted simulation experiments mimicking the chemical reactions in Titan's atmosphere utilizing crossed molecular beams in which the consequence of a single collision between molecules can be followed.
The team's experiments indicate that triacetylene can be formed by a single collision of a "radical" ethynyl molecule and a diacetylene molecule. An ethynyl radical is produced in Titan's atmosphere by the photodissociation of acetylene by ultraviolet light. Photodissociation is a process in which a chemical compound is broken down by photons.
"Surprisingly, the photochemical models show inconsistent mechanisms for the production of polyynes," said Kaiser, who is the principal investigator of this study.
The mechanism involved in the formation of triacetylene, was also confirmed by accompanying theoretical calculations by Alexander Mebel, a theoretical chemist at Florida International University. These theoretical computations also provide the 3D distribution of electrons in atoms and thus the overall energy level of a molecule. To apply these findings to the real atmosphere of Titan, Danie Liang and Yuk Yung, planetary scientists at Taiwan's Academia Sinica and California Institute of Technology, respectively, performed photochemical modeling studies of Titan's atmosphere. All data together suggest that triacetylene may serve as a building block to form more complex and longer polyynes and produce potential precursors for the aerosol-based layers of haze surrounding Titan.
Left to right: ball-and-stick images of a radical ethynyl, acetylene, diacetylene and triacetylene molecule. Ethynyl has a lone electron on its terminal carbon atom and it is this lone or radical electron that initiates ethynyl's attack on other molecules. The lone electron is depicted by the white triangle-shaped figure. All atoms in the molecules are connected by either a single or triple bond. Carbon atoms are black and hydrogen atoms are blue. Credit: Ralf Kaiser and Xibin Gu, Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii
The study demonstrated for the first time that a sensible combination of laboratory simulation experiments with theory and modeling studies can shed light on decade old unsolved problems crucial to understand the origin and chemical evolution of the solar system. The researchers hope to unravel next the mystery of the missing ethane lakes on Titan - postulated to exist for half a century, but not detected conclusively within the framework of the Cassini-Huygens mission.In the future, the UH Mānoa team will combine the research results with terrestrial-based observations of Titan's atmosphere. Alan Tokunaga, astronomer at UH Mānoa's Institute for Astronomy, and Henry Roe from Lowell Observatory in Arizona, are currently collecting observational data using the NASA infrared telescope facility on the snowcapped peak of Mauna Kea.
More information: "Chemical dynamics of triacetylene formation and implications to the synthesis of polyynes in Titan's atmosphere" is published in the online early edition of Proceedings of the National Academy of Sciences at http://www.pnas.org/content/early/2009/09/11/0900525106.abstract .
Source: University of Hawaii at Manoa
-
Titan's Purple Haze Points to a Fuzzy Past
Aug 02, 2004 |
not rated yet |
0
-
Titan gives clues to Earth's early history
Dec 01, 2005 |
not rated yet |
0
-
Keck telescope captures Titan but misses Huygens
Jan 16, 2005 |
not rated yet |
0
-
Just How Significant Is Methane On Titan?
Sep 12, 2005 |
not rated yet |
0
-
Organic Materials Spotted in Titan's Atmosphere
Apr 26, 2005 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (31) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (3) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (1) |
0
-
Scale of the Universe
8 hours ago
-
Titan's lack of impact craters
Feb 09, 2012
-
Real pictures of black hole eating a star?
Feb 08, 2012
-
Hypothetical way to travel faster than light, but not technically exceed lightspeed
Feb 06, 2012
-
How do scientists monitor the Sun's activity?
Feb 05, 2012
-
Search patterns in observational studies
Feb 05, 2012
- More from Physics Forums - General Astronomy
More news stories
Humans may have helped the decline of African rainforests 3000 years ago
(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...
Could Venus be shifting gear?
(PhysOrg.com) -- ESAs Venus Express spacecraft has discovered that our cloud-covered neighbour spins a little slower than previously measured. Peering through the dense atmosphere in the infrared, the ...
Space & Earth / Space Exploration
16 hours ago |
5 / 5 (7) |
7
|
NASA budget will axe Mars deal with Europe: scientists
US President Barack Obama's budget proposal to be submitted next week for 2013 will cut NASA's budget by 20 percent and eliminate a major partnership with Europe on Mars exploration, scientists said Thursday.
Space & Earth / Space Exploration
19 hours ago |
5 / 5 (2) |
18
Mars Science Laboratory computer issue resolved
(PhysOrg.com) -- Engineers have found the root cause of a computer reset that occurred two months ago on NASA's Mars Science Laboratory and have determined how to correct it.
Space & Earth / Space Exploration
17 hours ago |
4.7 / 5 (6) |
3
|
Two new moons for Jupiter
Advances in technology have lead to the discovery of new planets outside of our Solar System, and now even new moons in our own backyard.
Space & Earth / Space Exploration
16 hours ago |
4 / 5 (1) |
7
Anonymous knocks CIA website offline (Update)
The website of the Central Intelligence Agency was inaccessible on Friday after the hacker group Anonymous claimed to have knocked it offline.
Google users warned of threat to smartphone wallets
Users of Google smartphone wallets were being warned on Friday that there is a way to crack pass codes intended to thwart thieves from going on illicit shopping sprees.
New error-correcting codes guarantee the fastest possible rate of data transmission
Error-correcting codes are one of the triumphs of the digital age. Theyre a way of encoding information so that it can be transmitted across a communication channel such as an optical fiber o ...
New power source discovered
(PhysOrg.com) -- Researchers at the Massachusetts Institute of Technology (MIT) and RMIT University have made a breakthrough in energy storage and power generation.
The power of estrogen -- male snakes attract other males
A new study has shown that boosting the estrogen levels of male garter snakes causes them to secrete the same pheromones that females use to attract suitors, and turned the males into just about the sexiest ...
Small modular reactor design could be a 'SUPERSTAR'
(PhysOrg.com) -- Though most of today's nuclear reactors are cooled by water, we've long known that there are alternatives; in fact, the world's first nuclear-powered electricity in 1951 came from a reactor ...
