Featured Research

from universities, journals, and other organizations

Zapping Titan-like atmosphere with UV rays creates life precursors

Date:
June 30, 2010
Source:
University of Arizona
Summary:
The first experimental evidence showing how atmospheric nitrogen can be incorporated into organic macromolecules is being reported by researchers. The finding indicates what organic molecules might be found on Titan, the moon of Saturn that scientists think is a model for the chemistry of pre-life Earth. Earth and Titan are the only known planetary-sized bodies that have thick, predominantly nitrogen atmospheres.

In an experiment to simulate what happens when sunlight hits Titan's atmosphere, University of Arizona researchers put nitrogen and methane gas into a stainless steel cylinder and zapped it with high-energy UV light. The nitrogen molecules emit blue light when zapped by the UV light. The white in the picture surrounds the pinhole opening that is the source of the UV beam. The experiment was conducted at the Advanced Light Source facility at Lawrence Berkeley National Laboratory in Berkeley, Calif.
Credit: Hiroshi Imanaka, University of Arizona.

The first experimental evidence showing how atmospheric nitrogen can be incorporated into organic macromolecules is being reported by a University of Arizona team.

Related Articles


The finding indicates what organic molecules might be found on Titan, the moon of Saturn that scientists think is a model for the chemistry of pre-life Earth.

Earth and Titan are the only known planetary-sized bodies that have thick, predominantly nitrogen atmospheres, said Hiroshi Imanaka, who conducted the research while a member of UA's chemistry and biochemistry department.

How complex organic molecules become nitrogenated in settings like early Earth or Titan's atmosphere is a big mystery, Imanaka said.

"Titan is so interesting because its nitrogen-dominated atmosphere and organic chemistry might give us a clue to the origin of life on our Earth," said Imanaka, now an assistant research scientist in the UA's Lunar and Planetary Laboratory. "Nitrogen is an essential element of life."

However, not just any nitrogen will do. Nitrogen gas must be converted to a more chemically active form of nitrogen that can drive the reactions that form the basis of biological systems.

Imanaka and Mark Smith converted a nitrogen-methane gas mixture similar to Titan's atmosphere into a collection of nitrogen-containing organic molecules by irradiating the gas with high-energy UV rays. The laboratory set-up was designed to mimic how solar radiation affects Titan's atmosphere.

Most of the nitrogen moved directly into solid compounds, rather than gaseous ones, said Smith, a UA professor and head of chemistry and biochemistry. Previous models predicted the nitrogen would move from gaseous compounds to solid ones in a lengthier stepwise process.

Titan looks orange in color because a smog of organic molecules envelops the planet. The particles in the smog will eventually settle down to the surface and may be exposed to conditions that could create life, said Imanaka, who is also a principal investigator at the SETI Institute in Mountain View, Calif.

However, scientists don't know whether Titan's smog particles contain nitrogen. If some of the particles are the same nitrogen-containing organic molecules the UA team created in the laboratory, conditions conducive to life are more likely, Smith said.

Laboratory observations such as these indicate what the next space missions should look for and what instruments should be developed to help in the search, Smith said.

Imanaka and Smith's paper, "Formation of nitrogenated organic aerosols in the Titan upper atmosphere," is scheduled for publication in the Early Online edition of the Proceedings of the National Academy of Sciences the week of June 28. NASA provided funding for the research.

The UA researchers wanted to simulate conditions in Titan's thin upper atmosphere because results from the Cassini Mission indicated "extreme UV" radiation hitting the atmosphere created complex organic molecules.

Therefore, Imanaka and Smith used the Advanced Light Source at Lawrence Berkeley National Laboratory's synchroton in Berkeley, Calif. to shoot high-energy UV light into a stainless steel cylinder containing nitrogen-and-methane gas held at very low pressure.

The researchers used a mass spectrometer to analyze the chemicals that resulted from the radiation.

Simple though it sounds, setting up the experimental equipment is complicated. The UV light itself must pass through a series of vacuum chambers on its way into the gas chamber.

Many researchers want to use the Advanced Light Source, so competition for time on the instrument is fierce. Imanaka and Smith were allocated one or two time slots per year, each of which was for eight hours a day for only five to 10 days.

For each time slot, Imanaka and Smith had to pack all the experimental equipment into a van, drive to Berkeley, set up the delicate equipment and launch into an intense series of experiments. They sometimes worked more than 48 hours straight to get the maximum out of their time on the Advanced Light Source. Completing all the necessary experiments took years.

It was nerve-racking, Imanaka said: "If we miss just one screw, it messes up our beam time."

At the beginning, he only analyzed the gases from the cylinder. But he didn't detect any nitrogen-containing organic compounds.

Imanaka and Smith thought there was something wrong in the experimental set-up, so they tweaked the system. But still no nitrogen.

"It was quite a mystery," said Imanaka, the paper's first author. "Where did the nitrogen go?"

Finally, the two researchers collected the bits of brown gunk that gathered on the cylinder wall and analyzed it with what Imanaka called "the most sophisticated mass spectrometer technique."

Imanaka said, "Then I finally found the nitrogen!"

Imanaka and Smith suspect that such compounds are formed in Titan's upper atmosphere and eventually fall to Titan's surface. Once on the surface, they contribute to an environment that is conducive to the evolution of life.


Story Source:

The above story is based on materials provided by University of Arizona. The original article was written by Mari N. Jensen, College of Science. Note: Materials may be edited for content and length.


Cite This Page:

University of Arizona. "Zapping Titan-like atmosphere with UV rays creates life precursors." ScienceDaily. ScienceDaily, 30 June 2010. <www.sciencedaily.com/releases/2010/06/100629170951.htm>.
University of Arizona. (2010, June 30). Zapping Titan-like atmosphere with UV rays creates life precursors. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2010/06/100629170951.htm
University of Arizona. "Zapping Titan-like atmosphere with UV rays creates life precursors." ScienceDaily. www.sciencedaily.com/releases/2010/06/100629170951.htm (accessed October 31, 2014).

Share This



More Matter & Energy News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU, Russia, Ukraine Seal Breakthrough Gas Accord

EU, Russia, Ukraine Seal Breakthrough Gas Accord

AFP (Oct. 31, 2014) Russia agrees to resume gas deliveries to war-torn Ukraine through the winter in an EU-brokered, multi-billion dollar deal signed by the three parties in Brussels. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Relief After “gas War” Is Averted

Relief After “gas War” Is Averted

Reuters - Business Video Online (Oct. 31, 2014) A gas war between Russia and Ukraine has been averted. But as Hayley Platt reports a deal was only reached after Kiev's western creditors agreed to partly funding the deal. Video provided by Reuters
Powered by NewsLook.com
Jaguar Land Rover Opens $800 Million Factory in Britain

Jaguar Land Rover Opens $800 Million Factory in Britain

AFP (Oct. 30, 2014) British luxury car manufacturer Jaguar Land Rover opened a $800 million engine manufacturing centre in western England, creating 1,400 jobs. Duration: 00:45 Video provided by AFP
Powered by NewsLook.com
SkyCruiser Concept Claims to Solve Problem With Flying Cars

SkyCruiser Concept Claims to Solve Problem With Flying Cars

Buzz60 (Oct. 30, 2014) A start-up company called Krossblade says its SkyCruiser concept flying car solves the problem with most flying car concepts. Mara Montalbano (@maramontalbano) explains. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins