These infrared images of Saturn’s moon Titan represent some of the clearest global views of the icy moon’s surface. These scenarios were created using 13 years of data acquired by the on-zoom and infrared mapping spectrometer instrument in NASA’s Cassini spacecraft. Credit: NASA / JPL-Caltech / University of Nantes / University of Arizona
NASA Scientists have identified a molecule in Titan’s atmosphere that has never been found in any other atmosphere. In fact, many chemists have rarely heard of it or know how to pronounce it: cyclopropanylidine, or c.3H.2. Scientists say this simple carbon-based molecule could be a harbinger of more complex compounds that could build or feed potential life on Titan.
The image was returned on January 14, 2005, during a successful descent to the surface of Titan by the European Space Agency’s Huygens probe. This is the color view that has been processed to add reflection spectra data to give a better indication of the actual color of Titan’s surface.
Credit: NASA / JPL / ESA / University of Arizona
Researchers have found that c3H.2 By using a radio telescope observatory known as the Atacama Large Millimeter / Submillimeter Array in Northern Chile (Alma). They c3H.2, Which is composed of carbon and hydrogen, while running a stream through the spectrum of unique light signatures collected by a telescope; This exposes the chemical makeup of Titan’s atmosphere by emitting or absorbing its atoms.
“When I found out I was looking at cyclopropanylidine, my first thought was, ‘Well, this is really unexpected,'” said Connor Nixon, a planetary scientist at NASA’s Goddard Space Flight Center in MLN’s Greenbelt , On 2020, were published in Astronomical Journal.
Although scientists have c3H.2 In the pocket during the galaxy, it was amazing to meet him in the atmosphere. This is because cyclopropanelidine can easily react with other molecules that come into contact and form different species. Astronomers have so far c3H.2 Just in clouds of gas and dust floating between the star system – in other words, many cold and diffuse regions to facilitate many chemical reactions.
But a geense atmosphere like Titan is a hive of chemical activity. This is one of the main reasons why scientists are interested in the moon, which is the target of NASA’s upcoming Dragon Fly mission. Nixon’s team was able to identify a small amount of C3H.2 Probably because they were looking at the upper layers of the lunar atmosphere on Titan, where there are less other gases for C.3H.2 To interact with. Scientists do not yet know why cyclopropanylidene will appear in Titan’s atmosphere, but no other. “Titan is unique in our solar system,” Nixon said. “It has proven to be a storehouse of new molecules.”
The largest of Sat.62૨ Moon, Titan is an interesting world that in some ways is found with the Earth that we have found. Unlike any other moon in the Solar System – more than 200 – Titan’s ga thick atmosphere is four times less than that of the Earth, mountains, clouds, rain, lakes and rivers, and a saltwater satellite.
Titan’s atmosphere is largely composed of Earth-like nitrogen, a sign of methane. When the molecules of methane and nitrogen break down under the glare of the sun, their constituent atoms emit a complex web of biochemistry that has fascinated scientists and made this moon one of NASA’s most important targets for current or past discovery. Life in the Solar System.
“We’re trying to find out if Titan is fit to live,” said Rosalie Lopez, a senior research scientist at NASA’s Jet Propulsion Laboratory and a Titan expert.JPL) In Pasadena, California. “So we want to know what compounds from the atmosphere reach the surface, and then, whether that material can get into the ocean below through the ice crust, because we think the ocean is where it should be.”
The types of atoms sitting on the surface of Titan may be similar to those that formed the barrier to the formation of life on Earth. At the beginning of its history, 8.8 billion. Billions of years ago, when methane filled the Earth’s air instead of oxygen, the situation here could be similar to that on Titan today, scientists suspect.
“We think of Titan as a real-life laboratory where we can see chemistry similar to that of ancient Earth, when life was catching up here,” said Melissa Trainer, NASA’s Goddard astrobiologist. Trainer is the Deputy Principal Investigator of the Dragon Fly Mission and is the lead of an instrument on the Dragon Fly Rotorcraft that will analyze Titan’s surface composition.
“We will find atoms larger than C.3H.2“But to understand the chemical reactions that take complex organic molecules to the surface and lead to precipitation, we need to know what’s going on in the atmosphere,” Trainer said.
Dragonfly is a NASA mission aimed at exploring the chemistry and habitat of Saturn’s largest moon, Titan. Credit: NASA’s Goddard Space Flight Center / Johns Hopkins University Applied Physics Laboratory
Cyclopropanylidene is the only other “cyclical” or closed-loop molecule ever found in Titan’s atmosphere other than benzene. Although c3H.2 Not known to be used in modern biological reactions, such as closed loop molecules are important because they form backbone rings for nucleus ob bases. DNA, The complex chemical structure that carries the genetic code of life, and RNA, Another complex combination for life’s tasks. “The cyclical nature of them opens up this extra branch of chemistry that allows you to make these molecules of biologically important,” said Alexander Thalen, Goddard astrobiologist who worked with Nixon to discover3H.2.
Scientists like Thalen and Nixon are using a very large and highly sensitive Earth-based telescope to find simple life-related carbon atoms that can be found in Titan’s atmosphere. Benzene was considered to be the smallest unit of complex, colored hydrocarbon atoms found in any planetary atmosphere. But now c3H.2, With half the carbon atoms of benzene, it seems to have taken its place.
Nixon’s team used the ATM observatory in 2016 to view at Titan. They were amazed to find a strange chemical fingerprint, which Nixon identified through a database of all known atomic light signatures as cyclopropynalidine.
So far, cyclopropanylidene has only been found in gas and dust molecular clouds, such as the Taurus molecular cloud, which is more than 100 light-years away in the constellation Taurus. Recently, NASA Goddard scientist Conor Nixon with his team found this unique atom in Titan’s atmosphere; For the first time it has been found outside the atomic cloud. In addition to benzene at Titan, cyclopropanylidine is the only closed klop-molecule. Closed-loop molecules are important because they form the backbone rings for nucleobase cess of DNA, the complex chemical structure that carries the genetic code of life, and another crucial compound for life functions R.N. Credit: Connor Nixon / NASA’s Goddard Space Flight Center
To test whether the researchers were actually seeing this unusual combination, Nixon broke away from the analysis of NASA data through published research papers. Cassini The spacecraft, which built Flyby near Titan’s 127 between 2004 and 2017. He wanted to see if any of the instruments in the spacecraft that sniffed the chemical compounds around Saturn and Titan could confirm its new result. (An instrument – called a mass spectrometer – took the signals of many mysterious molecules at Titan that scientists are still trying to identify.) Indeed, Cassini spotted evidence for a similar atom, an electrically charged version, C.3H.3+.
Given that it is a rare discovery, scientists are trying to learn more about cyclopropanylidine and how it interacts with gases in Titan’s atmosphere.
“It’s a very strange little molecule, so you can’t learn in high school chemistry or undergraduate chemistry,” said Michael Malaska, a JPL planetary scientist who worked in the pharmaceutical industry before falling in love with Titan and switching. Career studies it. “Earth down here, it won’t be something you’re facing.”
But, Malaska said, looking for molecules like C.3H.2 It’s really important to look at the big picture of Titan: “Every little piece and piece you can find can help you put together a huge puzzle of all the things going on there.”
Reference: Colon a. Nixon, Alexander E. Thelen, Martin A. Cordiner, Zbignev Kissiel, Steven B. Charnley, Edward m. Molter, Joseph Serigano, Patrick G.J. Irwin, Nicholas a. Tanby and Yi-Zheng Kuan, 15 October October 2020, Astronomical Journal.
DOI: 10.3847 / 1538-3881 / AB 6767
