WEIRD MOLECULE DISCOVERED IN TITAN’S ATMOSPHERE: IS THERE LIFE ON SATURN’S SATELLITE
Are we alone in the Universe? One simple question that fascinates thousands and thousands of
people. Think about the multitude of scientific fictions produced in the last 50 years, hundreds
of tv series dealing with strange beings coming from the furthest places in our galaxy. Looking
for other living organisms in space is one of the most extraordinary tasks everyone would
love to accomplish. However, searching life according to the scientific
method is very different from what movies can tell you. For someone it might appear
less sexy and attractive, but I strongly disagree with this thought. Understanding if someone
shares with us this mysterious space called Universe and trying to find where he’s located
is a desire that always excites the mind and the soul at the same time.
One of the latest news revealed by NASA research group working with ALMA (Atacama Large Millimeter
Array), a radio-telescope in Northern Chile, has recently shocked the scientific community,
suggesting the possibility of future life on Titan, one of the most famous satellites
of Saturn. This simple carbon-based molecule could be a precursor that contributes to chemical
reactions that may create complex compounds. And those compounds could be the basis for
potential life on Titan. But what does it really mean? What did they
discover? Why is it linked with the possibility of finding life on Titan? And how is it really
like to search for life with a scientific team? We’ll answer these and other questions
in the following video, so, if you are interested, stick with me and I’ll tell you everything
in a moment.
Like I was previously saying, the research of life form in space is a bit different from
what you can imagine from articles describing observations of UFO or other paranormal events.
In recent years a whole new branch of Astronomy has developed, its name is Astrobiology. Practically,
it’s an interdisciplinary scientific field which focuses on origins, early evolution
and distribution of life in the Universe. After having introduced this discipline, let’s
directly move towards the main point of this video: what was recently discovered on Titan’s
atmosphere? Scientists discovered a really strange molecule
never detected in other atmospheres which is called cyclopropenylidene or C2H3.
But why is it so unexpected and important? How could they detect its presence? In order
to answer these questions let’s make a little step-back.
What is Titan? It’s the most famous and the largest satellite of Saturn. With its
2 574 km of radius, he’s the second bigger moon of the entire solar system. To understand
this value, just think that this satellite is bigger than Mercury, the closest planet
to the Sun. Discovered by the famous physicists Christiaan Huygens in 1655, Titan is an object
of several astronomical studies. Why? Because, today, it’s the main candidate for hosting
life in a different place from our Earth. If you want to know more about Titan check
other two videos we have published here on Insane Curiosity.
The largest of Saturn’s 62 moons, Titan is an intriguing world that’s in some ways
the most similar one to Earth we have found. Unlike any other moon in the solar system
— there are more than 200 — Titan has a thick atmosphere that’s four times denser
than Earth’s, plus clouds, rain, lakes and rivers, and even a subsurface ocean of salty
water. As a matter of fact, it is the only place (except for Earth) with evidence of
stable bodies of surface liquid that has been found. The presence of liquid water on its
surface remained unknown until the Cassini-Huygens mission in 2004 made possible to see under
the thick atmosphere which was hiding every possible information about the composition
of the ground. Surprisingly, Titan is full of underground oceans, covered by a thick
layer of ice crust. Absolutely amazing! Titan’s characteristics color is given by
the organonitrogen abundance in the atmosphere. Together with a hint of methane, this is the
principal component of Titan’s atmosphere. Why were Nasa scientists studying the chemical
compounds in the gas region around Saturn’s Moon? Here is a little piece from Rosaly Lopes,
a senior research scientist and Titan expert at NASA’s Jet Propulsion Laboratory (JPL)
in Pasadena, California: “We’re trying to figure out if Titan is habitable. So we
want to know what compounds from the atmosphere get to the surface, and then, whether that
material can get through the ice crust to the ocean below, because we think the ocean
is where the habitable conditions are.” This suggestion is one of the reason why this
crazy satellite is the object of the upcoming NASA Dragonfly Mission which will send a robotic rotorcraft to
the surface. The task is to study prebiotic chemistry and extraterrestrial habitability.
It will perform vertical-takeoffs and landings to move between exploration sites. Dragonfly
will launch in 2026 and arrive in 2034. It marks the first time NASA will fly a multi-rotor
vehicle for science on another planet; it has eight rotors and flies like a large drone.
It will take advantage of Titan’s dense atmosphere – four times denser than Earth’s
– to become the first vehicle ever to fly its entire science payload to new places for
repeatable and targeted access to surface materials.
Do you want to know more about this futuristic project? Check one of our videos here on Insane
Curiosity, which goes a little deeper in the Dragonfly mission.
"Before finding out more about this, be sure to like or dislike the video so that we can
continue to improve and make these videos better for you the viewer. Plus, be sure to
subscribe to the channel clicking the bell so that you don't miss ANY of our weekly videos."
Now that we have introduced the moon on which the discovery took place let’s analyze the
strange compound found by Nasa researchers. Cyclopropenylidene or C2H3 is an aromatic molecule
belonging to a highly reactive class of organic molecules known as carbenes. It is composed of Hydrogen and
Carbon. "It's a very weird little molecule, so it's not going be the kind you learn about
in high school chemistry or even undergraduate chemistry," said Malaska a researcher who
was not involved with this study, but a real expert of Titan.
Detected the first time in an astronomical mission in 1985, it’s mostly found in the
interstellar cloud (a denser region of the interstellar medium) which is an accumulation
of gas, dust and plasma located among different stars.
As a matter of fact, cyclopropenylidene can react easily with other molecules it comes
into contact with and form different species. Consequently, physicists have found C3H2 only
in regions that are too cold and diffuse to facilitate many chemical reactions.
When scientists recently observed the presence of this compound on Titan they were totally
surprised: “When I realized I was looking at cyclopropenylidene, my first thought was,
‘Well, this is really unexpected,’” said Conor Nixon, a planetary scientist at
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who led the ALMA search. Why? Because,
as we previously said, the atmosphere of Saturn’s largest satellite is the thickest among the
moons of the solar system. As a consequence of that, several chemical reactions can take
place in this type of region, which is not the natural habitat of C2H3 should form different
compounds with a really high probability. But how is it possible that this strange substance
has been detected in such a dense atmosphere? The research team lead by Nixon was able to
find it because they were pointing at the external layers of the atmosphere where there
are fewer gases to interact with. What does it mean that researchers have detected
this compound? How can they say with certainty that millions of kilometers away from their
observatory on earth, there’s a particular substance on Titan?
We know that science is really powerful and this is an appropriate example. The Nasa group
working at Alma has studied the radio waves (with wavelengths of nearly some millimeters)
reflected from Titan’s atmosphere. In physics we use to call spectrum the catalogue of light
frequencies emitted by an electromagnetic source. When a colder gas is positioned between
the source and the observer, we can see that the spectrum shows some black lines called
absorption lines. They are caused by the interaction between the electromagnetic wave and the gas,
photons (quantum of light) of different wavelengths interact with some specific elements of the
atmosphere and consequently each type of molecule or atom will create its characteristic absorption
lines that can be considered as a personal “fingerprint” of the elements. In the
case of Saturn’s atmosphere, Alma researchers “recognized” the absorption spectrum of
cyclopropenylidene. To double check this result, the scientists
controlled the data provided by the precedent mission Cassini-Huygens, which made 127 close
flybys of Titan between 2004 and 2017. The spacecraft of this important project had a
little device, a mass spectrometer, that could detect the presence of chemical compounds
on Titan’s atmosphere. How was it possible? Mass spectrometry is an analytical technique
that measures the mass-to-charge ratio of ions (which are atoms with an excess of a missing
od electrons). The results are typically presented as a mass spectrum, a plot of intensity as
a function of the mass-to-charge ratio. Typically, this device analyzes ionized samples (which
may be solid, liquid, or gaseous) for example by bombarding them with electrons. This may
cause some of the sample's molecules to break into charged fragments or simply become charged
without fragmenting. These ions are then separated according to their mass-to-charge ratio, for
example by accelerating them and subjecting them to an electric or magnetic field: ions
of the same mass-to-charge ratio will undergo the same amount of deflection. The results
are then presented with the previously citated example. Thanks to this technique, Cassini
spotted evidence for an electrically charged version of the cyclopropenylidene, C3H3+,
confirming the ALMA latest results. But why is this molecule so important? C2H3
is, together with benzene, the only cyclic compound detected in Titan’s atmosphere.
These types of molecules with a circular structure are crucial for the development of life. As
most of us know, our genetic code is carried in very thin sequences of DNA contained in
our cells. Do you know what are the backbone rings of this pivotal structures that are
probably the most important sign of life? The closed-loop molecules. Ring-shaped compounds
are the main ingredients that form Dna or Rna sequences, even though cyclopropenylidene
is not known to be used in modern-day biological reactions.
Nasa scientist Rosaly Lopes, that we previously mentioned, added: “We’ll be looking for
bigger molecules than C3H2, but we need to know what’s happening in the atmosphere
to understand the chemical reactions that lead complex organic molecules to form and
rain down to the surface.” From what we have seen, Titan is an incredible
place in which strange molecules rarely seen on Earth can unveil the possible formation
of life. Underground oceans hided below the ice surface crust might reveal as the most
habitable place in our solar system. Further NASA missions like Dragonfly are expected
to discover new signs and traces of aromatic compounds, which are essential for the composition
of DNA. While scientists and experts try to scan space
and find living organisms on other planets or moons, let’s enjoy our beloved Earth,
that is surely the most precious and important place to take care about.
"This video ends here! Thanks for watching everyone! Did you find this topic exciting?
Are you amazed by the possibility of future life on Titan? Do you think that is possible
that humanity will start living on Titan? Is there anything more you want to hear about
cyclopropenylidene? Are you afraid by the research of living organisms in space? Do
you think that it could be harmful for our planet and biosphere? Let me know in the comments
below, be sure to subscribe, and I'll see you next time on the channel!"