Kinetics of Titan

As we know, Titan has one of the most interesting atmospheres known to scientists. It is one of the few atmospheres that we think may be capable of sustaining life. Although, we know a lot about Titan, it still continues to surprise us whenever we look closer.

Titan's Haze

One thing that continues to intrigue us about Titan is the orange colored haze that surrounds the moon. This orange haze is what shields Titan from the sun; this also makes it difficult for us to study its surface. So what is the orange haze that is causing this problem? Scientists for the past 20 years have been trying to figure it out. The problem is that scientist could not get quality data in order to replicate the scenario. However, with recent data from the Cassini spacecraft that is investigating Saturn, scientist determined that the haze forms when ethynyl radicals react with hydrocarbons. Thermochemically, scientists understand the reaction however, they still cannot figure out the kinetics behind it.

Possible Molecules Involved with the Mechanism
(Far Left: Ethynyl Radical Far Right: Polyyne Triacetylene)

It was determined that this reaction has a bimolecular mechanism, but a plausible mechanism still has not been found. The conditions on Titan are nearly impossible to recreate because they are so different and because our data is not as accurate as we need it to be. In one proposed theory, polyyne triacetylene was thought to be an intermediate that was formed during this process. This is one of the only feasible options in Titan’s cold atmosphere. However further experimentation needs to be done for this mechanism to get legitimate consideration.

The Significance of Mars to Past Civilizations

While Saturn has played a huge part in the daily lives of past civilizations, Mars might have been debatably more important. When you look at images of Mars, you think of a red, angry planet that almost seems like it is stained from countless battles. This is exactly what the Greeks and Romans believed, and tied into much of their daily lives.

Ares, the god of war

The Greeks believed Mars was the Greek god of war Ares. While Ares represented strength and power in battle, he also represented fear, destruction, and mass killing. The Greeks believed that Ares murdered Poseidon's son Alirrothio and as a result was hated by his father Zeus. Along with this, the Greeks believed in countless stories of Ares trying to seduce other god and participating in many love affairs. Ares did whatever he wanted and did not care about what anyone else had to say. Due to this, it is no wonder that the Greeks were in awe of Mars. Mars was only ranked second behind Jupiter which was revered as the almighty Zeus.

Mars with Aphrodite

While the Greeks believed Mars was Ares, the Romans actually named the red planet Mars. To the Romans, Mars signified more than just war. Mars was the planet of energy, action and desire. The Romans thought of Mars as the animal instinct of humans and the idea of acting solely on impulse. The Romans would especially emphasize acting on a sexual nature as an impulse.  Like the Greeks, the Romans believed Mars signified aggression and anger and embodied the forceful nature like that of Ares. However, the Romans also believed that Mars was the guardian of agriculture and promoted good harvests and crops as well.


It's really amazing to see how important Mars was to the past civilizations of the Greeks and Romans. Although no one might believe in Greek and Roman mythology any longer, the planet of Mars still plays a part in our lives even after so many years later. While a lot of people know that Mars represents the war and fighting, we can see this in our entertainment as well. There are movies and books that appear all the time about Martians and the thought of aliens out there. Games like God of War have been ongoing for years that actually emphasize Greek and Roman mythology. While we might not view Mars in the same way as these past civilizations, Mars still plays a part in our lives today.

Life on Enceladus?

For many years, scientists have wondered whether life could be possible or already occurring in other locations in the universe other than in Earth. One location that gets a lot of attention is Enceladus. Enceladus is one of the innermost moons of Saturn. The surface is covered in ice but underneath, there is liquid. This can easily been seen by the geyser activity that Enceladus has, spewing water into space. Since the moon is covered in ice, it reflects nearly all of the light from the son, making the surface temperature a frigid -201 degrees Celsius. The Cassini spacecraft also discovered an atmosphere originating from the moon's surface or interior. 

Enceladus and Saturn

But how does this have anything to do with life? Well there are places on Earth with ecosystems similar to that on Enceladus where life exists. There are three of these ecosystems, two that are for methanogens, a type of archaea that pull their energy from the chemical interaction between rocks. And the other one is where the energy is produced from radioactive decay in rocks. The first two are located in deep volcanic rocks along the Columbia River and in the Idaho Falls. The third can be found deep below the surface in a mines in South Africa.

Tau  Tona mine located in South Africa which goes down 3.9 km

Now we know the feasibility of life on Enceladus, since we have seen microbial lifeforms existing in such ecosystems. But how would have life started in the first place? There is two theories, the primordial soup theory and the deep sea vent theory. Both are reasonably easy to understand, but extremely hard to replicate in a lab setting. The primordial soup states that in a soup of organic material, the building blocks of life would form by themselves in the soup, and gradually life would be formed. An experiment was done in which a spark passed through chemicals thought to be present in early Earth, such as methane and ammonia, caused the formation of  few amino acids. These organic chemicals or available on Saturn's moons, making this theory extremely viable. 

Amino acids forming proteinoids

In the deep sea vent theory, chemically rich fluids are heated and emerge from the sea floor. The chemical energy is provided by the reduced gases such as hydrogen sulfide and hydrogen coming out of vents in contact with oxidants such as carbon dioxide. These little hot spots on the Enceladus sea floor could be little hubs of life formation. 

Hydrothermal vents that spew out hot chemicals into the surrounding environment

All these theories indicate the possibility of life on Enceladus, but until there is solid evidence, this hope for life on a distant moon can never be supported. 

Why is Mars so small?

Ever wonder why Mars is ten times smaller than the Earth?

As you can see, Mars is noticeably smaller than both Earth and Venus

There are many theories, and one theory says that Mars never really "grew up". After initially evolving from dust particles to planetesimals to an early form of the planet, Mars stopped growing while its solar system siblings kept on developing. This is stage is called coined the term planetary embryo, and so while Earth kept on developing to reach "adulthood" 50 million years later, Mars stopped developing after 2-4 millions years after the solar system was formed. 

Representation of the solar system's nebula from which planets were created

Researchers hypothesized this idea when they obtained data in another interesting way. Nicolas Dauphas from the University of Chicago and Ali Pourmand from the University of Miami looked at isotope ratios in meteorites with similar compositions as the Martian mantle. This was done by inductively coupled plasma  mass spectrometry, or ICPMS, which is a power technique which allows the multielemental ultratrace analysis of a variety of samples. The researchers measured decay of hafnium-182 and tungsten-182. When planetismals collide while forming a planet, the metals in the mass of the two colliding objects tend to move towards the inside when they combine together. Therefore, the presence of the tungsten-182 in the Martian mantle millions of years later shows that the planet did not develop much after that. Also through the amount of decay of the isotopes the age of the samples could be calculated. The researchers are calling the state that Mars is in and "embryo" phase, since the planet never fully developed. We can only wonder if, had Mars gotten past the embryo stage, the humans on Earth would be able to have planetary neighbors that existed in all Scifi novels. 

To Infinity and Beyond!

When you look up into the sky, there are a lot of things you might see. Maybe some birds, a lot of clouds, and if you're lucky, the occasional airplane effortlessly gliding through the sky. But when you go inside an actual airplane that is ascending through the air, you feel a terrible tremble rocking throughout the whole vessel. Let's go one step further. If an airplane is bad, think of how ridiculous it must feel to be in a rocket while it is blasting off into space!

An airplane is able to ascend into the heights beyond by using jets. These jets propel the airplane up and forward using the properties of thrust and lift. Then why is a rocket so different? Actually they are both quite similar. A jet plane intakes first intakes oxygen and then compresses it. A fuel mixture is then introduced into the chamber and this is ignited. The exhaust is used to push the engine and the airplane forward while it also is used to turn shafts so this process can repeat itself. 

A rocket on the other hand focuses more on the final step of the process, the propulsion step. A rocket uses stored propellant to travel at high speeds. The key aspect in propulsion is that the process is exothermic. The propellant in the combustion chamber (which can be either a liquid or a gas), is ignited with fuel and oxidizer components at very high pressures. The propellant used has a low specific heat so that when combustion occurs, the temperature of the gas drastically increases. After the gas product travels through a propelling nozzle, the heat energy of the gas propels the exhaust at very high speeds down and out the nozzle of the rocket. By using propellants with low degrees of freedom, the thrust produced is generally straight up, reducing waste in propulsion. Likewise, the pressure building up in the combustion chamber of the rocket has an effect. Due to an unbalance of pressure, the rocket engine is only allowed to travel one way, upwards. While the high velocity exhaust is being pushed downward, the unequal pressure pushes the rocket upwards, allowing rockets to soar through the air in a matter of seconds. 

Rockets have been so beneficial to us because they have become the first step to exploring the great beyond. The only way different missions can be made to Mars and Saturn is due to the rockets sending the spacecrafts into space. Maybe if we're lucky, flying by rockets will become so common that one day each of us can explore the solar system too! 

Geothermal History of Mars

Within the various different studies on Mars, another very interesting one is the study of thermal history of the planet. There are some theories on whether Mars cooled off faster or slower than Earth. One theory for a slower cooling rate of Mars is based on the fact that it is only 1/3 the size of the Earth. But a paper from the Royal Society of Chemistry can proves that the cooling rate of Mars is actually slower than that of Earth.

Size comparison of Earth and Mars

This paper incorporates data that was collected from the gamma ray spectrometer (GRS) on the Mars Odyssey spacecraft. The GRS are used for elemental and isotopic analysis in airless environments, and work by measuring the distribution of the intensity of gamma radiation versus the energy of each photon. The GRS was specifically used to collect data of thorium, silicon, and iron from volcanic regions on Mars. The concentration of each elements helps the scientists learn something about Mars. 

• Thorium - A good indicator of how much the interior of the planet has melted. 
• Silicon - Found in silicon dioxide, this compound is good for measuring the depth at which melting occurs
• Iron - Useful for validating interference between thorium and silicon data

Incoming cosmic rays excite atoms in the soil which cause them to eventually release gamma radiation, which is what the GRS captures.

According to Michael Toplis, one of the French scientists working on this paper, the scientists converted the chemical composition into temperature and pressures to see hot the Martian mantle is and quantified the planet's rate of cooling. 

The potential temperature of the mantle, the temperature had there been no enthalpy change while extracting the elements, is 1400ºC, similar to that of Earth. And between older and younger volcano sites on Mars, there is only about 80ºC difference in temperature, showing that the planet would only have cooled about 80ºC during the last two or three billion years. 

Mars Odyssey Artistic Concept

It is amazing how even the Odyssey Orbiter, while not even on the surface of the planet, could gather such detailed data that scientists use to explain phenomenon in a logical method through chemistry. And interestingly, the Odyssey Orbiter is also the longest running Mars mission, being deployed on 2001 and besides making its own scientific observations, is used as a communications relay for robots on the surface. 

X-ray Diffraction Used by Curiosiy

As we talk about space and the chemistry of foreign bodies millions of miles from Earth, it seems silly not to discuss one of the most important aspects regarding the analysis of such data; the retrieval of samples. Presently there are probes traveling through space gathering data and sending it back to Earth, such as the New Horizons Probe, which was launched by NASA in 2006 and is expected to pass Pluto in July 2015, as well as rovers on Mars, such as the Mars Opportunity Rover, which was launched in 2003 and has already trekked 20 miles.

Mars Opportunity Rover

Currently, there is a new rover on Mars, called the Curiosity Rover. It was this rover that created so much hype as it descended successfully onto the Martian surface on August 6th. This rover is set apart from previous rovers for its sophisticated on board sample analysis system. Through such instruments, it is possible for the rover to send important data back to Earth. One of the most important equipment on Curiosity is a spectrometer called the Chemistry and Mineralogy instrument, or Chemin for short. It is about the size of a laptop computer inside a carrying case and it measures the abundances of various minerals of Mars, which are indicative of environmental conditions that existed when they formed. 

As the gif demonstrates, Chemin performs X-ray diffraction measurements. It fires thin beams of X-rays through powdered material gathered by Curiosity. Some of the X-rays get absorbed by the atoms in the sample and then re-emitted at energies that are specifically characteristic of the particular atoms present in the sample. X-rays can also bounce away at a certain angle that corresponds to the internal crystalline structure of the sample. Measuring this angle which which the X-rays are diffracted into the detector can identify the minerals.

The image above is the X-ray diffraction results produced by Chemin which is sent back to Earth. The diffraction signals are the rings that represent the fingerprint of the minerals. The rings provides information on both what minerals are present as well as how abundant they are. 

And Chemin is only one piece of equipment on the Curiosity Rover. There are also cameras, radiation detectors, environmental sensors, and atmospheric sensors. Weighing one ton, more than any other rover made, the Curiosity Rover truly deserves the name Mars Science Laboratory.