Amazing Haze

Using the world's most accurate molecular scale, a former astronaut wanna-be is studying Titan's hazy atmosphere, which resembles the ancient chemistry that once surrounded our own planet.

Julien Maillard

Scientists are very interested in Titan, the largest of Saturn's moons and the second-largest satellite in our solar system, But it's not just the moon's size, which is 50% larger the our Earth's lone satellite, that most intrigues them. Rather, it's Titan's outer atmosphere. Scientists believe it has the potential to one day yield life, if paired with the water that is theorized to lie below Titan's frozen surface. NASA's Cassini mission collected vast amounts of data on Titan, but many of the moon's mysteries remain unsolved. Chemist Julien Maillard is attacking one of them: What exactly is Titan's outer atmosphere made of?

Julien Maillard

Because it's not possible to collect actual samples of that atmosphere, a research team at the Université de Versailles Saint-Quentin-en-Yvelines in Paris, France, cooks up a facsimile in their lab. Maillard, a Ph.D. student working in planetology and mass spectrometry, studies the results in high magnetic fields, looking at the vast array of different kinds of molecules, called tholins, that can be raw materials for life.

What he is learning could shed light not just on the future of Titan, but on the past of Earth: before the chemicals in our atmosphere created tholins, and before those tholins created amino acids, and before those amino acids created the proteins that would one day assemble into simple organisms and, eventually, into your own body.

As much as he's learning from his imitation atmosphere, Maillard hopes one day to be able to compare his results to the real thing. "Maybe we will be right, maybe we will be wrong," he said.

To find out more, shimmy into your space suit and read about this science expedition, step-by-step. Customize your journey by clicking on the links for more details as needed. Enjoy your trip!

Story by Kristen Coyne

First, Produce A Plasma.

This plasma ? x What's plasma?
Plasma is a kind of ionized ? x What does ionized mean?
An atom or molecule is ionized if it has a negative or positive charge. gas. The sun, lightning and auroras are all plasma. approximates the outer atmosphere of Titan, and includes the same ingredients that scientists believe make up the gas that gives that moon its characteristic orange haze.

Credit: NASA

Fill'er Up.

At a laboratory in Paris, scientists fill up a reactor mostly with gas, then add a little bit of

Let The Sun Shine In.

The molecules in the real Titan’s haze don’t exist in a reactor: They are constantly bombarded by the energy of the sun’s UV rays. So Maillard needs to simulate this energy and get the gases in his reactor to socialize. To do this, he adds another kind of energy to his system; it’s kind of like turning up the radio at a lackluster party. In fact, Maillard actually sends through the reactor. Suddenly, molecules that had been waltzing like couples in a ballroom begin thrashing like teens in a mosh pit, sending electrons flying, ionizing each other, and morphing from a gas into a plasma bearing the same lovely, pink tint as Titan.

A Monster Mosh.

With all this molecular moshing going on, molecules that bump into each other sometimes bond together into new, larger molecules.

monster mosh image

A Mega Mosh.

As time passes, more molecules combine into bigger and bigger structures.

mega mosh image

Powder Down.

After a few days, those growing gas molecules reach a point at which gravity kicks in, and they float down into a waiting beaker in the form of a brown powder that contains the Maillard studies. The longer the process continues, the more complex the molecules become.

The Right Weigh.

Tholins come in all shapes and sizes, and Maillard’s job is to identify exactly which molecules he cooked up in his replica of Titan’s haze. So first, he puts the molecules inside a 12 - ion cyclotron resonance magnet located in Rouen, France.

The Big Reveal.

This 12-T instrument identified 15,000 different molecules in Maillard’s powder, each represented by a different in his data. But the instrument could only detect molecules up to 800

Bring In The Big Guns.

So Maillard flew to Florida, where the world’s strongest ICR magnet is housed at the National MagLab. Thanks to its 21-tesla field, it could weigh molecules up to 1,200 daltons, more than doubling the number of molecular species Maillard could see. Also, because of the instrument’s higher Maillard learned that some molecules that the 12-T magnet had identified were actually several different kinds of molecules that had been inaccurately represented by one peak. These details gave Maillard fresh insight into the chemical diversity surrounding Titan.

To Pluto — And Beyond!

In true astronaut spirit, Maillard and his colleagues are not content to stop at Titan. Venturing to the edges of our solar system, they recently approximated the atmosphere of Pluto (believed to include methane, nitrogen and carbon monoxide) and examined those chemicals in the 21-T as well. What did they learn? That’s an outta-this-world story for another time ...

Pluto image