There are a lot of goals that many scientist have during this mission, including numerous aspects of atmospheric chemistry and dynamics. The thing I am interested in for the mission are particles or aerosols.
What is an aerosol/particle?
Particles, or aerosols, are a very important aspect of the atmosphere; however, to understand their importance and impact on the atmosphere, you have to understand what an aerosol or particle is.
There are three states of matter: gas, solid, and liquid. These three states of matter are also found in the atmosphere, and the tailpipe of a diesel truck is a perfect place to look for all three.
If you ever have had a smog test, you will see on your report that amount of hydrocarbons, carbon monoxide (CO) and nitrogen dioxides (NOx) your car is emitting. These are all examples of gas phase emissions, and these are the emissions that we are trying to studying and the impact of these emissions on chemistry. If you have ever been behind a diesel truck and you witness a large plume of black smoke coming for its tailpipe, that is an example of the solid and liquid phase material found in the atmosphere. These two phases are lumped together and called aerosols.
Other places you may have observed aerosols include on the beach, watching waves break and water droplets flying into the air or having sand blow into your face, around a camp fire with the smoke, or around factories.
Why study aerosols?
The aerosols I described above are what we call primary aerosols. This just describes aerosols that come directly from the source without any chemistry.
Another source of aerosols originates from the chemistry of the gas phase emissions. This chemistry produces molecules that become very sticky, which can form aerosol. This source of aerosol is called secondary aerosol since it is produced through chemistry.
Both sources of aerosol present an opportunity in improving our understanding of emissions and chemistry of the atmosphere.
Aerosol impact numerous aspects of the environment and everyday life. The most direct way aerosols impact you include creating the haze and causing it harder to observe features some distance away.
Other impacts of aerosols include degradation of air quality and thus human health, cloud and rain formation, and the amount of sunlight that makes it to the surface of the planet. The source and chemistry that produces the aerosols has very different implications on these impacts that we scientists must understand.
With the direct impact on everything from aerosols and the large uncertainty in aerosol production, studying aerosols are both important and a great scientific question.