Dr. Hayes

Today was a VERY BIG day for the Hayes family. Alex successfully defended his PhD thesis. He's now a Dr.!*

Dr. Hayes and Family

Alex's thesis is titled "Hydrocarbon Lakes on Titan and Their Role in the Methane Cycle". While he has worked on a variety of topics during his graduate career, the majority of his time has been spent studying Titan's hydrocarbon (thought mostly to be Methane and Ethane) lakes.

There is no way I will do his work justice, but I'll try to summarize it a bit.

To study these features, he relied on data captured by Nasa's Cassini Spacecraft. This spacecraft, launched in 1997, has been orbiting Saturn since 2004.

Cassini Assembly (link)

Due to Titan's thick, Methane rich atmosphere, in order to 'see' the surface a RADAR instrument was required. Cassini's 5-horn RADAR was able to provide fairly good (up to 300 meter resolution) pictures of Titan and lead to the very exciting discovery of lakes on the surface (the first body besides Earth found to have them!).

Lakes on Titan (link)

So, where does Alex's thesis fit into all of this? He studied and drew conclusions from three major areas of interest surrounding Titan's lakes: Lake Distribution, Lake Properties and Seasonal Variations. The quick version of his conclusions is this:

• Titan has an active hydrologic cycle - only the third body ever confirmed to have one (Earth has one now, Mars had one in the past).
• Likely several dynamic forces are at play in this system: evaporation, a saturated subsurface, 'rain', etc.
• Seasonal variation plays a huge role, especially in explaining the dichotomy in lake distribution (much more are currently in the North vs. the South polar region.
• Alex was able to derive the dielectric constant of the lakes and confirmed it to be consistent with Earth based measurements of the dielectric constant of hydrocarbons (helped solidify that the lakes are actually methane/ethane).
• Alex's bathymetry map of one South polar lake, Ontario Lacus, combined with repeat observations, yielded confirmation of change in depth over time, consistent with the changing seasons.

There is so much more that could be said of Alex's work. The best compliment, though, came from his advisor, Oded, when he noted that several of Alex's discoveries will live on in the field. He has made a real contribution to our understanding of Titan.

Congratulations, Alex. We're very proud of you!

*Not to be outdone, Noelle had her own great accomplishment today: her first tooth broke through!