9 December, 1996

We made it up to Arrival Heights today. The interferometer that is being installed is an absorbtion interferometer that will use the sun as an energy source and measure the amount of infrared energy that is absorbed by different molecules in the atmosphere. We checked voltages of different components, measured the signal output of the laser, and worked on programming the computer. The instrument in many ways is like a large optical bench, with a series of mirrors that reflect light into detectors. We were able to work on alignment of the mirrors today. The first spectra we were able to print was one for hydrochloric acid. Each molecule will absorb infrared energy at a characteristic wavelength. That is how we can indentify the types of molecules in the atmosphere. The building at Arrival Heights contains experiments from the New Zealanders. Their base is called Scott Base and is close to McMurdo. On the drive to Scott Base we were able to spot some Weddell seals out on the ice.