Research
I am a co-investigator on the Composite
Infrared Spectrometer (CIRS)
instrument team. CIRS is one of twelve
scientific instruments located on the Cassini spacecraft.
Cassini is the orbiter part of the Cassini-Huygens
mission to the Saturn system. Huygens is the lander, which touched down
on the surface of Satun's largest moon Titan, on January 14th 2005.
This picture shows the location of CIRS on Cassini.
(click
for larger image)
The CIRS instrument is an infrared spectrometer: meaning that it
disperses infrared
light, or heat, into different wavelengths, or colors. This is the same
principle as a glass prism splitting visible light into the colors of
the rainbow (red, green, blue, ...) except that CIRS does this for
invisible heat rays.
Why are we interested in
invisible heat rays?
Planets
all radiate heat to varying degrees. By analysing the amount of heat
emitted at different wavelengths (the infrared spectrum),
scientists can tell a lot about where and how and by what the heat was
emitted. In particular, CIRS is used to tell the gaseous composition of
planetary atmospheres, how hot the gases are, and even what ices are on
the surfaces of moons or making up the rings of Saturn.
This figure is an example infrared spectrum of Saturn's giant moon
Titan taken by CIRS. The sharp peaks in the spectrum are the signature
of particular gas species. We can see that Titan's spectrum is
different to the Earth's, with many trace hydrocarbons present.

Titan is the only moon in the entire solar system to have a substantial
atmosphere. Titan's atmosphere is mostly nitrogen gas, like the Earth's
atmosphere, but has substantial differences too. Temperatures are much
colder on Titan, and there is no oxygen to breath.
You can download my Titan factsheet here
(90 kb PDF).
Research
Areas
My research is focused on the composition of planetary atmospheres,
including:
- The variation of
hydrocarbons in Jupiter's stratosphere.
- Isotopic composition of
Jupiter, Saturn and Titan.
- Tropospheric and
stratospheric composition of Titan, including
abundance of hydrocarbons, nitriles and oxygen species.
- Origin and evolution of
Titan's atmosphere.
You can browse list of my publications
and conference
presentations.
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