Wednesday, January 14, 2009

Origin of life: What can the Saturnian moon Titan tell us?

Today is the anniversary of the landing of the Huygens probe of Saturn's moon Titan, part of the most ambitious and expensive space probe ever mounted. The object has been to verify the extent to which Titan's atmosphere might resemble that of early Earth, and therefore provide clues as to the origin of life:
Among the measurements sent back to Earth were air temperature, pressure, composition and wind speed sampled at points ranging from the top of Titan's atmosphere to the ground. The temperature of the landing site itself was minus 291 degrees F. A "penetrometer" on the bottom of the probe poked into the ground. The soil, it found, has the consistency of wet sand or clay and is covered by a thin crust ... of something. Scientists are still analyzing all these data.
It turns out that there may have been water ice on Titan, but, given that the planet averages minus 178 degrees Celsius, no one supposes that life will actually be found there.

The willingness to spend so much on such an enterprise speaks to a deep desire to know our origins. It's a glorious enterprise, but there is a danger in all such enterprises - the risk of seeing things that are not really there, because we want them to be there so badly.

In the end, the scientific value of the mission will depend on whether - if Titan does not turn out to be a useful source of information, after all - researchers can simply accept that.