MadSci Network: Astronomy |
Good to hear from a fellow Calgarian. Luciferin is used to search for life on other planets because when it comes in contact with a special substance called Adenosine Triphosphate (or ATP) it starts glowing. ATP is only found in living tissues and is used to distribute energy throughout the cells of all organisms. Using the assumption that living cells throughout the universe would also use ATP for energy distribution, it is a logical conclusion that the presence of alien life forms would cause a similar reaction in Luciferin. This reaction is so acute that it will occur in the presence in as few as 1 000 cells. By examining the spectra of light given off, scientists can even tell the difference between microbial ATP and mammalian ATP, thereby giving an indication of what sort of life-form released these particles. Unfortunately, as dead cells decay, the ATP also decays. This means that this process can only be used for detecting current life, not past life in the area. Detectors using this process are incredibly small (see the picture links below) and are now included in many remote planetary probes. They are mostly used for detecting the presence of ATP in soil samples as soil below the permafrost layers (a few meters on most planets) can preserve traces of ATP for long periods of time. New research in this area is looking for ways to make the Luciferin reaction last longer (often it only glows for seconds), to make it more sensitive to ATP (it can take anywhere from 30 seconds to 10 hours for the reaction to occur), and to determine the effect of cosmic radiation on the necessary chemicals to make sure that extended periods of space travel will not affect the efficacy of the process. Most of this information came from a highly technical website detailing the work of R K Obousy and A C Tziolas, M R Sims. You can check it out yourself at the following link;http://www.ugcs.caltech.edu/~andreas/Aris/Exobiology/Paper/extant.htm PICTURE LINKS - check out these pictures of two designs currently being used;
http://www.ugcs.caltech.edu/~andreas/Aris/Exobiology/Paper/image162.jpg http://www.ugcs.caltech.edu/~andreas/Aris/Exobiology/Paper/image164.gif I hope this helps.
Try the links in the MadSci Library for more information on Astronomy.