ASTRON 10 Lecture Notes - Lecture 16: Space Age, Chemosynthesis, Natural Selection
Document Summary
The question about extraterrestrial life dates back to ancient times, where little to anything was known about the true nature of space. Most books about life in space take the same approach. Compares knowledge of life and knowledge of elsewhere to see if they are at all compatible. No actual data pertaining to extraterrestrial life in these books. Only since 1990s, extrasolar planets have been directly observed. They come in many sizes, orbits, and with many different types of stars. There are plenty that could possibly support life. No firm definition of life, but some basic descriptions. No other elements makes as complex chemical bonds and has such activity. Life makes and breaks chemical bonds all the time. Temperatures for optimal carbon bond breaking and forming are the same temperatures as that for liquid water. Thus looking for liquid water is an endeavour pursued by scientists. Until space age, thought to be very rare.
