aesmael

Questions, please. Anything I can clarify will help me to learn and help me to present. These notes are based mostly on the paper Astronomical Searches for Earth-Like Planets And Signs Of Life by Neville Woolf and J. Roger Angel. It dates back to 1998 so much may be out of date by now.

Lensing -
Off-the-cuff summary (Cuffs off! Yucky formal boy clothes!): Like all things light is affected by gravity. The presence of mass bends its path and if the situation is right a massive object can act as a lens, focusing light from an object in the background in our direction. What we are specifically interested in is when a star in the foreground passes in front of a star in the background and the lensing effect temporarily brightens the background star.And sometimes, just sometimes, if the background star has a planet we will see a secondary brightening from that too.

I am referred to the papers Peale 1997 & Paczynski 1996 for more information
Looking in the direction of the galactic centre the rate of microlensing events observed is 1 per day. It is suggested that 1 in 30 will show the presence of a giant planet
To find an Earth-like planet would require very high time resolution and telescopes dedicated to the search
Finding large numbers of giant planets would indicate there should be terrestrial planets too, as they are believed to be easier to form. The authors are careful to note, though, that 'should' =/= 'is'

I am going to leave the rest for now because I am tired and need to get up tomorrow. Est. 20 days to finish.