assuming that all life shares common properties, what should exobiologists be looking for as they explore other worlds?exobiology is the study of...

If you do assume common properties - and that is a very
big assumption - then liquid water is one of the things to look for. Exobiologists
define a "life zone", which is the distance a planet needs to be from its sun in order
to achieve temperatures that would allow liquid water to occur. Then if a planet is in
the life zone, they would look for signs of water on the
planet.

Beyond that, some sort of an atmosphere
is considered necessary, as atmospheres work as an insulating layer to even out huge
temperature swings between day and night. The planet would also need to be old enough to
have some stable surface - if the whole thing is spouting volcanoes, that would not be
considered too conducive to life developing.

The other big
thing is looking for evidence of DNA or RNA; that would be a big
find.