Terrestrial Planets and #1 Rating for Jupiter?

Most recent answer: 06/12/2011

Q:
Why terrestrial planets are near the Sun? Why Jupiter isn't the 1st planet for example?
- Anonymous
A:
If you want to rank the planets by mass, then Jupiter wins hands down.  It is huge.  If you want to rank the planets by closest distance to the sun, then Mercury, Venus, Earth and Mars are all closer than Jupiter.  

The word 'terrestrial' means 'Earth like' and implies habitable conditions.  Mercury is probably too hot.  The surface temperature of Venus is also pretty hot, probably 450o C or more, not friendly to living things.   Mars has been visited by the 'Mars Rover Expedition'  but simple tests for signs of organic compounds have not shown any results. Jupiter... no way.  The outer planets are just too cold.  That leaves our own Earth.  We are just lucky.

LeeH

p.s. Follow-up if you were asking something a little different.

(published on 06/12/2011)