Factoid for Today # 2

[Gregory Matthews]

The Sun that lights our solar system is simply a medium star.  It is neither small nor is it large.  It emits light at a temperature of about 15,000,000 degrees Kelvin.  In emitting that light it consumes some 700 million tons of protons each second.

On that basis, our Sun may be expected to have a life-span of some 10 billion years from birth to death.  It is believed to be about 4.6 billion years old today.

 

NOTE:  My information comes from the work of Alex Filippenko. 

[Planey]

Goldilocks star?

[Gregory Matthews]

Ah, the Goldilocks Zone:  What is that?

As we know life on Earth today, life is based on the element carbon and requires liquid water to exist.  If there are  other types of life that exist, perhaps on other planets, we do not have evidence of those.   NOTE: What we have  learned about living organisms in the deep oceans does not counter what I have said.

Based upon this, scientists believe that for each star there is an identifiable distance from that star in which life as we know it can exist.  Outside of the boundaries of that zone,  liquid water and carbon-based life can not exist.  The exact boundaries of that zone, by distance from the star, will depend upon the type of a star.  This zone is called the  Goldilocks Zone.

For the Sun that exists in our solar system, there are only three (3) planets that exist.  These are: Venus, Earth and Mars.  It must be noted that saying that a planet is in the Goldilocks Zone does not mean that we believe that life actually exists on that planet.

The atmosphere on Venus is such that a runaway greenhouse effect is believed to exist.  As a result, it is believed that the surface temperature of Venus is some 460 degrees Celsius.  Of course, at this temperature, liquid water could not exist, so life as we know it   could not exist on Venus.

The planet Mars is believed to exist as a freeze-dried desert, with a carbon-dioxide atmosphere and an atmospheric pressure that is 1/99th that of the Earth.  Again, liquid water could not exist on such a planet  so Mars   is not believed to have life as we know it.