Changes

===Our sun's fate as a red giant===

===Our sun's fate as a red giant===

It is estimated that in about 5 billion years our sun will have burned through it's hydrogen fuel needed for nuclear fusion and enter into the red giant phase itself<ref>http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993ApJ...418..457S&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf</ref>.  The sun is then estimated to expand to 200 times it's current diameter but will loss significant mass, perhaps enough so that the orbit the Earth will widen enough not to be swallowed by the expanding red giant, due to it's weakened gravity, although this is debated.  If the Earth does survive intact the red giant phase of the sun, it's atmosphere will be striped and the surface will become hot enough to be molten.

It is estimated that in about 5 billion years our sun will have burned through its hydrogen fuel needed for nuclear fusion and enter into the red giant phase itself<ref>http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993ApJ...418..457S&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf</ref>.  The sun is then estimated to expand to 200 times its current diameter but will loss significant mass, perhaps enough so that the orbit the Earth will widen enough not to be swallowed by the expanding red giant, due to its weakened gravity, although this is debated.  If the Earth does survive intact the red giant phase of the sun, its atmosphere will be striped and the surface will become hot enough to be molten.

[[Category:Astronomy]]

[[Category:Astronomy]]