In the February Astronomy
, I wrote a short piece on the Sun’s overall warming and why life on Earth may not exist within a billion years (“Snapshot,” p. 7). This has engendered a large volume of emails from readers on the subject, and I’ll be sharing many of them with you — and I still have many interesting comments from the previous month to share!
First off with the end of life on Earth is Hal Jandorf, adjunct professor at Moorpark College and president of the Ventura County Astronomical Society. Hal’s submission was so well done I want to share it with you, along with his terrific images of the Sun and Earth. Here goes:Time is running out! by Hal Jandorf
“The mass of the star and the consumption of usable hydrogen determines the lifespan of stars similar to our Sun at 10 billion years. The history of our Sun shows that it has expended half
of the usable hydrogen fuel at 5 billion years until our Sun becomes a red giant. Does that mean life on Earth has 5 billion years left?
“Five billion years. For most of us, this is a comfortable limit we can live with. Individual human life lasts approximately 80 years. We know about this, and we experience humans aging all around us. We are conditioned for this, too. But when our lifespan is lowered — that is individual life or life on Earth — our lifetime priorities must be changed.
“For a year, I have been presenting astronomy programs for elementary schools, explaining a bit of stellar evolution. The third graders are surprised that our Sun will not last indefinitely. Actually, they are very upset enough that I have to calm them that 5 billion years is a long time. Their conception of time and priorities in life
are not quite tuned at that young age.
“Your article in the February 2013 issue of Astronomy
gave me a bit of awakening. Life on Earth has a lot shorter amount of time left. Besides, our Sun is a dynamic star — it also is a changing star. My solar telescope (PST) in my backyard shows the power of our Sun; it gives us light, warmth . . . and life
. Our Sun gives us life on Earth, and in the end, it takes life away. Huge prominences of flames hover over the Sun’s surface daily.
“Tremendous bursts of energy, coronal mass ejections, travel toward Earth and affect communication. Only the Earth’s thin atmosphere shields us from the deadly high energy from the Sun that could cause our own extinction. Most of us are totally unaware of this as we carry on our lives. But the Sun will be unsuitable for life on Earth in only 800 MILLION YEARS! At that time, the small expansion of the Sun heats Earth and boils away the oceans. You thought the global warming was a crisis!
“Life on Earth traces down to 3.5 billion years ago where one-cell life forms swarmed in the warm oceans. Evolution seems to adapt from Earth’s changes and disasters. Our ancestors (Homo Sapiens
) walked on Earth for the last 2 million years. As time passes, our planet has used up 80 percent the span for life. Time is running out faster than we thought.
“Now I know [what] the third graders felt when I told them that the Sun will die. I have to change my own conception of time priorities! Our lives on Earth have become more precious and rare.
“This reminds me of an old television series 45 years ago: Run For Your Life
. The young actor Ben Gazzara was given only 18 months left due to a rare disease. He replies, ‘I'll have to squeeze a lifetime into a year or two.’ The inhabitants of Earth must squeeze a 4-billion-year lifetime into less than 800 million years. Live well and prosper.”