THE sun, our star, is essential for life on Earth. Should the sun’s energy vary by even a small amount, life on Earth may vanish.
It is estimated that the sun dumps 45 tons of energy on Earth every 24 hours. We get nearly all our energy from the sun - oil and coal are merely stored sunlight. The sun’s atmosphere of very thin gas reaches past the Earth’s orbit and any change in the sun’s atmosphere might have severe consequences for life on Earth.
Like all stars, the sun has a limited lifespan depending on its mass. A middle-mass star like the sun’s lifespan is 12 billion years. The sun is 5½ billion years old and humans will have to find another home before the sun dies. At the end of its life, the sun will become a red giant, the outer parts of its atmosphere will reach the Earth and the Earth will be burnt to ashes. The energy output of the sun will weaken long before it dies and it is vital for human survival to find a new home well before the time.
Research projects in this regard are under way and should be supported. The biggest problem, however, will be acceptance that humans will have to leave Earth in order to survive.
FRIKKIE DE BRUYN
Astronomical Society of SA