Question

what happened to sun 3 days before is it really becoming a gaint
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Answer 1

Answer:

And what will happen to the planets once the sun enters the red giant ... Let's take a quick jaunt through our solar system in the last days of the sun. ... as a billion years before the sun's radiation becomes too much for life ... But, in comparison, life has already existed on this planet for well over 3 billion years.

Explanation:

The expanding sun will engulf the Earth just before it reaches the tip of the red giant phase, and the sun would still have another 0.25 AU and 500,000 years to grow. Once inside the sun's atmosphere, the Earth will collide with particles of gas.