
In maybe 5 billion years from now, Earth is going to be a pretty uncomfortable place to live. Even though our Sun is a poster-child for alternative energy (the Sun’s source of energy is hydrogen fusion), even “green power” won’t last forever. The Sun is about half-way through its supply now.
And when it’s gone…
The Sun will get bigger. Much, much, much, much bigger than it is now, and that’s bad, bad, bad, bad news for us. Poor Earth will be totally engulfed in the atmosphere of our bloated Sun, and will be utterly destroyed. The outer planets will probably survive, for awhile, but their orbits will be disturbed. They’ll be crashing into each other, bombarded by asteroids and comets, and a whole bunch of debris will litter the skies.
Science fiction, or science fact?
It’s happened already in many other solar systems in the Universe. Just yesterday, NASA’s Spitzer Space Telescope released the picture above showing what happened in a distant solar system much like our own.
The tiny white dot in the middle is the remnant of the star. The small red circle around it is the dust from comets crashing into each other, at a distance from the star equivalent to the distance between our own Sun and Pluto. The red cloud around this small circle is dust thrown off into space. The spooky green glow comes from gas and dust thrown far into space as the dying star threw off its outermost layers. For those of you interested, such beasties are known to astronomers as “planetary nebulae.“
This is sort of a good news, bad news story.
The good news is that, in the Helix nebula at least, some of the material in the outer solar system survived when the star died.
The bad news is that the poor surviving planets, comets and asteroids are involved in a massive, ongoing smash up, and all we are seeing is the dust leftover as they pulverize each other.
Our solar system is going to look very similar in about 5 billion years. I guess that gives us some time to figure out where we are going next…