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Red Giants and White Dwarfs

Stars may become a red giant or a white dwarfs, depending on its size.

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A Planetary Slingshot

A Planetary Slingshot

Credit: NASA/ESA
Source: http://en.wikipedia.org/wiki/File:Artist%27s_view_of_watery_asteroid_in_white_dwarf_star_system_GD_61.jpg

We’ve only got about a billion years before the Sun makes Earth inhabitable. Can we use a passing asteroid to fling ourselves out away from our star?

Amazing But True!

• In about 1 billion years, the Sun will become hotter. Earth’s water will burn off and the land will all be desert.
• In about 6 billion years, land will melt and life will become extinct.
• In about 7.5 billion years, the Sun will become a red giant and engulf Earth.
• Isaac Newton observed that for every action there is an equal and opposite reaction.
• Using the ideas of gravity assist and Newton’s law, Earth could be catapulted away from the Sun. We are currently 146 million km from our star.
• Conditions at 225 million km from the Sun would be more pleasant. (Mars is 228 million on average, but its elliptical orbit varies from 206 to 249 million km.)
• Credit: NASA

The orbits of Earth and Mars around the Sun [Figure2]

Explore More

1. What big change will the sun experience in about 1 billion years?
2. How does a gravity assist work to boost a spacecraft toward its objective?
3. How could asteroids be used to move Earth further from the Sun?
4. Give one possible problem with this plan that is not mentioned in the video.

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