Citations:billion

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  • 1997 September 1 — R Naeye. Through the Eyes of Hubble: The Birth, Life and Violent Death of Stars. CRC Press. Page 15.
    The Sun is slowly fusing its hydrogen reserves into helium. At present, the Sun's core has converted roughly half of its hydrogen into helium. The Sun is almost 5 billion years old, so 5 billion years from now all of the hydrogen in the Sun's core will be gone. This will have grave consequences for the well-being of the Sun and Earth, as we shall see in Chapter 4.