446 One Giant Leap for Mankind

In the 200,000-year history of Homo sapiens, our species has accomplished some pretty amazing things. We invented the wheel, the printing press, and Velcro, and determined how stars shine and the cosmos began. But arguably the coolest thing we’ve done happened July 20, 1969, when American astronaut Neil Armstrong set foot on the Moon and […]

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447 Evidence for Big Bang

Just a few minutes after the Big Bang, the universe was a hot dense soup of hydrogen nuclei (protons), helium nuclei, electrons, and electromagnetic radiation (light) in the form of photons. But the photons were essentially trapped in the burgeoning universe—they could travel only short distances before being absorbed and then re-emitted by some particle […]

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448 Size of Jupiter

Jupiter is the largest planet in the solar system. Fittingly, it was named after the king of the gods in Roman mythology. In a similar manner, the ancient Greeks named the planet after Zeus, the king of the Greek pantheon. Let’s compare the planets. The first number column is the planet’s equatorial radius in kilometers […]

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451 Nearest Brown Dwarf

The nearest brown dwarf is actually two of them in the binary system Luhman 16, which lies 6.59 light-years away in the southern constellation Vela. Astronomers have used the NASA/ESA Hubble Space Telescope to track the two components of Luhman 16AB, the third closest system to the Solar System. Luhman 16AB, also known as WISE […]

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