astro scale

• the diameter of the earth is 12,756 km
• jupiter is 10.5 earths, and the sun is 109
• the distance between the earth and sun is 10,000 earths (150,000 km)
• the nearest star (Proxima Centauri) is 4.24 light years away

  ** 40 trillion km
• majority of the milky way is empty space since everything is so far apart
• the span of the Milky Way is 100,000 light years
• light travels six trillion miles in one year
• lightyears = distance ≠ time
• light travels at 186,000 miles per second
• a nanometer (nm) is a billionth of a meter

  • 10^-9
  • ex: DNA
• a picometer (pm) is a trillionth of a meter

  • 10^-12
  • ex: atom
• a femtometer (fm) is a quadrillionth of a meter

  • 10^-15
  • ex: proton, electron
• an angstrom is a ten-billionth of a meter, and is used to measure wavelengths and molecules

  10 angstroms = 1 nanometer
• it would take 40 hours to go around the Earth at 1000km/h (620 mph)
• it would take 4300 hours to go around the sun at 1000 km/h (620 mph)
• AU = astronomical unit, the distance from the earth to the sun = 150 million km

  • at 1000 km, it would take 17 years to get to the sum
  • 150,000 hours
  • 6,250 days