Covering topics in Nature, Technology and Culture

Planet Earth


The Earth is the third planet from the Sun in the Solar System. As a planet, it took a while before it was even realised it was even a planet or it's relationship to the solar system. For the humans on it it took quite some clever thinking to realise where it was.

A realtime image from 13:30 on 22/04/2019 from himawari8 satellite

The study of Earth is also known as the Earth Sciences

Orbit basics:

  • Distance from sun: between 147,098,291 and 152,098,233 km (the average is called 1 AU (astronomical unit at 1.495978707 x1011m). The difference is about 4,999,942 km or about 3.2 % of the furthest distance. 
  • Orbital period (it's year):  365.26 Earth days
  • Moons (natural satellite):
  • 1; Luna, The Moon, tidally locked orbit.

Planet basics:

  • Type of planet: The original rocky/terrestrial
  • Length of day: 23.934 hours
  • Average radius: 6,371.00 km
  • Mass: 5.9722 x 1024 kg
  • Surface gravity: 1 g or 9.80665 m/s2
  • Escape velocity: 11.186 km/s (40,270 km/h)
  • Mean density: 5.515 g/cm3
  • Surface temperature: min of−89.2 °C average of 14 °C maximum of 57.8 °C
  • Atmosphere: Substantial enough
  • Pressure: 1 bar or 101.325 kPa (Mean Sea Level) sea also air pressure
  • Atmospheric composition: 
  • 78.08% nitrogen (N2) (dry air)
  • 20.95% oxygen (O2)
  • 0.93% argon
  • 0.038% carbon dioxide
  • About 1% water vapor (varies with climate)
  • wide range other chemical traces, such as NOx(nitrous oxides), SO (sulphur oxides), O3 ozone (safer and essential in the ozone layer, but a health hazard at lower altitudes)