Heliocodex

Learn / Outward from here

Asteroids, comets and the far edge

On the scale of light: out to about 1.6 light years. 5 lessons, in the order to read them.

  1. Start hereRubble and ice: the small bodiesAsteroids, comets and the icy bodies beyond Neptune are what was left over when the planets were made. Where each kind lives tells you what it is made of.First look · How it works
  2. CometsA comet is a small dark lump of ice and dust. Near the Sun it boils off a cloud bigger than a planet and tails millions of kilometres long.First look · How it works
  3. Falling rocks: meteors, meteorites and impactsA shooting star is a grain of dust burning up. Bigger pieces reach the ground, and once in a long while one is big enough to change the world.First look · How it works
  4. The Oort cloudFar beyond the planets, a vast round shell of icy bodies is thought to surround the Sun. Nobody has seen it. Comets are the evidence.First look · How it works
  5. Things that hit the EarthRocks from space have hit the Earth before and will again. We now watch for them, and in 2022 a spacecraft moved one on purpose.First look · How it works

Outline Still to be written here

  1. The asteroid beltWhat lies between Mars and Jupiter, and how empty it really is.
  2. Meteor showersWhy they come on the same nights each year, and how to watch one.
  3. The Kuiper beltThe icy worlds past Neptune, and the one spacecraft that has flown through it.