- The `Northern Lights` are the result of collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun's atmosphere.
-`Solar winds` travelling toward Earth follow the lines of `magnetic force` created by Earth’s magnetic field (which is strongest near the **NORTH** and **SOUTH**`poles`).
- Near the poles, they come in contact with particles in Earth’s atmosphere, producing a display of `light` in the night sky.
|Mercury|88 days|59 days|None|180 to 400<sup>o</sup>C|0|No|- No atmosphere to trap heat<br>- Contains craters<br>- Rarely visible in our night sky because its is so close to the sun|
|Venus|224.7 days|243 days, `(Opposite rotation)`|Carbon dioxide, nitrogen|462<sup>o</sup>C|0|No|- Brightest object in the sky after the Sun & Moon|
|Earth|365.26 days|24 hours|Nitrogen, Oxygen|-88 to 58<sup>o</sup>C|1|No|- Ozone filters some of the damaging radiation from the Sun<br>- Temperatures are constant<br>- 70% of planet's surface is water|
|Mars|687 days|24.65 hours|Carbon dioxide, Nitrogen|-90 to -5<sup>o</sup>C|2|No|- Called the `red planet` due to its rusty soil<br>- Very dry<br>- Once had volcanoes, glaciers, & water|
### The Outer Planets
- Jupiter, Saturn, Uranus, Neptune
-`Large`, composed of `gas`.
- Atopsheres consist mainlyof the gases `hydrogen` and `helium`.
|Planet|Orbital Period|Rotation|Atmosphere|Temperature|Number of Moons|Rings?|Unique Characteristics|
|Jupiter|11.9 years|9.85 hours|Hydrogen, Helium, methane|-148<sup>o</sup>C|63|Yes|- Largest planet (11x the diameter of the Earth)<br>- Features are its coloured bands, the Great Red Spot & hurricanes<br>- Orbiting rings of rocks|
|Saturn|29.5 years|10.65 hours|Hydrogen, Helium, Methane|-178<sup>o</sup>C|60|Yes|- Second largest, no solid core<br>- Cloudy & windy, over 1000 separate rings|
|Uranus|84.1 years|17.3 hours `(on its side)`|Hydrogen, Helium, Methane|-216<sup>o</sup>C|27|Yes|- Winds blow up to 500km/h|
|Neptune|164.8 years|15.7 hours|Hydrogen, Helium, Methane|-214<sup>o</sup>C|13|Yes|- Uneven orbit, Bright blue & white clouds<br>- Has a dark region called the Great Dark Spot, which appears to be the center of a storm|
### Asteroids
- They are composed of rock & metal.
- Although they orbit the Sun, they are too small to be considered planets.
- Most asteroids lie in the asteroid belt, located between Mars & Jupiter.
- A **`meteroid`** is a piece of metal or rock that is `smaller` than an asteroid.
- Sometimes a meteroid get pulled in by `Earth's gravity`. They `burn` up in the Earth's `atmosphere`, creating a bright streak of `light` across the sky, know as **`meteor`** (shooting star).
- Larger meteors do not burn up completely in the atmosphere and their `remains`, which we call **`meteorites`**, crash to the ground.
