1. Temperature And Astronomical Measures

2. Temperature Temperature is a measure of the average kinetic energy of a molecule of a substance, or… How “hot” it is. On Temperature Scales a higher number of degrees indicates that a substance’s molecules are moving faster The lowest possible temperature is when the molecules don’t move at all. This is called Absolute Zero.

3. Temperature Scales There are 4 Temperature Scales: Fahrenheit: Water freezes at 32°F Boils at 212°F Absolute Zero is about -460°F Celsius(Centigrade): Water Freezes at 0°C Boils at 100 °C Absolute Zero is about -273 °C A Celsius Degree is nearly twice a Fahrenheit degree. Rankine: uses Fahrenheit degree, Absolute Zero = 0 °R (almost no-one uses it) Kelvin : uses Celsius Degree, Absolute Zero = 0 °K This is commonly used by astronomers

5. Common Measures PropertyUS (Imperial) SI (Metric) MassSlug Kilogram (kg) ForcePound (lb) Newton (N) DistanceFeet (ft) Meters (m) SpeedFeet/second (ft/s) Meters/second (m/s) Acceleration Ft/second²(ft/s²) Meters/second² (m/s²) We will also use a special metric prefix… “nano” 1 nanometer =.000000001 m

6. Special Measures Astronomy also uses three special measures for distance: Astronomical Unit (AU) 150 million km (From Sun to Earth) Light Year (LY)9.46 x 10¹³ m (How far light goes in a year) Parsec3.26 LY (Distance at which parallax is one second of an arc)