Size of the Solar System Lab - Astronomy 101
The Size of the Solar System
Overview
• Become familiar with the scale of the planets vs. their distances. • Get an overview of the solar system.
Introduction
It is easy to flip to the index of an astronomy textbook to discover that, say, the Sun lies 150 million kilometers away from Earth. It is far more difficult (if not impossible), however, to picture this distance in the human mind. In this exercise, we will learn to access the often unpalatable distances encountered in astronomy by simply scaling the huge distances to more recognizable, pedestrian numbers. So long as every distance within the system of interest is scaled by the same factor, we retain the meaningful information about relative distances between objects. This is exactly the same principle employed by map makers so that they can fit Texas, for example, onto a turnable page.
[pic]
Constructing the Model
Table 1 gives current measurements for the actual sizes and orbital distances of the planets. For moons, the semi-major axis is the distance to the planet.
Table 1: Measured Astronomical Distances in Solar System (*KBO radii are not well known)
|Object |Radius (km) |semi-major axis (km) |
|Sun |6.96 x 105 |-- |
|Mercury |2.44 x 103 |5.83 x 107 |
|Venus |6.05 x 103 |1.08 x 108 |
|Earth |6.38 x 103 |1.50 x 108 |
|Moon |1.74 x 103 |3.84 x 105 |
|Mars |3.40 x 103 |2.27 x 108 |
|Jupiter |7.14 x 104 |7.78 x 108 |
|Io |1.82 x 103 |4.22 x 105 |
|Ganymede |2.63 x 103 |1.07 x 106 |
|Saturn |6.03 x 104 |1.43 x 109 |
|Titan |2.58 x 103
Overview
• Become familiar with the scale of the planets vs. their distances. • Get an overview of the solar system.
Introduction
It is easy to flip to the index of an astronomy textbook to discover that, say, the Sun lies 150 million kilometers away from Earth. It is far more difficult (if not impossible), however, to picture this distance in the human mind. In this exercise, we will learn to access the often unpalatable distances encountered in astronomy by simply scaling the huge distances to more recognizable, pedestrian numbers. So long as every distance within the system of interest is scaled by the same factor, we retain the meaningful information about relative distances between objects. This is exactly the same principle employed by map makers so that they can fit Texas, for example, onto a turnable page.
[pic]
Constructing the Model
Table 1 gives current measurements for the actual sizes and orbital distances of the planets. For moons, the semi-major axis is the distance to the planet.
Table 1: Measured Astronomical Distances in Solar System (*KBO radii are not well known)
|Object |Radius (km) |semi-major axis (km) |
|Sun |6.96 x 105 |-- |
|Mercury |2.44 x 103 |5.83 x 107 |
|Venus |6.05 x 103 |1.08 x 108 |
|Earth |6.38 x 103 |1.50 x 108 |
|Moon |1.74 x 103 |3.84 x 105 |
|Mars |3.40 x 103 |2.27 x 108 |
|Jupiter |7.14 x 104 |7.78 x 108 |
|Io |1.82 x 103 |4.22 x 105 |
|Ganymede |2.63 x 103 |1.07 x 106 |
|Saturn |6.03 x 104 |1.43 x 109 |
|Titan |2.58 x 103