ASTR 1100 Lab 1: Universe Scale
The distances we use to describe astronomical objects are so large that it can be difficult to fathom them. We are familiar with inches and feet and miles, and can picture these distances in our mind. The distance between the Earth and Sun is about 93 million miles; much larger than any distance we experience. To make these large distances accessible, we can use scale models to shift all the numbers downwards. In class, we have discussed the Voyage Model (1:10,000,000,000) to scale down the distances in our solar system.
In this lab activity, you will explore the Voyage and other models in your real-world environment to represent astronomical distances. You are asked to calculate scaled distances from real astronomical distances, and find these scaled distances in your surroundings and take a picture. The distance does not have to match exactly, but should be reasonably close. Each picture should have the following information next to it:
• Name of Model: list the scale model you’re using in the photo.
• Name of Distance in Photo: explain what actual distance is being represented in the photo.
• Actual Distance: look up this information online or in the textbook.
• Scaled Distance: divide the actual distance by the model’s scale, like 10 billion for the Voyage Model. If the number is small or large, convert it to other units like inches or feet.
• Representation in Photo: explain the objects in the photo used to represent the distance.
Within each section below (A-C), a maximum of one picture may be an image you find online. If any section contains more than one online image, you will be asked to redo the activity.
Below is an example entry for the sun’s diameter and Earth-Mars separation distance:
Voyage Model
Distance 1: Diameter of Sun
Actual Distance: 865,000 miles
Scaled Distance: (865,000 miles)/(10 billion) =
0.00009 miles = 5 inches
Representation in Photo: fence pole
Distance 2: Closest Distance between Earth and Mars Actual Distance: 38.6 million miles
Scaled Distance: (38.6 million miles)/(10 billion) =
0.004 miles = 21 feet
Representation in Photo: two fence segments
Helpful Resources:
• Solar System Models: https://en.wikipedia.org/wiki/Solar_System_model
• Solar System Reference Table: https://www.jpl.nasa.gov/edu/pdfs/scaless_reference.pdf
• Distance Conversion: https://www.formulaconversion.com/formulaconversioncalculator.
php?convert=astronomicalunit_to_kilometers
Lab Writeup Instructions: Lab assignments such as this one will typically include an introduction, helpful resource links, and one or several activity sections. Throughout the sections, there will be numbered tasks. Your writeup must include responses to all the numbered tasks.
Section A: Voyage Model
The Voyage model was developed in
2001 as an outdoor structure on the National Mall in Washington, DC. The relative positions of the Sun and the planets in our solar system (including Pluto, classified now as a dwarf planet) are marked by metal posts.
The Voyage model uses a 1:10,000,000,000 (1:10 billion) scale, meaning that all distances are scaled down by a factor of 10 billion. For example, the average Earth-Sun distance becomes about 15 m under the Voyage model.
1. Take a picture that includes the diameter of the Earth, and the Earth-Sun distance under the Voyage model. (Use the guidelines in the introduction and example for this and every picture prompt.)
2. Take a picture that includes the diameters for both the Sun and Earth under the Voyage model.
3. Take a picture that includes the diameter of the Sun, and the distance between Neptune and the Sun under the Voyage model.
4. If you were asked to take a picture that that includes the distance between Earth and the next closest star aside from the Sun (Alpha Centauri) under the Voyage model, explain how you could or could not do this. No picture is needed here, just the explanation.
Section B: Ping Pong Model
The Ping Pong model uses a 1:310,000,000 scale, so all distances are scaled down by a factor of 310 million. This makes scaled distances about three times larger than they are in the Voyage model. Smaller values like the diameter of planets are easier to visualize under the Ping Pong model. For example, the size of the Earth is comparable to a ping pong ball under this model.
5. Take a picture that includes the diameter of the Earth, and the Earth-Sun distance under the Ping Pong model.
6. Take a picture that includes the diameters for both the Sun and Earth under the Ping Pong model.
7. Take a picture that includes the diameters of the Sun and Earth’s moon under the Ping Pong model.
8. If you were asked to take a picture that includes the distance between Anoka and Minneapolis under the Ping Pong model, explain how you could or could not do this. No picture is needed here, just the explanation.
Section C: Your Choice Model
In this section, you can select any model from the Solar System Model Wikipedia page, or design your own model using a custom scale. Be sure to choose a model that will let you take pictures for the following distances:
9. Take a picture that includes the diameter of the Earth, and the Earth-Sun distance under your chosen model.
10. Take a picture that includes the diameters for both the Sun and Earth under your chosen model.
11. Take a picture that includes the diameter of the Earth, and the distance between Earth and the asteroid belt under your chosen model.
Conclusions
12. Write a paragraph (at least five sentences) discussing why these Solar System scale models are useful. You should mention the importance of choosing an appropriate scale number, and how different distances may require different models.
