THE UNIVERSE IS A REALLY BIG PLACE.

THE UNIVERSE IS A REALLY BIG PLACE.

Learning Objectives

Gain an intuitive feel for different measures of distance

Convert between various units of balance

Understand scientific notation

Create scale models of solar system and galaxy using a familiar reference scale

As we begin our study of the natural sciences, you’ll find that our universe is indeed a really big place.  The distances between planets are unimaginably large, and the distance to the nearest star system is even larger.   The activities that follow ask you to carefully create several scale models and use them to reason about the size and scale of the universe.

PART A.   CONVERTING BETWEEN UNITS

1. Name a location (city, state; county/province; country) that is about a 1-hour drive from your present location. (3 POINTS)

ANSWER:   Click or tap here to enter text.

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2. Approximately how far (in miles) is the location you listed above? (1 POINT)

ANSWER:   Click or tap here to enter text.

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THE UNIVERSE IS A REALLY BIG PLACE.

Instead of miles, astronomers use a standard of measure that is used internationally, the kilometer (km).   Therefore, it will be useful for you to begin to think of distances in these terms.

Using your calculator, you can convert between miles and kilometers using the relationship that 1.609 kilometers = 1 mile.   For example:

15.0 miles x (1.609 km / 1 mile) = 24.1 km or about 24 km

Note that we keep only three “significant” figures in the final answer.   This is because there were only three figures in the initial value 15.0 miles.

3. Calculate the number of kilometers for the distance you estimated in Question 2. Clearly show all your work as in the example calculation above. (2 POINTS, Calculation and answer)

ANSWER:  Click or tap here to enter text.

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4. Current estimates suggest that a liquid ocean may exist about 100 km beneath the icy surface of Jupiter’s moon Europa. Give an example of two locations (city, state; county/province; country) on Earth that are about 100km apart. Attach or insert an image that shows the two locations as well as a scale that confirms the 100km separation distance. You will be providing one image, showing two locations on a map. (9 POINTS including map image of the two locations, 100km apart; map scale; city, state/province, country for both locations)   Consider the actual as-the-crow flies distance, not the distance by road between two places.

ANSWER: INSERT IMAGE

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When dealing with very large numbers, you can easily enter them into your calculator using scientific notation.   Scientific notation is a kind of shorthand used by scientists.   There is a special button on most scientific calculators that does this for you.   For example, 93,000,000 is typically written in scientific notation as 93×10⁶ and can easily be entered into your calculator as 93 EXP 6 or possibly as 93 EE 6 or 93 EE X 6.  In other words, the EXP or similar calculator key does the X10 operation for you.

If you need a review of scientific notation Khan Academy (khanacademy.org) has some excellent free lessons on the subject.

5. For distances as large as the distance between planets, scientists frequently use a unit called the astronomical unit, or AU. An AU is the average distance between Earth and the Sun (about 93 million miles; 1 AU = 93,000,000 miles). Calculate how many million kilometers there are in an AU.  Show your calculations. Provide final answer in scientific notation. (4 POINTS; show calculation, answer in scientific notation)

ANSWER:  Click or tap here to enter text.

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6. Earth orbits the Sun at a distance of 1.0 AU. Saturn orbits the Sun at a distance of 9.5 AU. Provide an original sketch/drawing of the orbits of Earth and Saturn that shows the relative distances of these planets’ orbits around the Sun. For simplicity, use circular orbits, rather than elliptical orbits. (You can take a photo of a hand drawing and insert the photo into this document, or you can use drawing tools to create digital art.) (6 POINTS; show sketch/drawing, relative distances in proportion, Earth and Saturn labeled, AU scale)

ANSWER:

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PART B:  SCALE OF THE SOLAR SYSTEM

To better appreciate the unimaginable distances between objects in our solar system, it is useful to construct a scale model that depicts these distances in a more familiar context.     We will use a scale factors to convert distances between objects within the solar system to a distance that appropriately fits our scale model.   A scale factor is simply “the desired size you would like for your model” divided by the “actual size” of the thing being modeled.

scale factor = desired size / actual size

In this activity, we will construct a scale model of our solar system to fit on a 100-yard football field.  The size of our solar system is roughly equivalent to the average distance between the Sun and Pluto, about 40 AU.  The scale factor for our football field-sized scale model will be:

scale factor = (desired size of the scale model)/(actual distance between Sun & Plato) = 100yards/40 AU

scale factor = 100 yards/50 AU

scale factor = 2.0 yards per AU or 2.0 yards/AU

Then you will calculate the distance between the Sun and each of the planets using your scale factor.   For example, Mercury is 0.4 AU from the Sun.   Therefore, the distance between the Sun and Mercury on the football field would be:

Distance between Sun and Mercury = 0.4 AU x 2.0 yards / AU = 0.8 yards

1. Determine an appropriate scale factor for a scale model of the solar system that will fit on to a football field and record it below. Use the scale factor 2.0 yards / AU.   The first one has been filled in for you. (8 POINTS)

THE UNIVERSE IS A REALLY BIG PLACE.

* Pluto has been classified as a planetoid / dwarf planet.

2. Using the numbers you computed and entered in the table, place labels clearly showing where each planet should be located on the sketch of a football field above. The Sun is at the Goal line or at 0 yards. (4 POINTS, label all 8 planets and planetoid; relative distances are proportional; full field is used)

OR INSERT IMAGE OF YOUR SCALE MODEL BELOW

3. The farthest astronauts have traveled is to the Moon, which is located about 0.003 AU from the Earth and represents a 3-day journey one-way. Using the scale factor from Part B #1 and #2 above, calculate the number of yards between Earth and the Moon. (3 POINTS; show calculation, use scale factor from questions #1 and #2 above, show answer)

ANSWER:       Click or tap here to enter text.

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4. If it takes 8 years for a spacecraft to travel from Earth to Jupiter, calculate the minimum time it would take (in years) to travel from Earth to Saturn. Explain how you approached your calculation. Read this question carefully. Show any calculations. (4 POINTS, show calculations, use algebra or scale factor from above, correct answer in years unit, explanation of approach)

ANSWER:  Click or tap here to enter text.

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TOTAL POINTS = 44

THE UNIVERSE IS A REALLY BIG PLACE.