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Measuring Outer Space

Measuring Outer Space

Introduction: (Initial Observation)

Since the beginning of civilization people have wondered about the stars. They have attempted to explain the seasons, the movements of the Sun, Moon and planets by incorporating them into their cultures.

the science of astronomy uses scientific techniques to probe our Universe, showing it to be even stranger and bigger than we ever realized. We have discovered a Universe containing unusual places and objects like red giant stars, hot white dwarf stars, multiple star systems, colliding galaxies and black holes.

Astronomers have identified many stars, planets and their moons. The size and distances of many plantlets and stars are measured and recorded. For example we know that the diameter of the moon is 3476 kilometers and its distance from the earth is about 385,000 km. But how can someone measure the diameter of the moon and it’s distance from the earth without ever leaving the earth? How can we remotely measure outer space sizes and distances?

Click Here for a different Moon Size project.

Click Here for Making a Telescope Experiment

Click Here for Making a Star Clock Experiment

Interview about brightness of stars

This project guide contains information that you need in order to start your project. If you have any questions or need more support about this project, click on the “Ask Question” button on the top of this page to send me a message.

If you are new in doing science project, click on “How to Start” in the main page. There you will find helpful links that describe different types of science projects, scientific method, variables, hypothesis, graph, abstract and all other general basics that you need to know.

Project advisor

Adults help and supervision is required for this project.

Information Gathering:

Find out about stars, planets and moons. How far they are from the earth? Read books, magazines or ask professionals who might know in order to learn about the effect or area of study. Keep track of where you got your information from. Following are samples of Information that you can find online and in the astronomy books.

Looking at the sky, stars look like a lot of bright dots, different for intensity, color and dimensions, that are printed on one area to draw the most varied forms. Since the old times, we could always group the nearest and the brightest ones to form some figures, called Constellations. In the reality they occupy these different parts of the sky because there is a perspective effect; in fact they are thousand of light years far…

constellation: An arbitrary formation of stars perceived as a figure or design, especially one of 88 recognized groups named after characters from classical mythology and various common animals and objects.

Betelgeuse is the 7th brightest star in the northern hemisphere. It’s also called Alpha Orionis and it is a variable star.

“Alpha Orionis”

Betelgeuse is one of the names of Alpha Orionis; it’s situated in the constellation of Orion and it’s the brightest star in the northern hemisphere…This name maybe comes from an Arabic expression: “vad al-giawza” that means “the shoulder of the giant”. The “original” meaning of this word designates a black sheep with a white spot in the center of its body; it could also have the same meaning of the Arabic word, “jauz”, which means “the center of anything” or “the central one”. A lot of changes in Arabic languages and the change of a d to a t evolved the current name, “Betelgeuse”. It’s a red super giant, 520 light years far from the Earth; it has a diameter 400 times more than the Sun’s and its diameter can vary by about 60% during the whole cycle, very different from the radius of the Earth’s orbit…! It has also a brilliance 10.000 times higher! Its own annual cycle is of 0”,32, whereas its radial component of the actual speed is of 21Km/s on removal. It’s so bright that it sometimes could became a competitor of Rigel…

Brightest Northern-Hemisphere Stars

Star Constellation Type Distance** Magnitude
Sirius* Canis Major blue-white main sequence 8.7 -1.5
Arcturus Boötes yellow giant 36 -0.1
Vega Lyra blue-white main sequence 26 0.0
Capella* Auriga white giant 46 0.1
Rigel Orion blue-white supergiant 800 0.1
Procyon Canis Minor white subgiant main sequence 11.2 0.4
Betelgeuse Orion yellow-orange supergiant 650 0.8
Altair Aquila blue-white main sequence 16 0.8
Aldebaran Taurus yellow giant 70 0.9
Spica* Virgo blue-white giant 250 1.0
Antares Scorpius yellow-orange supergiant 400 1.0
Pollux Gemini yellow giant 35 1.2
Fomalhaut Pisces Austrinus blue-white main sequence 23 1.1
Deneb Cygnus blue-white supergiant 1,600 1.3
* binary- or multiple-star system
** light-years

Question/ Purpose:

What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.

The purpose of this project is to demonstrate how we can measure the size and the distance of remote objects from where we are. This is a display project.

Identify Variables:

When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.

For a display project, you don’t need to identify variables.


Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.

For a display project, you don’t need to come up with a hypothesis.

Experiment Design:

Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”


In this experiment you will try to measure the size and the distance of an object that is far from you. This object can be a tall building, a tree or a flag pole. You will need an assistant to help you in doing your experiment.


While standing face to the building, ask your assistant to move a tall wooden stick toward the building and hold it somewhere between you and the building in a way that the top of the wooden stick be aligned with the top of the building from your position. (Top of the wooden stick is marked with letter C in the following diagram)

Now sit down or lay on the ground and look at the top of the building again. This time the top of the building must be crossing the wooden stick at some point. Ask your assistant to mark that point. (If your wooden stick is graduated, you can simply memorize the position and make a note of that.) This point is marked with letter D in the following diagram.

A is the position of your eyes while you are standing.

B is the position of your eyes while you are sitting or laying on the ground.

You will need to measure and record tree values in order to calculate the height of the building. These three values are:

  1. The distance from A to B. We call it your height change.
  2. The distance from C to D. We call it stick height change.
  3.  The distance from D to E. We call it stick height remainder.
  4. Your distance from the tall stick.


To calculate your distance from the building, subtract stick height change from your height change and call it a segment. Divide your height change by the segment and call it the multiplier. Finally multiply the multiplier by your distance from the tall stick.

Distance = AB : (AB-CD) * BE

To calculate the height of the building, subtract stick height change from your height change and call it a segment. Divide your height change by the segment and call it the multiplier. Finally multiply the multiplier by the stick height remainder.

Height = AB : (AB-CD) * DE

* Note: Your results will have a higher accuracy if the points B and E are at the same level.

(AB-CD) is called a segment

AB : (AB-CD) is called the multiplier

Note that “:” is a division sign. You can use “/” instead.

Experiment 2:
(What is the brightest Star in the northern hemisphere?)

The brightness of stars has always been a subject that astronomers paid a close attention to that. Bright stars are easily detectable, identifiable and can be used as a landmark on the wide sky. You may visually find the brightest star in the sky. You will then need to identify it. You will need to know its name. You will also need to know the name of it’s constellation.

Many believe the the brightest star is Sirius A in the constellation of Canis Major (Great Dog). What do you think?

The picture on the right shows the stars in the northern hemisphere; however, you can not use it to determine the brightest star.
After you find the brightest star, make a drawing to show the star and it’s relation with other stars in the same constellation.

The picture on the right shows the stars in the northern hemisphere; however, you can not use it to determine the brightest star.
After you find the brightest star, make a drawing to show the star and it’s relation with other stars in the same constellation.

Canis Major, the Great Dog, is visible in the northern hemisphere from December through March. It can be seen in the southern hemisphere between November and April. This constellation represents the largest of Orion’s two hunting dogs who accompany him as he hunts Lepus, the rabbit. This constellation is the home of Sirius, the brightest star in the night sky. Also known as the dog star, this magnitude -1.46 star dominates the winter skies. Sirius can be easily located by drawing a straight line through the three belt stars in the constellation Orion. The name Sirius means “scorching”, which more than likely refers to the star’s unmatched brilliance in the night sky. Canis Major contains one Messier object, M41. This is an open star cluster containing about 100 stars.

Can you find Sirius in the following image?

Notes: For your display you may draw the Canis Major constellation. You will not need a chart, however it is good to include a table to show the brightest stars in the northern hemisphere. (See this table in the gathering information section).

You may also use this table to draw a bar chart to show one bar for each star. The length of the bar may vary based on it’s brightness. Longest bar will be for Sirius.

Materials and Equipment:

List of material can be extracted from the experiment section.

Results of Experiment (Observation):

Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.


Included in the experiment section.

Summery of Results:

Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.

It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.


Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.

Related Questions & Answers:

What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.

Many of our observations on the earth can be used to determine the location, size and distances of stars, planets and moons. Think about these additional questions.

  1. Can you use the size of your shadow to determine the season?
  2. Can you use the size of the shadow of a building to determine the height of the building?
  3. Can you use the speed of sunrise or sunset to determine the height of buildings and mountains?
  4. Can you measure the diameter of the earth by the speed of sunset?

Possible Errors:

If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.

If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.

Project Advisor Notes:

If you want to observe stars, I recommend that you carry a small flashlight with you during your observations to help you write in the dark. Your eyes take time to adapt to the dark. You may notice that when you first walk outside at night that you can see relatively few stars. The longer you stay in the dark, the more stars you can see (up to a limit, of course). If you use old batteries in your flashlight so it is dim or color the light red, you will be able to make better observations

You may observe the stars in order to:

  1. Learn how to find objects in the night sky by using the star wheel, celestial maps and “star-hopping”.
  2.  Identify key constellations and stars.
  3. Become familiar with the operation of your telescope.

Items to be addressed in your notebook during your observation:

  1.  Constellations: Identify at least five constellations in the sky. Make a sketch of each constellation in your notebook. Try to rank the order of the five brightest stars in each constellation.
  2.  Stars: Identify at least five stars, two of which must be Polaris (the North Star, which is not the brightest star in the sky) and Sirius (which is the brightest star, with the exception of the sun). Also try to estimate the azimuth and elevation of each star.
  3. Planets: Find Jupiter. In what constellation is it in?
  4.  Telescopes and stars: Do stars appear to have color when viewed with only the eye?

Do they appear to have color when viewed through a telescope?

Find Big Dipper: The best known of all sky groups surely must be the Big Dipper. Its prominent seven-star outline is familiar to nearly everyone who has ever gazed skyward.

Facing north during these early spring evenings, the Big Dipper is found almost directly overhead. By extending a line from the two pointer stars in the end of the Dipper’s bowl, we can pinpoint Polaris, the North Star. Polaris is the end star in the handle of the Little Dippers.

In addition to finding the Little Dipper and the North Star, the Big Dipper serves as a terrific guidepost to other seasonal sky sights.

A most useful guide is the Big Dipper’s three-star handle. This arc begins a curving line that pinpoints the sky’s fourth brightest star. Know as Arcturus, it has a sparkling orange color.