Getting Started

Professional astronomers come in two varieties: observational and theoretical.

Professional observational astronomers mostly use expensive scientific instruments to look through their massive telescopes for them. They spend a lot of time measuring things, taking data, and crunching the numbers. They are very good at designing and performing experiments that answer the big questions to which no one knows the answers.

Professional theoretical astronomers think up new ideas and new models for fitting the data so that it makes sense in the field of physics. They are great at asking the big questions in the first place. Albert Einstein was a theoretical astronomer, as he hated to do experiments of any kind. Instead, he preferred to sit back and think about what might happen in the laboratory of his mind.

Here are the scientific concepts:

  • The number of stars that can be seen through telescopes is dramatically greater than can be seen by the unaided eye.
  • The structure and composition of the universe can be learned from the study of stars and galaxies.
  • How to use astronomical units and light years as measures of distance between the sun, stars, and Earth.
  • Stars are the source of light for all bright objects in outer space. The moon and planets shine by reflected sunlight, not by their own light.
  • The appearance, general composition, relative position and size, and motion of objects in the solar system, including planets, planetary satellites, comets, and asteroids.
  • Current detection methods of extrasolar planets.
  • Galaxies are clusters of billions of stars, and may have different shapes. The Sun is one of many stars in our own Milky Way galaxy. Stars may differ in size, temperature, and color.
  • Black holes are objects where the escape velocity is greater than the speed of light. They are the leftovers of a BIG star explosion. There is nothing to keep it from collapsing, so it continues to collapse forever. It becomes so small and dense that the gravitational pull is so great that light itself can’t escape.
  • Gravitational lensing occurs when black holes and other massive objects bend light.
  • Mass causes spacetime to curve. The amount of curvature depends on how massive the object is and your distance from the massive object.
  • Patterns of the apparent motion of the sun, the moon, and stars in the sky can be observed, described, predicted, and explained with models.
  • Earth and its solar system are part of the Milky Way galaxy, which is one of many galaxies in the universe.
  • The solar system consists of the sun and a collection of objects, including planets, their moons, and asteroids that are held in orbit around the sun by its gravitational pull on them.
  • A model of the solar system can explain eclipses of the sun and the moon. Earth’s spin axis is fixed in direction over the short term but tilted relative to its orbit around the sun.
  • The seasons are a result of that tilt and are caused by the differential intensity of sunlight on different areas of Earth across the year.

By the end of the labs in this unit, students will be able to:

  • Design an experiment that shown the Earth-sun-moon system and it's cyclic patterns of eclipses, lunar phases, and seasons.
  • Illustrate how gravity works in the motions within galaxies and the solar system.
  • Analyze and interpret data to determine properties of objects in the solar system.
  • Design and build a telescope using optical equipment such as mirrors and lenses.
  • Know the celestial objects in the solar system and how they relate and interact with each other.
  • Understand how to determine the structure and composition of celestial objects.
  • Differentiate observation from inference (interpretation) and know scientists’ explanations come partly from what they observe and partly from how they interpret their observations.
  • Measure and estimate the length and volume of objects.
  • Formulate and justify predictions based on cause-and-effect relationships.
  • Conduct multiple trials to test a prediction and draw conclusions about the relationships between predictions and results.
  • Construct and interpret graphs from measurements.
  • Follow a set of written instructions for a scientific investigation.

Select a Lesson

Special Science Teleclass: Solar Astronomy
This is a recording of a recent live class I did with an entire high school astronomy class. I’ve included it here so you can participate and learn, too! Light is energy that can travel through space. How much energy light has determines what kind of wave it is. It can be visible light, x-ray, radio, …
Special Science Teleclass: Astronomy
This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too Our solar system includes rocky terrestrial planets (Mercury, Venus, Earth, and Mars), gas giants (Jupiter and Saturn), ice giants (Uranus and Neptune), and assorted …
Special Science Teleclass: Black Holes
This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! We’re ready to deal with the topic you’ve all been waiting for! Join me as we find out what happens to stars that wander …
Kepler’s Swinging System
Kepler’s Laws of planetary orbits explain why the planets move at the speeds they do. You’ll be making a scale model of the solar system and tracking orbital speeds. Kepler’s 1st Law states that planetary orbits about the Sun are not circles, but rather ellipses. The Sun lies at one of the foci of the …
Retrograde Motion
If you watch the moon, you'd notice that it rises in the east and sets in the west. This direction is called 'prograde motion'. The stars, sun, and moon all follow the same prograde motion, meaning that they all move across the sky in the same direction.
Meteorites
A meteoroid is a small rock that zooms around outer space. When the meteoroid zips into the Earth’s atmosphere, it’s now called a meteor or “shooting star”. If the rock doesn’t vaporize en route, it’s called a meteorite as soon as it whacks into the ground.
What’s Up in the Sky?
Today you get to learn how to read an astronomical chart to find out when the Sun sets, when twilight ends, which planets are visible, when the next full moon occurs, and much more. This is an excellent way to impress your friends. The patterns of stars and planets stay the same, although they appear …
Jupiter’s Jolts
Jupiter not only has the biggest lightning bolts we’ve ever detected, it also shocks its moons with a charge of 3 million amps every time they pass through certain hotspots. Some of these bolts are cause by the friction of fast-moving clouds. Today you get to make your own sparks and simulate Jupiter’s turbulent storms. …
Moons of Jupiter
On a clear night when Jupiter is up, you’ll be able to view the four moons of Jupiter (Europa, Ganymede, Io, and Callisto) and the largest moon of Saturn (Titan) with only a pair of binoculars. The question is: Which moon is which? This lab will let you in on the secret to figuring it …
Eclipses and Transits
It just so happens that the Sun’s diameter is about 400 times larger than the Moon, but the Moon is 400 times closer than the Sun. This makes the Sun and Moon appear to be about the same size in the sky as viewed from Earth. This is also why the eclipse thing is such …
Phases of the Moon
The Moon appears to change in the sky. One moment it’s a big white circle, and next week it’s shaped like a sideways bike helmet. There’s even a day where it disappears altogether. So what gives? The Sun illuminates half of the Moon all the time. Imagine shining a flashlight on a beach ball. The …
Solar Rotation
You are going to start observing the Sun and tracking sunspots across the Sun using one of two different kinds of viewers so you can figure out how fast the Sun rotates. Sunspots are dark, cool areas with highly active magnetic fields on the Sun’s surface that last from hours to months. They are dark …
Cosmic Ray Detector
When high energy radiation strikes the Earth from space, it’s called cosmic rays. To be accurate, a cosmic ray is not like a ray of sunshine, but rather is a super-fast particle slinging through space. Think of throwing a grain of sand at a 100 mph… and that’s what we call a ‘cosmic ray’.
Diffraction
Ever play with a prism? When sunlight strikes the prism, it gets split into a rainbow of colors. Prisms un-mix the light into its different wavelengths (which you see as different colors). Diffraction gratings are tiny prisms stacked together. When light passes through a diffraction grating, it splits (diffracts) the light into several beams traveling …
Fire & Optics
Today you get to concentrate light, specifically the heat, from the Sun into a very small area. Normally, the sunlight would have filled up the entire area of the lens, but you’re shrinking this down to the size of the dot. Magnifying lenses, telescopes, and microscopes use this idea to make objects appear different sizes …
Light, Lasers, and Optics
When I was in grad school, I needed to use an optical bench to see invisible things. I was trying to ‘see’ the exhaust from a  new kind of F15 engine, because the aircraft acting the way it shouldn’t – when the pilot turned the controls 20o left, the plane only went 10o. My team …
Advanced Telescope Building
So you’ve played with lenses, mirrors, and built an optical bench. Want to make a real telescope? In this experiment, you’ll build a Newtonian and a refractor telescope using your optical bench. Materials: optical bench index card or white wall two double-convex lenses concave mirror popsicle stick mirror paper clip flash light black garbage bag …
Black Hole Bucket
What comes to mind when you think about empty space? (You should be thinking: “Nothing!”) One of Einstein’s greatest ideas was that empty space is not actually nothing – it has energy and can be influenced by objects in it. It’s like the T-shirt you’re wearing. You can stretch and twist the fabric around, just …