Earth, Moon, and Sun

• 2D Eclipse

Manipulate the position of the Moon to model solar and lunar eclipses. View Earth's shadow, the Moon's shadow, or both. Observe the Moon and Sun from Earth during a partial and total eclipse. The sizes of the three bodies and the Earth-Moon distance can be adjusted.

• 3D Eclipse

Observe the motions of the Earth, Moon and Sun in three dimensions to investigate the causes and frequency of eclipses. Observe Earth's shadow crossing the Moon during a lunar eclipse, and the path of the Moon's shadow across Earth's surface during a solar eclipse. The angle of the Moon's orbit can be adjusted, as well as the distance of the Moon from the Earth.

• Beam to Moon (Ratios and Proportions)

Apply ratios and proportions to find the weight of a person on the moon (or on another planet). Weigh an object on Earth and on the moon and weigh the person on Earth. Then set up and solve the proportion of the Earth weights to the moon weights.

• Beam to Moon (Ratios and Proportions)

Apply ratios and proportions to find the weight of a person on the moon (or on another planet). Weigh an object on Earth and on the moon and weigh the person on Earth. Then set up and solve the proportion of the Earth weights to the moon weights.

• Moonrise, Moonset, and Phases

Gain an understanding of moonrise and moonset times by observing the relative positions of Earth and the Moon along with a view of the Moon from Earth. A line shows the horizon for a person standing on Earth so that moonrise and moonset times can be determined.

• Penumbra Effect

Observe the partial shadows cast by a rectangular block lit by multiple light sources. The number of light sources ranges from one to five, and individual lights can be turned on or off. The light spacing, block width, and distance from the lights to the block can be varied. Light intensity can be observed on a detector.

• Phases of the Moon

Understand the phases of the Moon by observing the positions of the Moon, Earth and Sun. A view of the Moon from Earth is shown on the right as the Moon orbits Earth. Learn the names of Moon phases and in what order they occur. Click Play to watch the Moon go around, or click Pause and drag the Moon yourself.

• Seasons Around the World

Use a three dimensional view of the Earth, Moon and Sun to explore seasonal changes at a variety of locations. Strengthen your knowledge of global climate patterns by comparing solar energy input at the Poles to the Equator. Manipulate Earthâ€™s axis to increase or diminish seasonal changes.

• Seasons in 3D

Gain an understanding of the causes of seasons by observing Earth as it orbits the Sun in three dimensions. Observe the path of the Sun across the sky on any date and from any location. Create graphs of solar intensity and day length, and use collected data to describe and explain seasonal changes.

• Seasons: Earth, Moon, and Sun

Observe the motions of the Earth, Moon and Sun in three dimensions to explain Sunrise and Sunset, and to see how we define a day, a month, and a year. Compare times of Sunrise and Sunset for different dates and locations. Relate shadows to the position of the Sun in the sky, and relate shadows to compass directions.

• Seasons: Why do we have them?

Learn why the temperature in the summertime is higher than it is in the winter by studying the amount of light striking the Earth. Experiment with a plate detector to measure the amount of light striking the plate as the angle of the plate is adjusted (and then use a group of plates placed at different locations on the Earth) and measure the incoming radiation on each plate.

• Tides

Gain an understanding of high, low, spring, and neap tides on Earth by observing the tidal heights and the positions of the Earth, Moon, and Sun. Tidal bulges can be observed from space, and water depths can be recorded from a dock by the ocean.

• Tides

Gain an understanding of high, low, spring, and neap tides on Earth by observing the tidal heights and the position of the Earth, Moon, and Sun. Tidal bulges can be observed from space, and water depths can be recorded from a dock by the ocean.