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84 lessons · 1st Grade
Stars look tiny because they are very, very far away. The sun is our closest star.
Day and night happen because the Earth spins like a top. One full spin takes 24 hours!
The moon changes shape over a month. We see a full moon, half moon, crescent, and new moon.
Earth is one of eight planets that orbit the sun. The sun is the center of our solar system.
When you look at the night sky, the light from some stars took years to reach your eyes!
The moon orbits Earth. It takes about 29 days for the moon to go all the way around Earth.
A constellation is a pattern of stars that looks like a picture, like Orion the Hunter.
Astronauts travel to space in rockets. In space, there is no air and things float!
A solar eclipse happens when the moon moves between the Earth and the sun.
Seasons happen because Earth tilts on its axis. This tilt gives us summer and winter!
A telescope helps us see things in space that are too far away for our eyes alone.
The North Star (Polaris) stays in the same spot in the sky and helps people find north.
The sun is much bigger than Earth. Over a million Earths could fit inside the sun!
The Big Dipper is a group of stars that looks like a giant ladle in the sky.
Planets close to the sun are rocky and hot. Planets far from the sun are cold and made of gas.
The moon has craters—big holes made by rocks from space that crashed into it long ago.
Earth is the only planet we know that has liquid water and life.
A shadow forms when an object blocks light. On a sunny day, your shadow changes length!
In space, there is no gravity pulling you down, so astronauts float inside their spacecraft!
A year is the time it takes Earth to go all the way around the sun: about 365 days.
