| atmosphere |
All around the planet Earth are gases. These gases all together are called Earth's atmosphere. As our planet travels through space and around the sun, its atmosphere stays with it. Other planets can have an atmosphere too, but Earth's atmosphere has just the right mixture of gases for humans to live. Our atmosphere lets us breathe and also protects us from the strong energy of the sun. [1/2 definitions] |
| beach |
A beach is the land next to a lake or ocean. A beach is often a beautiful place where people go to lie in the sun. Beaches are sandy or full of small stones or rocks. |
| beam |
A beam is a line of light coming out of something. Beams of light from the sun shine through clouds. [1/2 definitions] |
| certain |
When something is certain to happen, it means that that thing is going to happen for sure. It is certain that the sun will go down tonight and come up tomorrow. [1/3 definitions] |
| day |
Day is the time after the sun comes up. It lasts until the sun goes down. It is day when it is light outside. [1/2 definitions] |
| early |
When we say that the sun goes down in the early evening, we mean that it goes down in the beginning of the evening. [1/4 definitions] |
| earth |
Earth is our world. It is a large thing, like a big ball in space, that travels around the sun. Earth and similar things in space are called planets. Earth is one of eight planets that go around our sun. It takes 365 days for Earth to make one trip around it. [1/3 definitions] |
| east |
East is a direction that you can go in or that you can face. If you are watching the sun as it comes up in the morning, you are looking to the east. [1/4 definitions] |
| energy |
Energy is power or heat that comes from things such as the sun, wind, moving water, natural gas, or oil. Energy from these things can be used to make electricity. Humans use energy to stay warm, cook, produce light, and make things move or operate. [1/2 definitions] |
| evaporation |
Evaporation is something that happens in nature. It is a kind of process. In this process, water and other liquids turn into gases and go into the air. Sometimes after it rains, you see puddles outside. But later, when the sun shines, the water in the puddles goes away. Do you ever wonder what happens to the water? You can't see it anymore because it has turned into a gas and gone up into the air. This process is called evaporation. |
| Jupiter |
Jupiter is a large, round object out in space. Like our Earth, it is a planet that travels around the sun. Jupiter is the largest of all the planets that go around the sun. Planet Earth could fit inside Jupiter many times. |
| light1 |
Light is the form of energy that lets your eyes see things. The sun sends out a great amount of light. If there is no light, you can't see anything! [2/7 definitions] |
| Mars |
Mars is a large, round object out in space. Like Earth, it is a planet that travels around the sun. Mars is colder than Earth, though, because it is farther from the sun. The surface of Mars is a sort of red color, and sometimes Mars is called the Red Planet. People from Earth have explored the surface of Mars with special robots. |
| mercury |
Mercury is a large, round object out in space. It is a planet, like our planet Earth, and it travels around the sun like Earth does. Mercury is very hot, though, because it is close to the sun. Of all the planets that go around our sun, Mercury is the closest to it. It is also the smallest planet. |
| morning |
Morning is the early part of the day. Morning begins when the sun rises and ends at noon. |
| Neptune |
Neptune is a large, round object out in space. Like Earth, it is a planet that goes around the sun. Neptune is very far from the sun, though, and it is very, very cold. It is also a very windy planet and can have big storms that last for years! |
| north |
North is a direction. If you face the sun as it rises in the morning, north is to your left. If someone is traveling from California to Alaska, the direction they are going in is north. [1/3 definitions] |
| outer space |
Outer space is all the space that is beyond our planet Earth. The sun, moon, stars, and planets are all in outer space. Things in outer space are very far away, so people often use a telescope to look at things like stars and other planets. |
| planet |
A planet is a large thing in space that moves around a star. Planets are much smaller than stars, and they don't give off light as stars do. Earth is a planet that moves around the star that we call the sun. The other planets that move around the sun are Mercury, Venus, Mars, Jupiter, Saturn, and Neptune. |
| plant |
A plant is a living thing that has leaves and roots that usually grow in the ground. Plants use light from the sun to make their own food. Grass, trees, vegetables, and flowers are plants. [1/3 definitions] |
| Pluto |
Pluto is a round object in outer space. Like our Earth, it moves around the sun. Scientists used to call Pluto a planet. It was the planet that was the smallest and farthest from the sun. But, now, scientists think Pluto is a little different from a real planet, and they don't call it a planet anymore. |