We have always known that Earth changes. Sunny days turn rainy, and rain turns to snow. We can see the changes from space, like in this picture of snow over parts of the United States and Canada. Every year many places go through the seasons. Earth changes in a lot of other ways, and NASA has been studying those changes with satellites, airplanes and scientists on the ground.
One of the most important ways Earth is changing is that it is becoming warmer. Our factories, our vehicles and even the way we grow food are polluting our world. This pollution is making Earth's temperature rise. That’s going to change a lot about our planet.
Large amounts of ice are melting in the far north and far south. That will make oceans rise along our coasts. Warming will cause other effects, including changes in what people can grow for food in different places on Earth.
Using satellites or instruments onboard airplanes, like the one in this picture, scientists can measure the changes.
This year, NASA is conducting a lot of different studies, called Earth Expeditions, to understand different aspects of Earth. Scientists will make measurements from airplanes, ships and from the ground to study the Earth.
Mars is the fourth planet from the Sun. It is the first one after the Earth. Mars has a day that lasts almost as long as Earth’s day. A year on Mars, though, is almost twice as long as ours. That’s because Mars is farther from the sun. So, it takes Mars longer to go around the sun than the Earth.
Mars has about one-third the gravity of Earth. A rock dropped on Mars would fall slower than a rock dropped on Earth. Things weigh less on Mars than they weigh on Earth. A person who weighs 100 pounds on Earth would only weigh about 37 pounds on Mars because of less gravity.
Mars has air, but not the kind that people can breathe. Even on the warmest days, the temperature is too cold for people to live comfortably. When astronauts go to Mars, they will always need to be in spacesuits or inside buildings to live.
Mars is rocky with canyons, volcanoes, and craters all over it. It has clouds and wind, much like Earth. Rusty dust covers almost all of Mars. Sometimes, the wind blows the dust into a dust storm. Tiny dust storms can look like small tornados, and large ones can cover the whole planet.
NASA wants to send humans to Mars 15 to 20 years from now. Future Mars explorers could uncover evidence that life has existed – or even might exist now – on Mars, answering one of the most basic questions humans have of the universe. A fleet of robotic spacecraft and rovers already are on and around Mars, dramatically increasing our knowledge about the Mars and paving the way for future human explorers.
Jupiter is the largest planet in our solar system. All the other planets could fit inside it. Jupiter is the fifth planet from the sun. And it is five times farther away from the sun than Earth is. Jupiter is made of layers of gases with clouds on top. The sun is made of gases too. Unlike the sun, Jupiter is extremely cold. But very hot liquids and solids may be under its clouds.
NASA wants to understand Jupiter and the rest of the solar system. That goal includes searching for life on other planets. The NASA spacecraft Juno (shown in this picture) will help accomplish this goal. NASA launched the spacecraft from Earth in August 2011. After a five-year trip, Juno will be orbiting Jupiter. Juno will help us understand how Jupiter formed. And the spacecraft will try to find out if Jupiter has a solid core like Earth. Juno will also study the air and gases around the giant planet.
Juno will help us understand how Jupiter formed. Using special instruments, it will look beneath Jupiter's clouds. It will try to find out if Jupiter has a solid core, like Earth does, and it will study the air and gases that surround the giant planet.
You can take part in the Juno mission. Do you know people who take pictures of stars and planets? They can send images of Jupiter from their own telescopes.
The International Space Station is a large spacecraft. It orbits around Earth. The space station is a home for astronauts while they live in space. Astronauts have lived aboard the space station since November 2000. More than 200 astronauts from 18 countries have lived there. Usually there are six people aboard the space station but at times there have been as many as nine.
To find out when the space station might be flying over your home, visit Spot the Station. (You might need an adult's help.)
The space station is also a science lab. Many countries worked together to build it. They also work together to use it. Astronauts spend most of their working time conducting research. The astronaut in this picture is researching how living without gravity can affect people's eyes and sight.
The space station is made of many pieces. The pieces were put together in space by astronauts. More than 100 launches were needed to send all the space station's pieces into orbit. The space station is larger than a house with six bedrooms. It is almost as long as a football field.
Lessons learned from experiments on the space station will help NASA with the journey to Mars.
American companies are now sending spacecraft with supplies to the space station. But astronauts ride aboard rockets from Russia. In a few years, a new rocket will launch from the U.S. to carry crews to space.