To answer this tricky question, we have to look back in time to when the Earth was born, 4.5 billion years ago.
Children will be responsible for the future protection of our fragile planet. Their knowledge and engagement are critical.
A public meeting of flat earthers is a product and sign of our times.
Indigenous communities lived in the Amazon for thousands of years without chopping down their forests.
The wired Earth of the 21st century is at the mercy of the volatile nature of the sun.
China's Tiangong-1 space station is hurtling around Earth out of control and about to come crashing down. It's just one of thousands of pieces of space junk left orbiting our planet.
Scientists believe since 2010 we have entered the sixth period of mass extinction. CO2 emissions will change the lives of plants and animals in the next three to four decades.
When and where you see the Moon in the daytime depends on what phase it is in.
A solar day is a measure of how long it takes the Earth to rotate from one noon to the next, and today's summer solstice also happens to be the longest solar day of the year.
Imagine the Earth pulling everything it is made up of, all of its mass, towards its centre. This happens evenly all over the Earth, causing it to take on a round shape.
How exactly do the stars twinkle in the night sky? As it turns out, the answer is full of hot air... and cold air.
More than 2,000 years ago, the Babylonians understood the cycle of eclipses. They also regarded them as signs that could foretell the death of a king.
A new detector could work out what's causing a heat flow from the Earth's interior. It may even solve the mystery of what powers the Earth's magnetic field.
An astronomer explains how and why – and when – eclipses happen, what we can learn from them, and what they would look like if you were standing on the moon.
In five or seven billion years time, the Sun's life will come to an end. And it will be really spectacular - if you're watching from far enough away.
Some people think the sky is blue because of sunlight reflected off the ocean and back into the sky. But that's not the real reason.
Canadians love to paddle on them and camp beside them, but our boreal lakes offer more than just peace and beauty. They could provide clues to how life on Earth began.
We need a positive vision for humanity, not tech-driven life on Mars.
You would not recognise Earth if you saw it 500 million years ago - the lands, oceans, climate and life were all very different. Scientists now have a new map of the deep history of Earth.
The planet is more similar to Earth than any other – except when it comes to supporting life.