Earth is a planet.
The world's tropical rainforests are critical links in the ecological chain of life on the planet.
Our planet, Earth, is always in motion.
I think it's unlikely that aliens similar to what we see in the movies have ever visited our planet.
Cole's Axiom: The sum of the intelligence on the planet is a constant; the population is growing.
There was a very simple reason for this: their planet was cooling down internally and would become uninhabitable within 500 years.
The smaller planets hovering around the planet Jupiter reminded him of the guards surrounding a king when he walked outdoors, and Kepler called them satellites.
For even as we celebrate tonight, we know the challenges that tomorrow will bring are the greatest of our lifetime — two wars, a planet in peril, the worst financial crisis in a century.
Through the internet, we are now able to acquaint ourselves, deeply and in detail, with the mental activities of even the furthest people on the planet.
In 2006, the International Astronomical Union decided to create a new category for solar system objects called "dwarf planets", and Pluto was reclassified as a dwarf planet.
NASA says it has sufficient information to say that a human visit to the red planet is feasible.
In fact, a group of their ancestors peopled a continent on the planet Earth about 250 000 of your Earth years ago.
The planet Arèmo X3 is almost twice the size of planet Earth, and as you can see on the screen, quite similar to your world.
For world peace, therefore, we must develop the consciousness that we are all one people of planet Earth through continual international cultural and economic exchange.
If there's a world-wide all-out nuclear war it's said that there will be a "nuclear winter" all over the planet for several months.
English word "行星"(planet) occurs in sets:风景，植被及生态 - Landscape, plants and ecology