Our home, Earth, is the third planet from the sun and the only world known to support an atmosphere with free oxygen, oceans of liquid water on the surface and — the big one — life. Here are some interesting things you may not have known:
Coral reefs support the most species per unit area of any of the planet’s ecosystems, rivaling rain forests. And while they are made up of tiny coral polyps, together they are the largest living structures on Earth, with some visible even from space, according to NOAA.
As the climate changes, glaciers are retreating and contributing to rising sea levels. It turns out that one particular glacier range is contributing a whopping 10 percent of all the meltwater in the world. That honor belongs to the Canadian Arctic, which lost a volume equivalent to 75 percent of Lake Erie between 2004 and 2009.
Humans leave our mark on the planet in all sorts of weird ways. For example, nuclear tests in the 1950s threw a dusting of radioactivity into the atmosphere. Those radioactive particles eventually fell as rain and snow, and some of that precipitation got trapped in glaciers, where it forms a little “you are here” layer for scientists trying to date the age of glacial ice. Some glaciers are melting so fast, however, that this half-century of history is gone.
The oceans cover some 70 percent of Earth’s surface, yet humans have only explored about 5 percent, meaning 95 percent of the planet’s vast seas have never been seen.
Every day our planet is sprinkled with fairy dust … or dust from the heavens. On a daily basis, about 100 tons of interplanetary material (mostly in the form of dust) drifts down to the Earth’s surface. The tiniest particles are released by comets as their ices vaporize near the sun.
The Earth is approximately 93 million miles (150 million kilometers) from the sun. At this distance, it takes about 8 minutes and 19 seconds for sunlight to reach our planet.
The driest spot on Earth is the Atacama Desert of Chile and Peru. In the center of this desert, there are places where rain has never been recorded.
Finally, there could be more planets like ours. Space scientists have found evidence of Earth-like planets orbiting distant stars, including an alien planet called Kepler 22-b circling in the habitable zone of a star much like ours. Whether any of these planets will harbor life is an open question.