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What is a fairy ring?

Have you ever noticed mushrooms growing in a big circle? It’s known as a fairy ring. How does it happen?

evergreen trees conifers

Earth has 3 trillion trees, says study

That’s more than previous estimates. But the number of trees has dropped by 46% since the start of human civilization, says the study.

What is dark energy?

We need dark energy to explain why gravity seems to be driving galaxies in our universe apart instead of pulling them together.

What is the Yellowstone supervolcano?

Beneath Yellowstone National Park lies a volcanic hotspot. The most recent enormous eruption occurred 640,000 years ago. What’s going on now?

Why do volcanoes erupt?

Volcanoes are channels that transfer molten rock from Earth’s crust to the surface. Here’s why eruptions happen.

Sun's path through the zodiac.

Dates of sun’s entry into each zodiac constellation

Dates of sun’s entry into each zodiacal constellation and the corresponding ecliptic longitude (sun’s position in degrees, east of the March equinox point).

Can a human singing voice shatter glass?

Not just any loud sound will shatter a glass. It has to be the right resonant frequency.

Measuring sea level on a dynamic Earth

Warming temps, and the rise and fall of coasts, complicate measurements of sea level. How do scientists establish sea level on a constantly changing Earth?

How much do oceans add to world’s oxygen?

Most of Earth’s oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents.

Aug 2012 CME

What is a coronal mass ejection or CME?

A CME can launch a billion tons of plasma from the sun’s surface into space, at speeds of over a million miles per hour.