By Patrick J. Kiger: Discovery.com, FactSlides.com:

April 22 is the International Mother Earth Day, the event that environmentalists created 46 years ago to raise awareness of issues such as pollution and deforestation, and the need for us all to come together to find solutions and protect the planet where we live.

But everyday we learn new things about our home planet and some of its characteristics. Here are some things that you may not know about the Earth:

– The most common mineral on Earth is one you’ve probably never heard of before. It’s Bridgmanite, a magnesium iron silicate that takes up 38% of our planet’s volume.

– Nearly a third of the Earth’s surface is covered with 3.04 trillion trees. Granted, it used to be a lot more than that. We’ve cut down about half of the world’s forests since the 1800s, but they still take up close to 10 billion acres, which works out to about 31% of the planet. Forests absorb and store much of the carbon dioxide that we spew into atmosphere, so they’re a vital bulwark against climate change.

– Most of the atmosphere is at the bottom. About 75-80% of the gases in the Earth’s atmosphere are concentrated in the Troposphere, the lowest portion, which extends about 6 miles up. That’s where almost all of the weather occurs too.

– Earth has about 1,500 volcanoes that could erupt. Fortunately, most of them are long dormant. According to the U.S. Geological Survey, only about a third of the potentially active volcanoes actually have blown during the course of human history. And between 10 and 20 of these volcanoes erupt somewhere on Earth every day.

– If you drilled a tunnel straight through the Earth and jumped in, it would take you about 42 minutes to get to the other side.

– There are more living organisms in a teaspoonful of soil than there are people on earth. And there are about 7500,000,000,000,000,000 grains of sand on Earth.

– Lightning strikes Earth about 100 times per second or 8.6 Million times per day. And there are about 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt, yet only 100 of them cause damage.

– You know that the water covers about 71% of the Earth’s surface, however, water constitutes only 0.07%of the earth by mass or 0.4% of the earth by volume. Also a reservoir of water three times the volume of all the oceans is located deep beneath the Earth’s surface.

– There is enough gold in Earth’s core to coat its entire surface to a depth of 1.5 feet (45cm).

– Earth days are getting longer by 1.7 milliseconds every century because of its slowing rotation around its axis. And if the earth didn’t have the moon, our days would only be 6 hours long.

– The Earth’s magnetic field has been steadily weakening over the past 180 years, especially around Brazil and Argentina.

– There’s an ongoing decrease in the pH of the Earth’s oceans: they are 30% more acidic than in 1751.

– Each day, up to 4 billion meteoroids fall to Earth.

– Rainbows are actually Circular. We don’t typically see a full circle rainbow because the Earth’s horizon blocks the lower part.