1. It is the 3rd planet from the sun.
2. It is part of the Milky Way Galaxy.
3. It is not spherical in shape. Its shape is geoid, like a weirdly shaped pear, wider at the middle than at the poles. Yes, the earth has a generous waistline.
   
4. It is the fifth largest of the planets.
5. 2/3 of the earth's surface is covered by water, a fact that most people misconstrue as to mean that the earth is 66.7% water. Not the same thing people, not the same thing.
6. It is composed of four main layers: outer crust overlaying a mantle, followed by an outer core and an inner core. Think of it like an onion...an onion that is no way similar in size or shape or color, to an actual onion.
7. The earth's weight increases every day by about 25 tons because fine space dust finds its way down to the surface.
8. The earth is constantly moving. It is constantly rotating around its axis as it's hurtling around the sun. This, together with Newton's first law of motion (the law of inertia) means that you're also constantly rotating as you hurtle around the sun. In short, you've got super speed and great balance...that no one can see (unless, of course, if you excel in some sport, then people notice). As passengers on earth, we're all carried around at an average speed of 107182km/h (66600miles per hour).
   
9. The earth is about 4.54 billion years old. Take good care of it.
10. The earth recycles. From rocks to organic materials...the earth recycles. Why shouldn't you? Let's borrow a leaf from mother earth.
11. Gravity is uneven on earth due to the earth's weight being distributed unevenly. Average gravitational force on earth can be calculated as approximately 10m/s² or 10N (NEWTONS). Large parts of Canada have less gravity than the rest of the earth.
    
12. There are more living organisms in a teaspoon of soil than there are people on earth.
13. 1/3 of the earth's land surface is partially or totally desert. Solar energy, anyone?
14. Before trees were common, the earth was covered in giant mushrooms. Green is good. Let's take care of our green coverage. Deforestation is a big no-no unless you're definitely going to take up afforestation and/or reforestation.
15. The earth's core is about as hot as the sun, so no, you cannot drill through the earth to get to the other side, unless of course you've got some super cooling technology, in which case the expected travel time is 42 minutes.
16. Lightning strikes earth about 8.6 million times per day. Anyone thinking of converting lightning to usable energy can definitely use this bit of information.
17. Earth is the only place in the solar system where water can be present in its 3 states: solid, liquid and vapour. Think of this before you decide that global warming is not a credible threat. Sustainable development, anyone?
18. According to the WWF, the earth lost 40% of its wildlife in the past 40 years. That's a lot. Think about the concept of the ecosystem. Every living thing has a role to play.
19. The percentage of oxygen in the earth's atmosphere is roughly 21%. About 78% of the earth's atmosphere is made up of nitrogen. Nitrogen keeps the atmosphere inert as it is an inert gas whereas oxygen is very reactive. This is why air pollution is very dangerous. Air pollution disrupts this balance. Once this balance is disrupted, all sorts of chemical reactions will be occurring anywhere, anyhow which could very well mean the end of the human race. And the animal race. And the plant race. Basically, all living things. Non-living things too will meet an untimely demise, although, technically speaking, non-living things are already not living and therefore cannot die.
    
20. The earth is the only planet whose name in English is not derived from a Greco-Roman god. Our planet is unique! It's also the only planet in the solar system that supports life so if we destroy it, we're doomed. Given the state of affairs, it's high time we integrate sustainable development and green living into our lives. Also, Reduce, Re-use and Recycle.

I hope you enjoyed those random interesting facts about the earth. I found about a hundred of them, which you can also find in various books, publications and search engines.

REFERENCES.

1. Webster's Reference Library: Concise Edition Encyclopaedia.
2. factslides.com
3. list25.com
4. livescience.com