Here are some fun facts about today's holiday, Earth Day! 

- Origins: Earth Day was first celebrated on April 22, 1970, initiated by Senator Gaylord Nelson of Wisconsin to raise awareness about environmental issues.

- Global Reach: What began as an American movement quickly turned into a global phenomenon. Earth Day is now celebrated in over 190 countries around the world.

- Massive Participation: The first Earth Day saw 20 million Americans, roughly 10% of the U.S. population at the time, participating in demonstrations across the country.

- Environmental Impact: The inaugural Earth Day led to the creation of significant U.S. environmental laws including the Clean Air Act, Clean Water Act, and the Endangered Species Act.

- Earth Day Network: The organization founded by the original Earth Day organizers coordinates global events and activities to celebrate Earth Day each year.

- 2020 Milestone: The 50th anniversary of Earth Day in 2020 was marked by digital protests due to the COVID-19 pandemic, making it one of the largest online mass mobilizations in history.

- Annual Themes: Each Earth Day has a specific theme; for example, "Restore Our Earth" in 2021 focused on natural processes, green technologies, and innovative thinking that can restore the world’s ecosystems. For 2024, it is, "Planet vs. Plastics." 

- Educational Impact: Earth Day is used as an opportunity to educate about environmental issues, with many schools and communities organizing learning events and activities.

- A Day of Action: Earth Day is often marked by tree planting, clean-up campaigns, and petitions for stronger environmental laws, demonstrating the proactive nature of the observance. 

- Symbol: The official Earth Day flag features a picture of the Earth taken from the Apollo 17 spacecraft, symbolizing peace and environmental stewardship.