“The ultimate test of man’s conscience may be his willingness to sacrifice something today for future generations whose words of thanks will not be heard.” ~ Gaylord Nelson, founder of Earth Day
First celebrated in the United States in 1970, Earth Day (known as International Mother Earth Day elsewhere) has expanded to 193 countries as a day to demonstrate support for environmental protection. The Theme for Earth Day 2019 is "Protect Our Species".
Earth Day is an annual event, celebrated on April 22, on which day events worldwide are held to demonstrate support for environmental protection. It was first celebrated in 1970, and is now coordinated globally by the Earth Day Network and celebrated in more than 193 countries each year.
The first Earth Day celebrations took place in two thousand colleges and universities, roughly ten thousand primary and secondary schools, and hundreds of communities across the United States. More importantly, it "brought 20 million Americans out into the spring sunshine for peaceful demonstrations in favor of environmental reform." It now is observed in 192 countries, and coordinated by the nonprofit Earth Day Network, chaired by the first Earth Day 1970 organizer Denis Hayes, according to whom Earth Day is now "the largest secular holiday in the world, celebrated by more than a billion people every year." Environmental groups have sought to make Earth Day into a day of action to change human behavior and provoke policy changes.
This tartan was designed on behalf of Charles Cockell, Professor of Astrobiology, Edinburgh University. Notes from the registry:
"Given the planetary-scale challenges of living successfully on the Earth without destroying it, this tartan represents the need for humans to preserve our Earth. Colours: blue represents Earth's oceans and sky; three green lines represent life on the third planet from the Sun and our efforts to successfully sustain it; white lines signify the planet's clouds; the brown line running through the middle green line represents the crust and the continents on which we dwell."
For more on the history of Earth Day, click the earth, from a 2015 image from a camera on board the Deep Space Climate Observatory (DSCOVR). This is the first picture of the whole Earth that has been seen since 1972. All of the previous pictures of the entire earth were produced by stitching together different pictures into a full image of the globe.
For more on NASA's best space photography, click the earth!