I believe Earth and Earth Day should be celebrated every day.
Earth Day celebrated its 50th anniversary in April.
Sadly this world wide event had to be done online.
Here is a link to wonderful NASA Earth Day posters
The planetarium look forward to celebrating Earth Day live in the future.
Sierra Club t-shirt
NASA has collected numerous activities to help you observe “Earth Day at Home."
Earth Day Toolkit
Global Climate Change
Earth at Night images
Earth as Art NASA ebook
Earth Day Image Gallery - Celbrating Earth's Beauty
Earth Science Lessons
Apollo Earth Day Posters
July 2019 was the 50th anniversary of the first human landing on the moon.
Earth Day 2020 Poster
Eyes on the Earth - using an app
11 Videos, meant for the ISS 20th anniversary, is a series to celebrate the Earth.
Earth Day Posters
Earth - Our Home Planet overview
50 Years of Earth Day Video