Why is the sky blue? Why does the sky matter?



Sky Day is September 20

Sky Day is a creative celebration of our one, shared sky and a day to reflect on the science of how it functions and what its vulnerabilities are. Celebrate Sky Day with your community. Learn more.

Take part in SkyDayProject

Stop for a moment, look up and reflect on what our one, shared sky means to us all while you document it’s dynamic changes in photography. Then join people worldwide who right now are posting their sky photos to skydayproject.org as a way of showing how much they care about our sky and want us to come together to protect it for the benefit of all. Learn more
Last September Sky Day Project was out of this world. Literally! Check out our installation on the International Space Station.

Our Mission

Inspiring citizen engagements on global sustainability.

Our Goals

To partner with artists, scientists and educators interested in promoting greater understanding of our sky. From the surface of the earth to the edge of space - How does our sky function? What are its vulnerabilities? Why should people care? And what are the implications for our definition of community?

We are inspired by the dynamic nature of our sky

As artists it moves us to observe it, paint it, photograph it and write and sing about it. As scientists it stokes our curiosities and pushes us to understand how it functions.  

we seek to build a global community

We want to encourage people to view themselves as members of a larger global community that must unite with a common will to protect our sky for the benefit of all.

Our Sky is the ultimate shared resource

Our sky wraps completely around our planet so everyone can see it and feel it. All you have to do is look up or breathe in! Yet this sharing of our sky presents us with great challenges since what we do to it in one place directly impacts our sky across the globe.

We integrate art and science

SkyDay initiatives combine art and science to challenge us to think in new ways about our relationship to the sky.  


We only have one sky.

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Ben founded Only One Sky® in 2014 after hearing Yo-Yo Ma talk about the need for artists to find new ways of using whatever skills they have to serve community - especially young people. Ben already knew what he wanted to talk about. The environment has been the subject of his work for over 30 years. Looking out the plane window heading home Ben had a something of a vision. He imagined people all over the world looking up, connecting to the sky and reflecting on how it connects us all as one global family. And while they were doing so they were photographing it's dynamic changes and then together, all over the globe, posting their photos to an evolving on-line sky mosaic that was as beautiful and varied as the sky itself. He imagined this citizen art work would stand as an emblem to show how much people worldwide recognized the importance of climate and sky and how important it was they come together across cultures and borders as an enlightened people to solve the climate change crisis. 

Ben asked his wife Judy Grimmer and friends Sascha Bopp and Chris Frye to help him flesh out the idea. The project sounded like a portal to something. But a portal to what?  They decided to create an educational NFP called Only One Sky®  and build an interactive educational platform called Sky Day® so artists could collaborate with scientists and schools on imaginative global initiatives. These initiatives would teach about how our sky functions and what its vulnerabilities are and encourage participants to think of themselves as being part of a global family with a shared problem to solve. To guide these initiatives they created a SkyTeam - a team of distinguished artists and scientists charged with advising on the development of Sky Day initiatives. Astronaut and artist Nicole Stott and Northwestern University climate scientist Daniel Horton were the first to join and together they worked to define Sky Day's educational goals. Soon afterwards they were joined by atmospheric scientist, University of Illinois Professor and IPCC lead author Don Wuebbles, and scientist, poet and lecturer in science communication Sam Illingworth.

Today Sky Day is a fast growing educational platform and also an annual celebration of our sky held on or around September 21. The first Sky Day was on September 21, 2017 with the inauguration of Sky Day Project - the project Ben had imagined on that plane in 2014. You can view Sky Day Project at skydayproject.org. That first Sky Day schools and organizations took part all over the world. Ben, Nicole Stott and Daniel Horton were interviewed on WBEZ Chicago’s Worldview program (listen) and Chicago’s great Adler Planetarium hosted a beautiful three day installation of Sky Day Project over Sky Day weekend September 22 - 24, 2017.

Today Sky Day Project is growing fast with new sky photos arriving from all over the world everyday. And we’ve even gone out of this world with an installation of Sky Day Project on the International Space Station! Check it out!


Ready to help?