This social art project used balloon mapping and open source software to aerially photograph greenspace in the public realm in Nottingham to creatively imagine greener futures for the city. The 6ft2 helium balloon functions as a DIY satellite attached to a 1km long string. I challenged pupils of a local school to design and develop a DIY camera rig made from recycled materials and worked with over 60 young volunteers, aged 9-29, to map seven urban greening sites in Nottingham. These aerial photographs were works of art in their own right, a snapshot in time of this fast-changing city. The photos were then stitched together to create one-of-a-kind maps showcasing the current areas of greenspace in the public realm. 'Greenness' is a proxy for photosynthetic activity, and living around more photosynthetically active greenspace has been linked to improved health and wellbeing. The project was truly collaborative – a local illustrator experiencing homelessness drew the mappings in a local park, an art collective and community garden team helped paint the balloon on the theme of greener futures. Working with a local architect Rachael Millner the photos have been used to imagine greener futures for the city, in a work titled ‘The Garden of Earthly Delights’. The project was presented to the Nottingham City Council planning authority, a scientific conference at the University of Cardiff and culminated in a public exhibition at Broadway multi-arts gallery in 2019, where all young people involved were invited.