In honor of International Dark Sky Week 2018—which will run from April 15th to the 21st—timelapse filmmakers Gavin Heffernan and Harun Mehmedinovic decided to create an interesting composite. Using their ample post-processing skills and footage they'd captured across the country, they replaced the light-polluted skies over New York City with long-exposure footage captured in pristine locations like Death Valley and Grand Canyon National Parks.

The whole thing is part of the duo's project Skyglow: an ongoing quest to raise awareness about and examine the dangers of light pollution. The project features a 192-page hardcover book and blu ray video series made up of footage and photos captured all over the United States, but it was also the impetus behind an inspiring series of Skyglow timelapses. The project began three years ago with another composite timelapse—in which they 'darkened' the skies over LA—so Heffernan and Mehmedinovic decided they would cross the country and do it again, this time in NYC, for Dark Sky Week 2018.

You can learn more about the Skyglow Project at this link, watch the new New York City composite timelapse above, and scroll through some stills from the project below.