The Millstone Times November 2021

FAMILY MATTERS USGS Teams Up With NASA for Release of Earth 3D Timelapse USGS Landsat satellite data and imagery are the key foundation for the newly released Google Earth 3D Timelapse tool. The upgraded Timelapse presents a global, zoom- able time-lapse video of the planet from 1984 to 2020. The USGS, along with NASA, the European Commission, and the European Space Agency, has been critical in the provision of imagery for this new version of Google Earth Timelapse that shows visual evidence of global changes spanning nearly 40 years. In the biggest update to Google Earth since 2017, you can now see our planet in an entirely new dimension: time. With Timelapse in Google Earth, 20 million satellite photos from the past 37 years have been embedded into Google Earth, allowing users to explore changes to our planet's surface over time. Now anyone can watch time unfold across the globe and witness nearly four decades of planetary change. The new Timelapse tool use allows researchers, educators, nonprofits, governments, and the world-wide community to access powerful 3D visuals to study our planet’s stories and consider actions regarding climate change, sustainable development and much more. None of this would have been possible without the help of USGS: The data from USGS/NASA Landsat satellites have been the major source for the global imagery behind the Google Earth application, including this new feature. USGS Landsat 8 image showing algal bloom in Lake Erie in September of 2017. Landsat’s spectral bands allow researchers to see photosynthetic activity that is invisible to the naked eye. Google partnered with Carnegie Mellon University’s CREATE Lab to create five thematic “Earth Voyager” stories that users can explore through guided tours: • forest change • urban growth • warming temperatures • mining and renewable energy sources • the Earth’s fragile beauty To explore Timelapse in Google Earth, go to g.co/Timelapse. You can use the search bar to choose any place on the planet where you want to see the changes over time in motion. Or open Google Earth and click on the ship’s wheel to find interactive guided tours of the new imagery and featured locations. Google is also releasing more than 800 time-lapse videos covering more than 300 locations on YouTube. The videos will be available for free download in ready-to-use MP4 format. Landsat is Indispensable for Google Timelapse The content served by 3D Timelapse is derived, in large part, from five decades of U.S. Government investment in Landsat observations and data distribution. These sub- stantial investments, measured in tens of billions of dollars, have created a Landsat archive containing nearly 300 billion square kilometers of global imagery. Every day, the Landsat data archive grows by about 40 million square kilometers – the size of Europe and North America combined. At an altitude of 705 km, one Landsat satellite takes 232 orbits, or 16 days, to complete global coverage. The baseline configuration of two operational Landsat satellites achieves 8-day repeat coverage of any location on Earth. Landsat’s unique multi-spectral instruments simultaneously collect visible, shortwave and thermal infrared data. By observing phenomena that can’t be seen by the human eye, Landsat helps users identify and analyze a wide variety of critical landscape changes.

In the past, data delivery was cumbersome, and users had to pay for access. Today, by leveraging digital communications, supercomputer technology, and cloud processing, USGS makes the world’s largest archive of land surface imagery accessible

to anyone for free. Landsat Highlights: •

The Landsat imagery collection is the world’s only long-term, continuous, data record of the entire Earth’s land surfaces dating back to 1972. • Processed Landsat data are globally recognized for their scientific quality, precision and consis- tency. • The processed data are at 30-meter resolution – meaning 1 pixel is 30 x 30 meters, roughly the size of a baseball field. This provides the ideal scale to observe and measure human- and natu- ral land change. • Consistent collection methods provide direct comparability across decades, making it easier to detect subtle land change. • More than 100 million Landsat scenes have been downloaded from the USGS since 2008, when the data became free as part of the Department of the Interior’s Open Data Policy.

This USGS Landsat 8 image shows the extent of Bear Glacier (upper) and Aialik Glacier (lower) on Alaska’s Kenai Peninsula, as of September 4, 2018. Both glaciers have retreated significant- ly since the launch of the first Landsat satel- lite in 1972. Scientists can use Landsat’s deep historical archive to study glacial loss.

The Future of Landsat To emphasize the USGS’s commitment to future Landsat missions, NASA and the USGS will con- tinue the global data record with the launch of the Landsat 9 satellite this September. The successor mission, Landsat Next, is currently being planned for lift-off toward the end of the decade. That satellite will include major improvements over today’s observation platforms to support a broader range of scientific and commercial uses. Continued dialogue with, and support from, Landsat data users will be essential to maintain Landsat continuity and improvements in the future. These enhancements will result in better information prod- ucts and services. To learn more about the history of the USGS/NASA Landsat missions, their societal benefits, how to download data and much more, go to: https://www.usgs.gov/core-science-systems/nli/ landsat

Screenshots from a Google Earth 3D Timelapse video that compare ur- ban growth and landchange in New York City from Landsat images, 1984 to 2018.

32 The Millstone Times

November 2021