"We came all this way to explore the Moon, and the most important thing is that we discovered the Earth," Anders famously said of his mission.

On Christmas Eve, 1968, the astronauts aboard NASA’s Apollo 8 spacecraft became the first humans to behold the entirety of Earth with their own eyes. That day, crew member Bill Anders took an iconic photograph called “Earthrise'' that captured our home world emerging from behind the Moon’s horizon.

More than 50 years later, Earth is being rediscovered from space once again, but this time it is through the "eyes" of satellites, supercomputers, and artificial intelligence (AI) networks. Geospatial science, a sprawling and multifaceted field dedicated to resolving ever-finer details about Earth and its systems, is poised to undergo an unprecedented growth spurt powered by this confluence of technologies across both the public and private sectors.

How will we deal with the petabytes of Earth-observation data that may document the collapse of whole ecosystems or the wreckage of natural disasters? What will we do with geospatial information that predicts such dire outcomes but also demands nimble and dramatic changes to our lifestyles?

The feeling of epiphanic connection with the planet experienced by astronauts gazing at Earth is known popularly as “the overview effect,” a term coined by author Frank White in his book of the same name. The new geospatial view of Earth, however, may offer something closer to an “overwhelm effect,” as our home world is imaged, valued, and monitored by millions of sensors on thousands of spacecraft orbiting Earth.

“With the proliferation of satellite platforms, essentially this is something that's almost become impossible to keep a handle on because there are so many new systems being launched and developed by so many different actors globally,” said Jonathan Chipman, director of Dartmouth College’s Citrin Family GIS/Applied Spatial Analysis Laboratory, in a call. “It's just mind-boggling the amount of data that's now being collected from low-Earth orbit."

It will take foresight to ensure that the deluge of information is managed in a way that equitably benefits communities and ecosystems around the world, and remains as accessible to the public as possible.

“The biggest challenge will be in making sense of all these data,” said Dawn Wright, chief scientist of the Environmental Systems Research Institute (Esri), a major geospatial software and data science company, in an email. “It is one thing to store, to distribute, even to analyze, but how do truly understand it? How do we make sense of it, and quickly so that we can make decisions?”

Tracking climate change, animals, and human beings

There are more than 2,000 active satellites orbiting Earth right now, many of which carry ultra-precise cameras, sensors, and other instruments that can resolve intimate details about our planet’s surface. Though geospatial data is heavily reliant on this complex space infrastructure, it is also augmented by a dizzying array of sources on the ground including smartphone geolocation, drones, government census reports, and even facial recognition software.

The result is an intertwined and cascading flood of information that is greater than the sum of its individual parts. Geospatial data can shed light on everything from the future of our warming planet to the unexplored ruins of bygone civilization to informed responses to pandemics. It is also critical to managing reactions to natural disasters, mass migrations, and urban developments. Meanwhile, satellites constantly keep tabs on planetary processes such as global ice melt, sea level rise, and atmospheric greenhouse gas content.

“There is enormous potential for good with this technology, yet at the same time there are real threats to civil liberties and individual privacy that were unthinkable even a few years ago.”

This incredible sprawl of geospatial data was a hot topic at the meeting of the American Association for the Advancement of Science (AAAS), an annual general science conference, which I attended a few weeks ago in Seattle. The meeting, themed “Envisioning Tomorrow’s Earth,” highlighted how the field unveils a complex global portrait of ecological and anthropogenic patterns, including forest cover, biodiversity, urban development, and even social conflicts.

For instance, University of Virginia oceanographer Scott Doney outlined how patterns in seawater color can be bellwethers of ecological health amid mounting human pressures. Satellites such as NASA’s Plankton, Aerosol, Cloud and ocean Ecosystem (PACE), which is due for launch in 2022, will be able to gather hyper-precise color data that will help fisheries and conservationists anticipate events such as phytoplankton blooms or marine food shortages.

“The new sensors on PACE would have much finer spectral resolution, and also a better spatial footprint,” Doney told me. “There are some sensors that can get down to a few hundred meters [of resolution] in coastal regions, and with the open ocean we can get down to a few kilometers.” Other technologies, such as submersible robots and AI, will help scientists predict future trends in addition to monitoring these patterns in near real-time.