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Government officials and scientists had high hopes for Landsat when the first experimental satellite launched July 23, 1972. Those hopes were soon realized when imagery came back depicting features never before seen. Since then, an archive of imagery surpassing 10 million scenes has amassed at EROS, collected from eight different Landsat satellites.

We don't need a scientist to tell us that city streets catch and hold heat. Anyone who's walked barefoot from a parking lot to a beach can tell you that. What scientists can help us understand, particularly scientists who work with spaceborne, remotely sensed data, is just how big a difference there is between cities and the countryside.

Spaceborne sensors orbit hundreds of miles over our heads. Even the most advanced among them struggle to capture high-resolution imagery of individual human beings. Mosquitos, of course, are far smaller than we are. Clearly, sensors on a satellite or space station can’t see them.

Clouds of dust kicked up in places like the Sahara can travel thousands of miles across the planet. We can see those clouds in satellite imagery, but we don’t typically know much about the composition of that dust. That’s a huge blind spot, because those unknown characteristics—such as the particles’ lightness or darkness—have an impact on what they do.

When the first Landsat satellite launched 50 years ago, it was the only game in town in terms of civilian land remote sensing. In the years that followed, a host of satellites have launched to serve similar purposes. But that data doesn't always play well together.

Some plants are simply better at making use of their water supply than others. More efficient plants can capture more carbon with less water, which has implications for carbon sequestration and ultimately for climate change modeling. In other words, the more we understand about water use efficiency, the more reliable our climate change models can be.

The boreal forest, or taiga, stretches across nearly 5.7 million square miles in the northern latitudes. That’s nearly a quarter of all forested lands in the world. This sprawling biome also happens to be one of the most rapidly shifting in the face of climate change.

In this episode of Eyes on Earth, we zero in on the use of USGS Land Change Monitoring, Assessment, and Projection (LCMAP) products to examine the effects of drought on California’s Blue Oaks. LCMAP datasets are built from Landsat data and reveal the land cover and change of every pixel in the conterminous United States, dating back to 1985.

Summary: The Earth observation data archived here have plenty of value to the study of aquatic ecosystems. Landsat satellites can capture harmful algal blooms, for example. Spaceborne sensors can also record land surface temperatures, and that includes water surfaces.

Land change is a constant. Even land areas that see little major change can see disruptions from storms, heat waves, wildfires, or invasive species. But major changes aren't uncommon, either. Each year in the U.S., farm fields become tracts of suburban homes, wetlands become more permanent bodies of water, and shrublands burn to be replaced with grasslands.

The sturdy root systems of mangrove forests act as buffer zones along the coastlines of some of the planet’s most vulnerable communities, protecting lives, ecosystems and property from the rigors of hurricanes and tsunamis.

If you want to know how much rain fell yesterday, you can catch it and measure it. Water vapor? That's not so easy. Which is a problem if you want to know how quickly that rate is returning to the atmosphere. Water vapor is the single largest part of the water budget, but without space-based observations, it would be all but impossible to measure at wide scale.

The rangelands of the western United States are changing more quickly than many other parts of the lower 48. Miles upon miles of the area or semi-arid landscapes in states like Idaho, Montana and Nevada are now carpeted by fire fueling invasive grasses. Cheatgrass is the most prevalent, which is troublesome for several reasons.

Satellites like Landsat are valuable for mapping fire perimeters and for monitoring trends in burn severity or in post-fire recovery. Satellites can cover wide areas with a single pass, whereas helicopter, drone, or airplane fire line mapping can take hours.

Outbreaks of native bark beetles can lead to conspicuous changes in a forest landscape. They’ve been present for thousands of years with occasional outbreaks, but there’s a lot we don’t yet understand about them. Exactly when and where have outbreaks occurred? How severe were they? What happened to the forest afterward?

Fires can be destructive or healthy for a landscape—often both. Fires have grown larger and more destructive in recent years, though, thanks to human activity, climate change, and a host of other factors. Satellite data helps us to map and monitor fire activity, but the study of post-fire plant life using remote sensing data goes further than fire mapping.

For our third and final episode of Eyes on Earth from the September launch of Landsat 9, we hear from Virginia Norwood. She blazed a trail for women in remote sensing in the 1960s and 70s while working for Hughes Aircraft, a contractor for NASA.

Hundreds of scientists, officials, international representatives, and others witnessed the launch of Landsat 9 on September 27, 2021, from a handful of viewing sites around Santa Barbara County, California.

Landsat 9 launched into orbit from Vandenberg Space Force Base on Monday, September 27, 2021, to carry on the legacy of a nearly 50-year record of continuous Earth observation that began in 1972. The days leading up to the event saw guests from around the world descend upon Santa Barbara County in California to watch the historic event take place.

The launch of Landsat 9 in September of 2021 represents a milestone for a joint USGS/NASA program that stretches back nearly 50 years. Landsat 9 will continue the legacy of unbroken, repeat Earth observations and contribute to our understanding of a changing planet.

Satellite imagery is everywhere. We see it on TV news and weather coverage, in our Twitter and Facebook feeds, and on our phones’ mapping apps. The data behind that imagery is nothing like a screenshot, though.