Humans leave a mark on Earth that is detectable from space. By analyzing satellite images, scientists can measure the extent of deforestation, agriculture, urbanization, and other features. Satellite analysts estimate that humans directly affect 83 percent of our planet's land surface, leaving a dwindling percentage of land truly "wild." This huge influence is called the "human footprint."
The Pearl River delta near Hong Kong is a dramatic example of the human footprint. Humans have continuously occupied the region for thousands of years, and the region's cities are among the fastest-growing urban centers ever observed. Scientists use the same techniques illustrated for the Pearl River delta to study human-altered surface features around the world, thus mapping the global human footprint.
Why is it that humans can speak but chimpanzees, our closest living relatives, cannot? The human brain is uniquely wired to produce language. Untangling this wiring is a major frontier of brain research. Peer into the mental machinery behind language with this feature video, which visits a brain-scanning laboratory, Columbia Universitys Program for Imaging and Cognitive Sciences, or PICS. Columbia neuroscientist Joy Hirsch and New York University psychologist Gary Marcus explain what researchers have learned about how our brain tackles language—and whats left to learn.
Watch how a unique dual-satellite mission called GRACE-NASA's Gravity and
Climate Experiment-is revealing an unprecedented view of our water planet.
For background information, educational resources and more, visit Grace:
Tracking Water from Space on the Science Bulletins website,
Science Bulletins is a production of the National Center for Science
Literacy, Education, and Technology (NCSLET), part of the Department of
Education at the American Museum of Natural History. This visualization
was supported by the National Oceanic and Atmospheric Administration
Modern human culture underwent a "creative explosion" in Ice Age Europe 40,000 to 10,000 years ago. The evidence, which ranges from fantastic cave paintings to elaborate graves to innovative tools, is a sure sign that human symbolic thought-our ability to create and combine meaningful symbols to represent the world-was in full bloom. What evolutionary steps seeded this mental flowering? This Human Bulletin video follows the ongoing excavations of Christopher Henshilwood, an archaeologist who is seeking the earliest evidence of our species' unique mental powers. Recent finds dating to 72,000 years ago at his South African excavation site, Blombos Cave, are slowly shedding light an era of human culture that has been all but dark.
The history of cosmic ray research is a story of scientific adventure. For nearly a century, cosmic ray researchers have climbed mountains, soared in hot air balloons, and traveled to the far corners of the Earth in the quest to understand these energetic particles from space. They have solved some scientific mysteries—and revealed many more. With each passing decade, scientists have discovered higher-energy and increasingly more rare cosmic rays. The Pierre Auger Project is the largest scientific enterprise ever conducted to search for the unknown sources of the highest-energy cosmic rays ever observed.
On cloudless, moonless nights, the stars are so bright over the remote village of Sutherland, South Africa, that a person can walk by starlight alone. Learn more about the village’s Southern African Large Telescope (SALT).
Scientists have been studying brown dwarfs, or failed stars, for nearly a century. What have they learned? And what answers are they still seeking about these objects stuck somewhere between stars and planets?
Two teams working independently in 1998 came to the same conclusion: An invisible force, one that seems to act opposite gravity, is separating the matter in space at an increasing pace. Find out more about their “jaw-dropping” discovery.
If LIGO regularly registers gravitational waves, it will more than vindicate Einstein. The observatory may help answer pressing questions about the cosmos’s biggest mysteries, among them black holes, dark matter, and the Big Bang.