Gamma-ray bursts—flashes of intense radiation in space that are often just seconds long—were accidentally discovered in the 1960's by satellites built to monitor nuclear bomb explosions. They've been one of the leading astrophysical mysteries ever since. This Astro Bulletin introduces you to the scientists and instruments working to unravel the origins of gamma-ray bursts. It highlights Swift, NASA's burst-detecting satellite, and PAIRITEL, one of a fleet of ground-based telescopes that point toward a gamma-ray burst in response to Swift's alert to capture the afterglow before it fades. Astrophysicists at Penn State and other institutions are analyzing these afterglows to understand what causes the most powerful explosions known
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.
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.
In 1912, Viktor Hess took to the sky in a hot-air balloon and discovered a radioactive energy now called “cosmic rays.” Travel to Argentina to see how scientists now hope to discover at long last where the highest-energy cosmic rays are coming from.
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?