“How can you see the atmosphere? By tracking what is carried on the wind. Tiny aerosol particles such as smoke, dust, and sea salt are transported across the globe, making visible weather patterns and other normally invisible physical processes.
This visualization uses data from NASA satellites, combined with mathematical models in a computer simulation allowing scientists to study the physical processes in our atmosphere. By following the sea salt that is evaporated from the ocean, you can see the storms of the 2017 hurricane season. During the same time, large fires in the Pacific Northwest released smoke into the atmosphere. Large weather patterns can transport these particles long distances: in early September, you can see a line of smoke from Oregon and Washington, down the Great Plains, through the South, and across the Atlantic to England.
Dust from the Sahara is also caught in storms systems and moved from Africa to the Americas. Unlike the sea salt, however, the dust is removed from the center of the storm. The dust particles are absorbed by cloud droplets and then washed out as it rains.”
“Atmospheric carbon dioxide is the most important human-made greenhouse gas responsible for global warming. Oceans assist in removing carbon dioxide from the atmosphere: phytoplankton accumulate carbon dioxide through photosynthesis and their chlorophyll colours the ocean’s waters. Satellites use this colour to measure chlorophyll, which helps scientists to calculate how much carbon dioxide is absorbed or emitted.”
Video credit: ESA/CCI Ocean Colour/Climate Monitoring User Group/Planetary Visions
“Explorer 1 showed that the United States was capable of not only launching a satellite but also carrying out scientific research in space. For four months after launch, instruments aboard Explorer 1 measured and sent back data on temperature, micrometeorites and cosmic rays, or high-energy radiation. University of Iowa physicist James Van Allen’s instrument for measuring cosmic rays, a Geiger counter, helped make the first major scientific find of the Space Age: a belt of radiation around Earth that would later be named in Van Allen’s honor.
“Explorer 1 was a beginning. It was the beginning of going beyond our sphere of life out into space,” said Thomas Zurbuchen, NASA associate administrator for science. “At first, quite frankly, space looked like a pretty boring place. But the instrument that Van Allen and his team built showed that space is beautiful.”
On the heels of Explorer 1’s success, the nation entered a new era of discovery on Earth and beyond that continues to this day.
In 1960, NASA launched the world’s first weather satellite, the Television and Infrared Observation Satellite (TIROS). The United States now has an extensive fleet of weather satellites operated by the National Oceanographic and Atmospheric Administration (NOAA) that monitors storms and other natural disasters and provides critical data that helps save lives and protect critical infrastructure.
In 1972, NASA designed and launched Earth Resources Technology Satellite 1, later renamed Landsat 1, as the first spacecraft designed to monitor the planet’s land masses. Subsequent Landsat satellites, now operated by the U.S. Geological Survey, have produced over four decades of continuous data about our changing planet that have been applied to such uses as crop health monitoring, freshwater and forest management and infectious disease tracking.
NASA has a long history of using the vantage point of space to advance our understanding of our complex home planet. The Nimbus-1 satellite launched in 1964 was the first of seven such spacecraft that revolutionized Earth science. Nimbus satellites measured snow cover at the North and South poles, estimated the size of volcanic eruptions and the distribution of phytoplankton in the oceans and confirmed the existence of the annual ozone hole in Antarctica. NASA’s current fleet of more than a dozen Earth-observing missions continues to provide new insights about Earth’s interconnected systems.
Looking beyond Earth’s horizon, in 1962 NASA launched Mariner 2, the first satellite to encounter another planet as the spacecraft flew within 21,000 miles of Venus and sent back information on not only the Venusian atmosphere but also the solar wind. The space agency has since dispatched satellites to explore every planet in the solar system, in addition to the Sun and a number of moons, comets and asteroids.
NASA has also long set its gaze out into the cosmos. From 1966 to 1972, the Orbiting Astronomical Observatory series of satellites provided the first high-quality ultraviolet observations of stars at the edge of the Milky Way. The space agency has continued its groundbreaking research into the mysteries of the universe with the 2004 launch of the Swift Gamma-ray Burst Explorer, which has imaged the most luminous known galaxies in addition to detecting millions of black holes and dwarf stars.
America’s 60 years of space science has yielded profound insights and practical benefits for the nation and the world. And NASA continues to blaze new trails of discovery.”
Video credit: NASA’s Goddard Space Flight Center/LK Ward
“The more we see other planets, the more the question comes into focus: Maybe we’re the weird one? Decades of observing Earth from space has informed our search for signs of habitability and life on exoplanets and even planets in our own solar system. We’re taking a closer look at what we’ve learned about Earth – our only example of a planet with life – to our search for life the universe.”
Music credit: Curious Events by Independent Film Score – Andrew Skeet; Teapot Waltz by Benjamin James Parsons; Patisserie Pressure by Benjamin James Parsons
Video credit: NASA’s Goddard Space Flight Center/LK Ward
“When exoplanet scientists first spotted patterns in disks of dust and gas around young stars, they thought newly formed planets might be the cause. But a recent NASA study cautions that there may be another explanation: one that doesn’t involve planets at all. An alternative explanation suggests the dust and gas in the disk can form the patterns themselves when they interact with starlight.
When high-energy UV starlight hits dust grains, it strips away electrons. Those electrons collide with and heat nearby gas. As the gas warms, its pressure increases and it traps more dust, which in turn heats more gas. The resulting cycle, called the photoelectric instability (PeI), can work in tandem with other forces to create some of the features astronomers have previously associated with planets in debris disks.
A 2013 study suggested PeI could explain the narrow rings seen in some disks. The model also predicted that some disks would have arcs, or incomplete rings, which weren’t directly observed in a disk until 2016. The new simulation includes an additional new factor: radiation pressure, a force caused by starlight striking dust grains. Light exerts a minute physical force on everything it encounters. This radiation pressure propels solar sails and helps direct comet tails so they always point away from the Sun. The same force can push dust into highly eccentric orbits, and even blow some of the smaller grains out of the disk entirely. The new research modeled how radiation pressure and PeI work together to affect the movement of dust and gas, and also found that the two forces manifest different patterns depending on the physical properties of the dust and gas.”
Music credit: “Hyperborea” from Killer Tracks
Video credit: NASA’s Goddard Space Flight Center/Scott Wiessenger
“Observations by NASA’s Swift spacecraft, now renamed the Neil Gehrels Swift Observatory after the mission’s late principal investigator, have captured an unprecedented change in the rotation of a comet. Images taken in May 2017 reveal that comet 41P/Tuttle-Giacobini-Kresak — 41P for short — was spinning three times slower than it was in March, when it was observed by the Discovery Channel Telescope at Lowell Observatory in Arizona. The abrupt slowdown is the most dramatic change in a comet’s rotation ever seen.
Comet 41P orbits the Sun every 5.4 years. As a comet nears the Sun, increased heating causes its surface ice to change directly to a gas, producing jets that launch dust particles and icy grains into space. This material forms an extended atmosphere, called a coma.
Ground-based observations established the 41P’s initial rotational period at about 20 hours in early March 2017 and detected its slowdown later the same month. The comet passed 13.2 million miles (21.2 million km) from Earth on April 1, and eight days later made its closest approach to the Sun. Swift’s Ultraviolet/Optical Telescope imaged the comet from May 7 to 9, revealing brightness variations associated with material recently ejected into the coma. These slow changes indicated 41P’s rotation period had more than doubled, to between 46 and 60 hours.
UVOT-based estimates of 41P’s water production, coupled with the body’s small size, suggest that more than half of its surface area contains sunlight-activated jets. That’s a far greater fraction of active real estate than on most comets, which typically support jets over only about 3 percent of their surfaces. Astronomers suspect these active areas are favorably oriented to produce torques that slowed 41P’s spin.
Such a slow spin could make the comet’s rotation unstable, allowing it to begin tumbling with no fixed rotational axis. This would produce a dramatic change in the comet’s seasonal heating and may result in future outbursts of activity.”
Music credit: “Valley of Crystals” from Killer Tracks
Video credit: NASA’s Goddard Space Flight Center/Scott Wiessinger
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