Satellites give us views of our planet’s constantly-changing systems as never seen before (Earth From Space, ©PBS)

Earth… our home planet, a brilliant “blue marble” tirelessly turning through space on an endless journey around the Sun and across the galaxy. Basically a ball of  molten rock and metal, its relatively thin crust is mostly covered by a sea of liquid water as well as wrapped in a sea of air… and it’s the complex interaction between all of these things that have allowed life to evolve, thrive, and — so far, anyway — continue to exist on this one particular world.

But how exactly does this work? How, and why, do all of these different factors combine to make a habitable planet? Energy from the Sun, the movement of the atmosphere, the planet’s rotation, the constant churning of ocean currents,  the upwelling of materials from deep inside the Earth… all of these play essential roles every day in the survival of nearly every living thing on our planet — including us. To truly understand life on Earth, we must first understand the complex interactions of these forces, and more.

Luckily we have satellites, our “eyes in the sky” that let us look at the entire world on a daily basis and measure and monitor many different processes like never before, letting us see the otherwise invisible big picture of Earth From Space.

Produced by PBS as part of their long-running and much-respected NOVA series, Earth From Space shows us how some of the more than 120 satellites orbiting the planet are providing invaluable and unprecedented data on the atmospheric, geologic, and hydrologic processes taking place across the globe.

From the ways the Sun heats the planet to the complex behavior of ice at the poles, from how ocean currents provide food for oxygen-producing phytoplankton to how ancient dust from the Sahara fertilizes soil in the Amazon, from Mumbai’s monsoons to the Atacama desert, Earth From Space tells how these seemingly separate events are all actually related in a web of connections fundamental to life as we know it.

Earth From Space shows there’s not a day that goes by that any one point on the planet isn’t influenced  by what’s happening somewhere else, whether ten or ten thousand — or 93 million! — miles away. And without satellites, there’s no way we’d even know about many of these processes and connections.

“The real power of satellites is that they represent  objective truth.” (©PBS)

“It’s really the last bastion of human discovery,” says Emily Shuckbergh of the British Antarctic Survey, “we’re discovering new things every day.”

Presented as an engrossing 120-minute documentary with amazing high-definition images of the planet from satellites, from the ISS and from exotic locations around the world, Earth From Space is a beautiful presentation of the informative power of these orbiting instruments — as well as a testament to their continued importance.

“The real power of satellite observations is that they represent objective truth,” says Piers Sellers of NASA’s Goddard Space Flight Center.

Sadly, with many satellites coming to the end of their operational lives — some after several decades — and with no replacements planned, we may soon be left in the dark about ongoing global processes we have just begun to understand. And in a world of growing human population, rapidly changing climates, and increasingly unstable ecosystems, losing sight of the big picture is a frightening prospect indeed.

Want to learn more? You can watch Earth From Space on PBS’s website here, buy the video on iTunes or order a copy of the DVD or Blu-Ray ($19.99 DVD/$24.99 Blu-Ray). And, if you want to WIN a free copy, send an email to “lightsinthedark” at “me.com” with subject line “Earth From Space.” On May 31 I’ll select five random winners to receive a free copy… two will receive a high-definition Blu-Ray version! (Note your preference, if possible.)

Good luck, and find this and more science presentations from NOVA here.

Screenshots via Earth From Space ©2013 PBS. All rights reserved.

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Now in its 40th season, NOVA is the most-watched primetime science series on American television, reaching an average of five million viewers weekly. The series remains committed to producing in-depth science programming in the form of hour-long (and occasionally longer) documentaries, from the latest breakthroughs in technology to the deepest mysteries of the natural world. NOVA airs Wednesdays at 9pm ET/PT on WGBH Boston and most PBS stations. 

The spinning vortex over Saturn’s north pole, imaged by Cassini. (NASA/JPL-Caltech/SSI)

An incredible 1,200-mile-wide vortex of spiraling clouds swirling above Saturn’s north pole is seen in all its glory in this stunning image from NASA’s Cassini spacecraft, originally captured last year but recently released by NASA on April 29.

Taking advantage of a new orbital trajectory that puts it high above Saturn’s rings and poles, Cassini acquired the near-infrared images used to make this composite back on Nov. 27, 2012. The resulting image is false color — our eyes aren’t sensitive to those particular wavelengths of light — but still no less amazing!

Read the rest of my article here.

Five images of Saturn’s rings, taken by NASA’s Cassini spacecraft between 2009 and 2012, show clouds of material ejected from impacts of small objects into the rings. (NASA/JPL-Caltech/SSI)

NASA’s Cassini spacecraft has provided the first direct evidence of small meteoroids breaking into streams of rubble and crashing into Saturn’s rings.

These observations make Saturn’s rings the only location besides Earth, the Moon and Jupiter where meteor impacts have been observed as they occur. The meteoroids at Saturn are estimated to range from about one-half inch to several yards (1 centimeter to several meters) in size.

“These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth — two very different neighborhoods in our solar system — and this is exciting to see,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It took Saturn’s rings acting like a giant meteoroid detector — 100 times the surface area of the Earth — and Cassini’s long-term tour of the Saturn system to address this question.”

Results from Cassini have already shown Saturn’s rings act as very effective detectors of many kinds of surrounding phenomena, including the interior structure of the planet and the orbits of its moons. For example, a subtle but extensive corrugation that ripples 12,000 miles (19,000 kilometers) across the innermost rings tells of a very large meteoroid impact in 1983.

The Saturnian equinox in summer 2009 was an especially good time to see the debris left by meteoroid impacts. The very shallow sun angle on the rings caused the clouds of debris to look bright against the darkened rings in pictures from Cassini’s imaging science subsystem.

“We knew these little impacts were constantly occurring, but we didn’t know how big or how frequent they might be, and we didn’t necessarily expect them to take the form of spectacular shearing clouds,” said Matt Tiscareno, lead author of the paper and a Cassini participating scientist at Cornell University in Ithaca, N.Y. “The sunlight shining edge-on to the rings at the Saturnian equinox acted like an anti-cloaking device, so these usually invisible features became plain to see.”

Tiscareno and his colleagues now think meteoroids of this size probably break up on a first encounter with the rings, creating smaller, slower pieces that then enter into orbit around Saturn. The impact into the rings of these secondary meteoroid bits kicks up the clouds. The tiny particles forming these clouds have a range of orbital speeds around Saturn. The clouds they form soon are pulled into diagonal, extended bright streaks.

This animation depicts the shearing of an initially circular cloud of debris as a result of the particles in the cloud having differing orbital speeds around Saturn. (Click to play)

“Saturn’s rings are unusually bright and clean, leading some to suggest that the rings are actually much younger than Saturn,” said Jeff Cuzzi, a co-author of the paper and a Cassini interdisciplinary scientist specializing in planetary rings and dust at NASA’s Ames Research Center in Moffett Field, Calif. “To assess this dramatic claim, we must know more about the rate at which outside material is bombarding the rings. This latest analysis helps fill in that story with detection of impactors of a size that we weren’t previously able to detect directly.”

Source: NASA/JPL Cassini news release