Posted on by Nancy Atkinson

The Black Marble: Stunning New Orbital Views of Earth at Night

This image of Asia and Australia at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. Credit: NASA, NOAA, and the Department of Defense.

Two months of night-time imagery gathered by the Suomi NPP satellite have resulted in a stunning new look at Earth at night, appropriately nicknamed the Black Marble.

The nighttime views were made possible by the new satellite’s “day-night band” of the Visible Infrared Imaging Radiometer Suite. VIIRS detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as city lights, gas flares, auroras, wildfires, and reflected moonlight. In this case, auroras, fires, and other stray light have been removed to emphasize the city lights.

“This is not your father’s low light sensor!” said Steve Miller, senior research scientist and deputy director of the Cooperative Institute for Research in the Atmosphere (CIRA), Colorado State University, speaking at the American Geophysical Union conference this week.

See more views and a video presentation of the VIIRS data below:

The new satellite is providing a much higher resolution across a greater band of light than previous night-light gathering satellites.

Originally developed for meteorologists to be able to look at nighttime clouds, the VIIRS data is providing a wide variety of information. “We are getting as much mileage from these data sets as we can,” said Chris Elvidge, who leads the Earth Observation Group at NOAA’s National Geophysical Data Center.

Elvidge and Miller said the data is being used to model population distribution, fossil fuel and CO2 emissions, and other information that can be gleaned from nighttime lights such finding power outages, determining astronomical viewing conditions, providing site selection for astronomical observatories, and looking at impacts of artificial lights on humans and animals.

The difference between electrical lights and fires, and night glow and auroras can even be determined by VIIRS.

North and South America at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. Credit: NASA, NOAA, and the Department of Defense.

Europe, Africa, and the Middle East at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. Credit: NASA, NOAA, and the Department of Defense.

Named for satellite meteorology pioneer Verner Suomi, NPP flies over any given point on Earth’s surface twice each day at roughly 1:30 a.m. and p.m. The polar-orbiting satellite flies 824 kilometers (512 miles) above the surface, sending its data once per orbit to a ground station in Svalbard, Norway, and continuously to local direct broadcast users distributed around the world,
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See more imagery and get additional information about the night-time VIIRS Data at the NASA Earth Observatory website.

Posted on by Jason Major

In the Shadow of the Moon: Experience a Solar Eclipse From 37 Kilometers Up

The Moon’s shadow stretches over the Earth in this balloon-mounted camera view of the November 14 solar eclipse (Catalin Beldea, Marc Ulieriu, Daniel Toma et. al/Stiinta&Tehnica)

On November 14, 2012, tens of thousands of viewers across northeastern Australia got a great view of one of the most awe-inspiring sights in astronomy — a total solar eclipse. Of course many fantastic photos and videos were taken of the event, but one team of high-tech eclipse hunters from Romania went a step further — or should I say higher — and captured the event from a video camera mounted on a weather balloon soaring over 36,800 meters (120,000 feet) up!

Their video can be seen below:

During a solar eclipse the Moon passes in front of the disk of the Sun, casting its shadow upon the Earth. Any viewers within the darkest part of the shadow — the umbra — will experience a total eclipse, while those within the wider, more diffuse shadow area along the perimeter — the penumbra — will see a partial eclipse.

By launching a weather balloon carrying a wide-angle camera into the stratosphere above Queensland, eclipse hunter and amateur astronomer Catalin Beldea, ROSA research scientist Florin Mingireanu and others on the team were able to obtain their incredible video of the November 14 total eclipse from high enough up that the shadow of the Moon was visible striking Earth’s atmosphere. Totality only lasted a couple of minutes so good timing was essential… but they got the shot. Very impressive!

The mission was organized by teams from the Romanian Space Agency (ROSA) and  Stiinta&Tehnica.com, with the video assembled by Daniel Toma and posted on YouTube by editor-in-chief Marc Ulieriu. Music by Shamil Elvenheim.

Posted on by Jason Major

A Branching “Tree” of Solar Plasma

Hydrogen-alpha photo of the Sun by Alan Friedman

An enormous tree-shaped prominence spreads its “branches” tens of thousands of miles above the Sun’s photosphere in this image, a section of a photo acquired in hydrogen alpha (Ha) by Alan Friedman last week from his backyard in Buffalo, NY.

Writes Alan on his blog, “gotta love a sunny day in November!”

Check out the full image — along with an idea of just how big this “tree” is — after the jump:

Taken through a special solar telescope and a Grasshopper CCD camera, Alan’s gorgeous solar photos show the Sun in a wavelength absorbed by atomic hydrogen — most present in the photosphere and chromosphere — thus revealing the complex and dynamic activity of the Sun’s “surface”.

Here’s the full image:

The dark circle at upper left (added by me) shows approximately the scale size of Earth (12,756 km, or about 7,926 miles diameter.) As you can see, that particular prominence is easily six times that in altitude, and spreads out many more times wider… and this isn’t even a particularly large prominence! As far as solar activity goes, this is a non-event. (Not like what was seen by SDO on Nov. 16!)

Regardless, it makes for an impressive backyard photo.

Check out more of Alan’s photos on his blog and on his website, AvertedImagination.com. Many of his photos, some of which have been shown at galleries across the U.S., are available as limited-edition prints. (Alan also runs a greeting card print studio.) I’ve found that he usually shares at least a couple of fantastic solar shots every month, if not more.

Image © Alan Friedman. All rights reserved. Used with permission.

 

Posted on by Jason Major

From Eternity to Here: The Amazing Origin of our Species (in 90 Seconds)

From the initial expansion of the Big Bang to the birth of the Moon, from the timid scampering of the first mammals to the rise — and fall — of countless civilizations, this fascinating new video by melodysheep (aka John D. Boswell) takes us on a breathless 90-second tour through human history — starting from the literal beginnings of space and time itself. It’s as imaginative and powerful as the most gripping Hollywood trailer… and it’s even inspired by a true story: ours.

Enjoy!

(Video by melodysheep, creator of the Symphony of Science series.)

Posted on by Jason Major

Isotopic Evidence of the Moon’s Violent Origins

Artist’s impression of an impact of two planet-sized worlds (NASA/JPL-Caltech)

Scientists have uncovered a history of violence hidden within lunar rocks, further evidence that our large, lovely Moon was born of a cataclysmic collision between worlds billions of years ago.

Using samples gathered during several Apollo missions as well as a lunar meteorite that had fallen to Earth (and using Martian meteorites as comparisons) researchers have observed a marked depletion in lunar rocks of lighter isotopes, including those of zinc — a telltale element that can be “a powerful tracer of the volatile histories of planets.”

The research utilized an advanced mass spectroscopy instrument to measure the ratios of specific isotopes present in the lunar samples. The spectrometer’s high level of precision allows for data not possible even five years ago.

Scientists have been looking for this kind of sorting by mass, called isotopic fractionation, since the Apollo missions first brought Moon rocks to Earth in the 1970s, and Frédéric Moynier, PhD, assistant professor of Earth and Planetary Sciences at Washington University in St. Louis — together with PhD student, Randal Paniello, and colleague James Day of the Scripps Institution of Oceanography — are the first to find it.

The team’s findings support a now-widely-accepted hypothesis — called the Giant Impact Theory, first suggested by PSI scientists William K. Hartmann and Donald Davis in 1975 — that the Moon was created from a collision between early Earth and a Mars-sized protoplanet about 4.5 billion years ago. The effects of the impact eventually formed the Moon and changed the evolution of our planet forever — possibly even proving crucial to the development of life on Earth.

(What would a catastrophic event like that have looked like? Probably something like this:)

Read more: What’s the Moon Made Of? Earth, Most Likely.

“This is compelling evidence of extreme volatile depletion of the moon,” said Scripps researcher James Day, a member of the team. “How do you remove all of the volatiles from a planet, or in this case a planetary body? You require some kind of wholesale melting event of the moon to provide the heat necessary to evaporate the zinc.”

In the team’s paper, published in the October 18 issue of Nature, the researchers suggest that the only way for such lunar volatiles to be absent on such a large scale would be evaporation resulting from a massive impact event.

“When a rock is melted and then evaporated, the light isotopes enter the vapor phase faster than the heavy isotopes, so you end up with a vapor enriched in the light isotopes and a solid residue enriched in the heavier isotopes. If you lose the vapor, the residue will be enriched in the heavy isotopes compared to the starting material,” explains Moynier.

The fact that similar isotopic fractionation has been found in lunar samples gathered from many different locations indicates a widespread global event, and not something limited to any specific regional effect.

The next step is finding out why Earth’s crust doesn’t show an absence of similar volatiles, an investigation that may lead to clues to where Earth’s surface water came from.

“Where did all the water on Earth come from?” asked Day. “This is a very important question because if we are looking for life on other planets we have to recognize that similar conditions are probably required. So understanding how planets obtain such conditions is critical for understanding how life ultimately occurs on a planet.”

“The work also has implications for the origin of the Earth,”  adds Moynier, “because the origin of the Moon was a big part of the origin of the Earth.”

Read more on the Washington University news release and at the UC San Diego news center.

Inset image: Cross-polarized transmitted-light image of a lunar rock. Photo by James Day, Scripps/UCSD

Posted on by Jason Major

35 Years Ago: Our First Family Portrait of the Earth and Moon

A crescent Earth and Moon as seen by Voyager 1 on September 18, 1977 (NASA)

35 years ago today, September 18, 1977, NASA’s Voyager 1 spacecraft turned its camera homeward just about two weeks after its launch, capturing the image above from a distance of 7.25 million miles (11.66 million km). It was the first time an image of its kind had ever been taken, showing the entire Earth and Moon together in a single frame, crescent-lit partners in space.

The view of Earth shows eastern Asia, the western Pacific Ocean and part of the Arctic. Voyager 1 was actually positioned directly above Mt. Everest when the images were taken (the final color image was made from three separate images taken through color filters.)

The Moon was brightened in the original NASA images by a factor of three, simply because Earth is so much brighter that it would have been overexposed in the images were they set to expose for the Moon. (Also I extended the sides of the image a bit above to fit better within a square format.)

Read the latest on Voyager 1: Winds of Change at the Edge of the Solar System

Previous images may have shown the Earth and Moon together, but they were taken from orbit around one or the other and as a result didn’t have both worlds fully — and in color! — within a single frame like this one does. In fact, it was only 11 years earlier that the very first image of Earth from the Moon was taken, acquired by NASA’s Lunar Orbiter I spacecraft on August 23, 1966.

It’s amazing to think what was happening in the world when Voyager took that image:
• World population was 4.23 billion (currently estimated to be 7.04 billion)
• The Space Shuttle Enterprise made its first test flight from a 747
• Star Wars, Close Encounters of the Third Kind and Saturday Night Fever were out in U.S. theaters
• Charlie Chaplin and Elvis Presley died
• U.S. federal debt was “only” $706 billion (now over $16 trillion!)
• And, of course, both Voyagers launched on their Grand Tour of the Solar System, ultimately becoming the most distant manmade objects in existence
(See more world stats and events here.)

Image: NASA/JPL

“Once a photograph of the Earth, taken from outside, is available – once the sheer isolation of the Earth becomes known – a new idea as powerful as any in history will be let loose.”
– Sir Fred Hoyle

Posted on by Jenny Winder

Scientists Find Clues of Plate Tectonics on Mars

Valles Marineris NASA World Wind map Mars Credit NASA

Caption: Valles Marineris NASA World Wind Map Mars Credit: NASA

Until now, Earth was thought to be the only planet with plate tectonics. But a huge “crack” in Mars’ surface — the massive Valles Marinaris — shows evidence of the movement of huge crustal plates beneath the planet’s surface, meaning Mars may be showing the early stages of plate tectonics. This discovery can perhaps also shed light on how the plate tectonics process began here on Earth.

Valles Marineris is no ordinary crack on the Martian surface. It is the longest and deepest system of canyons in the Solar System. Stretching nearly 2,500 miles, it is nine times longer than Earth’s Grand Canyon.

An Yin, a planetary geologist and UCLA professor of Earth and space sciences, analyzed satellite images from THEMIS (Thermal Emission Imaging System), on board the Mars Odyssey spacecraft, and from the HIRISE (High Resolution Imaging Science Experiment) camera on NASA’s Mars Reconnaissance Orbiter.

“When I studied the satellite images from Mars, many of the features looked very much like fault systems I have seen in the Himalayas and Tibet, and in California as well, including the geomorphology,” he said.

The two plates that Yin calls Valles Marineris North and Valles Marineris South are moving approximately 93 miles horizontally relative to each other. By comparison, California’s San Andreas Fault, which is similarly over the intersection of two plates, has moved about twice as much, because Earth is about twice the size of Mars.

Yin believes Mars has no more than two plates whereas Earth has seven major plates and dozens of smaller ones. As Yin puts it “Earth has a very broken ‘egg shell,’ so its surface has many plates; Mars’ is slightly broken and may be on the way to becoming very broken, except its pace is very slow due to its small size and, thus, less thermal energy to drive it. This may be the reason Mars has fewer plates than on Earth.”

Mars also has several long, straight chains of volcanoes, including three that make up the Tharsis Montes, three large shield volcanoes which includes Olympus Mons, the tallest mountain in the Solar System at 22 km high. These volcanic chains may have formed from the motion of a plate sitting over a “hot spot” in the Martian mantle, in the same way the Hawaiian Islands are thought to have formed here on Earth. Yin also identified a steep cliff similar to cliffs in California’s Death Valley, which are generated by a fault, as well as a very smooth and flat side of a canyon wall which Yin says is also strong evidence of tectonic activity.

Yin also suggests that the fault is shifting occasionally, and may even produce “Marsquakes” every now and again. “I think the fault is probably still active, but not every day. It wakes up every once in a while, over a very long duration — perhaps every million years or more,” he said.

It is not known how far beneath the surface the plates on Mars are located. Yin admits “I don’t quite understand why the plates are moving with such a large magnitude or what the rate of movement is; maybe Mars has a different form of plate tectonics,” Yin said. “The rate is much slower than on Earth.”

“Mars is at a primitive stage of plate tectonics,” Yin added. “It gives us a glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth.”

Yin’s study was published in the August issue of the journal Lithosphere and he also plans to publish a follow-up paper hoping to shed more light on plate tectonics on both Mars and Earth.

Read the abstract.

Find out more at the

Posted on by Jason Major

New Satellites Will Tighten Knowledge of Earth’s Radiation Belts


Surrounding our planet like vast invisible donuts (the ones with the hole, not the jelly-filled kind) are the Van Allen radiation belts, regions where various charged subatomic particles get trapped by Earth’s magnetic fields, forming rings of plasma. We know that the particles that make up this plasma can have nasty effects on spacecraft electronics as well as human physiology, but there’s a lot that isn’t known about the belts. Two new satellites scheduled to launch on August 23 August 24 will help change that.

“Particles from the radiation belts can penetrate into spacecraft and disrupt electronics, short circuits or upset memory on computers. The particles are also dangerous to astronauts traveling through the region. We need models to help predict hazardous events in the belts and right now we are aren’t very good at that. RBSP will help solve that problem.”
– David Sibeck, RBSP project scientist, Goddard Space Flight Center

NASA’s Radiation Belt Storm Probes (RBSP) mission will put a pair of identical satellites into eccentric orbits that take them from as low as 375 miles (603 km) to as far out as 20,000 miles (32,186 km). During their orbits the satellites will pass through both the stable inner and more variable outer Van Allen belts, one trailing the other. Along the way they’ll investigate the many particles that make up the belts and identify what sort of activity occurs in isolated locations and across larger areas.

“Definitely the biggest challenge that we face is the radiation environment that the probes are going to be flying through,” said Mission Systems Engineer Jim Stratton at APL. “Most spacecraft try to avoid the radiation belts — and we’re going to be flying right through the heart of them.”

Read: The Van Allen Belts and the Great Electron Escape

Each 8-sided RBSP satellite is approximately 6 feet (1.8 meters) across and weighs 1,475 pounds (669 kg).

The goal is to find out where the particles in the belts originate from — do they come from the solar wind? Or Earth’s own ionosphere? — as well as to find out what powers the belts’ variations in size and gives the particles their extreme speed and energy. Increased knowledge about Earth’s radiation belts will also help in the understanding of the plasma environment that pervades the entire Universe.

Read: What Are The Radiation Belts?

Ultimately the information gathered by the RBSP mission will help in the design of future science and communications satellites as well as safer spacecraft for human explorers.

The satellites are slated to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station no earlier than 4:08 a.m. EDT on August 24.

Find out more about the RBSP mission here.

Video/rendering: NASA/GSFC.

Posted on by Jason Major

Greenland Glacier Calves Another Huge Ice Island

Petermann glacier, a 70 km (43 mile) long tongue of ice that flows into the Arctic Ocean in northwest Greenland, recently calved an “ice island” approximately 130 square kilometers (50 sq. miles) — about twice the area of Manhattan. The image above, acquired by NASA’s Terra satellite, shows the ice island as it drifts toward the ocean five days after breaking off the main glacier.

Petermann glacier has been known for birthing massive ice islands; previously in August 2010 an even larger island broke away from the glacier, measuring 251 square kilometers (97 sq. miles). That slab of ice eventually drifted into the northern Atlantic and was even visible from the Space Station a year later!

Read: Manhattan-Sized Ice Island Seen From Space

Although some of Greenland’s glaciers have been observed to be quickening their seaward pace as a result of global warming, this particular calving event — which occurred along a crack that appeared in 2001 satellite imagery — isn’t thought to be a direct result of climate but rather of ocean currents and isn’t expected to have any significant effect on the rate of Greenland’s ice loss as a whole. Still, satellite observation of such events provides valuable data for researchers monitoring the processes that are involved with rapidly accelerating Arctic ice loss.

And if you want an idea of what a slab of ice this large looks like up close, here’s a video taken by researchers on approach to a smaller chunk of the 2011 island:

NASA Earth Observatory image by Jesse Allen, using data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. (NASA/Terra)

Posted on by Jason Major

The Top 5 “Earth as Art” Images, Thanks to Landsat

NASA’s first Earth-observing Landsat satellite launched from Vandenberg Air Force Base on July 23, 1972, and to celebrate the 40th anniversary of the program they asked the public to vote on their favorite images of the planet from the Landsat Earth as Art gallery. After over 14,000 votes, these were chosen as the top 5 favorites. Happy 40th anniversary, Landsat!

Landsat images from space are not merely pictures. They contain many layers of data collected at different points along the visible and invisible light spectrum. A single Landsat scene taken from 400 miles above Earth can accurately detail the condition of hundreds of thousands of acres of grassland, agricultural crops or forests.

“Landsat has given us a critical perspective on our planet over the long term and will continue to help us understand the big picture of Earth and its changes from space,” said NASA Administrator Charles Bolden. “With this view we are better prepared to take action on the ground and be better stewards of our home.”

In cooperation with the U.S. Geological Survey (USGS), a science agency of the Interior Department, NASA launched six of the seven Landsat satellites. The resulting archive of Earth observations forms a comprehensive record of human and natural land changes.

“The first 40 years of the Landsat program have delivered the most consistent and reliable record of Earth’s changing landscape.”

– Michael Freilich, director of NASA’s Earth Science Division

“Over four decades, data from the Landsat series of satellites have become a vital reference worldwide for advancing our understanding of the science of the land,” said Interior Department Secretary Ken Salazar. “The 40-year Landsat archive forms an indelible and objective register of America’s natural heritage and thus it has become part of this department’s legacy to the American people.”

The next satellite in the series, the Landsat Data Continuity Mission (LDCM) is scheduled to launch on February 11, 2013.

(Source: NASA/GSFC)

Find out more about the ongoing Landsat mission here, and see recent visualizations from Landsat on the USGS site here.

Video: NASA/GSFC. Inset image: Industrial growth in Binhai New Area, China.  Sub-feature: Erg Iguidi, an area of ever-shifting sand dunes extending from Algeria into Mauritania in northwestern Africa, one of the chosen top 5 Earth as Art images. NASA/GSFC/USGS.