The Goddard Space Flight Center has a Flickr account showcasing a series of images of our own home planet. Called “Blue Marble,” these spectacular images are the most detailed true-color image of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations in 2001 of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. Your tax dollars at work, these images are freely available to educators, scientists, museums, and the public. This record includes preview images and links to full resolution versions up to 21,600 pixels across.
Our blue marble. Credit: NASA
Compare these new images to the original “Blue Marble” photograph, below, taken by the Apollo 17 crew in 1968. The original Blue Marble by Apollo 17.
This view of Earth comes from NASA's Moderate Resolution Imaging Spectroradiometer aboard the Terra satellite.
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Yikes! Just how big was the magnitude 8.8 earth quake in Chile? One scientist says the shaking may have affected the entire planet by shifting Earth on its axis. This possibly may have shortened the length of a day on Earth by about 1.26 microseconds. Using a complex model JPL research scientist Richard Gross computed how Earth’s rotation should have changed as a result of the Feb. 27, 2010 quake. If his figures are correct, the quake should have moved Earth’s figure axis (the axis about which Earth’s mass is balanced) by 2.7 milliarcseconds (about 8 centimeters, or 3 inches).
Earth’s figure axis is not the same as its north-south axis; they are offset by about 10 meters (about 33 feet). By comparison, Gross said the same model estimated the 2004 magnitude 9.1 Sumatran earthquake should have shortened the length of day by 6.8 microseconds and shifted Earth’s axis by 2.32 milliarcseconds (about 7 centimeters, or 2.76 inches).
Gross said that even though the Chilean earthquake is much smaller than the Sumatran quake, it is predicted to have changed the position of the figure axis by a bit more for two reasons. First, unlike the 2004 Sumatran earthquake, which was located near the equator, the 2010 Chilean earthquake was located in Earth’s mid-latitudes, which makes it more effective in shifting Earth’s figure axis.
Second, the fault responsible for the 2010 Chiliean earthquake dips into Earth at a slightly steeper angle than does the fault responsible for the 2004 Sumatran earthquake. This makes the Chile fault more effective in moving Earth’s mass vertically and hence more effective in shifting Earth’s figure axis.
Gross said the Chile predictions will likely change as data on the quake are further refined.
Zonal swishing in the Earth's outer core (Credit: Akira Kageyama, Kobe University)
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Why does the Earth’s magnetic field ‘flip’ every million years or so? Whatever the reason, or reasons, the way the liquid iron of the Earth’s outer core flows – its currents, its structure, its long-term cycles – is important, either as cause, effect, or a bit of both.
The main component of the Earth’s field – which defines the magnetic poles – is a dipole generated by the convection of molten nickel-iron in the outer core (the inner core is solid, so its role is secondary; remember that the Earth’s core is well above the Curie temperature, so the iron is not ferromagnetic).
But what about the fine structure? Does the outer core have the equivalent of the Earth’s atmosphere’s jet streams, for example? Recent research by a team of geophysicists in Japan sheds some light on these questions, and so hints at what causes magnetic pole flips.
About the image: This image shows how an imaginary particle suspended in the liquid iron outer core of the Earth tends to flow in zones even when conditions in the geodynamo are varied. The colors represent the vorticity or “amount of rotation” that this particle experiences, where red signifies positive (east-west) flow and blue signifies negative (west-east) flow. Left to right shows how the flow responds to increasing Rayleigh numbers, which is associated with flow driven by buoyancy. Top to bottom shows how flow responds to increasing angular velocities of the whole geodynamo system.
The jet stream winds that circle the globe and those in the atmospheres of the gas giants (Jupiter, Saturn, etc) are examples of zonal flows. “A common feature of these zonal flows is that they are spontaneously generated in turbulent systems. Because the Earth’s outer core is believed to be in a turbulent state, it is possible that there is zonal flow in the liquid iron of the outer core,” Akira Kageyama at Kobe University and colleagues say, in their recent Nature paper. The team found a secondary flow pattern when they modeled the geodynamo – which generates the Earth’s magnetic field – to build a more detailed picture of convection in the Earth’s outer core, a secondary flow pattern consisting of inner sheet-like radial plumes, surrounded by westward cylindrical zonal flow.
This work was carried out using the Earth Simulator supercomputer, based in Japan, which offered sufficient spatial resolution to determine these secondary effects. Kageyama and his team also confirmed, using a numerical model, that this dual-convection structure can co-exist with the dominant convection that generates the north and south poles; this is a critical consistency check on their models, “We numerically confirm that the dual-convection structure with such a zonal flow is stable under a strong, self-generated dipole magnetic field,” they write.
This kind of zonal flow in the outer core has not been seen in geodynamo models before, due largely to lack of sufficient resolution in earlier models. What role these zonal flows play in the reversal of the Earth’s magnetic field is one area of research that Kageyama and his team’s results that will now be able to be pursued.
Launch Complex 41: Atlas rocket was rolled from VIF at left to pad at right on Feb 9, 2010. Credit: Ken Kremer
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(Editor’s Note: Ken Kremer is at the Kennedy Space Center for Universe Today covering the launch of SDO and Endeavour.)
NASA’s nearly $1 Billion hi tech sun probe, the Solar Dynamics Observatory or SDO, was rolled out today (Feb 9) to Launch Pad 41 on a rainy day here in Florida at 1 day from blast off. SDO will be carried aloft atop an Atlas V rocket at 10:26 AM EST on Feb 10 at Cape Canaveral Air Force Station. The launch window extends for 1 hour. The current weather prediction is only 40% “GO”. The primary concerns for launch day are ground winds with gusts and thick clouds.
NASA’s SDO sun explorer is encapsulated inside 4 meter payload fairing and is bolted atop Centaur Upper Stage of Atlas V rocket at Launch Complex 41. Umbilical lines at right carry cryogenic propellants, electrical power and purge gases. Credit: Ken KremerAt the Kennedy Space Center, I was thrilled to watch the rocket rollout to the pad this morning as part of a NASA Media event along with Universe Today Senior Editor Nancy Atkinson. We were accompanied by a group of SDO managers and science investigators from across the country. The rollout started from inside the 30 story gantry known as the VIF, or Vertical Integration Facility, and ended at the launch pad. It took approximately 35 minutes for the twin “trackmobiles” to push the Atlas rocket about 1800 ft along railroad tracks.
Atlas V booster is 12.5 ft in diameter and 106.5 ft in length. Centaur Upper Stage is 10 ft in diameter and 41.5 ft long. SDO payload fairing is 14 ft in diameter. Total Vehicle height is about 189 ft. Credit: Ken KremerThis afternoon I traveled directly inside the highly restricted security zone which surrounds Launch Complex 41 for a photo shoot to observe the assembled Atlas V rocket and SDO spacecraft directly at the pad. Fantastic experience despite the rainstorm.
SDO, Atlas V and Ken in ditch below rocket less than 24 hours from blast off. Credit: Ken Kremer
SDO project scientist Dean Pesnell told me in an interview today that “SDO will acquire movies of the entire surface of the Sun on a 24/7 basis with 10 times greater resolution than High Definition. That’s about equivalent in size to an IMAX movie”. The three science instruments will collect a staggering 1.5 terabytes of data per day which is equivalent to downloading 500,000 songs. The data will be beamed back continuously to two dedicated ground stations in New Mexico which were specially constructed for SDO. There are no on board recorders due to the huge volume of data.
“It’s perfect timing to launch and study the sun as it starts the rise to a solar maximum,” according to Pesnell. “The sun patiently waited for us to be ready to launch as we waited for a launch opportunity. After a long period of inactivity, Sun spots recently started appearing at the North Pole. And they also just started at the South Pole”.
“SDO was conceived by the scientists around 1996 and formally approved by NASA in 2002”, Prof. Phillip Scherrer said to me. He is the Principal Investigator for the Helioseismic and Magnetic Imager (HMI) instrument.
“The primary mission phase will last 5 years and hopefully extend out to 10 and perhaps even longer. The longevity depends on the health of the science instruments. Remember SOHO was projected to last 2 years and has now operated for over 15 years ! “
HMI will study the origin of solar variability and attempt to characterize and understand the Sun’s interior and magnetic activity.
Both HMI, and the Atmospheric Imaging Assembly, or AIA, will allow scientists to see the entire disc of the sun in very high resolution — 4,096 by 4,096 mm CCDs. In comparison, a standard digital camera uses a 7.176 by 5.329 mm CCD sensor.
AIA also will image the outer layer of the sun’s atmosphere, while the Extreme ultraviolet Variability Experiment, or EVE, measures its ultraviolet spectrum every 10 seconds, 24 hours a day.
We are now less than 12 hours from launch of SDO, NASA’s “New Eye on the Sun”.
Read my earlier SDO reports, including from on site at the KSC launch pads for both SDO and STS 130.
Atlas rocket has been rolled to pad 41 on Feb 8, 2010 and is locked in place surrounded by four lightening masts. Credit: Ken KremerAtlas V rocket begins the 1800 ft rollout from VIF to Pad 41. Credit: Ken Kremer
SDO and two piece payload fairing inside “clean room” at Astrotech Spaceflight facility near KSC on Jan 21. Fairing protects spacecraft during ascent through earths atmosphere. Credit: Ben Cooper/Spaceflight Now
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NASA’s new solar science satellite, dubbed the Solar Dynamics Observatory, or SDO, moved an important step closer to launch when it was encapsulated inside its two piece payload fairing on Thursday (Jan 21) at the Astrotech Space Operations Facility nearby to the Kennedy Space Center (KSC). SDO is the most sophisticated spacecraft ever designed and constructed to study the sun and its dynamic behavior.
“SDO will revolutionize our view of the sun. It will reveal how solar activity affects our planet and help us anticipate what lies ahead”, said Madhulika Guhathakurta at a Jan 21 press briefing. She is the SDO program scientist at NASA Headquarters.
The enclosed observatory will be transported on a specially designed trailer to Launch Complex 41 on Tuesday (Jan. 26) and then be hoisted up and bolted atop the two stage booster rocket. The 19 story tall Atlas V will propel the 8,800 pound spacecraft into an inclined geosynchronous orbit where it will study the sun in multiple wavelengths during its 5 year primary mission. It carries sufficient fuel to operate for another 5 years.
An Atlas rocket similar to this vehicle I observed at Cape Canaveral Pad 41 will launch SDO. Credit: Ken KremerSDO arrived at KSC on July 9 for final processing, testing and fueling operations. It was shipped from NASA’s Goddard Space flight Center where it was built by teams of technicians, engineers and scientists at a cost of $848 million.
SDO is the first spacecraft to be launched as part of NASA’s Living with a Star (LWS) science program initiative. The goal is to better understand the causes of solar variability and to create better forecasts for predicting “space weather” which directly affects the Earth and all life inhabiting it. Furthermore, this information will be used to help protect and provide early warning to valuable satellites operating in space as well as astronaut crews working aboard the International Space Station.
When active regions on the sun erupt suddenly and violently in the form of a solar flare or coronal mass ejection (CME), they hurl millions of tons of solar material and charged particles toward Earth which can damage orbiting satellites, disrupt navigation systems and cause failures in the power grid.
SDO is equipped with 3 science instruments which will measure and characterize in-depth the Suns interior and atmosphere, magnetic field, hot plasma of the solar corona and the density of the radiation that creates the ionosphere of the planets.
SDO will collect huge volumes of data which amount to a staggering 1.5 terabytes per day. This is the equivalent of downloading a half million songs each day or filling a CD every 36 seconds. “That’s almost 50 times more science data than any other mission in NASA history”, says Dean Pesnell, the SDO project scientist at NASA Goddard.
SDO is enclosed in its payload fairing and ready for transport on Jan 26 to Atlas V launch pad. Credit: NASA/Jim Grossman“SDO is going to send us images ten times better than high definition television” according to Pesnell. “The pixel count is comparable to an IMAX movie — an IMAX filled with the raging sun, 24 hours a day.”
“We’ll be getting IMAX-quality images every 10 seconds,” says Pesnell. “We’ll see every nuance of solar activity.” Because no orbiting spacecraft has ever come even close to this incredible speed, there is a vast potential for ground breaking science discoveries. Scientists hope to learn how storms are generated inside the sun and how they then evolve and propagate outwards through the suns atmosphere and towards earth and the rest of the solar system.
Since SDO has no on-board recording system, the data will be transmitted continuously on a 24/7 basis to dedicated receiving stations on the ground in New Mexico as it maintains position over 22,000 miles high above earths equator.
I will be reporting on site from the Kennedy Space Center in February and directly from the launch pads for both SDO and STS 130. See my earlier STS 130 reports here.
The orange glow of magma is visible on the left of the sulfur-laden plume. The area shown in this image is approximately six feet across in an eruptive area approximately the length of a football field that runs along the summit. (Image courtesy of NSF, NOAA, and WHOI Advanced Imaging and Visualization Lab)
Ever seen fire and smoke under water before? Oceanographers using a remotely operated underwater vehicle discovered and recorded the first video and still images of the deepest underwater volcano actively erupting molten lava on the seafloor. The ROV Jason vehicle captured the powerful event nearly 1.2 km (4,000 feet) below the surface of the Pacific Ocean, in the “Ring of Fire” region, near Fiji, Tonga and Samoa. “It was very exciting. We’ve never seen anything like that on the ocean floor,” said Bob Embley, a marine geologist with NOAA, who described the event an underwater Fourth of July. “When we started to see red flashes of light, everyone was extremely excited. Then we had to get down to the work of actually understanding of what we were seeing.”
The scientists presented their findings, along with HD video at the American Geophysical Union’s fall meetings in San Fransciso. The video was taken in May of 2009, and the science team said the undersea volcano is likely to still be erupting, and may have started activity in late 2008.
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Embly said the eruption couldn’t be seen above the water, but there were “water column anomlies which indicated an eruption going on. We knew within a few hundred feet where the eruption was taking place.”
There were actually two erupting regions, but the video shows the most dramatic one. Visible in the video is magma – sometimes fiery, red hot at 1,371 C (2,500 degrees F) – bursting up through the seawater, with fragments of rock being propelled and magma flowing down the slope of the volcano. Hot sulfer “smoke” plumes can also be seen.
The volcano is spewing a type of lava known as Boninite, which until now had only been seen in extinct volcanoes more than a million years old.
A underwater “hydrophone” recorded the sound, and it was synched with the video.
Samples collected near the volcano showed the seawater to be highly acidic, similar to battery or stomach acid, the researchers said. Despite the harsh conditions, scientists found and photographed a species of shrimp apparently thriving near the volcanic vents.
“Nobody would have predicted that things would have survived long enough in water that acidic. It seems like it’s too harsh a condition,” said University of Washington chemical oceanographer Joseph Resing.
They hope to go back in a few months and see all the other creatures that have taken up residence there.
A new study from the University of Heidelberg suggests that flash-heating and carbon depletion could have been intrinsic to the emergence and evolution of life on Earth. Credit: NASA
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A new study finds the gases which formed the Earth’s atmosphere – as well as its oceans – did not come from inside the Earth but from comets and meteorites hitting Earth during the Late Heavy Bombardment period. A research team tested volcanic gases to uncover the new evidence. “We found a clear meteorite signature in volcanic gases,” said Dr. Greg Holland the project’s lead scientist. “From that we now know that the volcanic gases could not have contributed in any significant way to the Earth’s atmosphere. Therefore the atmosphere and oceans must have come from somewhere else, possibly from a late bombardment of gas and water rich materials similar to comets.”
Holland said textbook images of ancient Earth with huge volcanoes spewing gas into the atmosphere will have to be rethought.
According to the theory of the Late Heavy Bombardment, the inner solar system was pounded by a sudden rain of solar system debris only 700 million years after it formed, which likely had monumental effects on the nascent Earth. So far, the evidence for this event comes primarily from the dating of lunar samples, which indicates that most impact melt rocks formed in this very narrow interval of time. But this new research on the origin of Earth’s atmosphere may lend credence to this theory as well.
The researchers analyzed the krypton and xenon found in upper-mantle gases leaking from the Bravo Dome gas field in New Mexico. They found that the two noble gases have isotopic signatures characteristic of early Solar System material similar to me teorites instead of the modern atmosphere and oceans. It therefore appears that noble gases trapped within the young Earth did not contribute to Earth’s later atmosphere.
The study is also the first to establish the precise composition of the Krypton present in the Earth’s mantle.
“Until now, no one has had instruments capable of looking for these subtle signatures in samples from inside the Earth – but now we can do exactly that,” said Holland.
The team’s research, “Meteorite Kr in Earth’s Mantle Suggests a Late Accretionary Source for the Atmosphere” was published in the journal Science.
We live in a cosmic shooting gallery. In Phil Plait’s Death From the Skies, he lays out the dangers of a massive impact: destructive shockwaves, tsunamis, flash fires, atmospheric darkening…. The scenario isn’t pretty should a big one come our way. Fortunately, we may have a silent guardian: Jupiter.
Although many astronomers have assumed that Jupiter would likely sweep out dangerous interlopers (an important feat if we want life to gain a toehold), little work has been done to actually test the idea. To explore the hypothesis, a recent series of papers by J. Horner and B. W. Jones explores the effects of Jupiter’s gravitational pull on three different types of objects: main belt asteroids (which orbit between Mars and Jupiter), short period comets, and in their newest publication, submitted to the International Journal of Astrobiology, the Oort cloud comets (long period comets with the most distant part of their orbits far out in the solar system). In each paper, they simulated the primitive solar systems with the bodies in question with an Earth like planet, and gas giants of varying masses to determine the effect on the impact rate.
Somewhat surprisingly, for main belt asteroids, they determined, “that the notion that any ‘Jupiter’ would provide more shielding than no ‘Jupiter’ at all is incorrect.” Even without the simulation, the astronomers say that this should be expected and explain it by noting that, although Jupiter may shepherd some asteroids, it is also the main gravitational force perturbing their orbits and causing them to move into the inner solar system, where they may collide with Earth.
Contrary to the popular wisdom (which expected that the more massive the planet, the better it would shield us), there were notably fewer asteroids pushed into our line of sight for lower masses of the test Jupiter. Also surprisingly, they found that the most dangerous scenario was an instance in which the test Jupiter had 20% in which the planet “is massive enough to efficiently inject objects to Earth-crossing orbits.” However, they note that this 20% mass is dependent on how they chose to model the primordial asteroid belt and would likely change had they chosen a different model.
When the simulation was redone for for short period comets, they again found that, although Jupiter (and the other gas giants) may be effective at removing these dangerous objects, quite often they did so by sending them our way. As such, they again concluded that, as with asteroids, Jupiter’s gravitational jiggling was more dangerous than it was helpful.
Their most recent treatise explored Oort cloud objects. These objects are generally considered the largest potential threat since they normally reside so far out in the solar system’s gravitational well and thus, will have a greater distance to fall in and pick up momentum. From this situation, the researchers determined that the more massive the planet in Jupiter’s orbit, the better it does protect us from Oort cloud comets. The attribute this to the fact that these objects are initially so far from the Sun, that they are scarcely bound to the solar system. Even a little bit of extra momentum gained if they swing by Jupiter will likely be sufficient to eject them from the solar system all together, preventing them from settling into a closed orbit that would endanger the Earth every time it passed.
So whether or not Jupiter truly defends us or surreptitiously nudges danger our way depends on the type of object. For asteroids and short period comets, Jupiter’s gravitational agitation shoves more our direction, but for the ones that would potentially hurt is the most, the long period comets, Jupiter does provide some relief.
Earth's Rings over San Bernadino. Credit: Kevin Gill (CC BY-SA 2.0)
Here’s a video that poses — and answers — an interesting question: what would Earth look like if it had rings like Saturn? This animation was done by artist Roy Prol, and it shows not only how the rings would look from space, but also the view Earthlings would have of the rings.
Prol says the ring views from Earth’s surface were created according to the location’s latitude and the viewer’s orientation, and that the size of the rings was calculated respecting the Roche limit for the Earth. As you can se in the video, the rings would look different, depending on where you were on our planet. A very intriguing concept, and the video is very well done.
The only bad thing about Earth having rings is that we probably wouldn’t have our beautiful Moon. Imagine, instead of all the songs, poems and paintings of the Moon over the past centuries, we’d have odes to our rings.
One of our favorite image editing artists is Kevin Gill, and he’s also created imagery of Earth having rings, such as our lead image, which shows Earth’s Rings over San Bernadino, California and this one, below:
Earth’s Rings from New Hampshire. Credit: Kevin Gill (CC BY-SA 2.0)
Global Temperature graph. Credit: National Climatic Data Center, via the Associated Press.
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The idea that the world is now cooling has been repeated in opinion columns, talk radio, pundit television and more. After a poll was released last week indicating that only 57 percent of Americans now believe there is strong scientific evidence for global warming, which is down from 77 percent in 2006, Seth Borenstein from the Associated Press decided to check out what the statistics are really saying about global warming or cooling. In a blind test, Borenstein sent accumulated ground temperature data from the past 130 years to four independent statisticians. He disguised the sources (NASA, NOAA and British meteorological data) and didn’t tell the statisticians what the numbers represented; he asked them to just look for trends in the data. The experts found no true temperature declines over time; additionally, the last ten years comprise not only the highest data set in the record, but they also have a continued, positive trend.
It seems recent weather trends have been cool — 2008 was cooler than previous years, especially the really hot years of 1998 and 2005. Global land and ocean temperature indexes. Credit: Goddard Institute for Space Studies.
Borenstein wanted to know if this was a longer climate trend or just weather’s normal ups and downs. All four of the statisticians agreed independently the statistics overall clearly show an upward trend of warming. Also included was a data set of satellite temperature data that is often favored by skeptics of global warming. Same story there: global temps are on the rise.
The ups and downs during the last decade, which some skeptics say show a cooling rather than warming, are variations that are repeated randomly in data as far back as 1880.
One statistician said that “cherry-picking” a micro-trend within a bigger trend is not the way to look at data.
This “blind” review of the data isn’t the only review that has shown obvious warming. Borenstein said that NOAA recently re-examined its data because of the recent “chatter” about cooling, and no cooling trend was found, and earlier this year, climate scientists in two peer-reviewed publications statistically analyzed recent years’ temperatures against claims of cooling and found them not valid.
For the full story, read Borenstein’s article here.
