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Scientists believe that deep down inside the Earth, there’s a huge ball of liquid and solid iron. This is the Earth’s core, and it protects us from the dangerous radiation of space.
When the Earth first formed, 4.6 billion years ago, it was a hot ball of molten rock and metal. And since it was mostly liquid, heavier elements like iron and nickel were able to sink down into the planet and accumulate at the core. The core is believed to have two parts: a solid inner core, with a radius of 1,220 km, and then a liquid outer core that extends to a radius of 3,400 km. The core is through to be 80% iron, as well as nickel and other dense elements like gold, platinum and uranium.
The inner core is solid, but the outer core is a hot liquid. Scientists think that movements of metal, like currents in the oceans, create the magnetic field that surrounds the Earth. This magnetic field extends out from the Earth for thousands of kilometers, and redirects the solar wind blowing from the Sun. Without this magnetic field, the solar wind would blow away the lightest parts of our atmosphere, and make our environment more like cold, dead Mars.
Although the Earth’s crust is cool, the inside of the Earth is hot. The mantle is only about 30 km beneath our feet, and it’s hot enough to melt rock. At the core of the Earth, temperatures are thought to rise to 3,000 to 5,000 Kelvin.
Since the core is thousands of kilometers beneath our feet, how can scientists know anything about it? One way is to just calculate. The average density of the Earth is 5.5 grams per cubic cm. The Earth’s surface is made of less dense materials, so the inside must have something much more dense than rock. The second part is through seismology. When earthquakes rock the surface of the Earth, the planet rings like a bell, and the shockwaves pass through the center of the Earth. Monitoring stations around the planet detect how the waves bounce, and scientists are able to use this to probe the interior of the Earth.
The atmosphere of Titan, similar to the Earth's early atmosphere.
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The atmosphere we enjoy today is radically different from the atmosphere that formed with the Earth billions of years ago. And yet, the Earth’s early atmosphere somehow transformed into the life giving atmosphere we enjoy today.
The Earth formed with the Sun 4.6 billion years ago. At this point, it was nothing more than a molten ball of rock surrounded by an atmosphere of hydrogen and helium. Because the Earth didn’t have a magnetic field to protect it yet, the intense solar wind from the young Sun blew this early atmosphere away.
As the Earth cooled enough to form a solid crust (4.4 billion years ago), it was covered with active volcanos. These volcanos spewed out gasses, like water vapor, carbon dioxide and ammonia. This early toxic atmosphere was nothing like the atmosphere we have today.
Light from the Sun broke down the ammonia molecules released by volcanos, releasing nitrogen into the atmosphere. Over billions of years, the quantity of nitrogen built up to the levels we see today.
Although life formed just a few hundred million years later, it wasn’t until the evolution of bacteria 3.3 billion years ago that really changed the early Earth atmosphere into the one we know today. During the period 2.7 to 2.2 billion years ago, these early bacteria – known as cyanobacteria – used energy from the Sun for photosynthesis, and release oxygen as a byproduct. They also sequestered carbon dioxide in organic molecules.
In just a few hundred million years, this bacteria completely changed the Earth’s atmosphere composition, bringing us to our current mixture of 21% oxygen and 78% nitrogen.
We have written many articles about the Earth for Universe Today. Here’s an article about how the Earth’s early atmosphere was very different from the one we see today, and an another that describes how Titan’s atmosphere is probably similar to the Earth’s early atmosphere.
Breathe in and you can appreciate that the Earth’s atmosphere has everything needed to support life on Earth. But what’s in it? Let’s take a look at the composition of the Earth’s atmosphere. Of course, things haven’t always been balanced they way they are today. But more of that in a second.
The Earth’s atmosphere is composed of the following molecules: nitrogen (78%), oxygen (21%), argon (1%), and then trace amounts of carbon dioxide, neon, helium, methane, krypton, hydrogen, nitrous oxide, xenon, ozone, iodine, carbon monoxide, and ammonia. Lower altitudes also have quantities of water vapor.
The atmosphere we have today is very different from the Earth’s early atmosphere. When the planet first cooled down 4.4 billion years ago, volcanos spewed out steam, carbon dioxide and ammonia, and it was 100 times as dense as today’s atmosphere.
The earliest bacteria, known as cyanobacteria, were probably the first oxygen-producing organisms on Earth. Approximately 2.7 to 2.2 billion years ago, they released large amounts of oxygen and sequestered the carbon dioxide. As oxygen was released, it reacted with ammonia to release nitrogen. The carbon dioxide in the atmosphere is exhaled by plants (and produced by human industry burning fossil fuels).
We have written many articles about the Earth for Universe Today. Here’s an article about how the Earth’s atmosphere is slowly leaking into space, and here’s an article about how the early Earth’s atmosphere was similar to Titan’s atmosphere.
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The size of Earth, like the size of all of the celestial bodies, is measured in a number of parameters including mass, volume, density, surface area, and equatorial/polar/mean diameter. While we live on this planet, very few people can quote you the figures for these parameters. Below is a table with many of the pieces of the data used to measure the size of the Earth.
Mass
5.9736×1024kg
Volume
1.083×1012 km3
Mean diameter
12,742 km
Surface area
510,072,000 km2
Density
5.515 g/cm3
Circumference
40,041 km
Those numbers tell you the size of the Earth, but what about its other statistics? The atmospheric pressure at the surface is 101.325 kPa, average temperature is 14°C, the axial tilt is approximately 23°, and it has an orbital speed of 29.78 km/s. Earth orbits with a perihelion of 147,098,290 km, and an aphelion of 152,098,232 km, making for a semi-major axis of 149,598,261 km. Even though we need oxygen to survive, it is the second most abundant component of Earth’s atmosphere. Nitrogen accounts for 78% of the gases in the atmosphere and oxygen occupies 21%.
The Earth only has one moon. That is pretty uncommon in our Solar System. There are currently 166 recognized moon in our system. There is one asteroid that has a quasi relationship with Earth. 3753 Cruithne has a 1:1 orbital resonance with the Earth. It is a periodic inclusion planetoid that has a horseshoe orbit. It was discovered in 1986.
Since we occupy this planet, it is understandably the most extensively studied body in space. We have sent scientist to most of the corners of our world. Yet, we find dozens of new species each year and there are areas that have rarely seen a human’s footprints. There are aspects of our world that we do not understand and have theories too inadequate to explain. Science is light years ahead of where it was just 50 years ago. These advancements are exciting enough to make the possibilities of the near future seem boundless.
Now that you know the size of the Earth, you could look for information on extremophiles, the Mariana Trench, and the Tunguska event. Earth bound events are often taken for granted since we live here, but, with a little research, you may find much more excitement outside of your back door than you ever expected.
We have written many articles about the Solar System for Universe Today. Here’s an article about the size of Mars, and here’s one about the size of the Moon.
Rice University professors Patrick McGovern and Julia Morgan are proposing that pockets of water could be trapped under Olympus Mons on Mars -- and could support life. Credit: Rice University
Rice University professors Patrick McGovern and Julia Morgan are proposing that pockets of water could be trapped under Olympus Mons on Mars -- and could support life. Credit: Rice University
Olympus Mons is the latest hotspot in the hunt for habitable zones on Mars.
The Martian volcano is about three times the height of Mount Everest, but it’s the small details that matter to Rice University professors Patrick McGovern and Julia Morgan. After studying computer models of Olympus Mons’ formation, McGovern and Morgan are proposing that pockets of ancient water could still be trapped under the mountain. Their research is published in February’s issue of the journal Geology.
Olympus Mons is tall, standing almost 15 miles (24 km) high, and slopes gently from the foothills to the caldera, a distance of more than 150 miles (241 km). That shallow slope is a clue to what lies beneath, say the researchers. They suspect if they were able to stand on the northwest side of Olympus Mons and start digging, they’d eventually find clay sediment deposited there billions of years ago, before the mountain was even a molehill.
In modeling the formation of Olympus Mons with an algorithm known as particle dynamics simulation, McGovern and Morgan determined that only the presence of ancient clay sediments can account for the volcano’s asymmetric shape. The presence of sediment indicates water was or is involved.
The European Space Agency’s Mars Express spacecraft has in recent years found abundant evidence of clay on Mars. This supports a previous theory that where Olympus Mons now stands, a layer of sediment once rested that may have been hundreds of meters thick.
Morgan and McGovern show in their computer models that volcanic material was able to spread to Olympus-sized proportions because of the clay’s friction-reducing effect, a phenomenon also seen at volcanoes in Hawaii.
Credit: Rice University
But fluids embedded in an impermeable, pressurized layer of clay sediment would allow the kind of slipping motion that would account for Olympus Mons’ spread-out northeast flank – and they may still be there. And because NASA’s Phoenix lander found ice underneath the Martian surface last year, Morgan and McGovern believe it’s reasonable to suspect water could be trapped in the sediment underneath the mountain.
“This deep reservoir, warmed by geothermal gradients and magmatic heat and protected from adverse surface conditions, would be a favored environment for the development and maintenance of thermophilic organisms,” they wrote. On Earth, such primal life forms exist along deep geothermal vents on the ocean floor.
Finding a source of heat will be a challenge, Morgan and McGovern admit. “We’d love to have the answer to that question,” said McGovern. He noted that evidence of methane on Mars is considered by some to be another marker for life.
LEAD IMAGE CAPTION: Rice University professors Patrick McGovern and Julia Morgan are proposing that pockets of water could be trapped under Olympus Mons on Mars — and could support life. Credit: Rice University
SN 2009ab as seen by the AlbaNova Telescope in Stockholm, Sweden. Credit: Magnus Persson, Robert Cumming and Genoveva Micheva/Stockholm University
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SN 2009ab as seen by the AlbaNova Telescope in Stockholm, Sweden. Credit: Magnus Persson, Robert Cumming and Genoveva Micheva/Stockholm University
Have you ever discovered a supernova? Well, I haven’t, but I can only imagine finding a star that has blown itself to smithereens must be pretty exciting. At least that’s what I thought, anyway….
Seemingly, a fair amount of folks must be out there who have found supernovae. In 2008 alone, 278 supernovae were found, one by a 14-year old girl. But 2008 was a really slow year in the supernova department. In 2007, 584 were discovered – a record number – and in 2006, 557 supernovae were spied by astronomers, both professional and amateur. 40 have been found so far in 2009. But even with those fairly big numbers, I still gotta believe that finding a supernova must be absolutely incredible. So when someone I knew, Robert Cumming from Stockholm University in Sweden, recently played a part in finding a supernova, I emailed him my congratulations. Imagine my surprise when he replied, “It’s no big deal, really.”
But Robert, it’s a SUPERNOVA!
I had heard of Scandinavian stoicism, but this was off the charts! Besides that, I knew Robert is not originally from Sweden.
So, I begged him to tell me all about it.
“Well, since you ask,” he said with a smile. Okay, maybe, just maybe he was more excited than he was letting on. Robert Cumming.
Here’s the story of how Supernova 2009ab was discovered:
“I’ve observed a few supernovae before and I’ve had my name on the odd IAU circular, but this is the first time I’ve been one of the first to actually confirm one,” said Robert, with just a hint of excitement in his voice.
On February 8, the Katzman Automatic Imaging Telescope (KAIT), a 30-inch fully robotic telescope at the Lick Observatory on Mt. Hamilton in California discovered a bright spot not seen before in the outskirts of the spiral galaxy UGC 2998, 150 million light years away. Astronomers from KAIT wanted to make a second observation to verify, but bad weather made it impossible for them to confirm that the new object was not an asteroid or instrumental error. So, the KAIT astronomers requested observations from other telescopes around the world.
Magnus Persson, also from the Stockholm University was getting ready to do some observations using the University’s AlbaNova Telescope, when Robert received an email from KAIT about needing confirmation observations. AlbaNova Telescope. Credit: Teresa Riehm/Stockholm University.
“I knew Magnus was going to be observing – he was planning to take some pictures of the Crab nebula for a colleague,” said Robert. “And I had this mail from the KAIT in California.”
So, the two set to work in an effort to locate the possible supernova.
Robert and Persson used different filters and took a few images of galaxy UGC 2998. “The supernova was right there on our first 45-second exposure – we were kind of amazed!” he said.
The two astronomers from Sweden were able to establish that the new light source showed all the signs of being a supernova. The supernova shines in a blue color, in contrast to the stars in the galaxy which are generally old and red, and the other stars in the image which lie in our galaxy. Shortly after the explosion, such a supernova emits as much energy as the entire host galaxy.
“We did the observations properly, and then I picked the best data to make very rough photometry, got comparison magnitudes from Gregor Dusczanowicz, Sweden’s amateur supernova discoverer, talked to a colleague to check we hadn’t forgotten anything important, and mailed off the measurements to the Central Bureau for Astronomical Telegrams.”
Other telescopes have now observed SN 2009ab, but the AlbaNova telescope was the first to successfully take images and confirm it as a new supernova. The following day, astronomers on the Canary Islands took a spectrum using the considerably bigger Telescopio Nationale Galileo and were able to determine the supernova was of type Ia, that is a white dwarf star which had exploded in a binary system. As Magnus’ and Robert’s confirmation was published in an astronomical telegram, the new supernova was named SN 2009ab, this year’s 28th supernova.
It’s also the story of a new telescope in an unlikely location being used to make new and exciting — yes exciting –discoveries. The Stockholm University Department of Astronomy uses the AlbaNova telescope, a 1-meter reflector, mainly for education and instrumental development. Robert said the plan is to use the telescope to do environmental monitoring, using LIDAR to monitor ozone and particle pollution in the city.
But Robert said the discovery of the supernova shows it is also possible to do scientifically interesting astronomical observations with the telescope, despite the limitations from Stockholm’s bad weather and light pollution. The AlbaNova Observatory in Stockholm. Credit: Magnus Näslund/Stockholm University
“Our site is right in the city, so our sky brightness is scary. So far we haven’t measured just how bad it is, so it was a really nice surprise to get something out of it,” he said.
“The telescope is still pretty new, and with the Stockholm weather lately the experience of observing at all is pretty exciting,” Robert said. “And it is exciting that the telescope is now in full use. If we can do observations like these, we can do much more.”
So finally, I got Robert to admit he was excited. But the Scandinavian modesty and stoicism quickly returned.
The circumference of the Earth in kilometers is 40,075 km, and the circumference of the Earth in miles is 24,901. In other words, if you could drive your car around the equator of the Earth (yes, even over the oceans), you’d put on an extra 40,075 km on the odometer. It would take you almost 17 days driving at 100 km/hour, 24 hours a day to complete that journey.
If you like, you can calculate the Earth’s circumference yourself. The formula for calculating the circumference of a sphere is 2 x pi x radius. So, the radius of the Earth is 6371 km. Plug that into the formula, and you get 2 x 3.1415 x 6378.1 = 40,074. It would be more accurate if you use more digits for pi.
You might be interested to know that the circumference of the Earth is different depending on how you measure it. If you measure the circumference around the Earth’s equator, you get the 40,075 km figure I mentioned up to. But if you measure it from pole to pole, you get 40,007 km. This is because the Earth isn’t a perfect sphere; it bulges around the equator because it’s rotating on its axis. The Earth is a flattened sphere, and so the distance around the equator is further than the circumference around the poles.
Want some comparison? The circumference of the Moon is 10,921 km, and the circumference of Jupiter is 500,000 km.
Here are a bunch of measurements for you:
Circumference of the Earth in kilometers: 40,075 km
Circumference of the Earth in meters: 40,075,000 meters
Circumference of the Earth in centimeters: 4,007,500,000 centimeters
Circumference of the Earth in miles: 24,901 miles
Circumference of the Earth in feet: 131,477,280 feet
Circumference of the Earth in inches: 1,577,727,360 inches
Using a new imaging technique on an 11 year old Hubble observation, an exoplanet has been discovered orbiting the young star HR 8799 (NASA/HST)
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The Hubble Space Telescope has recently provided us with some astonishing images of exoplanets orbiting distant stars. This is a departure from the indirect detection of exoplanets by measuring the “wobble” of stars (revealing the gravitational presence of a massive planetary body) or the transit of exoplanets through the line of sight of the parent star (causing its brightness to dim). Scientists have refined Hubble’s exoplanet hunting abilities to directly image these alien worlds in visible light. However, astronomers now have another trick to find these mysterious worlds. A new imaging technique is allowing us to see exoplanets already hiding in archival Hubble data…
It has been estimated that another 100 previously unknown exoplanets could be discovered in old Hubble data. The technique being tested by astronomers at the University of Toronto could be a very powerful new way to reveal the existence of a huge number of buried jewels buried by the glare of star light.
In November 2008, a spate of direct imagery of exoplanets showed the world how advanced our ground and space-based observatories were becoming. One such discovery was an observing campaign of the young star HR 8799 by the near-infrared adaptive optics observations of the Gemini and Keck telescopes. HR 8799 (140 light years away, approximately 50% more massive than our Sun) plays host to three massive gas giants (10, 10 and 7 times the size of Jupiter). Now that HR 8799 is known to have large exoplanets orbiting around it, the University of Toronto astronomers, headed by David Lafrenière, have re-examined images taken by Hubble of that same star in 1998, to see if there is any trace of these exoplanets in the old data. In 1998, HR 8799 appeared to be a lonely star, with no associated exoplanets.
Using a new technique to extract the weak exoplanet emission in the Hubble image, Lafrenière’s team have been able to cut down the glare of the parent star to reveal the presence of the outermost exoplanet of the trio known to be orbiting HR 8799 (pictured top). The other two exoplanets remain too close to the star to be resolved.
The University of Toronto result “definitely indicates that we should reanalyze all the existing Hubble images of young stars with the new approach — there’s probably 100 to 200 stars where planets could be seen,” comments planet-hunter Bruce Macintosh of the Lawrence Livermore National Laboratory in California. Many of these stars have already been studied by the powerful Keck observatory in Hawaii, so astronomers now have an exciting and powerful new analysis tool to hopefully reveal more overlooked exoplanets.
However, this most recent result was achieved by using a space-based observatory, as some of the near-infrared emission from the exoplanet will be absorbed by the Earth’s atmosphere.
The new exoplanet discovery potential has excited many astronomers, and it has highlighted the importance of maintaining a good archive of astronomical observations. “The first thing it tells you is how valuable maintaining long-term archives can be. Here is a major discovery that’s been lurking in the data for about 10 years!” said Matt Mountain, director of the Space Telescope Science Institute in Baltimore. “The second thing its tells you is having a well calibrated archive is necessary but not sufficient to make breakthroughs — it also takes a very innovative group of people to develop very smart extraction routines that can get rid of all the artifacts to reveal the planet hidden under all that telescope and detector structure.”
Hopefully we’ll be seeing even more exoplanet discoveries over the coming months, not just from new observing campaigns, but possibly from old observations using archived observatory data. Exciting times!
Artist concept of ancient pulsar J0108. Image credit: X-ray: NASA/CXC/Penn State/G.Pavlov et al. Optical: ESO/VLT/UCL/R.Mignani et al. Illustration: CXC/M. Weiss
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It may be old, but it ain’t dead. The Chandra X-Ray Observatory has found the oldest isolated pulsar ever detected. While this pulsar is ancient, this exotic object is still kicking and is surprisingly active. According to radio observations, the pulsar, PSR J0108-1431 (J0108 for short) is about 200 million years old. Among isolated pulsars — ones that have not been spun-up in a binary system — it is over 10 times older than the previous record holder. A team of astronomers led by George Pavlov of Penn State University observed J0108 in X-rays with Chandra, and found that it glows much brighter in X-rays than was expected for a pulsar of such advanced years.
At a distance of 770 light years, it is also one of the nearest pulsars we know of.
Pulsars are created when stars that are much more massive than the Sun collapse in supernova explosions, leaving behind a small, incredibly weighty core, known as a neutron star. At birth, these neutron stars, which contain the densest material known in the Universe, are spinning rapidly, up to a hundred revolutions per second. As the rotating beams of their radiation are seen as pulses by distant observers, similar to a lighthouse beam, astronomers call them “pulsars”.
Astronomers observe a gradual slowing of the rotation of the pulsars as they radiate energy away. Radio observations of J0108 show it to be one of the oldest and faintest pulsars known, spinning only slightly faster than one revolution per second. J0108 in a combination of optical and X-ray. Image credit: X-ray: NASA/CXC/Penn State/G.Pavlov et al. Optical: ESO/VLT/UCL/R.Mignani et al.
Some of the energy that J0108 is losing as it spins more slowly is converted into X-ray radiation. The efficiency of this process for J0108 is found to be higher than for any other known pulsar.
“This pulsar is pumping out high-energy radiation much more efficiently than its younger cousins,” said Pavlov. “So, although it’s clearly fading as it ages, it is still more than holding its own with the younger generations.”
It’s likely that two forms of X-ray emission are produced in J0108: emission from particles spiraling around magnetic fields, and emission from heated areas around the neutron star’s magnetic poles. Measuring the temperature and size of these heated regions can provide valuable insight into the extraordinary properties of the neutron star surface and the process by which charged particles are accelerated by the pulsar.
The younger, bright pulsars commonly detected by radio and X-ray telescopes are not representative of the full population of objects, so observing objects like J0108 helps astronomers see a more complete range of behavior. At its advanced age, J0108 is close to the so- called “pulsar death line,” where its pulsed radiation is expected to switch off and it will become much harder, if not impossible, to observe.
“We can now explore the properties of this pulsar in a regime where no other pulsar has been detected outside the radio range,” said co- author Oleg Kargaltsev of the University of Florida. “To understand the properties of ‘dying pulsars,’ it is important to study their radiation in X-rays. Our finding that a very old pulsar can be such an efficient X-ray emitter gives us hope to discover new nearby pulsars of this class via their X-ray emission.”
The Chandra observations were reported by Pavlov and colleagues in the January 20, 2009, issue of The Astrophysical Journal. However, the extreme nature of J0108 was not fully apparent until a new distance to it was reported on February 6 in the PhD thesis of Adam Deller from Swinburne University in Australia. The new distance is both larger and more accurate than the distance used in the Chandra paper, showing that J0108 was brighter in X-rays than previously thought.
“Suddenly this pulsar became the record holder for its ability to make X-rays,” said Pavlov, “and our result became even more interesting without us doing much extra work.” The position of the pulsar seen by Chandra in X-rays in early 2007 is slightly different from the radio position observed in early 2001. This implies that the pulsar is moving at a velocity of about 440,000 miles per hour, close to a typical value for pulsars.
Currently the pulsar is moving south from the plane of the Milky Way galaxy, but because it is moving more slowly than the escape velocity of the Galaxy, it will eventually curve back towards the plane of the Galaxy in the opposite direction.
Map of dunes on Titan, with arrows indicating the general wind direction. Dark areas without arrows might have dunes but have not yet been imaged with radar. Credit: NASA/JPL/Space Science Institute (Boulder, Colorado)
Scientists have mapped vast dune fields on Titan that may align with the wind on Saturn’s biggest moon — flowing opposite the way climate models had predicted.
The maps, as above, represent four years of radar data collected by the Cassini spacecraft. They reveal rippled dunes that are generally oriented east-west, which means Titan’s winds probably blow toward the east instead of the west. If so, Titan’s surface winds blow opposite the direction suggested by previous global circulation models. On the example above, the arrows indicate the general wind direction. The dark areas without arrows might have dunes but have not yet been imaged.
“At Titan there are very few clouds, so determining which way the wind blows is not an easy thing, but by tracking the direction in which Titan’s sand dunes form, we get some insight into the global wind pattern,” says Ralph Lorenz, Cassini radar scientist at Johns Hopkins University in Maryland. “Think of the dunes sort of like a weather vane, pointing us to the direction the winds are blowing.”
Titan’s dunes are believed to be made up of hydrocarbon sand grains likely derived from organic chemicals in Titan’s smoggy skies. The dunes wrap around high terrain, which provides some idea of their height. They accumulate near the equator, and may pile up there because drier conditions allow for easy transport of the particles by the wind. Titan’s higher latitudes contain lakes and may be “wetter” with more liquid hydrocarbons, not ideal conditions for creating dunes.
“Titan’s dunes are young, dynamic features that interact with topographic obstacles and give us clues about the wind regimes,” said Jani Radebaugh, from Brigham Young University in Utah. “Winds come at these dunes from at least a couple of different directions, but then combine to create the overall dune orientation.”
Researchers say the wind pattern is important for planning future Titan explorations that might involve balloon-borne experiments. Some 16,000 dune segments were mapped out from about 20 radar images, digitized and combined to produce the new map, which is available at http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. A paper based on the new findings appeared in the Feb. 11 issue of Geophysical Research Letters.
Cassini, which launched in 1997 and is now in extended mission operations, continues to blaze its trail around the Saturn system and will visit Titan again on March 27. Seventeen Titan flybys are planned this year.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA’s Jet propulsion Laboratory (JPL) in Pasadena, California manages the Cassini-Huygens mission. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.
LEAD IMAGE CREDIT: NASA/JPL/Space Science Institute (Boulder, Colorado)
