Discovered by the Cassini mission, Saturn Kilometric Radiation (SKR) has been something of an enigma to astronomers. According to the radio and plasma wave instruments, variations occur in sync with the planet’s rotation. However, there are periodic “bursts” of radiation which are in line with Saturn’s magnetosphere. What makes this odd? The rate isn’t quite the same.
Thanks to investigations of Enceladus by Cassini in 2008, new information about the plasma environment surrounding Saturn’s satellite could show a marked impact on the magnetosphere. This image and video show a changing pattern of radio waves from Saturn known as Saturn Kilometric Radiation, as detected by NASA’s Cassini spacecraft. The colors indicate the emitted power of the radio waves, with red as the strongest.
How is it being affected? Thanks to Enceladus’ “spraying” nature, the huge plume of water vapor and ice from its southern pole provides a hefty source of plasma to feed Saturn’s magnetosphere and E-Ring. These negatively charged particles are again impacting the motion of the localized plasma.
“These signatures result from half or more of the electrons being attached to dust grains and by the interaction between the surrounding cold plasma and the predominantly negatively charged submicrometer-sized dust grains.” says M. W. Morooka (et al). “The dust and plasma properties estimated from the observations clearly show that the dust-plasma interaction is collective.”
According to the AGU Journal, this dust-plasma interaction impacts the dynamics of Saturn’s magnetosphere, possibly influencing the rate of SKR emissions.
Dawn Orbiting Vesta. NASA's Dawn spacecraft achieved orbit at the giant asteroid Vesta in July 2011. The depiction of Vesta is based on images obtained by Dawn's framing cameras. Dawn is an international collaboration of the US, Germany and Italy. Credit: NASA/JPL-Caltech
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A year ago, 2011 was proclaimed as the “Year of the Solar System” by NASA’s Planetary Science division. And what a year of excitement it was indeed for the planetary science community, amateur astronomers and the general public alike !
NASA successfully delivered astounding results on all fronts – On the Story of How We Came to Be.
“2011 was definitely the best year ever for NASA Planetary Science!” said Jim Green in an exclusive interview with Universe Today. Green is the Director of Planetary Science for the Science Mission Directorate at NASA HQ. “The Search for Life is a significant priority for NASA.”
This past year was without doubt simply breathtaking in scope in terms of new missions, new discoveries and extraordinary technical achievements. The comprehensive list of celestial targets investigated in 2011 spanned virtually every type of object in our solar system – from the innermost planet to the outermost reaches nearly touching interplanetary space.
There was even a stunningly evocative picture showing “All of Humanity” – especially appropriate now in this Holiday season ! You and all of Humanity are here !
-- Earth & Moon Portrait by Juno from 6 Million miles away --
First Photo transmitted from Jupiter Bound Juno shows Earth (on the left) and the Moon (on the right). Taken on Aug. 26, 2011 when spacecraft was about 6 million miles (9.66 million kilometers) away from Earth. Credit: NASA/JPL-Caltech
Three brand new missions were launched and ongoing missions orbited a planet and an asteroid and flew past a comet.
“NASA has never had the pace of so many planetary launches in such a short time,” said Green.
And three missions here were awarded ‘Best of 2011’ for innovation !
Mars Science Laboratory (MSL), Dawn and MESSENGER named “Best of What’s New” in 2011 by Popular Science magazine. 3 NASA Planetary Science missions received the innovation award for 2011 from Popular Science magazine. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech
Here’s the Top NASA Planetary Science Stories of 2011 – ‘The Year of the Solar System’ – in chronological order
1. Stardust-NExT Fly By of Comet Tempel 1
Starting from the first moments of 2011 at the dawn of Jan. 1, hopes were already running high for planetary scientists and engineers busily engaged in setting up a romantic celestial date in space between a volatile icy comet and an aging, thrusting probe on Valentine’s Day.
The comet chasing Stardust-Next spacecraft successfully zoomed past Comet Tempel 1 on Feb. 14 at 10.9 km/sec (24,000 MPH) after flying over 6 Billion kilometers (3.5 Billion mi).
6 Views of Comet Tempel 1 and Deep Impact crater during Stardust-NExT flyby on Feb. 14, 2011
Arrows show location of man-made crater created in 2005 by NASA’s prior Deep Impact comet mission and newly imaged as Stardust-NExT zoomed past comet in 2011. The images progress in time during closest approach to comet beginning at upper left and moving clockwise to lower left. Credit: NASA/JPL-Caltech/University of Maryland. Post process and annotations by Marco Di Lorenzo & Kenneth Kremer
The craft approached within 178 km (111mi) and snapped 72 astonishingly detailed high resolution science images over barely 8 minutes. It also fulfilled the teams highest hopes by photographing the human-made crater created on Tempel 1 in 2005 by a cosmic collision with a penetrator hurled by NASA’s Deep Impact spacecraft. The probe previously flew by Comet Wild 2 in 2004 and returned cometary coma particles to Earth in 2006
Tempel 1 is the first comet to be visited by two spaceships from Earth and provided the first-ever opportunity to compare observations on two successive passages around the Sun.
Don Brownlee, the original Principal Investigator, summarized the results for Universe Today; “A great bonus of the mission was the ability to flyby two comets and take images and measurements. The wonderfully successful flyby of Comet Tempel 1 was a great cap to the 12 year mission and provided a great deal of new information to study the diversity among comets.”
“The new images of Tempel showed features that form a link between seemingly disparate surface features of the 4 comets imaged by spacecraft. Combining data on the same comet from the Deep Impact and Stardust missions has provided important new insights in to how comet surfaces evolve over time and how they release gas and dust into space”.
2. MESSENGER at Mercury
On March 18, the Mercury Surface, Space Environment, Geochemistry, and Ranging, or MESSENGER, spacecraft became the first spacecraft inserted into orbit around Mercury, the innermost planet.
So far MESSENGER has completed 1 solar day – 176 Earth days- circling above Mercury. The probe has collected a treasure trove of new data from the seven instruments onboard yielding a scientific bonanza; these include global imagery of most of the surface, measurements of the planet’s surface chemical composition, topographic evidence for significant amounts of water ice, magnetic field and interactions with the solar wind.
“MESSENGER discovered that Mercury has an enormous core, larger than Earth’s. We are trying to understand why that is and why Mercury’s density is similar to Earth’s,” Jim Green explained to Universe Today.
The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Small gaps will be filled in during the next solar day. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
“The primary mission lasts 2 solar days, equivalent to 4 Mercury years.”
“NASA has granted a 1 year mission extension, for a total of 8 Mercury years. This will allow the team to understand the environment at Mercury during Solar Maximum for the first time. All prior spacecraft observations were closer to solar minimum,” said Green.
MESSENGER was launched in 2004 and the goal is to produce the first global scientific observations of Mercury and piece together the puzzle of how Mercury fits in with the origin and evolution of our solar system.
NASA’s Mariner 10 was the only previous robotic probe to explore Mercury, during three flyby’s back in the mid-1970’s early in the space age.
3. Dawn Asteroid Orbiter
The Dawn spacecraft achieved orbit around the giant asteroid Vesta in July 2011 after a four year interplanetary cruise and began transmitting the history making first ever close-up observations of the mysteriously diverse and alien world that is nothing short of a ‘Space Spectacular’.
“We do not have a good analog to Vesta anywhere else in the Solar System,” Chris Russell said to Universe Today. Russell, from UCLA, is the scientific Principal Investigator for Dawn.
Before Dawn, Vesta was just another fuzzy blob in the most powerful telescopes. Dawn has completely unveiled Vesta as a remarkably dichotomous, heavily battered and pockmarked world that’s littered with thousands of craters, mountains and landslides and ringed by mystifying grooves and troughs. It will unlock details about the elemental abundances, chemical composition and interior structure of this marvelously intriguing body.
Cataclysmic collisions eons ago excavated Vesta so it lacks a south pole. Dawn discovered that what unexpectedly remains is an enormous mountain some 16 miles (25 kilometers) high, twice the height of Mt. Everest.
Dawn is now about midway through its 1 year mission at Vesta which ends in July 2012 with a departure for Ceres, the largest asteroid. So far the framing cameras have snapped more than 10,000 never-before-seen images.
“What can be more exciting than to explore an alien world that until recently was virtually unknown!. ” Dr. Marc Rayman said to Universe Today. Rayman is Dawn’s Chief Engineer from NASA’s Jet Propulsion Lab (JPL) in Pasadena, Calif.
“Dawn is NASA at its best: ambitious, exciting, innovative, and productive.”
4. Juno Jupiter Orbiter
The solar powered Juno spacecraft was launched on Aug. 5 at Cape Canaveral Air Force Station in Florida, to embark on a five year, 2.8 billion kilometer (1.7 Billion mi) trek to Jupiter, our solar system’s largest planet. It was the first of three NASA planetary science liftoffs scheduled in 2011.
Juno Jupiter Orbiter soars skyward to Jupiter on Aug. 5, 2011 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer
Juno’s goal is to map to the depths of the planets interior and elucidate the ingredients of Jupiter’s genesis hidden deep inside. These measurements will help answer how Jupiter’s birth and evolution applies to the formation of the other eight planets.
The 4 ton spacecraft will arrive at the gas giant in July 2016 and fire its braking rockets to go into a polar orbit and circle the planet 33 times over about one year.
The suite of nine instruments will scan the gas giant to find out more about the planets origins, interior structure and atmosphere, measure the amount of water and ammonia, observe the aurora, map the intense magnetic field and search for the existence of a solid planetary core.
“Jupiter is the Rosetta Stone of our solar system,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary — to interpret what Jupiter has to say.”
5. Opportunity reaches Endeavour Crater on Mars
The long lived Opportunity rover finally arrived at the rim of the vast 14 mile (22 kilometer) wide Endeavour Crater in mid-August 2011 following an epic three year trek across treacherous dune fields – a feat once thought unimaginable. All told, Opportunity has driven more than 34 km ( 21 mi) since landing on the Red Planet way back in 2004 for a mere 90 sol mission.
Endeavour Crater Panorama from Opportunity Mars Rover in August 2011
Opportunity arrived at the rim of Endeavour on Sol 2681, August 9, 2011 after a three year trek. The robot photographed segments of the huge craters eroded rim in this panoramic vista. Endeavour Crater is 14 miles (22 kilometers) in diameter. Mosaic Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Kenneth Kremer
In November, the rover discovered the most scientifically compelling evidence yet for the flow of liquid water on ancient Mars in the form of a water related mineral vein at a spot dubbed “Homestake” along an eroded ridge of Endeavour’s rim.
Read my story about the Homestake discovery here, along with our panoramic mosaic showing the location – created by Ken Kremer and Marco Di Lorenzo and published by Astronomy Picture of the Day (APOD) on 12 Dec. 2011.
Watch for my upcoming story detailing Opportunity’s accomplishments in 2011.
6. GRAIL Moon Mappers
The Gravity Recovery and Interior Laboratory, or GRAIL mission is comprised of twin spacecraft tasked to map the moon’s gravity and study the structure of the lunar interior from crust to core.
Twin GRAIL Probes GO for Lunar Orbit Insertion on New Year’s Eve and New Year’s Day
GRAIL spacecraft will map the moon's gravity field and interior composition. Credit: NASA/JPL-Caltech
The dynamic duo lifted off from Cape Canaveral on September 10, 2011 atop the last Delta II rocket that will likely soar to space from Florida. After a three month voyage of more than 2.5 million miles (4 million kilometers) since blastoff, the two mirror image GRAIL spacecraft dubbed Grail-A and GRAIL-B are sailing on a trajectory placing them on a course over the Moon’s south pole on New Year’s weekend.
Each spacecraft will fire the braking rockets for about 40 minutes for insertion into Lunar Orbit about 25 hours apart on New Year’s Eve and New Year’s Day.
Engineers will then gradually lower the satellites to a near-polar near-circular orbital altitude of about 34 miles (55 kilometers).
The spacecraft will fly in tandem and the 82 day science phase will begin in March 2012.
“GRAIL is a Journey to the Center of the Moon”, says Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT). “GRAIL will rewrite the book on the formation of the moon and the beginning of us.”
“By globally mapping the moon’s gravity field to high precision scientists can deduce information about the interior structure, density and composition of the lunar interior. We’ll evaluate whether there even is a solid or liquid core or a mixture and advance the understanding of the thermal evolution of the moon and the solar system,” explained co-investigator Sami Asmar to Universe Today. Asmar is from NASA’s Jet Propulsion Laboratory (JPL)
7. Curiosity Mars Rover
The Curiosity Mars Science Lab (MSL) rover soared skywards on Nov. 26, the last of 2011’s three planetary science missions. Curiosity is the newest, largest and most technologically sophisticated robotic surveyor that NASA has ever assembled.
“MSL packs the most bang for the buck yet sent to Mars.” John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.
The three meter long robot is the first astrobiology mission since the Viking landers in the 1970’s and specifically tasked to hunt for the ‘Ingredients of Life’ on Mars – the most Earth-like planet in our Solar System.
Video caption: Action packed animation depicts sequences of Curiosity departing Earth, the nail biting terror of the never before used entry, descent and landing on the Martian surface and then looking for signs of life at Gale Crater during her minimum two year expedition across hitherto unseen and unexplored Martian landscapes, mountains and craters. Credit: NASA
Curiosity will gather and analyze samples of Martian dirt in pursuit of the tell-tale signatures of life in the form of organic molecules – the carbon based building blocks of life as we know it.
NASA is targeting Curiosity to a pinpoint touch down inside the 154 km (96 mile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering 3 mile (5 km) high mountain.
“10 science instruments are all aimed at a mountain whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life,” Grotzinger told me.
Titan Upfront
The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science InstituteCuriosity Mars Science Laboratory Rover and Ken Kremer - inside the Cleanroom at the Kennedy Space Center. Last View of Curiosity just prior to folding and encapsulation for launch. Credit: Ken Kremer
This past year Ken was incredibly fortunate to witness the ongoing efforts of many of these magnificent endeavors.
January Sky Northern Hemisphere Credit: Adrian West
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January brings us striking views of the night skies! You’ll be able to see well known constellations during the long hours of darkness in the Northern hemisphere, with crisp cold skies. This is an ideal time to get out and look at the wonders of the night sky as there is so much to see for the beginner and seasoned astronomer alike.
You will only need your eyes to see most of the things in this simple guide, but some objects are best seen through binoculars or a small telescope.
So what sights are there in the January night sky and when and where can we see them?
Meteor Showers Quadrantid Meteor Credit: nasa.gov
As soon as the month starts we receive a welcome treat in the form of the Quadrantid meteor shower on the evening of the 3rd/ morning of the 4th of January.
The Quadrantids can be quite an impressive shower with rates (ZHR) of up to 120 meteors per hour at the showers peak (under perfect conditions) and can sometimes produce rates of up to 200 meteors per hour. The peak is quite narrow lasting only a few hours, with activity either side of the peak being quite weak.
Due to a waxing gibbous moon, the best time to look is after midnight and through the early hours when the moon sets in time for us to see the peak which is 07:20 UT.
The radiant of the Quadrantids (where the meteors radiate from) is in the constellation of Boötes, however many people are mislead in thinking they need to look at the radiant to see the meteors – this is not true. Meteors will come from the radiant, but will appear anywhere in the whole sky at random. You can trace the shooting stars path back to the radiant to confirm if it is a meteor from the meteor shower.
For more information on how to observe and enjoy the Quadrantid meteor shower, visit meteorwatch.org
Planets
Mercury is low down in the southeast before sunrise in the first week of January.
Venus will be shining brightly in the southwest until May and will pass within 1° of Neptune the furthest planet on the 12th and 13th of January. You can see this through binoculars or a small telescope. On the 26th Venus and the Moon can be seen together after sunset. Venus
On the 5th of January, Earth will be at “Perihelion” its closest point to the Sun.
Mars brightens slightly to -0.5 during January and can be found in the tail of Leo; it can be easily spotted with the naked eye. The red Planet is close to the Moon on the night of the 13th/ 14th January. Mars
On January 2nd Jupiter and the Moon will be very close to each other with a separation of only 5° with Jupiter just below the Moon. Jupiter will continue to be one of the brightest objects in the sky this month. Jupiter
Saturn now lies in the constellation of Virgo and follows after just after Mars in Leo. Saturn
Uranus is just barely visible to the naked eye in the constellation of Pisces and can be easily spotted in binoculars or small telescopes throughout the month. The Moon will pass very close to Uranus on the 27th and will be just 5.5° to the left of the planet. Uranus Moon phases
First Quarter – 1st and 31st January
Full Moon – 9th January
Last Quarter – 16th January
New Moon – 23rd January
Constellations
Credit: Adrian West
In January the most dominant and one of the best known constellations proudly sits in the south of the sky – Orion the hunter.
Easily distinguishable as a torso of a man with a belt of three stars, a sword, club and shield, Orion acts as the centre piece of the surrounding winter constellations. Orion is viewed upside down in the Northern sky as seen from the Southern hemisphere.
Orion contains some exciting objects and its most famous are the Great Nebula in Orion(M42), which makes up the sword and is easily seen in binoculars or a telescope and bright Betelgeuse, Orion’s bright alpha star (α Orionis). Betelgeuse is a red supergiant many times larger than our Sun; it would engulf everything in our solar system out to the orbit of Jupiter, if the two stars swapped places. Betelgeuse will eventually end its life in a Supernova explosion and some people believe that it may have already exploded and the light hasn’t reached us yet. It would make for a fantastic sight! The Great Orion Nebula. Image Credit: Patrick Cullis
If you draw an imaginary line through the three belt stars of Orion and keep going up and to the right, you will come to a bright orange coloured star – Aldebaran (α Tauri) in the constellation of Taurus. Pleiades Cluster/ Seven Sisters
Taurus depicts a head of a bull with Aldebaran as its eye with a V shape that creates long horns starting from what we call the Hyades cluster, a V shaped open cluster of stars. If you continue to draw a line through the belt stars of Orion, through Aldebaran and keep going, you will eventually get to one of the gems in Taurus – The Pleiades cluster or Seven Sisters (M45) a stunning cluster of blue and extremely luminous stars and from our vantage point on Earth, the most recognisable cluster with the naked eye. A great object to scan with binoculars. A great object to hunt for with a small telescope is the Crab Nebula (M1) near the end of the lower horn of Taurus. The Crab Nebula
If you go back to our imaginary line drawn through the belt stars of Orion and draw it in the other direction, to left and below, you will come to the very bright star Sirius (α CMa) – The Dog Star in Canis Major. Sirius is the brightest star in the sky and is only 8.6 light years away, it is the closest star visible to the naked eye after the Sun.
Sirius along with Betelgeuse and Procyon (α CMi) in Canis Minor, form an asterism known as the Winter Triangle.
Directly above Orion and the Winter Triangle are the constellations of Gemini (The Twins), with the two bright stars of Castor and Pollux marking their heads and Auriga the charioteer, with its bright alpha star Capella (α Aur). Auriga is host to M36, M37 and M38 which are globular clusters and easily seen through binoculars or small telescope and Gemini plays host to M35. M37
Only a few of the objects available to see have been mentioned, so get yourself a good map, Planisphere or star atlas and see what other objects you can track down!
The moons Titan and Dione are photographed with rings and Saturn in the background. Credit: NASA/JPL-Caltech/Space Science Institute
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“Hey! Look what our Santa at Saturn has sent our way!” said Carolyn Porco, the Cassini imaging team lead, in a post on Twitter. This wonderful collection of just-released colorful images from the Saturn system are a holiday gift from the Cassini and CICLOPS (Cassini Imaging Central Laboratory for Operations)team.
Above, Saturn’s third-largest moon, Dione, can be seen through the haze of the planet’s largest moon, Titan, in this view of the two posing before the planet and its rings from NASA’s Cassini spacecraft.
More treats below!
Saturn's moon Tethys, with its stark white icy surface, peeps out from behind the larger, hazy, colorful Titan in this view of the two moons obtained by NASA's Cassini spacecraft. Saturn's rings lie between the two. Credit: NASA/JPL-Caltech/Space Science InstituteThese views from NASA's Cassini spacecraft look toward the south polar region of Saturn's largest moon, Titan, and show a depression within the moon's orange and blue haze layers near the south pole. Credit: NASA/JPL-Caltech/Space Science InstituteThe colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science InstituteSaturn's largest moon, Titan, appears deceptively small paired here with Dione, Saturn's third-largest moon, in this view from NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute
To see more details and larger versions of these images, visit the CICLOPS website. (And thanks, Carolyn and team for the beautiful gifts!)
The Voyager 1 spacecraft has started to transverse what JPL has dubbed as a "cosmic purgatory" between our solar system - and interstellar space. Image Credit: NASA/JPL
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Voyager 1 is in uncharted territory. The long-lived spacecraft has entered a new region of space that lies between where our solar system ends and where interstellar space begins. This area is not a place of sightseeing however, as a NASA press release referred to it as a kind of “cosmic purgatory.”
Here, the solar winds ebb somewhat, the magnetic field increases and charged particles from within our solar system – is leaking out into interstellar space. This data has been compiled from information received from Voyager 1 over the course of the last year.
The Voyager spacecraft's compliment of scientific instruments have provided scientists back on Earth with information about what the space environment at the fringes of our sun's influence is truly like. Image Credit: NASA/JPL - Caltech
“Voyager tells us now that we’re in a stagnation region in the outermost layer of the bubble around our solar system,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “Voyager is showing that what is outside is pushing back. We shouldn’t have long to wait to find out what the space between stars is really like.”
Despite the fact that Voyager 1 is approximately 11 billion miles (18 billion kilometers) distant from the sun – it still has not encounter interstellar space. The information that scientists have gleaned from the Voyager 1 spacecraft indicates that the spacecraft is still located within the heliosphere. The heliosphere is a “bubble” of charged particles that the sun blows around itself and its retinue of planets.
Voyager 1 has traveled far past the realm of the gas or even ice giants and is now in uncharted territory where scientists are learning more and more about the dynamic environment at the far-flung edges of our solar system. Image Credit: NASA/JPL - Caltech
The latest findings were made using Voyager’s Low Energy Charged Particle instrument, Cosmic Ray Subsystem and Magnetometer.
Experts are not certain how long it will take the Voyager 1 spacecraft to finally breach this bubble and head out into interstellar space. Best estimates place the length of time when this could happen anywhere from the next few months – to years. These findings counter findings announced in April of 2010 that showed that Voyager 1 had essentially crossed the heliosphere boundary. The discoveries made during the past year hint that this region of space is far more dynamic than previously thought.
Voyager 1 has entered into a region of space between the sun's influence and the beginning of interstellar space that NASA has dubbed the "stagnation region." Image Credit: NASA/JPL - Caltech
The magnetometer aboard Voyager 1 has picked up an increase in the intensity of the magnetic field located within this “stagnation field.” Essentially the inward pressure from interstellar space is compressing the magnetic field to twice its original density. The spacecraft has also detected a 100-fold increase in the intensity of high-energy electrons diffusing into our solar system from outside – this is yet another indicator that Voyager 1 is approaching the heliosphere.
The interplanetary probe was launched from Cape Canaveral Air Force Station’s Space Launch Complex 41 (SLC-41) on Sept. 5, 1977, Voyager 1’s sister ship, Voyager 2 is also in good health and is about 9 billion miles (15 billion kilometers) from the sun (it too was launched in 1977). The spacecraft itself was built by NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
“Voyager is a mission of discovery and it’s at the edge of the solar system still making discoveries,” said Stone said. “The stagnation is the latest in the whole journey of discovery. We are all excited because we believe it means we’re getting very close to boundary of heliosphere and the entry into interstellar space.”
Both of the Voyager spacecraft were thrust to orbit by the powerful Titan boosters - and both in the same year - 1977. Photo Credit: NASA
Saturn's northern storm marches through the planet's atmosphere in the top right of this false-color mosaic from NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute
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Nearly a year ago a small, bright white storm emerged on Saturn’s northern hemisphere. This storm has now wrapped around the planet, creating a colossal atmospheric disturbance that has become the largest storm seen on the planet since 1990. And the Cassini spacecraft has been there to see it all.
“It is the singular distinction of being in orbit, and able to turn a scrutinizing eye wherever it is needed, that has allowed us to be present to witness this extraordinary phenomenon,” said Carolyn Porco, the Cassini Imaging Team Leader. “The storm has spread to become a planet-encircling colossus, a wide kaleidoscopic band of commingled waves, vortices, and eddies, all in continuous swirling motion …. a mesmerizing display of snaking, sensuous, churning, turning, chaotic, roiling atmospheric turmoil.”
If Porco sounds like she’s waxing poetic, she has good reason. The images put out by the Cassini imaging team today are a “sublime visual extravaganza,” and both true and false color images are gorgeous to behold.
This is nearly true-color view by Cassini of the storm. Credit: Credit: NASA/JPL-Caltech/Space Science Institute
The huge storm extends around Saturn’s northern hemisphere and from north to south spread approximately 9,000 miles, or 15,000 kilometers. It has become the largest observed on Saturn in the past 21 years, and the largest by far ever observed on the planet from an interplanetary spacecraft. What timing for Cassini to be there!
“Seven years of chasing such opportunities across the solar system’s most magnificent planetary system have already made Cassini one of the most scientifically productive planetary missions ever flown,” said Porco on the CICLOPS website. “And with any luck, there’ll be a great deal more to come.”
These false-color mosaics from NASA's Cassini spacecraft chronicle the changing appearance of the huge storm that developed from a small spot in Saturn's northern hemisphere. Here Cassini captures the changes over the short time span of one Saturn day; the two images were taken 11 hours apart. Credit: NASA/JPL-Caltech/Space Science Institute
Cassini has taken hundreds of images of this storm as part of the imaging team’s “Saturn Storm Watch” campaign. Cassini has been able to take quick looks at the storm in between other scheduled observations, of either Saturn or its rings and moons.
Other instruments on Cassini have detected the storm’s electrical activity and revealed it to be a convective thunderstorm. Its active convecting phase ended in late June, but the turbulent clouds it created linger in the atmosphere today.
“The Saturn storm is more like a volcano than a terrestrial weather system,” said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena, Calif. “The pressure builds up for many years before the storm erupts. The mystery is that’s there’s no rock to resist the pressure – to delay the eruption for so many years.”
This storm’s 200-day active period makes it the longest-lasting planet-encircling storm ever seen on Saturn. The previous record holder was an outburst sighted in 1903 which lingered for 150 days. The large disturbance imaged 21 years ago by NASA’s Hubble Space Telescope was comparable in size to the current storm. That 1990 storm lasted for only 55 days.
This series of images from NASA's Cassini spacecraft shows the development of the largest storm seen on the planet since 1990. Credit: NASA/JPL-Caltech/Space Science Institut
Enceladus and Epimetheus as seen by Cassini on October 1, 2011.
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Taken during the Cassini spacecraft’s October 1 flyby of Saturn’s ice-spewing moon, this image – released today – shows a crescent-lit Enceladus with southern geysers in action… and the much smaller Epimetheus peeking out from behind!
Epimetheus
The 70-mile (113-km) -wide Epimetheus is dwarfed by its larger sibling Enceladus, which is 313 miles (504 km) in diameter… about the width of the state of Arizona.
One of the most reflective objects in the solar system, Enceladus appears to be casting some reflected light onto Epimetheus as well. (Image processors at the Cassini Imaging Lab have brightened the moons by a factor of 1.8 relative to the rings in order to bring out detail.)
Some bright clumps of material can also be seen orbiting within Saturn’s rings at upper left, possibly stirred up by the movement of the shepherd moon Pan.
And I agree with Cassini imaging team lead Carolyn Porco who said on Twitter of this image: “You’d have to be dead to tire of such magnificent vistas of alien worlds. Eerie Titan, the rings, Pan & Pandora. Glory!”
Titan is the largest in the background, and also the largest moon at 5,150 kilometres (3,200 miles) across, with Dione in front of it, which is 1,123 kilometres (698 miles) in diameter. Just to the right of the edge of the rings is Pandora, which is only about 81 kilometres (50 miles) in diameter. Tiny little Pan, only about 28 kilometres (17 miles) across, can just barely be seen as a speck inside the Encke Gap of the A ring on the left side of the image (look closely!).
Another amazing natural montage showing the alien beauty of the worlds in the Saturnian system. The full-size image can be seen here.
Enceladus and Tethys hang below Saturn's rings in this image from the Cassini spacecraft. Credit: NASA/JPL-Caltech/SS
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Another Cassini stunner! This gorgeous, suitable-for-framing image shows two of Saturn’s moons hanging below the planet’s rings, as if strung on a necklace. Beautiful! Enceladus (504 kilometers, 313 miles across) appears just below the rings, while Tethys (1062 kilometers, 660 miles across) appears below. In this shot, Cassini is also closer to Tethys than Enceladus: the spacecraft is 208,000 kilometers (139,000 miles) from Tethys and 272,000 kilometers (169,000 miles) from Enceladus. This image was taken on September 13, 2011.
See below for some raw images from Cassini’s October 1 close fly by of Enceladus, including a great shot of the moon hovering in front of Saturn’s rings, and a view of the geysers.
A closeup view of Enceladus with Saturn's rings in the background. This raw image was taken on Oct. 1, 2011. Credit: NASA/JPL/Space Science Institute
A view of Enceladus from farther away, with the rings slicing through the view of Saturn in the background. Credit: NASA/JPL/Space Science InstituteA view of the geysers on Enceladus, from Cassini's latest close flyby of the moon, on October 1, 2011.Credit: NASA/JPL/Space Science Institute
Global mosaic of VIMS infrared images acquired during the nominal and equinox Cassini mission. Differences in composition translate into subtle differences of colours in this mosaic, revealing the diversity of terrains on Titan, such as the brownish equatorial dune fields or the bright elevated terrains. (Colour coding : Red=5 um, Green=2.0 um, Blue=1.27 um). Credits JPL/NASA/Univ. of Arizona/CNRS/LPGNantes
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At the University of Nantes, a group of international scientists have been piecing together one of the most amazing jigsaw puzzles of all times… a color image of Saturn’s moon, Titan. For six years the Cassini mission has been busy gathering images and the resulting compilation was presented on October 4 by Stephane Le Mouelic at the 2011 EPSC-DPS Joint Meeting in Nantes, France. While it might not win the Cannes Film Festival, it’s certainly near and dear to an astronomer’s heart…
During the first seventy fly-bys of the famous Saturnian satellite, the Visual and Infrared Mapping Spectrometer (VIMS) gathered imaging records. But sewing together such a large quilt of information wasn’t an easy task. Not only does each image have to be adjusted for differences in lighting conditions, but a pixel-by-pixel match up has to occur to take atmospheric distortions into account. Titan’s methane rain and nitrogen atmosphere isn’t conducive to easy imaging and only a narrow band of infrared wavelengths allow us to take a closer look at the hidden, frozen surface. However, the results have been spectacular and little by little some very “terrestrial” features have come to light.
“As Cassini is orbiting Saturn and not Titan, we can observe Titan only once a month on average. The surface of Titan is therefore revealed year after year, as pieces of the puzzle are progressively put together.” says Le Mouelic. “Deriving a final map with no seams is challenging due to the effects of the atmosphere – clouds, mist etc. – and due to the changing geometries of observation between each flyby.”
Since 2004, Cassini has made 78 fly-bys of the exotic frozen world and another 48 are planned over the next five years. However, VIMS has had very few chances to image Titan with a high spatial resolution. While this still leaves many areas in the proverbial dark, all this can change in the future.
“We have created the maps using low resolution images as a background with the high resolution data on top. In the few opportunities where we have VIMS imagery from the closest approach, we can show details as low as 500 metres per pixel. An example of this is from the 47th flyby, which allowed the observation of the site where the Huygens descent module landed. This observation is a key one as it might help us to bridge the gap between the ground truth provided by Huygens, and ongoing global mapping from orbit, which will continue up to 2017.”
And what does the future hold? Along with updated spatial coverage, the team plans on documenting Titan’s changing seasons from both an atmospheric and surface viewpoint. Changes that are just now beginning to occur.
“Lakes in Titan’s northern hemisphere were first discovered by the RADAR instrument in 2006, appearing as completely smooth areas. However, we had to wait up to June 2010 to obtain the first infrared images of the northern lakes, emerging progressively from the northern winter darkness,” says Le Mouelic. “The infrared observations provide the additional opportunity to investigate the composition of the liquids within the lakes area. Liquid ethane has already been identified by this means.”
Fill ‘er up… We’ll be watching!
Original Story Source: Europlanet News Release. For an even more impressive look, check out the Animation of Titan Mosaic.
