UV image of Titan acquired by Cassini on April 13 (NASA/JPL-Caltech/SSI)
As high summer slowly but steadily approaches on Saturn, Cassini is opening a window to the seasonal changes that occur not only on the ringed planet but also its moons. Here we can see a dark band developing around Titan’s north polar latitudes, a “fancy collar” made visible in ultraviolet wavelengths.
Polar collars have previously been seen by both Hubble and Voyager 2, and in fact a southern version was observed by HST 5 years after the planet’s 1995 equinox.
This summer collar is thought to be part of a seasonal process, related to the migration of upper-level haze material within Titan’s atmosphere.
Source: CICLOPS (Cassini Imaging Central Laboratory for OPerationS)
The Solar System: it’s our home in space, the neighborhood that we all grew up in and where — unless we figure out a way to get somewhere else — all of our kids and grandkids and great-great-great-great-times-infinity-great-grandkids will grow up too. That is, of course, until the Sun swells up and roasts Earth and all the other inner planets to a dry crunchy crisp before going into a multi-billion year retirement as a white dwarf.
But until then it’s a pretty nice place to call home, if I may say so myself.
Edu-film designer Philipp Dettmer and his team have put together a wonderful little animation explaining the basic structure of the Solar System using bright, colorful graphics and simple shapes to illustrate the key points of our cosmic neighborhood. It won’t teach you everything you’ll ever need to know about the planets and it’s not advisable to use it as a navigation guide, but it is fun to watch and well-constructed, with nice animation by Stephan Rether and narration by Steve Taylor.
Check out the full video below:
“Through information design, concepts can be made easy and accessible when presented in a short, understandable edu-film or perhaps an infographic. Whether explaining the vastness of the universe or the tiniest building blocks of life – all information can be presented in a way that everyone understands. Regardless of prior knowledge.”
– Philipp Dettmer
(And come on, admit it… you learned something new from this!)
Has Voyager 1 actually left the Solar System? Some researchers are saying yes. (Image: NASA/JPL-Caltech)
Nearly 18.7 billion kilometers from Earth — about 17 light-hours away — NASA’s Voyager 1 spacecraft is just about on the verge of entering interstellar space, a wild and unexplored territory of high-energy cosmic particles into which no human-made object has ever ventured. Launched in September 1977, Voyager 1 will soon become the first spacecraft to officially leave the Solar System.
Or has it already left?
I won’t pretend I haven’t heard it before: Voyager 1 has left the Solar System! Usually followed soon after by: um, no it hasn’t. And while it might all seem like an awful lot of flip-flopping by supposedly-respectable scientists, the reality is there’s not a clear boundary that defines the outer limits of our Solar System. It’s not as simple as Voyager rolling over a certain mileage, cruising past a planetary orbit, or breaking through some kind of discernible forcefield with a satisfying “pop.” (Although that would be cool.)
The outer edge of the heliosphere has been found to contain many different regions, which Voyager 1 has been passing through since 2004. (NASA/JPL-Caltech)
Rather, scientists look at Voyager’s data for evidence of a shift in the type of particles detected. Within the transitionary zone that the spacecraft has most recently been traveling through, low-energy particles from the Sun are outnumbered by higher-energy particles zipping through interstellar space, also called the local interstellar medium (LISM). Voyager’s instruments have been detecting dramatic shifts in the concentrations of each for over a year now, unmistakably trending toward the high-energy end — or at least showing a severe drop-off in solar particles — and researchers from the University of Maryland are claiming that this, along with their model of a porous solar magnetic field, indicates Voyager has broken on through to the other side.
“It’s a somewhat controversial view, but we think Voyager has finally left the Solar System, and is truly beginning its travels through the Milky Way,” said Marc Swisdak, UMD research scientist and lead author of a new paper published this week in The Astrophysical Journal Letters.
According to Swisdak, fellow UMD plasma physicist James F. Drake, and Merav Opher of Boston University, their model of the outer edge of the Solar System fits recent Voyager 1 observations — both expected and unexpected. In fact, the UMD-led team says that Voyager passed the outer boundary of the Sun’s magnetic influence, aka the heliopause… last year.
But, like some of last year’s claims, these conclusions aren’t shared by mission scientists at NASA.
“Details of a new model have just been published that lead the scientists who created the model to argue that NASA’s Voyager 1 spacecraft data can be consistent with entering interstellar space in 2012,” said Ed Stone, Voyager project scientist at Caltech, in a press release issued today. “In describing on a fine scale how magnetic field lines from the sun and magnetic field lines from interstellar space can connect to each other, they conclude Voyager 1 has been detecting the interstellar magnetic field since July 27, 2012. Their model would mean that the interstellar magnetic field direction is the same as that which originates from our sun.
The famous “Golden Record” carried aboard both Voyager 1 and 2 contains images, sounds and greetings from Earth. (NASA)
“Other models envision the interstellar magnetic field draped around our solar bubble and predict that the direction of the interstellar magnetic field is different from the solar magnetic field inside. By that interpretation, Voyager 1 would still be inside our solar bubble.”
Stone says that further discussion and investigation will be needed to “reconcile what may be happening on a fine scale with what happens on a larger scale.”
Whether still within the Solar System — however it’s defined — or outside of it, the bottom line is that the venerable Voyager spacecraft are still conducting groundbreaking research of our cosmic neighborhood, 36 years after their respective launches and long after their last views of the planets. And that’s something nobody can argue about.
“The Voyager 1 spacecraft is exploring a region no spacecraft has ever been to before. We will continue to look for any further developments over the coming months and years as Voyager explores an uncharted frontier.”
– Ed Stone, Voyager project scientist
Built by JPL and launched in 1977, both Voyagers are still capable of returning scientific data from a full range of instruments, with adequate power and propellant to remain operating until 2020.
Note: The definition of “Solar System” used in this article is in reference to the Sun’s magnetic influence, the heliosphere, and all that falls within its outermost boundary, the heliopause (wherever that is.) Objects farther out are still gravitationally held by the Sun, such as distant KBOs and Oort Cloud comets, but orbit within the interstellar medium.
A mosaic by the Mars Science Laboratory Curiosity rover, assembled by Ken Kremer and Marco Di Lorenzo is now part of the permanent Solar System Exhibit outside the National Air and Space Museum on the US National Mall in Washington, D.C. Image courtesy Ken Kremer.
Congratulations to Universe Today writer Ken Kremer and his partner in image editing, Marco Di Lorenzo, who have had one of the panoramas they created from the Curiosity rover’s imagery included in a permanent Solar System exhibit outside the National Air and Space Museum on the US National Mall in Washington, D.C. The exhibit is called “Voyage” and was created by the National Center for Earth and Space Science Education (NCESSE) and is sponsored in part by NASA.
Ken said the NCESSE contacted him a few months ago back to use the mosaic — from Sol 169 of Curiosity’s time on Mars — and the project is finally complete. “They liked and chose it because it evokes a human presence on Mars with the rover in the foreground,” Ken said.
The exhibit is a one to 10-billion scale model of our Solar System—spanning 600 meters (6,000 feet) from the National Air and Space Museum to the Smithsonian Castle Building, and Ken and Marco’s image from the Curiosity rover is part of the information about Mars.
Here’s a description of the exhibit from NCESSE website:
“The Voyage exhibition on the National Mall, installed in 2001, was created through a partnership between Challenger Center for Space Science Education, the Smithsonian Institution, and NASA. A summer 2013 update of this exhibition’s content was undertaken by the National Center for Earth and Space Science Education and the Smithsonian Institution, through a grant from the District of Columbia Space Grant Consortium. To learn more, and view photo albums of all Voyage exhibitions, visit the Voyage National Program page.”
Here’s a closeup of Ken and Marco’s mosaic:
Close up of the Mars placard for the Voyager Solar System exhibit. Image courtesy of Ken Kremer.
And a full view of the image is below.
You can learn more about the exhibit at the NCESSE Voyage webpage. Again, congratulations to Ken and Marco!
Curiosity accomplished Historic 1st drilling into Martian rock at John Klein outcrop on Feb 8, 2013 (Sol 182), shown in this context mosaic view of the Yellowknife Bay basin taken on Jan. 26 (Sol 169). The robotic arm is pressing down on the surface at John Klein outcrop of veined hydrated minerals – dramatically back dropped with her ultimate destination; Mount Sharp. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo
Earth and Moon imaged from Cassini on July 19, 2013
Did you smile and wave at Saturn on Friday? If you did (and even if you didn’t) here’s how you — and everyone else on Earth — looked to the Cassini spacecraft, 898.4 million miles away.
Hope you didn’t blink!
The image above is a color-composite made from raw images acquired by Cassini in red, green, and blue visible light wavelengths. Some of the specks around the edges are background stars, and others are the result of high-energy particle noise, of which some have been digitally removed.
The Moon is the bright dot just below and to the left of Earth. (An original raw image can be seen here.)
Cassini acquired the images while capturing views of Saturn in eclipse against the Sun between 22:24:00 UTC on July 19 and 02:43:00 UTC on July 20 (6:24 to 10:43 pm EDT July 19.) On Cassini time, the Earth imaging took place between 22:47:13 UTC (6:47:13 pm EDT) and 23:01:56 UTC (7:01:56 pm EDT) on the 19th.
Full mosaic arrangement acquired by Cassini on July 19-20 UTC. Earth was positioned just below the planet. (NASA/JPL-Caltech/SSI)
The world was invited to “Wave at Saturn” beginning 5:27 pm EDT on Friday — which allowed enough time for the photons from a waving world to actually reach Cassini’s camera just beyond Saturn, 1.44 billion kilometers away. (Did you wave? I did!) It was the first time Earth’s population was made aware beforehand that their picture would be taken from such a cosmic distance.
A crowd gathered on the mall at NASA’s Jet Propulsion Laboratory in Pasadena to wave at Saturn on July 19 (NASA/JPL-Caltech)
The image of our planet and moon, seen as merely a couple of bright points of light against the blackness of space, recalls Sagan’s poignant “pale blue dot” passage from Cosmos…
“From this distant vantage point, the Earth might not seem of any particular interest. But for us, it’s different. Consider again that dot. That’s here, that’s home, that’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.
The “pale blue dot” of Earth captured by Voyager 1 in Feb. 1990 (NASA/JPL)
The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”
— Carl Sagan (1934–1996)
A full mosaic of Cassini’s imaging of Saturn silhouetted against the Sun is expected in the coming weeks.
UPDATE: Here’s another RGB color composite, made from raw images acquired with Cassini’s wide-angle camera. It shows a view of Saturn and the rings in eclipse as seen from below and behind, backlit by the Sun. Earth is the bright point light near the center. (See original here.)
Raw image (RGB composite) of Saturn in eclipse with Earth in the distance — just a pale blue dot. (NASA/JPL-Caltech/SSI. Composite by J. Major.)
Images: NASA/JPL-Caltech/Space Science Institute. Composites by Jason Major.
Just one of the many images from Cassini used to make up "Around Saturn"
In honor of this today’s Wave at Saturn and The Day the Earth Smiled events, celebrating images to be taken of Earth from Saturn, here’s a wonderful movie showing highlights from Cassini’s exploration of the giant planet, its magnificent rings, and fascinating family of moons.
Assembled by Fabio Di Donato in memory of astrophysicist, author and activist Margherita Hack, who passed away June 29 at the age of 91, this video is an impressive tour of the Saturnian system — and a truly stunning tribute as well.
“She made me love the stars,” Fabio wrote.
This video shows a selection from more than 200,000 pictures taken by the Cassini spacecraft around Saturn’s rings in a period between 2005 and 2013. RAW images were processed to PNG thanks to the Vicar-to-PNG procedure provided by Jessica McKellar.
The music is Jazz Suite No.2: VI Waltz 2 by Shostakovich, performed by the Armonie Symphony Orchestra.
As always, you can see the latest images and news from the Cassini mission here, and find out how your photo is going to be taken from 900 million miles away (and also 60 million miles away from Mercury!) here.
Video: Fabio Di Donato. Original images: NASA/JPL-Caltech/SSI.
P.S.: Want to get a personalized certificate saying you “Waved at Saturn?” Click here.
Comet ISON seen against a background of stars and galaxies (Source: /hubblesite.org)
This image of the steadily-approaching Comet ISON, made from observations with the Hubble Space Telescope on April 30, show not only the comet itself but also a rich background of stars located within our own galaxy and even the distant spirals of entire galaxies much, much farther away — as Josh Sokol describes it on HubbleSite.org’s ISONblog it’s like the astronomy stickers you’d get for your kid’s bedroom, except you’d never get to see such a scene in real life “unless, of course, you had Hubble.”
Comet C/2012 S1 (ISON) is currently on its way into the inner Solar System on course for a close encounter with the Sun, zooming along at 77,250 km/h (48,000 miles per hour). It will make its closest pass by the Sun on November 28 (coming within just .012 AU) and will hopefully put on a pretty spectacular show in the night sky — especially if it survives the trip.
Comet ISON’s projected path through the night sky prior to perihelion. (Credit: NASA/GSFC/Axel Mellinger)
The image above was created from multiple Hubble observations earlier this year, some geared toward capturing ISON and others calibrated more for distant, dimmer objects like galaxies and far-flung stars. By combining the results we get a view of a comet speeding through space with an almost too-perfect hyperrealism, courtesy of NASA’s hardest-working space telescope.
“The result is part science, part art. It’s a simulation of what our eyes, with their ability to dynamically adjust to brighter and fainter objects, would see if we could look up at the heavens with the resolution of Hubble. The result is a hodepodge of almost all the meat-and-potatoes subjects of astronomy – no glow-in-the-dark stickers required.”
IBEX observations of spectral slope, where red and yellow indicate lower energy particles and green and blue higher energy ones. The central portion (circle) is looking down the heliotail and shows two lower energy “lobes” on the port and starboard sides and high energy regions at higher northern and southern latitudes.
Figure taken from McComas et al. , Astrophysical Journal, 2013.
Our Solar System is moving through interstellar space and scientists have long thought that the “bubble” around our Solar System – called the heliosphere – might have a tail, similar to how a comet has a tail or how other stars have astrospheres. But that has all been conjecture…. until now.
The IBEX spacecraft (Interstellar Boundary Explorer) has now seen the tail and has mapped out its structure. IBEX scientists were surprised to see the tail has twists and turns, with four separate “lobes,” making it appear somewhat like a four-leaf clover. This downwind region of the heliosphere is called the heliotail.
“Scientists have always presumed that the heliosphere had a tail,” said Eric Christian, IBEX mission scientist, speaking during a Google+ Hangout announcing the new findings. “But this is actually the first real data that we have to give us the shape of the tail.”
IBEX measures the neutral particles created by collisions at the solar system’s boundaries. This technique, called energetic neutral atom imaging, relies on the fact that the paths of neutral particles are not affected by the solar magnetic field. Instead, the particles travel in a straight line from collision to IBEX. Consequently, observing where the neutral particles came from describes what is going on in these distant regions.
“By collecting these energetic neutral atoms, IBEX provides maps of the original charged particles,” said David McComas, lead author on the team’s paper and principal investigator for IBEX at Southwest Research Institute. “The structures in the heliotail are invisible to our eyes, but we can use this trick to remotely image the outermost regions of our heliosphere.”
What they found was unexpected, McComas said.
“By very carefully assembling the statistical observations from the first three years of IBEX data we’ve been able to fill in what we couldn’t see before,” McComas said during the Hangout, “and what we found was that the heliotail was a much larger structure with a much more interesting configuration.
What they found was a tail that appears to have a combination of fast and slow moving particles. There are two lobes of slower particles on the sides, with faster particles above and below. The entire structure is twisted from the pushing and pulling of magnetic fields outside the solar system. McComas likened it to a how a beach ball might twist around if it was attached to a bungee cord.
The IBEX scientists speaking during the Hangout today said this new information will help us understand what the Voyager spacecraft may encounter as they reach the edge of our Solar System.
“IBEX and Voyager are incredibly complimentary missions,” said Christian. “I’ve often said that IBEX is like an MRI, where it can take an image to understand the big picture of what is going on, where the Voyagers are like biopsies, where we can see what is going on in the local area.”
This was the first time a NASA used a Google+ Hangout to broadcast a press briefing. You can watch the full Hangout below:
You can read David McComas’ blog post on the new findings here, and NASA’s press release here.
Saturn's rings. Credit: NASA/JPL/Space Science Institute.
It’s been 9 years (to the day, in fact) since the Cassini spacecraft first entered orbit around Saturn and ever since it has been sending a steady stream of incredible images from the ringed planet back to Earth, bridging the 900-million-mile distance with countlesswonders and groundbreaking discoveries. The views Cassini has provided us of Saturn and its family of moons are unparalleled and unprecedented, but something one could remain in want of is the element of motion: Cassini’s cameras are designed to capture still images, not true video, and thus most of our best views of Saturn are static shots.
That’s where filmmaker Stephen van Vuuren and his current project, “In Saturn’s Rings,” comes in.
An award-winning filmmaker, musician, and photographer (and self-confessed übergeek) from South Africa, Stephen van Vuuren has spent the last several years compiling hundreds of thousands of images acquired by Cassini — as well as other exploration spacecraft — into a single high-definition feature film, one that will allow viewers to experience the beauty, grandeur, and reality of the Solar System like never before.
“In Saturn’s Rings” (formerly “Outside In”) is slated for release in IMAX theaters, planetariums, and museums in the spring of 2014 — and the first official teaser trailer is below, released today. Check it out (or visit the YouTube page to watch in original, eye-melting 4k high-resolution):
“‘In Saturn’s Rings’ is a film that’s both personal and universal, experimental and sincere, science and spirit , non-narrative and documentary. The goal is to use large screen imagery, synchronized to powerful but moving music, to create an experience for those who see it, hear it and feel it.”
– “In Saturn’s Rings” official website
This is one film that I’ll be eagerly looking forward to over the next few months, without a doubt!
Read more on van Vuuren’s official film site here, and check out a full minute of film footage (originally released in 2011) on Vimeo here. Also, you can keep up with updates on the movie’s Twitter and Facebook pages.
Mosaic of Saturn seen in eclipse in September 2006. Earth is the bright dot just inside the F ring at upper left. (CICLOPS/NASA/JPL-Caltech/SSI)
Citizens of Earth, get ready for your Cassini close-up: once again the spacecraft is preparing to capture images of Saturn positioned between it and the Sun, allowing for incredible views of the ring system and its atmosphere — and also a tiny “pale blue dot” in the distance we call home.
Earth seen from Cassini (NASA/JPL/SSI)
The mosaic above was composed of images captured during such an eclipse event in September 2006, and quickly became an astronomical sensation. It’s not often we get an idea of what we look like from so far away, and seeing our entire world represented as a small speck of light nestled between Saturn’s rings is, to me anyway, both impressive and humbling.
Humbling because of how small we look, but impressive because as a species we have found a way to do it.
And next month, on Friday, July 19 between 21:27 and 21:42 UTC (5:27 – 5:42 p.m. EDT) Cassini will do it again.
“Ever since we caught sight of the Earth among the rings of Saturn in September 2006 in a mosaic that has become one of Cassini’s most beloved images, I have wanted to do it all over again, only better,” said Cassini imaging team leader, Carolyn Porco. “And this time, I wanted to turn the entire event into an opportunity for everyone around the globe, at the same time, to savor the uniqueness of our beautiful blue-ocean planet and the preciousness of the life on it.”
Porco was involved in co-initiating and executing the famous “Pale Blue Dot” image of Earth taken by NASA’s Voyager 1 from beyond the orbit of Neptune in 1990.
“It will be a day for all the world to celebrate,” she said.
The intent for the upcoming mosaic is to capture the whole scene, Earth and Saturn’s rings from one end to the other, in Cassini’s red, green and blue filters that can be composited to form a natural color view of what our eyes might see at Saturn. Earth and the Moon will also be imaged with a high resolution camera — something not yet done by Cassini.
We can all consider ourselves pretty lucky, too… this is the first time in history that we humans will know in advance that our picture is going to be taken from nearly a billion miles away.
“While Earth will be only about a pixel in size from Cassini’s vantage point 898 million miles [1.44 billion kilometers] away, the Cassini team is looking forward to giving the world a chance to see what their home looks like from Saturn,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory. “With this advance notice, we hope you’ll join us in waving at Saturn from Earth, so we can commemorate this special opportunity.”
So on July 19, remember to look up and wave… Cassini will be watching!
Read more on the CICLOPS news release here and on the NASA/JPL Cassini mission site here.
“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives… There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”
