Yes there really are six moons visible in this image — click the image to help spot them. If you still can’t spot them all (and I could not at first) you will find a link to an annotated version below NASA’s caption:
NASA — After more than 13 years at Saturn, and with its fate sealed, NASA’s Cassini spacecraft bid farewell to the Saturnian system by firing the shutters of its wide-angle camera and capturing this last, full mosaic of Saturn and its rings two days before the spacecraft’s dramatic plunge into the planet’s atmosphere.
During the observation, a total of 80 wide-angle images were acquired in just over two hours. This view is constructed from 42 of those wide-angle shots, taken using the red, green and blue spectral filters, combined and mosaicked together to create a natural-color view.
Six of Saturn’s moons — Enceladus, Epimetheus, Janus, Mimas, Pandora and Prometheus — make a faint appearance in this image. (Numerous stars are also visible in the background.)
A second version of the mosaic is provided in which the planet and its rings have been brightened, with the fainter regions brightened by a greater amount. (The moons and stars have also been brightened by a factor of 15 in this version.)
The ice-covered moon Enceladus — home to a global subsurface ocean that erupts into space — can be seen at the 1 o’clock position. Directly below Enceladus, just outside the F ring (the thin, farthest ring from the planet seen in this image) lies the small moon Epimetheus. Following the F ring clock-wise from Epimetheus, the next moon seen is Janus. At about the 4:30 position and outward from the F ring is Mimas. Inward of Mimas and still at about the 4:30 position is the F-ring-disrupting moon, Pandora. Moving around to the 10 o’clock position, just inside of the F ring, is the moon Prometheus.
This view looks toward the sunlit side of the rings from about 15 degrees above the ring plane. Cassini was approximately 698,000 miles (1.1 million kilometers) from Saturn, on its final approach to the planet, when the images in this mosaic were taken. Image scale on Saturn is about 42 miles (67 kilometers) per pixel. The image scale on the moons varies from 37 to 50 miles (59 to 80 kilometers) pixel. The phase angle (the Sun-planet-spacecraft angle) is 138 degrees.
The Cassini spacecraft ended its mission on Sept. 15, 2017.
Very cool. An interstellar asteroid called Oumuamua.
We are getting some great information starting with two videos about Oumuamua. The first is from ESO:
And the second from NASA:
Finally a press release from NASA:
Now, new data reveal the interstellar interloper to be a rocky, cigar-shaped object with a somewhat reddish hue. The asteroid, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date. While its elongated shape is quite surprising, and unlike asteroids seen in our solar system, it may provide new clues into how other solar systems formed.
The observations and analyses were funded in part by NASA and appear in the Nov. 20 issue of the journal Nature. They suggest this unusual object had been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our star system.
“For decades we’ve theorized that such interstellar objects are out there, and now – for the first time – we have direct evidence they exist,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “This history-making discovery is opening a new window to study formation of solar systems beyond our own.”
Immediately after its discovery, telescopes around the world, including ESO’s Very Large Telescope in Chile and other observatories around the world were called into action to measure the object’s orbit, brightness and color. Urgency for viewing from ground-based telescopes was vital to get the best data.
Combining the images from the FORS instrument on the ESO telescope using four different filters with those of other large telescopes, a team of astronomers led by Karen Meech of the Institute for Astronomy in Hawaii found that ‘Oumuamua varies in brightness by a factor of ten as it spins on its axis every 7.3 hours. No known asteroid or comet from our solar system varies so widely in brightness, with such a large ratio between length and width. The most elongated objects we have seen to date are no more than three times longer than they are wide.
“This unusually big variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape,” said Meech. We also found that it had a reddish color, similar to objects in the outer solar system, and confirmed that it is completely inert, without the faintest hint of dust around it.”
These properties suggest that ‘Oumuamua is dense, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over hundreds of millions of years.
A few large ground-based telescopes continue to track the asteroid, though it’s rapidly fading as it recedes from our planet. Two of NASA’s space telescopes (Hubble and Spitzer) are tracking the object the week of Nov. 20. As of Nov. 20, ‘Oumuamua is travelling about 85,700 miles per hour (38.3 kilometers per second) relative to the Sun. Its location is approximately 124 million miles (200 million kilometers) from Earth — the distance between Mars and Jupiter – though its outbound path is about 20 degrees above the plane of planets that orbit the Sun. The object passed Mars’s orbit around Nov. 1 and will pass Jupiter’s orbit in May of 2018. It will travel beyond Saturn’s orbit in January 2019; as it leaves our solar system, ‘Oumuamua will head for the constellation Pegasus.
Observations from large ground-based telescopes will continue until the object becomes too faint to be detected, sometime after mid-December. NASA’s Center for Near-Earth Object Studies (CNEOS) continues to take all available tracking measurements to refine the trajectory of 1I/2017 U1 as it exits our solar system.
This remarkable object was discovered Oct. 19 by the University of Hawaii’s Pan-STARRS1 telescope, funded by NASA’s Near-Earth Object Observations(NEOO) Program, which finds and tracks asteroids and comets in Earth’s neighborhood. NASA Planetary Defense Officer Lindley Johnson said, “We are fortunate that our sky survey telescope was looking in the right place at the right time to capture this historic moment. This serendipitous discovery is bonus science enabled by NASA’s efforts to find, track and characterize near-Earth objects that could potentially pose a threat to our planet.”
Preliminary orbital calculations suggest that the object came from the approximate direction of the bright star Vega, in the northern constellation of Lyra. However, it took so long for the interstellar object to make the journey – even at the speed of about 59,000 miles per hour (26.4 kilometers per second) — that Vega was not near that position when the asteroid was there about 300,000 years ago.
While originally classified as a comet, observations from ESO and elsewhere revealed no signs of cometary activity after it slingshotted past the Sun on Sept. 9 at a blistering speed of 196,000 miles per hour (87.3 kilometers per second).
The object has since been reclassified as interstellar asteroid 1I/2017 U1 by the International Astronomical Union (IAU), which is responsible for granting official names to bodies in the solar system and beyond. In addition to the technical name, the Pan-STARRS team dubbed it ‘Oumuamua (pronounced oh MOO-uh MOO-uh), which is Hawaiian for “a messenger from afar arriving first.”
Astronomers estimate that an interstellar asteroid similar to ‘Oumuamua passes through the inner solar system about once per year, but they are faint and hard to spot and have been missed until now. It is only recently that survey telescopes, such as Pan-STARRS, are powerful enough to have a chance to discover them.
“What a fascinating discovery this is!” said Paul Chodas, manager of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory, Pasadena, California. “It’s a strange visitor from a faraway star system, shaped like nothing we’ve ever seen in our own solar system neighborhood.”
This galaxy is called NGC 4625 and it is a dwarf galaxy located 30-million light-years away in the constellation Canes Venatici.
It is indeed quite lop-sided. I would imagine the rotation of the galaxy would reflect the absence of mass by the center of gravity being just a little off and producing a distinct wobble.
From ESA/NASA/Hubble: This new picture of the week, taken by the NASA/ESA Hubble Space Telescope, shows the dwarf galaxy NGC 4625, located about 30 million light-years away in the constellation of Canes Venatici (The Hunting Dogs). The image, acquired with the Advanced Camera for Surveys (ACS), reveals the single major spiral arm of the galaxy, which gives it an asymmetric appearance. But why is there only one such spiral arm, when spiral galaxies normally have at least two?
Astronomers looked at NGC 4625 in different wavelengths in the hope of solving this cosmic mystery. Observations in the ultraviolet provided the first hint: in ultraviolet light the disk of the galaxy appears four times larger than on the image depicted here. An indication that there are a large number of very young and hot — hence mainly visible in the ultraviolet — stars forming in the outer regions of the galaxy. These young stars are only around one billion years old, about 10 times younger than the stars seen in the optical center. At first astronomers assumed that this high star formation rate was being triggered by the interaction with another, nearby dwarf galaxy called NGC 4618.
They speculated that NGC 4618 may be the culprit “harassing” NGC 4625, causing it to lose all but one spiral arm. In 2004 astronomers found proof for this claim. The gas in the outermost regions of the dwarf galaxy NGC 4618 has been strongly affected by NGC 4625.
Credit: ESA/Hubble & NASA
Text credit: European Space Agency
Oh my, just look at this picture, it is beautiful. Thanks to Ollie Taylor for taking it and ESA for sharing it out. ESA has a nice press release and include other footage of this event which was widely seen across Europe.
ESA — On 14 November 2017 at about 16:45 GMT a football-sized meteoroid entered Earth’s atmosphere about 50 km northeast of Darmstadt, Germany. It created a bright fireball in the sky, which was seen by thousands of people in Germany, France, Switzerland, Austria and Luxembourg, and was reported widely by media.
This remarkable image was taken by Ollie Taylor, a photographer from Dorset, UK, who happened to be on a shoot in Italy, in the Dolomites. The landscape scene shows the village of La Villa, Alta Badia, with Ursa Major seen in the background sky.
At dusk on 14 November, he was setting up for a night landscape shoot at Passo Falzarego, at 2200 m altitude, in clear but chilly –6ºC weather.
Ollie reports: “I was composing a shot of this scene and Ursa Major, seen above the meteor. I wanted to get it at twilight so the sky had a nice pink hue. I just decided I was not getting close enough, and was reaching for my other camera with a longer lens, luckily I left this camera exposing!
“It was a stroke of luck, as it’s given me not only the meteor, but great landscape background, too.”
Small lumps of rock enter our atmosphere every day, but it is rare for one to burn so brightly and to be seen by so many people.
“Owing to the meteoroid’s very high speed, estimated to be at least 70 000 km/h, it super-heated the air molecules in its path as it decelerated, creating a very luminous fireball,” adds Rudiger Jehn, of ESA’s Space Situational Awareness programme.
“Observers reported the meteoroid in detail, which allowed us to estimate its final fate: burning up at an altitude of around 50 km above Luxembourg.”
By yesterday, over 1150 sightings had been submitted to the International Meteor Organization, which runs a website to gather sightings of such events worldwide.
Four other fireballs were reported in France and the US 14–15 November, and the fireball over Luxembourg could be linked to the Taurid Meteor Shower , according to the organisation.
ESA supports the global effort to spot natural objects such as asteroids – much larger than this object – that can potentially strike Earth and cause damage. Access more information on the Space Situational Awareness programme via http://www.esa.int/ssa_neo.
The Zuma mission did not launch as you may know. SpaceX is “take a closer look at data from recent fairing testing /for another customer.” Launch range has been preserved for 17/18 November but not date is solid as yet.
Will SpaceX put the “zoom” in Zuma? The launch window opens shortly at 01:00 UT / 20:00 EST.
Well if you are here on time you are seeing the same result “Live stream offline” message. Keep in mind the window is two-hours. I will just leave the feed up just in case.
I will try to have a live-link up for an expected launch of “Zuma” atop a Falcon 9 rocket.
Launch time is expected to be between 01:00 UT and 03:00 UT (17 Nov 2017) / 20:00 ET and 22 ET (16 Nov 2017) from the Kennedy Space Center with back up slots 24 hours later if needed.
What is Zuma? Zuma is a classified American government payload and to be honest I don’t want to know. LOL.
What I do want is for Space X to keep the telemetry on the first-stage all the way to landing back at Cape Canaveral which they probably will do so I can continue to chart the altitude/time profile. Please? Usually there is breaks in the published data. Hey it is a very interesting graph plot — yes I am a data geek.
It strikes me as it always does: science research done collaboratively should serve as an excellent role model of what can be accomplished TO so many other unrelated (non-science) endeavors.
University of Southampton — An international team of astronomers, including a University of Southampton expert, has discovered a new type of explosion in a distant galaxy.
The explosion, called PS1-10adi, seems to prefer active galaxies that house supermassive black holes consuming the gas and material around them.
Using telescopes on La Palma and Hawaii, the team detected an explosion that was so energetic it must have originated from one of two sources: an extremely massive star – up to several hundred times more massive than our Sun – exploding as a supernova, or from a lower mass star that has been shredded by the ultra-strong gravitational forces close to the supermassive black hole.
The explosion – detailed in a study published in Nature Astronomy – occurred 2.4 billion years ago, but the enormous distance that light from the event had to travel to reach Earth meant it wasn’t observed by astronomers until 2010. The slow evolution of the explosion allowed scientists to monitor it for several years.
Dr Cosimo Inserra, of the University of Southampton, was involved in the analysis of data and helped identify the only two possible scenarios that could explain the event. He also tested the data using established physical supernova models to support the results.
He commented: “The discovery we made has revealed explosions capable of releasing an amount of energy ten times bigger than normal explosions.
“Our data show that events like this are not very unusual and challenge our knowledge of exploding and disrupting stars.
“At the same time, their existence provides us with important information about the extreme environment in the central, hidden, part of galaxies.”
Lead author Dr Erkki Kankare, of Queen’s University Belfast, added: “If these explosions are tidal disruption events – where a star gets sufficiently close to a supermassive black hole’s event horizon and is shredded by the strong gravitational forces – then its properties are such that it would be a brand new type of tidal disruption event.
“If they are supernova explosions then their properties are more extreme than we have ever observed before, and are likely connected to the central environments of the host galaxies.”
The international team included research institutes from Finland, Sweden, Ireland, Italy, Spain, Chile, and the US.
Cassini keeps on giving even after it became part of Saturn and the end of the epic mission.
Original caption from NASA:
Saturn’s C ring is home to a surprisingly rich array of structures and textures (see also PIA21618). Much of the structure seen in the outer portions of Saturn’s rings is the result of gravitational perturbations on ring particles by moons of Saturn.
Such interactions are called resonances. However, scientists are not clear as to the origin of the structures seen in this image which has captured an inner ring region sparsely populated with particles, making interactions between ring particles rare, and with few satellite resonances.
In this image, a bright and narrow ringlet located toward the outer edge of the C ring is flanked by two broader features called plateaus, each about 100 miles (160 kilometers) wide.
Plateaus are unique to the C ring. Cassini data indicates that the plateaus do not necessarily contain more ring material than the C ring at large, but the ring particles in the plateaus may be smaller, enhancing their brightness. This view looks toward the sunlit side of the rings from about 53 degrees above the ring plane. The image was taken in green light with the Cassini spacecraft narrow-angle camera on Aug. 14, 2017.
The view was acquired at a distance of approximately 117,000 miles (189,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 74 degrees. Image scale is 3,000 feet (1 kilometer) per pixel.
The Cassini spacecraft ended its mission on Sept. 15, 2017.
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.