A gas stream from galaxy ESO 137-001 shines brightly in X-rays captured by the Chandra X-Ray Observatory. The galaxy is captured in other wavelengths by the Hubble Space Telescope. Credit: NASA, ESA, CXC
Is that a tractor beam trying to latch on to galaxy ESO 137-001? While the bold blue stripe in the picture above looks like a Star Trek-like technology, this new picture combination captures a stream of gas shining brightly in X-rays.
The “galactic disrobing” is taking place as the galaxy moves through the center of a star cluster full of superheated gas, scientists said. You can see another shot of the chaos below the jump.
From Earth’s perspective, the galaxy (which looks a little like a jellyfish) is found in the Triangulum Australe (The Southern Triangle) , and is part of the Norma Cluster that is about 200 million light-years from the Milky Way (our own galaxy). ESO 137-001 is moving through a galaxy cluster called Abell 3627. All of the superheated gas in this region is making ESO 137-001 bleed gas from its own structure as it goes.
“These streaks are actually hot young stars, encased in wispy streams of gas that are being torn away from the galaxy by its surroundings as it moves through space,” stated the Hubble European Space Agency Information Centre. “This violent galactic disrobing is due to a process known as ram pressure stripping — a drag force felt by an object moving through a fluid. The fluid in question here is superheated gas, which lurks at the centres of galaxy clusters.”
“This image also shows other telltale signs of this process, such as the curved appearance of the disc of gas and dust — a result of the forces exerted by the heated gas,” the centre added. “The cluster’s drag may be strong enough to bend ESO 137-001, but in this cosmic tug-of-war the galaxy’s gravitational pull is strong enough to hold on to the majority of its dust — although some brown streaks of dust displaced by the stripping are visible.”
This stripping has been caught in other images, such as these 2007 and 2010 pictures from the Chandra X-Ray Observatory.
A Hubble Space Telescope image of spiral galaxy ESO 137-001 moving through galaxy cluster Abell 3627. The tendrils (visible in ultraviolet light) are gas flowing away from the galaxy as it moves through superheated gas in the area. Credit: NASA, ESA
The 51st entry in Charles Messier's famous catalog is perhaps the original spiral nebula--a large galaxy with a well defined spiral structure also cataloged as NGC 5194. Over 60,000 light-years across, M51's spiral arms and dust lanes clearly sweep in front of its companion galaxy, NGC 5195. Image data from the Hubble's Advanced Camera for Surveys was reprocessed to produce this alternative portrait of the well-known interacting galaxy pair. The processing sharpened details and enhanced color and contrast in otherwise faint areas, bringing out dust lanes and extended streams that cross the small companion, along with features in the surroundings and core of M51 itself. The pair are about 31 million light-years distant. Not far on the sky from the handle of the Big Dipper, they officially lie within the boundaries of the small constellation Canes Venatici. Image Credit: NASA
The tangled remains of vast cosmic collisions can be seen across the universe, such as the distant Whirlpool Galaxy’s past close encounter with a nearby galaxy, which resulted in the staggering beauty we see today.
Such colossal collisions between galaxies appear to be common. It’s likely giant galaxies, such as our own, originated long ago after smaller dwarf galaxies crashed together. Unfortunately, Hubble has yet to peer into the early Universe and catch two dwarf galaxies merging by chance. And they’re extremely rare to catch in the present nearby universe.
But for the first time, astronomers have uncovered evidence of a similar collision much closer to home.
The Milky Way is part of a large cosmic neighborhood. A collection of more than 35 galaxies compose the Local Group. While the largest and heavier members are the Milky Way and the Andromeda galaxy, there are many smaller satellite galaxies orbiting the two. Anyone who has looked at the southern sky should be familiar with the Large and Small Magellanic Clouds: two satellite galaxies of the Milky Way less than 200,000 light years away.
Andromeda has over 20 satellite galaxies circling its nearly a trillion stars. A team of European astronomers has analyzed measurements of the stars in the dwarf galaxy Andromeda II — the second largest dwarf galaxy in the Local Group — and made a surprising discovery: an odd stream of stars that simply doesn’t belong.
The team led by Dr. Nicola C. Amorisco from the Dark Cosmology Centre at the Niels Bohr Institute in Copenhagen used the Deep Imaging Multi-Object (DEIMOS) spectrograph onboard the Keck II telescope in Hawaii in order to measure the velocities of more than 700 stars in the Andromeda II dwarf galaxy.
Stars in a large spiral galaxy will move, on average, with the rotation of the galaxy. On one side of the galaxy’s spinning disk, the stars will be moving away from the Earth, and their light waves will be stretched to redder wavelengths. On the opposite side, the stars will be moving toward the Earth, and their light waves will be compressed to bluer wavelengths.
But the stars in dwarf galaxies don’t exhibit such a pattern. Instead they move around entirely at random.
Amorisco and colleagues, however, found a rather different case present in Andromeda II. They observed a stream of stars — roughly 16,000 light years in length and 980 light years in thickness — that didn’t exhibit random motions at all. They orbit the center of the galaxy in a very coherent fashion.
But it gets better: the stars in this stream are also much colder than the stars outside the stream. In astronomy this is the equivalent of saying that the stars in this stream are much older. Amorisco’s team now believes they once belonged to a different galaxy entirely and remain only as a remnant of the past collision, which likely occurred over 3 billion years ago.
Streams of stars often result from collisions. As two galaxies begin to interact, the stars nearest the approaching galaxy feel a much stronger gravitational pull than the stars further away. Eventually the gravitational pull on the closer side of the galaxy will pull the stars from their initial galaxy, creating a stream of stars, dust and gas.
This is the smallest known example of two galaxies merging. The finding adds further evidence that mergers between dwarf galaxies plays a fundamental role in creating the large and beautiful galaxies we see today.
The paper has been published in Nature and is available for download here.
An aurora around Saturn's north pole in 2013. Credit: NASA/ESA/University of Leicester and NASA/JPL-Caltech/University of Arizona/Lancaster University
Above is the latest rave-like video from NASA. While the images are reminiscent of what could play during an awesome Friday night party, what you’re actually seeing is a timelapse of auroras on Saturn. These pictures are pretty to look at, but they also tell us more about how the sun’s belches of stuff influence the magnetic field around the ringed gas giant.
“Saturn’s auroras can be fickle — you may see fireworks, you may see nothing,” stated Jonathan Nichols of the University of Leicester in England, who led the work on the Hubble Space Telescope images shown in the video. “In 2013, we were treated to a veritable smorgasbord of dancing auroras, from steadily shining rings to super-fast bursts of light shooting across the pole.”
The light show was captured by both the Saturn-orbiting Cassini spacecraft and the Earth-orbiting Hubble. Cassini managed to nab its images from three Saturn distances away (which is apparently an unusually close vantage point.) This location “provided a look at the changing patterns of faint emissions on scales of a few hundred miles (kilometers) and tied the changes in the auroras to the fluctuating wind of charged particles blowing off the sun and flowing past Saturn,” NASA stated.
Here are a few things scientists are learning (or hoping to learn soon) from the light show:
How auroras are formed. The Cassini images suggest that as magnetic field lines forge new links, this is where the storms are centered. This process happens on Earth, so it would make sense for it to happen elsewhere. Researchers also found that some of the auroras stick close to the orbital position of Mimas, suggesting that the moon may be influencing some of the storms (a process already known to happen with Enceladus).
The nature of Saturn’s atmosphere. While the answers are still forthcoming, scientists are examining why the top of Saturn’s atmosphere (and other gas giants) are warmer than would be expected given how far they are from the sun. “By looking at these long sequences of images taken by different instruments, we can discover where the aurora heats the atmosphere as the particles dive into it and how long the cooking occurs,” stated Sarah Badman, a Cassini visual and infrared mapping spectrometer team associate at Lancaster University, England.
What color the auroras are. Red on the bottom, and purple on the top, depending on how Saturn’s hydrogen is excited and what light it emits. (For reference, Earth’s is green on bottom and red at top due to excitement of nitrogen and oxygen).
Where charged particles around Saturn go. More data from the W.M. Keck Observatory and NASA’s Infrared Telescope Facility (both in Hawaii) could show “how particles are ionized in Saturn’s upper atmosphere,” NASA stated. Better yet, scientists can compare that information to the stuff gathered from outside of Earth’s atmosphere by Hubble and Cassini. This will allow them to see what distortions the ground-based observatories experienced due to Earth’s atmosphere, and improve the accuracy of the observations.
Not bad work for a single music video, isn’t it? For more information on auroras on Saturn, check out these past Universe Today stories:
Hubble Space Telescope deep image of galaxy cluster Abell 2744. Credit: NASA, ESA, J. Lotz, M. Mountain, A. Koekemoer, and the HFF Team (STScI), and N. Laporte (Instituto de Astrofisica de Canarias)
Peering deep into the universe with the Hubble Space Telescope, a team of researchers have found an extremely distant galaxy. It was discovered in Abell 2744, a galaxy cluster. The galaxy (called Abell2744_Y1) was spotted at a time when it was just 650 million years after the universe-forming Big Bang (which makes it more than 13 billion years old).
This demonstrates the potential of a relatively new project, researchers said, called “Hubble Frontier Fields.” It’s part of an effort where Hubble and fellow NASA space telescopes Spitzer and the Chandra X-ray Observatory will examine six galaxy clusters that bend the light from more distant objects in the background. By doing this, researchers hope to learn more about galaxies formed in the universe’s first billion years.
“We expected to find very distant galaxies close to the cluster core, where the light amplification is maximum. However, this galaxy is very close to the edge of the Hubble image where the light is not strongly amplified,” stated Nicolas Laporte, a post-doctoral researcher at the Institute of Astrophysics of the Canary Islands (Instituto de Astrofisica de Canarias) who led the study.
“We are really lucky that we could find it in the small field of view of Hubble. In a related study led by Hakim Atek … more galaxies are analyzed but none is more distant than Abell2744_Y1.”
The quasar QSO 0957+561 appears twice in the center of this image due to a phenomenon known as gravitational lensing, which takes place when light bends around another (massive) object. Credit: ESA/NASA
Optical illusions are awesome. In the center of this image are what appear to be two quasars (or galaxies with huge black holes). In fact, however, it’s the same quasar seen twice. So what’s going on?
QSO 0957+561, also called the “Twin Quasar”, was first spotted in 1979. It lies almost 14 billion light-years from Earth (making it about as old as the Universe itself). Initially, astronomers thought it was indeed two objects, but the distances and characteristics of the twins were too similar.
We “see” the quasar twice because of a ginormous galaxy called YGKOW G1. Its immense gravitational mass is bending the light of the quasar so that it appears twice from our perspective. This phenomenon is called “gravitational lensing”, and it turned out in 1979 that QSO 0957+561 was the first object ever confirmed to experience that. (You can read the original Nature research paper here.)
While the discovery is decades old, it’s still fun to turn telescopes in that direction once in a while to spot the illusion. This particular image is a new one from the Hubble Space Telescope.
The dual Atlas V rocket engines roar to life on a United Launch Alliance Atlas V rocket at Cape Canaveral Air Force Station's Space Launch Complex 41. The launch vehicle will boost NASA's Tracking and Data Relay Satellite, or TDRS-L, spacecraft to Earth orbit. Liftoff was at 9:33 p.m. EST on Jan. 23, 2014. Credit: NASA
The dual Atlas V rocket engines roar to life on a United Launch Alliance Atlas V rocket at Cape Canaveral Air Force Station’s Space Launch Complex 41. The launch vehicle will boost NASA’s Tracking and Data Relay Satellite, or TDRS-L, spacecraft to Earth orbit. Liftoff was at 9:33 p.m. EST on Jan. 23, 2014.
Credit: NASA Story updated[/caption]
A spectacular nighttime blastoff lit up the evening skies for hundreds of miles around the Florida Space coast on a mission that sent a critical NASA communications relay satellite to orbit this evening, Jan. 23.
NASA’s huge Tracking and Data Relay Satellite L (TDRS-L) is now safely in orbit following tonight’s successful launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida.
The Atlas V rocket was launched at 9:33 p.m. EST from Space Launch Complex 41 into crystal clear skies that gave excited spectators an uncommonly long and stunning launch spectacle that was well worth the wait.
The 3.8 ton TDRS-L satellite will become part of a network providing high-data-rate communications to the International Space Station (ISS), Hubble Space Telescope, launch vehicles and a host of other research spacecraft that relay absolutely critical flight, telemetry and science data.
Water reflection shot of NASA TDRS-L satellite launch aboard Atlas V rocket on Jan. 23, 2014. Credit: Walter Scriptunas II – www.scriptunasimages.com
The ISS, Hubble and all these other spacecraft could not function without the TDRS network of relay satellites.
Liftoff of NASA”s TDRS-L atop Atlas V rocket on Jan. 23, 2014 from CAPE CANAVERAL, Fla. Credit: NASA
The TDRS-L satellite will also be used to track and relay vital information for the maiden launch of NASA’s next generation Orion human spaceflight capsule slated for Fall 2014.
“TDRS-L and the entire TDRS fleet provide a vital service to America’s space program by supporting missions that range from Earth-observation to deep space discoveries,” said NASA Administrator Charles Bolden.
“TDRS also will support the first test of NASA’s new deep space spacecraft, the Orion crew module, in September. This test will see Orion travel farther into space than any human spacecraft has gone in more than 40 years.”
A United Launch Alliance (ULA) Atlas V rocket successfully launched NASA’s Tracking and Data Relay Satellite (TDRS-L) payload at 9:33 p.m. EST today from Space Launch Complex-41. Credit: Ben Cooper/Launch photography
TDRS-L arrived in geosynchronous transfer orbit about two hours after liftoff. It will orbit at an altitude of 22,300 miles.
The venerable Atlas V rocket is one of the most reliable and well built rockets in the world.
Indeed the Atlas V has been entrusted to launch many high value missions for NASA and the Defense Department- such as Curiosity, JUNO and the X-37 B.
Clear of the lightning wires, the Atlas 5-401 accelerates to orbit. Credit: nasatech.net
The last Atlas V launch from the Cape occurred in November 2013 and sent NASA’s MAVEN Mars orbiter on a voyage to the Red Planet.
NASA’s Mars bound MAVEN spacecraft launches atop Atlas V booster at 1:28 p.m. EST from Space Launch Complex 41 at Cape Canaveral Air Force Station on Nov. 18, 2013. Image taken from the roof of the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
And the two stage rocket is being man-rated right now to launch humans to low Earth orbit in the near future.
The Atlas V has been chosen to launch two of the upcoming astronaut ‘space taxis’ as part of NASA’s commercial crew initiative to launch human crews to the International Space Station.
Just today, Sierra Nevada Corp announced that their Dream Chaser mini shuttle will launch to orbit on its first flight on Nov. 1, 2016.
TDRS-L is the 12th in this series of communications satellites.
It is identical to the TDRS-K spacecraft launched in 2013, which was the first of the third generation of TDRS satellites.
They were built by Boeing Space and Intelligence Systems of El Segundo, Calif., and have a 15 year design lifetime.
NASA will now conduct a three month in orbit checkout.
TDRS-M, the next spacecraft in this series, is on track to be ready for launch in late 2015.
TDRS-L awaits launch atop Atlas V rocket. Credit: Mike Killian/mikekillianphotography.com
This is the third generation of TDRS satellites.
“The TDRS fleet began operating during the space shuttle era with the launch of TDRS-1 in 1983. Of the 11 TDRS spacecraft placed in service to date, eight still are operational. Four of the eight have exceeded their design life,” said NASA.
The Atlas V launched in the 401 configuration vehicle, which includes a 4-meter diameter payload fairing and no solid rocket motors. The first stage was powered by the RD AMROSS RD-180 engine. The Centaur upper stage was powered by a single Aerojet Rocketdyne RL10A-4 engine.
Stay tuned here for Ken’s continuing Orion, Chang’e-3, Orbital Sciences, SpaceX, commercial space, LADEE, Mars and more news.
Pictured in Astrotech’s payload processing facility on 3 January 2014, TDRS-L resembles an enormous insect and will form the 12th member of NASA’s Tracking and Data Relay Satellite family. Photo Credit: Mike Killian Photography/AmericaSpacePhoto Credit: Alan Walters / AmericaSpace
NASA's Hubble Space Telescope and Spitzer Space Telescope joined forces to discover and characterize four unusually bright galaxies as they appeared more than 13 billion years ago, just 500 million years after the big bang. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.
What was the Universe like more than 13 billion years ago, just 500 million years after the big bang? New data from the Hubble and Spitzer space telescopes reveal some surprisingly bright galaxies that are about 10 to 20 times more luminous than anything seen previously in that epoch.
Garth Illingworth from the University of California, Santa Cruz said the discovery of these four bright galaxies came from combining the power of both telescopes, but these galaxies lie right at the limit of the telescopes’ capabilities.
“We’re actually reaching back 13.2 billion years through the life of the Universe — that’s 96% of the life of the Universe that we are looking back at these galaxies,” said Illingworth, speaking at the American Astronomical Society meeting in Washington D.C. this week. “That’s an astonishing undertaking and an astonishing accomplishment that Hubble and Spitzer have achieved.”
Detail of the Hubble and Spitzer observations of a galaxy from the early Universe. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.
Illingworth said the typical galaxy candidate from that far back in time is very faint and hard to see. But these new galaxies are about 15-20 % brighter than what astronomers have seen before at redshift 10.
The tiny are bright because they are bursting with star formation activity. The brightest one is forming stars approximately 50 times faster than the Milky Way does today. Although these fledgling galaxies are only one-twentieth the size of the Milky Way, they probably contain around a billion stars crammed together.
Astronomers think these bright, young galaxies grew exceptionally fast because of interactions and mergers of smaller infant galaxies that started forming stars even earlier in the Universe. Since the ancient time billions of years ago when the light that we now see started its long journey to us, they have probably kept growing to become similar to the largest modern galaxies. Many of the stars of these infant galaxies likely live on today in the centers of giant elliptical galaxies, much larger even than our own Milky Way.
Slide from Garth Illingworth’s presentation at the 223rd American Astronomical Society meeting, describing the discovery of bright galaxies from early in the Universe. Credit: Garth Illingworth.
Illingworth said this era appears to be a timeframe where things were changing quite rapidly. “We’ve gone back to a very interesting time when the Universe is changing,” he said.
The galaxies were first detected with Hubble, and astronomers were able to measure their star-formation rates and sizes. But using Spitzer, the scientists were also able to measure the galaxies’ masses.
“This is the first-ever measurement of the mass density of the galaxies when the Universe was at 500 million years of age,” Illingworth said. “These galaxies are about a billion times the mass of our Sun, which is massive for those times, but still only 1% the mass of the Milky Way.”
Illingworth added that the mass measurements are rough estimates because of how challenging the task was.
Illingworth and team member Ivo Labbé from Leiden University said they are looking forward to finding out more about these galaxies, particularly from future observations with the upcoming James Webb Space Telescope.
“At the same time, the extreme masses and star formation rates are really mysterious,” Labbé said, “and we are eager to confirm them with future observations on our powerful telescopes.”
You can find out more about these early galaxies — and more — at the First Galaxies website.
Each of the four panels is a combination of two separate exposures made by the Hubble Space Telescope as it tracked Comet ISON's position. Had the comet been in any of these frames, it would have appeared as a small fuzzy glow or stellar point(s) in the center. The stars are trailed because the camera tracked the comet. Credit: NASA/ESA
On December 18, the Hubble Space Telescope slewed to Comet ISON’s expected position and found nothing down to the incredibly faint magnitude of 25. According to astronomer Hal Weaver, who planned the ISON search, that limit implies any remaining fragments would have to be smaller than about 500 feet (160 meters) in diameter.
Composite photo of one of two Comet ISON locations photographed by the Hubble Space Telescope. No trace of the comet is visible. Credit: NASA/ESA
Nothing is visible in any of the images in the photo panel except trailed stars and galaxies, reflections and the occasional zap of a cosmic ray. After ISON was torn asunder by the sun, there existed the possibility that comet’s remains would follow a slightly different orbit. To make sure he was covered, Weaver photographed two separate comet positions, stacking several exposures together.
Comet ISON photographed at a second location. Again, nothing detected. Credit: NASA/ESA
“The images have been combined so that features not at the same place in the various images are suppressed. Any comet fragments would show up more clearly in this composite, though stars still show up as faint streaks”, writes Zolt Lavay, author of the ISONblog at the Hubble site.
Again, nothing shows up in these either. While no one can say that ISON has completely disappeared, we now know that at the very least it’s broken into pieces too small for even Hubble to see. What was once a beautiful sight in binoculars has expanded into a vast cloud of gas and dust thinner than Ebenezer Scrooge’s gruel.
Hubble image of variable star RS Puppis (NASA, ESA, and the Hubble Heritage Team)
6,500 light-years away in the southern constellation Puppis an enormous star pulses with light and energy, going through the first throes of its death spasms as it depletes its last reserves of hydrogen necessary to maintain a stable, steady radiance. This star, a Cepheid variable named RS Puppis, brightens and dims over a 40-day-long cycle, and newly-released observations with Hubble reveal not only the star but also the echoes of its bright surges as they reflect off the dusty nebula surrounding it.
The image above shows RS Puppis shining brilliantly at the center of its dusty cocoon. (Click the image for a super high-res version.) But wait, there’s more: a video has been made of the variable star’s outbursts as well, and it’s simply mesmerizing. Check it out below:
Assembled from observations made over the course of five weeks in 2010, the video shows RS Puppis pulsing with light, outbursts that are then reflected off the structure of its surrounding nebula. What look like expanding waves of gas are really “light echoes,” radiation striking the densest rings of reflective dust located at farther and farther distances from the star.
According to the NASA image description:
RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of so-called Cepheid variable stars. Its average intrinsic brightness is 15,000 times greater than our sun’s luminosity.
The nebula flickers in brightness as pulses of light from the Cepheid propagate outwards. Hubble took a series of photos of light flashes rippling across the nebula in a phenomenon known as a “light echo.” Even though light travels through space fast enough to span the gap between Earth and the moon in a little over a second, the nebula is so large that reflected light can actually be photographed traversing the nebula. (Source)
RS Puppis is ten times more massive than our Sun, and 200 times larger.
Cepheid variables are more than just fascinating cosmic objects. Their uncanny regularity in brightness allows astronomers to use them as standard candles for measuring distances within our galaxy as well as others — which is trickier than it sounds. Because of its predictable variation along with the echoing light from its surrounding nebula, the distance to RS Puppis (6,500 ly +/- 90) has been able to be calculated pretty accurately, making it an important calibration tool for other such stars. (Read more here.)
Full image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration. Acknowledgment: H. Bond (STScI and Penn State University)
UV observations from Hubble show the size of water vapor plumes coming from Europa's south pole (NASA, ESA, and M. Kornmesser)
It’s been known since 2005 that Saturn’s 300-mile-wide moon Enceladus has geysers spewing ice and dust out into orbit from deep troughs that rake across its south pole. Now, thanks to the Hubble Space Telescope (after 23 years still going strong) we know of another moon with similar jets: Europa, the ever-enigmatic ice-shelled moon of Jupiter. This makes two places in our Solar System where subsurface oceans could be getting sprayed directly into space — and within easy reach of any passing spacecraft.
(Psst, NASA… hint hint.)
The findings were announced today during the meeting of the American Geophysical Union in San Francisco.
“The discovery that water vapor is ejected near the south pole strengthens Europa’s position as the top candidate for potential habitability,” said lead author Lorenz Roth of the Southwest Research Institute (SwRI) in San Antonio, Texas. “However, we do not know yet if these plumes are connected to subsurface liquid water or not.”
The 125-mile (200-km) -high plumes were discovered with Hubble observations made in December 2012. Hubble’s Space Telescope Imaging Spectrograph (STIS) detected faint ultraviolet light from an aurora at the Europa’s south pole. Europa’s aurora is created as it plows through Jupiter’s intense magnetic field, which causes particles to reach such high speeds that they can split the water molecules in the plume when they hit them. The resulting oxygen and hydrogen ions revealed themselves to Hubble with their specific colors.
Unlike the jets on Enceladus, which contain ice and dust particles, only water has so far been identified in Europa’s plumes. (Source)
Rendering showing the location and size of water vapor plumes coming from Europa’s south pole.
The team suspects that the source of the water is Europa’s long-hypothesized subsurface ocean, which could contain even more water than is found across the entire surface of our planet.
“If those plumes are connected with the subsurface water ocean we are confident exists under Europa’s crust, then this means that future investigations can directly investigate the chemical makeup of Europa’s potentially habitable environment without drilling through layers of ice,” Roth said. “And that is tremendously exciting.”
One other possible source of the water vapor could be surface ice, heated through friction.
Cassini image of ice geysers on Enceladus (NASA/JPL/SSI)
In addition the Hubble team found that the intensity of Europa’s plumes, like those of Enceladus, varies with the moon’s orbital position around Jupiter. Active jets have been seen only when Europa is farthest from Jupiter. But the researchers could not detect any sign of venting when Europa is closer.
One explanation for the variability is Europa undergoes more tidal flexing as gravitational forces push and pull on the moon, opening vents at larger distances from Jupiter. The vents get narrowed or even seal off entirely when the moon is closest to Jupiter.
Still, the observation of these plumes — as well as their varying intensity — only serves to further support the existence of Europa’s ocean.
“The apparent plume variability supports a key prediction that Europa should tidally flex by a significant amount if it has a subsurface ocean,” said Kurt Retherford, also of SwRI.
(Science buzzkill alert: although exciting, further observations will be needed to confirm these findings. “This is a 4 sigma detection, so a small uncertainly that the signal is just noise in the instruments,” noted Roth.)
“If confirmed, this new observation once again shows the power of the Hubble Space Telescope to explore and opens a new chapter in our search for potentially habitable environments in our solar system.”
– John Grunsfeld, NASA’s Associate Administrator for Science
So. Who’s up for a mission to Europa now?(And unfortunately in this case, Juno doesn’t count.)
“Juno is a spinning spacecraft that will fly close to Jupiter, and won’t be studying Europa,” Kurt Retherford told Universe Today. “The team is looking hard how we can optimize, maybe looking for gases coming off Europa and look at how the plasma interacts with environment, so we really need a dedicated Europa mission.”
We couldn’t agree more.
The findings were published in the Dec. 12 online issue of Science Express.
Image credits: Graphic Credit: NASA, ESA, and L. Roth (Southwest Research Institute and University of Cologne, Germany) Science Credit: NASA, ESA, L. Roth (Southwest Research Institute and University of Cologne, Germany), J. Saur (University of Cologne, Germany), K. Retherford (Southwest Research Institute), D. Strobel and P. Feldman (Johns Hopkins University), M. McGrath (Marshall Space Flight Center), and F. Nimmo (University of California, Santa Cruz)
