Excitement Builds for NASA Probe's 2015 Encounter with Dwarf Planet Ceres

As NASA's Dawn mission draws closer to its encounter with the dwarf planet Ceres in early 2015, excitement continues to mount for scientists looking forward to what the spacecraft might observe.

Britney Schmidt, of the George Institute of Technology, and Nicole Gugliucci of CosmoQuest, recently hosted a Google+ Hangout titled "Ceres: Great Expectations" to discuss the upcoming visit to the nearest dwarf planet in the solar system.

Orbiting in the asteroid belt, a little more than three times as far from the sun as Earth, Ceres is thought to contain an icy mantle that makes up approximately one-third of its mass.

"Ceres is very different and very exciting in a lot of ways, totally different from any place that we've been," Schmidt said in the broadcast. "It may be the only primarily icy planet that's out there, at least within reach."

Scratching the surface

Seen through a telescope, Ceres may not appear very exciting. Scientists can use the light reflected off of a body to find out information about its composition.

"Ceres, to the eye, would appear basically pretty black because it's reflecting most colors more or less the same, and reflecting very little light at all," said Andy Rivkin of the Johns Hopkins University Applied Physics Lab.

Even the infrared spectrum, which tends to reveal more information about asteroids such as Vesta— Dawn's first stop — provided very little information about its composition. By utilizing instruments such as the SpeX instrument on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea in Hawaii, scientists were able to catch hints about the dwarf planet's surface.

These observations revealed suggestions of brucite, hydroxyls, and two other features Rivkin says are thought to be due to carbonate minerals.

"[This] makes Ceres one of only a few places where we've found carbonates," Rivkin said. "I think other than Earth and Mars, it's Ceres."

He went on to explain that scientists think water interacting with the minerals formed the brucite and the carbonates.

"For Ceres, we think it is much more consistent with a body that had a lot of water available to interact with."

But water, considered a potential habitatfor life, can't exist on the surface of the dwarf planet in either solid or liquid form.

"We see no real evidence for ice at the surface of Ceres," Rivkin said, noting that the dwarf planet is too warm. "However, conditions beneath Ceres’ surface should allow buried ice to remain there."

At the same time, observations from the Hubble Space Telescope, as well as theoretical data such as the planet's density, suggest that a large amount of ice exists.

"That creates this interesting paradox. We think there's a lot of ice there, (but) we don't see any at the surface," Rivkin said. "How that's going to translate into what we find when we show up there is still very much an open question."

Samples sent to Earth

When Dawn arrived at Vesta in mid-2011, scientists already had a head start on what the spacecraft might find. That's because debris from the asteroid had split off and fallen to Earth in the form of meteorites some time ago.

Katie Dyl, of Curtin University in Australia, studies different types of meteorites in an effort to understand what the solar system was like in its earliest stages.

By comparing the composition of the meteorites in laboratories with asteroids in space, scientists are able to locate their sources.

"That's how we learned we have meteorites from Vesta," Dyl said. "People like Andy [Rivkin] measured spectra in space, and people like me took meteorites from the lab and measured their spectra, and they're exactly the same."

But scientists have yet to locate any samples that come from Ceres.

"We can't quite do that with Ceres yet," Dyl said. "That's why it's really interesting to actually go there and get a better look."

Rivkin agreed.

"We're pretty sure we don't have meteorites from Ceres itself, so we're missing that link that we had for Vesta to be able to put it all together," he said. "Dawn is really going into new territory in that sense."

But the spacecraft isn't flying completely blind. Although scientists don't have samples from Ceres, they are using other meteorites to garner insight into what the dwarf planet might contain.

Two competing theories suggest why carbonates lie on the dwarf planet's surface.

The first has to do with the early days of Ceres. Like full-sized planets, Ceres was once a collection of dust and gas orbiting the young sun in a pancake-like disk. Gravity drew the different components together, and the collection grew into the dwarf planet. (Were it not for the disrupting presence of Jupiter, Ceres might have continued growing into a full-scale planet.)

During its formation, the ice and rock separated, with the rocky crust sinking down through the ice and water. But Ceres lies too close to the sun for ice to remain at its surface, especially near the equator, though it may continue to exist at the poles.

"That ice would then start to sublime away, and leave whatever was collected in the ice behind," Rivkin said — including the brucites and carbonates now seen on the surface.

The other option involves punctures in Ceres’ rocky crust due to impacts or natural stresses. Icy lava welling up to the surface would drag brucites and carbonates with it. When the ice sublimated, the materials themselves would be left behind.

"Hopefully we'll be able to determine which of those two is going on at Ceres," Rivkin said.

Dyl echoed Rivkin's enthusiasm at Dawn's impending arrival.

"I can't wait to be astounded, because it's just kind of how every single step we take in space seems to go," she said. "We see something that we couldn't have predicted."

Source of Article: Space.com

Zap! NASA's Curiosity Rover Fires 100,000th Laser Shot on Mars

NASA's trigger-happy Curiosity rover has fired its 100,000th laser shot on Mars, a science milestone in its mission to determine what rocks on the Red Planet are made of, NASA announced Thursday (Dec. 5).

Each laser pulse shot by the Curiosity rover packs the power nearly 1 million light bulbs — strong enough to vaporize rock and dust from up to 30 feet (9 meters) away.

"#PewPewPew I've fired my ChemCam laser 100,000+ times on Mars for SCIENCE!" Curiosity's team wrote in the voice of the rover in a Twitter post Thursday.

Originating from the French-made ChemCam instrument on Curiosity's "head," these beams are used to study the chemical composition of Mars. ChemCam has a spectrometer that analyzes the light emitted by the zapped targets on Mars. The instrument is sensitive enough to detect light from every element on the periodic table. 

The 100,000th laser firing came as Curiosity was shooting a target called "Ithaca" in late October, according to NASA.

Roger Wiens, a planetary scientist at Los Alamos National Laboratory and principal investigator for ChemCam, said the laser-firing instrument has exceeded expectations.

"The information we've gleaned from the instrument will continue to enhance our understanding of the Red Planet, and will nicely complement information from the other nine instruments aboard Curiosity as we continue our odyssey to Mount Sharp," Wiens said in a statement from Los Alamos.

Rising 3 miles (5 kilometers) from the center of Mars' huge Gale Crater — where Curiosity landed in August 2012 — Mount Sharp is the rover's main destination. Scientists hope Curiosity, which is about the size of a small SUV, will uncover clues about the ancient environment and habitability of Mars while scouring the foothills of the mountain.

The Curiosity rover has already made some amazing discoveries on Mars using ChemCam and its other instruments. Besides findings that Mars had a rather wet past, Curiosity recently helped scientists determine that each cubic foot of surface soil on Mars is made up of 2 percent water, which may be enough to quench the thirst of future astronauts.

"ChemCam was designed to fire one million shots, so we’ll have lots of stories to tell later on," Wiens added.

Source of Article: Space.com

Giant Alien Planet Discovered in Most Distant Orbit Ever Seen

An enormous alien planet — one that is 11 times more massive than Jupiter — was discovered in the most distant orbit yet found around a single parent star.

The newfound exoplanet, dubbed HD 106906 b, dwarfs any planetary body in the solar system, and circles its star at a distance that is 650 times the average distance between the Earth and the sun. The existence of such a massive and distantly orbiting planet raises new questions about how these bizarre worlds are formed, the researchers said.

"This system is especially fascinating because no model of either planet or star formation fully explains what we see," study lead researcher Vanessa Bailey, a fifth-year graduate student in the University of Arizona's department of astronomy, said in a statement.

In the most commonly accepted theories of planet formation, it is thought that planets that orbit close to their parent star, such as Earth, began as small, asteroid-type bodies that clumped together in the primordial disk of gas and dust around the burgeoning star. 

Yet, this process operates too slowly to explain how giant planets form far away from their star, the researcher said.

Alternative hypotheses have suggested that distant giant planets may form in ways similar to mini binary star systems, Bailey said.

"A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit," she explained.

In the HD 106906 system, the star and planet may have collapsed independently, but the materials that clumped together to form the planet were insufficient for it to grow large enough to ignite into a new star, Bailey said.

But, there are still problems with this scenario. For one, difference between the masses of two stars in a binary system is typically no more than a ratio of 10 to 1.

"In our case, the mass ratio is more than 100-to-1," Bailey said. "This extreme mass ratio is not predicted from binary star formation theories — just like planet formation theory predicts that we cannot form planets so far from the host star."

Researchers are also keen to study the new planet, because leftover material from when the planet and star formed can still be detected.

"Systems like this one, where we have additional information about the environment in which the planet resides, have the potential to help us disentangle the various formation models," Bailey said. "Future observations of the planet's orbital motion and the primary star's debris disk may help answer that question." 

The planet HD 106906 b is only 13 million years old, and is still glowing from the residual heat from its formation," the researchers said. By comparison, Earth formed 4.5 billion years ago, which makes it roughly 350 times older than the newfound exoplanet.

The planet was found using a thermal infrared camera mounted on the Magellan telescope in the Atacama Desert in Chile. The researchers used data from the Hubble Space Telescope to confirm their discovery.

The study, which has been accepted for publication in a future issue of The Astrophysical Journal Letters, could lead to a better understanding of distantly orbiting exoplanets.

"Every new directly detected planet pushes our understanding of how and where planets can form," study co-investigator Tiffany Meshkat, a graduate student at Leiden Observatory in the Netherlands, said in a statement. "Discoveries like HD 106906 b provide us with a deeper understanding of the diversity of other planetary systems."

Source of Article: Space.com

Air Force's Mysterious X-37B Space Plane Nears One Year In Orbit

The U.S. Air Force's mysterious X-37B space plane is nearing a major milestone — one year of travel in Earth orbit, performing duties in support of long-term space objectives.

The unmanned X-37B spacecraft — flying a mission known as Orbital Test Vehicle 3 (OTV-3) — launched into space atop an Atlas 5 rocket from Florida’s Cape Canaveral Air Force Station on Dec. 11, 2012. What payloads the space plane is toting and the overall mission goals on its confidential cruise are classified.

But it is known that the OTV-3 mission signals a milestone for the X-37B program.

This same vehicle was flown on the X-37B program's inaugural flight back in 2010. That OTV-1 mission lasted nearly 225 days in orbit, gliding back to Earth on autopilot over the Pacific Ocean and touching down at Vandenberg Air Force Base in California.

An OTV-2 mission, which used a different X-37B space plane, was lofted in 2011. That vehicle flew for 469 days, more than doubling its sister ship’s space stay, concluding its mission by also making a Vandenberg landing.

Altitude changes

A global network of skywatchers has been keeping an eye on the robotic space plane's movements during its three flights to date.

"All three OTV missions maneuvered to change altitude at least once between launch and landing. Between maneuvers, they made frequent small thruster firings to counteract the effects of atmospheric drag, to maintain a nearly constant altitude," said Ted Molczan of Toronto, a leader in the worldwide community of satellite trackers.

Taking a look at the military space plane's past flights and the present-day mission, Molczan told SPACE.com that OTV-1 occupied a half-dozen different orbital altitudes during its 225-day mission. OTV-2 occupied two different orbital altitudes during its days aloft, accomplished by a series of small thruster firings over a seven-week period. 

"OTV-3, as of day 343 in flight, has occupied two different orbital altitudes, accomplished using standard Hohmann transfer maneuvers about 11 weeks after launch," Molczan said in a Nov. 22 email.

Lifting-body design

The two known X-37B space planes have been built for the Air Force by Boeing Government Space Systems, with flights conducted under the auspices of the Air Force’s Rapid Capabilities Office.

The 11,000-pound (4,990 kilograms) X-37B is one-fourth the size of an orbiter in the now-retired NASA space shuttle fleet but relies upon the same type of lifting-body design.

The vehicle is 29 feet (8.8 meters) long and nearly 15 feet (4.5 m) wide and has a payload bay that measures 7 feet (2.1 meters) long and 4 feet (1.2 meters) wide. Traveling in low-Earth orbit, the space plane operates from 110 miles (177 kilometers) to 500 miles (805 km) in altitude.

Next-generation technology

According to a Boeing fact sheet, each space plane is built with lightweight composite structures, rather than traditional aluminum. A new generation of high-temperature leading-edge tiles for the wings is utilized, distinct from the space shuttle’s carbon leading-edge segments.

The X-37B is outfitted with toughened uni-piece fibrous insulation impregnated silica tiles, which are significantly more durable than the first-generation tiles used by the space shuttle. Advanced conformal reusable insulation blankets are used for the first time on the X-37B.

The Boeing fact sheet also points out that avionics on an X-37B are designed to automate all de-orbit and landing functions. Additionally, there are no hydraulics onboard the winged vehicle; flight controls and brakes use electromechanical actuation.

Air Force mission control 

Mission control for OTV flights are handled by the 3rd Space Experimentation Squadron at Schriever Air Force Base in Colorado. This unit is billed as the Air Force Space Command’s premier organization for space-based demonstrations, pathfinders and experiment testing, gathering information on objects high above Earth and carrying out other intelligence-gathering duties.

While details are scant about the X-37B program, a little light on the project may be shed during the National Space Club'’s 57th Annual Robert H. Goddard Memorial Dinner, to be held next March in Washington, D.C.

Slated to receive the General Bernard Schriever Award at the event is Major Joshua Chumley, USAF, Commander, Operating Location Alpha, 3d Space Experimentation Squadron, U.S. Air Force Space Command.

Chumley is on tap to pick up the prestigious award "for leading a selectively manned team responsible for operation of the United States’ first unmanned, autonomous, reusable space plane — the Orbital Test Vehicle, or X-37B," according to a National Space Club press release.

Source of Article: Space.com

Spooky Physics Phenomenon May Link Universe's Wormholes

Wormholes — shortcuts that in theory can connect distant points in the universe — might be linked with the spooky phenomenon of quantum entanglement, where the behavior of particles can be connected regardless of distance, researchers say.

These findings could help scientists explain the universe from its very smallest to its biggest scales.

Scientists have long sought to develop a theory that can describe how the cosmos works in its entirety. Currently, researchers have two disparate theories, quantum mechanics and general relativity, which can respectively mostly explain the universe on its tiniest scales and its largest scales. There are currently several competing theories seeking to reconcile the pair.

One prediction of the theory of general relativity devised by Einstein involves wormholes, formally known as Einstein-Rosen bridges. In principle, these warps in the fabric of space and time can behave like shortcuts connecting any black holes in the universe, making them a common staple of science fiction.

Intriguingly, quantum mechanics also has a phenomenon that can link objects such as electrons regardless of how far apart they are — quantum entanglement.

"This is true even when the electrons are light years apart," saidKristan Jensen, a theoretical physicist at Stony Brook University in New York.

Einstein derisively called this seemingly impossible connection "spooky action at a distance." However, numerous experiments have proven quantum entanglement is real, and it may serve as the foundation of advanced future technologies, such as incredibly powerful quantum computers and nigh-unhackable quantum encryption.

"Entanglement is one of the most bizarre but important features of quantum mechanics," Jensen said. And if entanglement really is connected to wormholes, that could help reconcile quantum mechanics with general relativity, the two examples of this phenomenon, on tiny and huge scales.

Entanglement and wormholes

Recently, theoretical physicists Juan Martín Maldacena at the Institute for Advanced Study in Princeton and Leonard Susskind at Stanford University argued that wormholes are linked with entanglement. Specifically, they suggested that wormholes are each pairs of black holes that are entangled with one another.

Entangled black holes could be generated in a number of ways. For instance, a pair of black holes could in principle be made simultaneously, and these would automatically be entangled. Alternatively, radiation given off by a black hole could be captured and then collapsed into a black hole, and the resulting black hole would be entangled with the black hole that supplied the ingredients for it.

Maldacena and Susskind not only suggested that wormholes are entangled black holes, but they argued that entanglement in general was linked to wormholes. They conjectured that entangled particles such as electrons and photons were connected by extraordinarily tiny wormholes.

At first sight, such a claim might sound preposterous. For instance, entanglement works even when gravity is not known to play a role.

Now two independent groups of researchers suggest entanglement may indeed be linked to wormholes. If this connection is true, it could help bridge quantum mechanics with general 

relativity, potentially helping better understand both.

Holograms and wormholes

Jensen and his colleague theoretical physicist Andreas Karch at the University of Washington in Seattle investigated how entangled pairs of particles behave in a supersymmetric theory, which suggests that all known subatomic particles have "superpartner" particles not yet observed. The theory was one proposed to help unite quantum mechanics and general relativity.

An idea in this theory is that if one imagines certain quantum mechanical systems exist in only three dimensions, their behavior can be explained by objects behaving in the four dimensions that general relativity describes the universe as having — the three dimensions of space, and the fourth of time. This notion that actions in this universe may emerge from a reality with fewer dimensions is known as holography, akin to how two-dimensional holograms can give the illusion of three dimensions.

Jensen and Karch found that if one imagined entangled pairs in a universe with four dimensions, they behaved in the same way as wormholes in a universe with an extra fifth dimension. Essentially, they discovered that entanglement and wormholes may be one and the same.

"Entangled pairs were the holographic images of a system with a wormhole," Jensen said. Independent research from theoretical physicist Julian Sonner at the Massachusetts Institute of Technology supports this finding.

"There are certain things that get a scientist's heart beating faster, and I think this is one of them," Jensen told LiveScience. "One really exciting thing is that maybe, inspired by these results, we can better understand the relation between entanglement and space-time."

Source of Article: Space.com

Alien Super-Earth Planets Plentiful in Exoplanet Search

Our solar system hosts a cornucopia of worlds, from the hellfire of Venus to the frozen plains of Mars to the mighty winds of Uranus. In that range, the Earth stands alone, with no planet coming close to its life-friendly position near the Sun.

Outside our solar system, however, it's a different story. Observations using space-based and ground-based telescopes have indicated that a new class of objects dubbed super-Earths – worlds that are about two to 10 times our planet's mass and up to two times its radius – could be among the most common type of planets orbiting other stars.

That's because during the past few years, astronomers have found plenty of these super-sized rocky bodies orbiting different types of stars. Among these planetary systems, those around M-class stars, which are cooler and fainter than our Sun, are particularly important. Because of the low surface temperatures of these stars, the regions around them where an Earth-like planet can maintain liquid water on its surface (also known as the Habitable Zone) are closer to them -- making such potentially habitable super-Earths in those regions more detectable.

Scientists also believe that these smaller stars are the most abundant in the Sun's corner of the universe, implying super-Earths would be plentiful in our solar neighbourhood, as well.

Nader Haghighipour is a member of the NASA Astrobiology Institute and the University of Hawaii-Manoa's Institute for Astronomy. Among his research interests is figuring out how these worlds form, and most importantly, how they arrive in their current orbits.

Some of his work hints that migrating giant planets could be responsible for the close-in orbits of smaller bodies. Their massive gravity could excite the rocks and protoplanetary debris on their paths and cause them to be scattered out of the system or coalesce into smaller planets such as super-Earths.

"When giant planets approach the central star, especially around an M-dwarf, I'm interested in how they affect accretion of small planetesimals in a disc in front of them and how that will result in the formation of super-Earths, particularly in the habitable zone," Haghighipour said.

Faster discovery pace for super-Earths

Haghighipour recently surveyed the state of super-Earth research in a paper that appeared in the Annual Review of Earth and Planetary Sciences. The first super-Earths were discovered in 1992 around pulsar star PSR B1257+12, but it's only in the past five years that the pace of discovery picked up.

This was in large part due to the arrival of the NASA Kepler space telescope, which spent close to four years hunting planets in a small region of the sky in the constellation Cygnus. Kepler ended its primary mission in 2013 after the telescope exceeded its design lifetime. During this time, it provided a treasure trove of extremely high quality data that has revolutionized the field of exoplanetary science.

Short period super-Earths are easier to detect around smaller stars than those that are the Sun's size or larger. This is because smaller stars show larger reactions to the tug of the planet as the planet orbits the star. If the planet happens to go across the face of the star from Earth's perspective, a super-Earth blocks out more of a small star's light, making it easier to detect.

"That super-Earths in short-period orbits around cooler and smaller stars are easier to detect   has set the ground for this becoming fashionable, and now there's a great deal of attention in using radial velocity and transit photometry techniques to find such planets in the habitable zones of M stars," Haghighipour said.

These planets are both detectable by the Kepler telescope and also ground-based ones. Most commonly, discoveries from the ground take place with two instruments. One of them is the High Accuracy Radial Velocity Planet Searcher (HARPS) on a European Southern Observatory 3.6m telescope at La Silla, Chile. The other is the W. M. Keck Observatory’s High Resolution Echelle Spectrograph (HiRES) in Mauna Kea, Hawaii.

While NASA scientists re-examine Kepler's mission – its science work is on hold after two of its four reaction wheels failed – they are hard at work planning its successor mission, the Transiting Exoplanet Survey Satellite (TESS).  TESS will have both advantages and disadvantages while searching for super-Earths, Haghighipour said.

"Because TESS is going to cover the entire sky, as opposed to Kepler that focused on only one portion of the sky, it may be able to find more [exoplanets]," he said. "As far as accuracy and precision, because it’s not going to stay on one region of the sky for as long as the Kepler did, the accuracy may not be as high as that of the Kepler."

Habitability?

One particular star system of interest to Haghighipour is Gliese 667, a triple star system which lies about 22 light-years from Earth. Haghighipour was part of a team that identified at least one super-Earth in the habitable zone of GJ 667C in 2012.

This year, another group led by the University of Göttingen in Germany revealed that where there was one super-Earth, there may actually be many.  The new analysis found that the M-star in the GJ 677 system (known as GJ 677c) has about six or seven planets, including anywhere from three to five "super-Earths" in the habitable zone. 

Because the star is so faint and dim, to be in its habitable zone these planets must crowd in close. The researchers estimated that the planets have very short years, between 20 and 50 days, and may even have one side perpetually facing their host star. Even in this state, however, the astronomers believe it is possible that life could survive there.

"It's the most reliable detection [of potentially habitable exoplanets] that we’ve had," Haghighipour said. The challenge, he added, is to understand the planets' habitable environments from a distance.

While calculating the location of the habitable zone of a star is relatively straightforward, modelling the planets' dynamics and climate is far trickier. It is unknown if these worlds have plate tectonics, for example – a geophysical processes that regulates the abundance of CO₂ and H₂O in Earth’s atmosphere. Their interiors remain masked to astronomers, and understanding exoplanet atmosphere composition is something that some teams are only starting to accomplish.

Identification efforts continue, however. Haghighipour has been working on detecting super-Earths in the habitable zones of M-stars since 2009 along with observers at the University of California, Santa Cruz and the Carnegie Institution of Washington. Gliese 667Cc is the most cited discovery from this collaboration, but there are others.

On the theoretical side, Haghighipour has two papers published in the Astrophysical Journalabout habitability in binary star systems. He also has been trying to figure out how super-Earths form at different distances from their stars.

"It's possible each system has had its own history, and its own way of formation. There is no reason to believe that one way of formation for planets in a system, or for super-Earths in habitable zones, can be applied to all systems," he said.

Perhaps this research could shed some light on the formation of our own solar system. 

Both super-Earths and "hot Jupiters" – gas giant planets that closely orbit their parent stars – appear to be common in other systems, so why not ours?

"Honestly, we have no definite answer for that. There are many different models that present  different ideas for why there are no super-Earths and hot Jupiters in our solar system. But in order for these models to be successful, they have to explain other properties of the solar system as well," he said.

For example, a giant gas planet close to our Sun would likely have disturbed any rocky planets wanting to orbit nearby. It will be an interesting theoretical puzzle for astronomers to figure out as they continue classifying worlds outside of the solar system.

Source of Article: Space.com

Signs of Water Found on 5 Alien Planets by Hubble Telescope

NASA's Hubble Space Telescope has detected water in the atmospheres of five planets beyond our solar system, two recent studies reveal.

The five exoplanets with hints of water are all scorching-hot, Jupiter-size worlds that are unlikely to host life as we know it. But finding water in their atmospheres still marks a step forward in the search for distant planets that may be capable of supporting alien life, researchers said.

"We're very confident that we see a water signature for multiple planets," Avi Mandell, of NASA's Goddard Space Flight Center in Greenbelt, Md., lead author of one of the studies, said in a statement. "This work really opens the door for comparing how much water is present in atmospheres on different kinds of exoplanets — for example, hotter versus cooler ones." 

The two research teams used Hubble's Wide Field Camera 3 to analyze starlight passing through the atmospheres of the five "hot Jupiter" planets, which are known as WASP-17b, HD209458b, WASP-12b, WASP-19b and XO-1b.

The atmospheres of all five planets showed signs of water, with the strongest signatures found in the air of WASP-17b and HD209458b.

"To actually detect the atmosphere of an exoplanet is extraordinarily difficult. But we were able to pull out a very clear signal, and it is water," Drake Deming of the University of Maryland, lead author of the other recent study, said in a statement.

Water is thought to be a common constituent of exoplanet atmospheres and has been found in the air of several other distant worlds to date. But the new work marks the first time scientists have measured and compared profiles of the substance in detail across multiple alien worlds, researchers said.

The water signatures were less intense than expected in all cases, likely because the five hot Jupiters are surrounded by a haze of dust, researchers said.

"These studies, combined with other Hubble observations, are showing us that there are a surprisingly large number of systems for which the signal of water is either attenuated or completely absent," Heather Knutson of the California Institute of Technology in Pasadena, a co-author on Deming's paper, said in a statement. "This suggests that cloudy or hazy atmospheres may in fact be rather common for hot Jupiters."

Source of Article: Space.com