In 2021, NASA’s next-generation observatory, the James Webb Space Telescope (JWST), will take to space. Once operational, this flagship mission will pick up where other space telescopes – like Hubble, Kepler, and Spitzer– left off. This means that in addition to investigating some of the greatest cosmic mysteries, it will also search for potentially habitable exoplanets and attempt to characterize their atmospheres.
This is part of what sets the JWST apart from its predecessors. Between its high sensitivity and infrared imaging capabilities, it will be able to gather data on exoplanet atmospheres like never before. However, as a NASA-supported study recently showed, planets that have dense atmospheres might also have extensive cloud cover, which could complicate attempts to gather some of the most important data of all.
Rigorous testing is at the heart of any successful space mission. The James Webb Space Telescope (JWST) will be a million miles away when it deploys its mission-critical sun-shield, and if it doesn’t function as planned, that’s it. Game over.
When it comes to the first galaxies, the James Webb Space Telescope will attempt to understand the formation of those galaxies and their link to the underlying dark matter. In case you didn’t know, most of the matter in our universe is invisible (a.k.a. “dark”), but its gravity binds everything together, including galaxies. So by studying galaxies – and especially their formation – we can get some hints as to how dark matter works. At least, that’s the hope. It turns out that astronomy is a little bit more complicated than that, and one of the major things we have to deal with when studying these distant galaxies is dust. A lot of dust.
That’s right: good old-fashioned dust. And thanks to some fancy simulations, we’re beginning to clear up the picture.
Once deployed, the James Webb Space Telescope (JWST) will be the most powerful telescope ever built. As the spiritual and scientific successor to the Hubble, Spitzer, and Kepler space telescopes, this space observatory will use its advanced suite of infrared instruments to the look back at the earliest stars and galaxies, study the Solar System in depth, and help characterize extra-solar planets (among other things).
Unfortunately, the launch of the JWST has been subject to multiple delays, with the launch date now set for some time in 2019. Luckily, on Thursday, March 8th, engineers at the Northrop Grumman company headquarters began the final step in the observatory’s integration and testing. Once complete, the JWST will be ready to ship to French Guiana, where it will be launched into space.
This final phase consisted of removing the combined optics and science instruments from their shipping containers – known as the Space Telescope Transporter for Air, Road and Sea (STTARS) – which recently arrived after being testing at NASA’s Johnson Space Center in Houston. This constitutes half the observatory, and includes the telescope’s 6.5 meter (21.3 foot) golden primary mirror.
The science payload was also tested at NASA’s Goddard Space Flight Center last year to ensure it could handle the vibrations associated with space launches and the temperatures and vacuum conditions of space. The other half of the observatory consists of the integrated spacecraft and sunshield, which is in the final phase of assembly at the Northrop Grumman company headquarters.
These will soon undergo a launch environment test to prove that they are ready to be combined with the science payload. Once both halves are finished being integrated, addition testing will be performed to guarantee the fully assembled observatory can operate at the L2 Earth-Sun Lagrange Point. As Eric Smith, the program director for the JWST at NASA Headquarters, said in a recent NASA press statement:
“Extensive and rigorous testing prior to launch has proven effective in ensuring that NASA’s missions achieve their goals in space. Webb is far along into its testing phase and has seen great success with the telescope and science instruments, which will deliver the spectacular results we anticipate.”
These final tests are crucial to ensuring that that the observatory deploys properly and can operate once it is in space. This is largely because of the telescope’s complicated design, which needs to be folded in order to fit inside the Ariane 5 rocket that it will carry it into space. Once it reaches its destination, the telescope will have to unfold again, deploying its sunshield, mirrors and primary mirror.
Not only does all of this represented a very technically-challenging feet, it is the first time that any space telescope has had to perform it. Beyond that, there are also the technical challenges of building a complex observatory that is designed to operate in space. While the JWST’s optics and science instruments were all built at room temperature here on Earth, they had to be designed to operate at cryogenic temperatures.
As such, its mirrors had to be precisely polished and formed that they would achieve the correct shape once they cool in space. Similarly, its sunshield will be operating in a zero gravity environment, but was built and tested here on Earth where the gravity is a hefty 9.8 m/s² (1 g). In short, the James Webb Space Telescope is the largest and most complex space telescope ever built, and is one of NASA’s highest priority science projects.
It is little wonder then why NASA has had to put the JWST through such a highly-rigorous testing process. As Smith put it:
“At NASA, we do the seemingly impossible every day, and it’s our job to do the hardest things humankind can think of for space exploration. The way we achieve success is to test, test and retest, so we understand the complex systems and verify they will work.”
Knowing that the JWST is now embarking on the final phase of its development – and that its engineers are confident it will perform up to task – is certainly good news. Especially in light of a recent report from the US Government Accountability Office (GAO), which stated that more delays were likely and that the project would probably exceed its original budget cap of $8 billion.
As the report indicated, it is the final phase of integration and testing where problems are most likely to be found and schedules revised. However, the report also stated that “Considering the investment NASA has made, and the good performance to date, we want to proceed very systematically through these tests to be ready for a Spring 2019 launch.”
In other words, there is no indication whatsoever that Congress is considering cancelling the project, regardless of further delays or cost overruns. And when the JWST is deployed, it will use its 6.5 meter (21-foot) infrared-optimized telescopes will search to a distance of over 13 billion light years, allow astronomers to study the atmospheres of Solar Planets, exoplanets, and other objects within our Solar System.
So while the JWST may not make its launch window in 2019, we can still expect that it will be taking to space in the near future. And when it does, we can also expect that what it reveals about our Universe will be mind-blowing!
When the James Webb Space Telescope takes to space, some tremendous scientific discoveries are expected to result. As the spiritual and scientific successor to the Hubble, Spitzer, and Kepler Space Telescopes, this space observatory will use its advanced suite of infrared instruments to the look back at the early Universe, study the Solar System, and help characterize extra-solar planets.
Unfortunately, the launch of this mission has been delayed several times now, with the launch date now set for some time in 2019. And based on the amount of work NASA needs to do complete the JWST before launch, the Government Accountability Office (GAO) believes that more delays are coming and believes that the project is likely to exceed the cost cap set by Congress in 2011 at $8 billion.
Part of the problem is that all the remaining schedule reserve – the extra time set aside in the event of delays or unforeseen risks – was recently used to address technical issues. These include the “anomalous readings” detected from the telescope during vibration testing back in December 2016. NASA responded to this by giving the project up to 4 months of schedule reserve by extending the launch window.
However, in 2017, NASA delayed the launch window again by 5 months, from October 2018 to a between March and June 2019. This delay was requested by the project team, who indicated that they needed to address lessons learned from the initial folding and deployment of the observatory’s sunshield. As Eric Smith, the program director for the James Webb Space Telescope at NASA Headquarters, explained to Congress at the time:
“Webb’s spacecraft and sunshield are larger and more complex than most spacecraft. The combination of some integration activities taking longer than initially planned, such as the installation of more than 100 sunshield membrane release devices, factoring in lessons learned from earlier testing, like longer time spans for vibration testing, has meant the integration and testing process is just taking longer. Considering the investment NASA has made, and the good performance to date, we want to proceed very systemmatically through these tests to be ready for a Spring 2019 launch.”
Given the remaining integration and test work that lies ahead, more delays are expected. According to the GAO, it is this phase where problems are most likely to be found and schedules revised. Coupled with the fact that only 1.5 months of schedule reserves remain until the end of the launch window, they anticipate that additional launch delays are likely, which will also require budget increases.
Initially, the budget estimates that were set by Congress indicated that the observatory would cost $1.6 billion and would launch by 2011, with an overall cost cap set at $8 billion. However, NASA has revised the budget multiple times since then (in conjunction with the multiple delays) and estimates that the budget for a 2019 launch window would now be $8.8 billion.
Once deployed, the JWST will be the most powerful space telescope ever built and will serve thousands of astronomers worldwide. As a collaborative project between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA), it also representative of the new era of international cooperation. But by far, the most impressive thing about this mission is the scientific discoveries it is expected to make.
It’s 6.5 meter (21-foot) infrared-optimized telescopes will search to a distance of over 13 billion light years, allowing it to study the first stars and galaxies that formed. It will also allow astronomers to study the atmospheres of Solar Planets and exoplanets and other objects within our Solar System. As such, and delays and cost overruns in the project are cause for concern.
In the meantime, the project’s Standing Review Board will conduct an independent review in early 2018 to determine if the June 2019 launch window can still be met. With so many experiments and surveys planned for the telescope, it would be no exaggeration to say that a lot is riding on its successful completion and deployment. Best of luck passing review James Webb Space Telescope!
The two halves of the James Webb Space Telescope are now in the same location and ready to take the next step on JWST’s journey. On February 2nd, Webb’s Optical Telescope and Integrated Science instrument module (OTIS) arrived at Northrop Grumman Aerospace Systems in Redondo Beach, California. The integrated spacecraft, consisting of the spacecraft bus and sunshield, were already there, waiting for OTIS so they could join together and become a complete spacecraft.
“The team will begin the final stages of integration of the world’s largest space telescope.” – Scott Willoughby, Northrop Grumman’s Program Manage for the JWST.
“It’s exciting to have both halves of the Webb observatory – OTIS and the integrated spacecraft element – here at our campus,” said Scott Willoughby, vice president and program manager for Webb at Northrop Grumman. “The team will begin the final stages of integration of the world’s largest space telescope.”
OTIS arrived from the Johnson Space Center in Houston, where it had successfully completed its cryogenic testing. To prepare for that journey, OTIS was placed inside a custom shipping container designed to protect the delicate and expensive Webb Telescope from any damage. That specially designed container is called the Space Telescope Transporter for Air, Road and Sea (STTARS).
STTARS is a massive container, measuring 4.6 meters (15 feet) wide, 5.2 meters (17 feet) tall, and 33.5 meters feet (110) long, and weighing approximately 75,000 kilograms (almost 165,000 pounds). It’s much larger than the James Webb itself, but even then, the primary mirror wings and the secondary mirror tripod must be folded into flight configuration in order to fit.
The next step for the JWST is to join the spacecraft itself with OTIS. Once that happens, JWST will be complete and fully integrated. Then there’ll be more tests called observatory-level testing. After that, another journey inside STTARS to Kouru, French Guiana, where the JWST will be launched in 2019.
“This is a major milestone.” – Eric Smith, director of the James Webb Space Telescope Program at NASA.
“This is a major milestone,” said Eric Smith, director of the James Webb Space Telescope Program at NASA. “The Webb observatory, which is the work of thousands of scientists and engineers across the globe, will be carefully tested to ensure it is ready to launch and enable scientists to seek the first luminous objects in the universe and search for signs of habitable planets.”
You can’t fault people, either NASA personnel or the rest of us, for getting excited about each development in the James Webb Space Telescope story. Every time the thing twitches or moves, our excitement re-spawns. It seems like everything that happens with the JWST is now a milestone in its long, uncertain journey. It’s easy to see why.
The Space Telescope That Almost Wasn’t
The James Webb ran into a lot of problems during its development. As can be expected for a ground-breaking, technology-pushing project like the Webb, it’s expensive. In 2011, when the project was well underway, it was revealed that the Webb would cost $8.8 billion, much more than the initial budget of $1.6 billion. The House of Representatives cancelled the project, then restored it, though funding was capped at $8 billion.
That was the main hurdle facing the development of the JWST, but there were others, including timeline delays. The most recent timeline change moved the launch date from 2017 to Spring 2019. As of now, the James Webb is on schedule, and on target to meet its revised budget.
The First “Super Telescope”
The JWST is the first of the “Super Telescopes” to be in operation. Once it’s in place at LaGrange Point 2 (L2), about 1.5 million km (930,000 miles) from Earth, it will begin observing, primarily in infrared. It will surpass both the Hubble Telescope and the Spitzer Telescope, and will “look back in time” to some of oldest stars and galaxies in the universe. It will also examine exoplanets and contribute to the search for life.
When the James Webb Space Telescope finally takes to space, it will study some of the most distant objects in the Universe, effectively looking back in time to see the earliest light of the cosmos. It will also study extra-solar planets around nearby stars and even bodies within the Solar System. In this respect, the JWST is the natural successor to Hubble and other pioneering space telescopes.
It is therefore understandable why the world is so eager for the JWST to be launched into space (which is now scheduled to take place in 2019). And recently, the telescope passed another major milestone along the road towards deployment. After spending three months in a chamber designed to simulate the temperatures and vacuum conditions of space, the JWST emerged and was given a clean bill of health.
The tests took place inside Chamber A, a thermal vacuum testing facility located at the Johnson Space Center in Houston, Texas. This chamber was built back in 1965 as part of NASA’s race to the Moon, where it conducted tests to ensure that the Apollo command and service modules were space-worthy. Beginning in mid-July, the telescope was put into the chamber and subjected to temperatures ranging from 20 to 40 K (-253 to -233 °C; 423 to 387 °F).
Once the temperature and vacuum conditions were just right, a team of NASA engineers began testing the alignment of the JWST’s 18 primary mirror segments to make sure they would act as a single, 6.5-meter telescope. As Bill Ochs – the James Webb telescope project manager at NASA’s Goddard Space Flight Center – indicated to ArsTechnica, this latest test has shown that the telescope is indeed space-worthy.
“We now have verified that NASA and its partners have an outstanding telescope and set of science instruments,” he said. “We are marching toward launch.”
The team of engineers also tested the JWST’s guidance and optical systems by simulating the light of a distant star. Not only was the telescope able to detect the light, its optical systems were able to process it. The telescope was also able to track the simulated star’s movement, which demonstrated that the JWST will be able to acquire and hold research targets once it is in space.
Many tests are still needed before the JWST can take to space next year. These will be conducted at Northrop Grumman’s company headquarters in Los Angeles, where the telescope will be transported after leaving the Johnson Space Center in late January or early February. Once there, the optical instrument will mated to the spacecraft and sunshield to complete the construction of the telescope.
These tests are necessary since NASA will be hard-pressed to service the telescope once it is in space. This is due to the fact that it will be operating at the Earth-Sun L2 Lagrange Point (which will place farther away from Earth than the Moon) for a minimum of five years. At this distance, any servicing missions will be incredibly difficult, time-consuming and expensive to mount.
However, once the JWST has passed its entire battery of tests and NASA is satisfied it is ready to take to space, it will be shipped off to the Guiana Space Center in Kourou, French Guiana. Once there, it will launch aboard a European Space Agency (ESA) Ariane V booster. Originally, this was scheduled to take place in October of 2017, but is now expected to take place no earlier than Spring of 2018.
When the James Webb Space Telescope is operational, it is expected to reveal some truly amazing things about our Universe. In addition to looking farther into space than any previous telescope (and further back in time), its other research goals include studying nearby exoplanets in unprecedented detail, circumstellar debris disks, supermassive black holes at the centers of galaxies, and even searching for life in the Solar System by examining Jupiter’s moons.
For this reason, NASA can be forgiven for pushing the launch back to make sure everything is in working order. But of course, we can be forgiven for wanting to see it launched as soon as possible! There are mysteries out there that are just waiting to be revealed, and some amazing scientific finds that need to be followed up on.
In the meantime, be sure to check out this video about the JWST, courtesy of NASA:
Ever since the project was first conceived, scientists have been eagerly awaiting the day that the James Webb Space Telescope (JWST) will take to space. As the planned successor to Hubble, the JWST will use its powerful infrared imaging capabilities to study some of the most distant objects in the Universe (such as the formation of the first galaxies) and study extra-solar planets around nearby stars.
However, there has been a lot of speculation and talk about which targets will be the JWST’s first. Thankfully, following the recommendation of the Time Allocation Committee and a thorough technical review, the Space Telescope Science Institute (STScI) recently announced that it has selected thirteen science “early release” programs, which the JWST will spend its first five months in service studying.
As part of the JWST Director’s Discretionary Early Release Science Program (DD-ERS), these thirteen targets were chosen by a rigorous peer-review process. This consisted of 253 investigators from 18 counties and 106 scientific institutions choosing from over 100 proposals. Each program has been allocated 500 hours of observing time, once the 6-month commissioning period has ended.
As Ken Sembach, the director of the Space Telescope Science Institute (STScI), said in an ESA press statement:
“We were impressed by the high quality of the proposals received. These programmes will not only generate great science, but will also be a unique resource for demonstrating the investigative capabilities of this extraordinary observatory to the worldwide scientific community… We want the research community to be as scientifically productive as possible, as early as possible, which is why I am so pleased to be able to dedicate nearly 500 hours of director’s discretionary time to these early release science observations.”
The thirteen programs selected include “Through the looking GLASS“, which will rely on the astronomical community’s experience using Hubble to conduct slitless spectroscopy and previous surveys to gather data on galaxy formation and the intergalactic medium, from the earliest epochs of the Universe to the present day. The Principal Investigator (PI) for this program is Tommaso Treu of the University of California Los Angeles.
Another is the Cosmic Evolution Early Release Science (CEERS) program, which will conduct overlapping observations to create a coordinated extragalactic survey. This survey is intended to let astronomers see the first visible light of the Universe (ca. 240,000 to 300,000 years after the Big Bang), as well as information from the Reionization Epoch (ca. 150 million to 1 billion years after the Big Bang) and the period when the first galaxies formed. The PI for this program is Steven Finkelstein of the University of Texas at Austin.
However, compared to earlier missions, the JWST will be able to study transiting planets in unprecedented detail, which is anticipated to reveal volumes about their respective atmospheric compositions, structures and dynamics. This program, for which the PI is Imke de Pater from the University of California Berkeley, is therefore expected to revolutionize our understanding of planets, planet formation, and the origins of life.
Also focused on the study of exoplanets is the High Contrast Imaging of Exoplanets and Extraplanetary Systems program, which will focus on directly imaged planets and circumstellar debris disks. Once again, the goal is to use the JWST’s enhanced capabilities to provide detailed analyses on the atmospheric structure and compositions of exoplanets, as well as the cloud particle properties of debris disks.
But of course, not all the programs are dedicated to the study of things beyond our Solar System, as is demonstrated by the program that will focus on Jupiter and the Jovian System. Adding to the research performed by the Galileo and Juno missions, the JWST will use its suite of instruments to characterize and produce maps of Jupiter’s cloud layers, winds, composition, auroral activity, and temperature structure.
This program will also focus on some of Jupiter’s largest moons (aka. the “Galilean Moons”) and the planet’s ring structure. Data obtained by the JWST will be used to produce maps of Io’s atmosphere and volcanic surface, Ganymede’s tenuous atmosphere, provide constrains on these moons thermal and atmospheric structure, and search for plumes on their surfaces. As Alvaro Giménez, the ESA Director of Science, proclaimed:
“It is exciting to see the engagement of the astronomical community in designing and proposing what will be the first scientific programs for the James Webb Space Telescope. Webb will revolutionize our understanding of the Universe and the results that will come out from these early observations will mark the beginning of a thrilling new adventure in astronomy.”
During its mission, which will last for a minimum of five years (barring extensions), the JWST will also address many other key topics in modern astronomy, probing the Universe beyond the limits of what Hubble has been capable of seeing. It will also build on observations made by Hubble, examining galaxies whose light has been stretched into infrared wavelengths by the expansion of space.
Beyond looking farther back in time to chart cosmic evolution, Webb will also examine the Supermassive Black Holes (SMBH) that lie at the centers of most massive galaxies – for the purpose of obtaining accurate mass estimates. Last, but not least, Webbwill focus on the birth of new stars and their planets, initially focusing on Jupiter-sized worlds and then shifting focus to study smaller super-Earths.
John C. Mather, the Senior Project Scientist for the JWST and a Senior Astrophysicist at NASA’s Goddard Space Flight Center, also expressed enthusiasm for the selected programs. “I’m thrilled to see the list of astronomers’ most fascinating targets for the Webb telescope, and extremely eager to see the results,” he said. “We fully expect to be surprised by what we find.”
For years, astronomers and researchers have been eagerly awaiting the day when the JWST begins gathering and releasing its first observations. With so many possibilities and so much waiting to be discovered, the telescope’s deployment (which is scheduled for 2019) is an event that can’t come soon enough!
The most powerful space telescope ever built will have to wait on the ground for a few more months into 2019 before launching to the High Frontier and looking back nearly to the beginning of time and unraveling untold astronomical secrets on how the early Universe evolved – Engineers need a bit more time to complete the Webb telescopes incredibly complex assembly and testing here on Earth.
“NASA’s James Webb Space Telescope now is planning to launch between March and June 2019 from French Guiana, following a schedule assessment of the remaining integration and test activities,” the agency announced.
Until now the Webb telescope was scheduled to launch on a European Space Agency (ESA) Ariane V booster from the Guiana Space Center in Kourou, French Guiana in October 2018.
“The change in launch timing is not indicative of hardware or technical performance concerns,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at Headquarters in Washington, in a statement.
“Rather, the integration of the various spacecraft elements is taking longer than expected.”
NASA’s says the currently approved budget will not bust the budget or reduce the science output. It “accommodates the change in launch date, and the change will not affect planned science observations.”
NASA’s $8.8 Billion James Webb Space Telescope is the most powerful space telescope ever built and is the scientific successor to the phenomenally successful Hubble Space Telescope (HST).
The Webb Telescope is a joint international collaborative project between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).
Since Webb is not designed to be serviced by astronauts, the extremely thorny telescope deployment process is designed to occur on its own over a period of several months and must be fully successful. Webb will be positioned at the L2 Lagrange point- a gravitationally stable spot approximately 930,000 miles (1.5 million km) away from Earth.
So its better to be safe than sorry and take the extra time needed to insure success of the hugely expensive project.
Various completed components of the Webb telescope are undergoing final testing around the country to confirm their suitability for launch.
Critical cryogenic cooling testing of Webb’s mirrors and science instrument bus is proceeding well inside a giant chamber at NASA’s Johnson Space Center in Texas.
However integration and testing of the complex multilayered sunshield at Northrup Grumman’s Redondo Beach, Ca. facility is taking longer than expected and “has experienced delays.”
The tennis court sized sunshield will protect the delicate optics and state of the art infrared science instruments on NASA’s Webb Telescope.
Webb’s four research instruments cannot function without the essential cooling provided by the sunshield deployment to maintain them at an operating temperature of minus 388 degrees F (minus 233 degrees C).
The Webb telescopes groundbreaking sunshield subsystem consists of five layers of kapton that will keep the optics and instruments incredibly cool, by reducing the incoming sunside facing temperature more than 570 degrees Fahrenheit. Each layer is as thin as a human hair.
“Webb’s spacecraft and sunshield are larger and more complex than most spacecraft. The combination of some integration activities taking longer than initially planned, such as the installation of more than 100 sunshield membrane release devices, factoring in lessons learned from earlier testing, like longer time spans for vibration testing, has meant the integration and testing process is just taking longer,” said Eric Smith, program director for the James Webb Space Telescope at NASA Headquarters in Washington, in a statement.
“Considering the investment NASA has made, and the good performance to date, we want to proceed very systematically through these tests to be ready for a Spring 2019 launch.”
Northrop Grumman designed the Webb telescope’s optics and spacecraft bus for NASA’s Goddard Space Flight Center in Greenbelt, Maryland, which manages Webb.
Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
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In October of 2018, the James Webb Space Telescope (JWST) will be launched into orbit. As part of NASA’s Next Generation Space Telescope program, the JWST will spend the coming years studying every phase of cosmic history. This will involve probing the first light of the Universe (caused by the Big Bang), the first galaxies to form, and extra-solar planets in nearby star systems.
In addition to all of that, the JWST will also be dedicated to studying our Solar System. As NASA recently announced, the telescope will use its infrared capabilities to study two “Ocean Worlds” in our Solar System – Jupiter’s moon Europa and Saturn’s moon Enceladus. In so doing, it will add to observations previously made by NASA’s Galileo and Cassini orbiters and help guide future missions to these icy moons.
The moons were chosen by scientist who helped to develop the telescope (aka. guaranteed time observers) and are therefore given the privilege of being among the first to use it. Europa and Enceladus were added to the telescope’s list of targets since one of the primary goals of the telescope is to study the origins of life in the Universe. In addition to looking for habitable exoplanets, NASA also wants to study objects within our own Solar System.
One of the main focuses will be on the plumes of water that have been observed breaking through the icy surfaces of Enceladus and Europa. Since 2005, scientists have known that Enceladus has plumes that periodically erupt from its southern polar region, spewing water and organic chemicals that replenish Saturn’s E-Ring. It has since discovered that these plumes reach all the way into the interior ocean that exists beneath Enceladus’ icy surface.
In 2012, astronomers using the Hubble Space Telescope detected similar plumes coming from Europa. These plumes were spotted coming from the moon’s southern hemisphere, and were estimated to reach up to 200 km (125 miles) into space. Subsequent studies indicated that these plumes were intermittent, and presumably rained water and organic materials from the interior back onto the surface.
These observations were especially intriguing since they bolstered the case for Europa and Enceladus having interior, warm-water oceans that could harbor life. These oceans are believed to be the result of geological activity in the interior that is caused by tidal flexing. Based on the evidence gathered by the Galileo and Cassini orbiters, scientists have theorized that these surface plumes are the result of these same geological processes.
The presence of this activity could also means that these moons have hydrothermal vents located at their core-mantle boundaries. On Earth, hydrothermal vents (located on the ocean floor) are believed to have played a major role in the emergence of life. As such, their existence on other bodies within the Solar System is viewed as a possible indication of extra-terrestrial life.
The effort to study these “Ocean Worlds” will be led by Geronimo Villanueva, a planetary scientist at NASA’s Goddard Space Flight Center. As he explained in a recent NASA press statement, he and his team will be addressing certain fundamental questions:
“Are they made of water ice? Is hot water vapor being released? What is the temperature of the active regions and the emitted water? Webb telescope’s measurements will allow us to address these questions with unprecedented accuracy and precision.”
Villanueva’s team is part of a larger effort to study the Solar System, which is being led by Heidi Hammel – the executive VP of the Association of Universities for Research in Astronomy (AURA). As she described the JWST’s “Ocean World” campaign to Universe Today via email:
“We will be seeking signatures of plume activity on these ocean worlds as well as active spots. With the near-infrared camera of NIRCAM, we will have just enough spatial resolution to distinguish general regions of the moons that could be “active” (creating plumes). We will also use spectroscopy (examining specific colors of light) to sense the presence of water, methane and several other organic species in plume material.”
For Enceladus, the team will be analyze the molecular composition of its plumes and perform a broad analysis of its surface features. Due to its small size, high-resolution of the surface will not be possible, but this should not be a problem since the Cassini orbiter already mapped much of its surface terrain. All told, Cassini has spent the past 13 years studying the Saturn system and will conclude the “Grande Finale” phase of its mission this September 15th.
These surveys, it is hoped, will find evidence of organic signatures in the plumes, such as methane, ethanol and ethane. To be fair, there are no guarantees that the JWST’s observations will coincide with plumes coming from these moons, or that the emissions will have enough organic molecules in them to be detectable. Moreover, these indicators could also be caused by geological processes.
Nevertheless, the JWST is sure to provide evidence that will allow scientists to better characterize the active regions of these moons. It is also anticipated that it will be able to pinpoint locations that will be of interest for future missions, such as NASA’s Europa Clipper mission. Consisting of an orbiter and lander, this mission – which is expected to launch sometime in the 2020s – will attempt to determine if Europa is habitable.
As Dr. Hammel explained, the study of these two “Ocean Moons” is also intended to advance our understanding about the origins of life in the Universe:
“These two ocean moons are thought to provide environments that may harbor water-based life as we know it. At this point, the issue of life elsewhere is completely unknown, though there is much speculation. JWST can move us closer to understanding these potentially habitable environments, complementing robotic spacecraft missions that are currently in development (Europa Clipper) and may be planned for the future. At the same time, JWST will be examining the far more distant potentially habitable environments of planets around other stars. These two lines of exploration – local and distant – allow us to make significant advances in the search for life elsewhere.”
Once deployed, the JWST will be the most powerful space telescope ever built, relying on eighteen segmented mirrors and a suite of instruments to study the infrared Universe. While it is not meant to replace the Hubble Space Telescope, it is in many ways the natural heir to this historic mission. And it is certainly expected to expand on many of Hubble’s greatest discoveries, not the least of which are here in the Solar System.
Be sure to check out this video on the kinds of spectrographic data the JWST will provide in the coming years, courtesy of NASA: