Artist's concept of the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets. Credit: NASA/JPL
To assist with future efforts to locate and study exoplanets, engineers with NASA’s Jet Propulsion Laboratory – in conjunction with the Exoplanet Exploration Program (ExEP) – are working to create Starshade. Once deployed, this revolutionary spacecraft will help next-generation telescopes by blocking out the obscuring light coming from distant stars so exoplanets can be imaged directly.
While this may sound pretty straightforward, the Starshade will also need to engage in some serious formation flying in order to do its job effectively. That was the conclusion of the reached by the Starshade Technology Development team (aka. S5) Milestone 4 report – which is available through the ExEP website. As the report stated, Starshade will need to be perfectly aligned with space telescopes, even at extreme distances.
Welcome to the 575th Carnival of Space! The Carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. We have a fantastic roundup today including news from the IAU, so now, on to this week’s worth of stories! Continue reading “Carnival of Space #575”
Artist's impression of the Jupiter-size extrasolar planet, HD 189733b, being eclipsed by its parent star. Credits: ESA, NASA, M. Kornmesser (ESA/Hubble), and STScI
The James Webb Space Telescope is like the party of the century that keeps getting postponed. Due to its sheer complexity and some anomalous readings that were detected during vibration testing, the launch date of this telescope has been pushed back many times – it is currently expected to launch sometime in 2021. But for obvious reasons, NASA remains committed to seeing this mission through.
Once deployed, the JWST will be the most powerful space telescope in operation, and its advanced suite of instruments will reveal things about the Universe that have never before been seen. Among these are the atmospheres of extra-solar planets, which will initially consist of gas giants. In so doing, the JWST will refine the search for habitable planets, and eventually begin examining some potential candidates.
The JWST will be doing this in conjunction with the Transiting Exoplanet Survey Satellite (TESS), which deployed to space back in April of 2018. As the name suggests, TESS will be searching for planets using the Transit Method (aka. Transit Photometry), where stars are monitored for periodic dips in brightness – which are caused by a planet passing in front of them relative to the observer.
Artist concept of the Transiting Exoplanet Survey Satellite and its 4 telescopes. Credit: NASA/MIT
Some of Webb’s first observations will be conducted through the Director’s Discretionary Early Release Science program – a transiting exoplanet planet team at Webb’s science operation center. This team is planning on conducting three different types of observations that will provide new scientific knowledge and a better understanding of Webb’s science instruments.
As Jacob Bean of the University of Chicago, a co-principal investigator on the transiting exoplanet project, explained in a NASA press release:
“We have two main goals. The first is to get transiting exoplanet datasets from Webb to the astronomical community as soon as possible. The second is to do some great science so that astronomers and the public can see how powerful this observatory is.”
As Natalie Batalha of NASA Ames Research Center, the project’s principal investigator, added:
“Our team’s goal is to provide critical knowledge and insights to the astronomical community that will help to catalyze exoplanet research and make the best use of Webb in the limited time we have available.”
For their first observation, the JWST will be responsible for characterizing a planet’s atmosphere by examining the light that passes through it. This happens whenever a planet transits in front of a star, and the way light is absorbed at different wavelengths provides clues as to the atmosphere’s chemical composition. Unfortunately, existing space telescopes have not had the necessary resolution to scan anything smaller than a gas giant.
The JWST, with its advanced infrared instruments, will examine the light passing through exoplanet atmospheres, split it into a rainbow spectrum, and then infer the atmospheres’ composition based on which sections of light are missing. For these observations, the project team selected WASP-79b, a Jupiter-sized exoplanet that orbits a star in the Eridanus constellation, roughly 780 light-years from Earth.
The team expects to detect and measure the abundances of water, carbon monoxide, and carbon dioxide in WASP-79b, but is also hoping to find molecules that have not yet been detected in exoplanet atmospheres. For their second observation, the team will be monitoring a “hot Jupiter” known as WASP-43b, a planet which orbits its star with a period of less than 20 hours.
Like all exoplanets that orbit closely to their stars, this gas giant is tidally-locked – where one side is always facing the star. When the planet is in front of the star, astronomers are only able to see its cooler backside; but as it orbits, the hot day-side slowly comes into view. By observing this planet for the entirety of its orbit, astronomers will be able to observe those variations (known as a phase curve) and use the data to map the planet’s temperature, clouds, and atmospheric chemistry.
This data will allow them to sample the atmosphere to different depths and obtain a more complete picture of the planet’s internal structure. As Bean indicated:
“We have already seen dramatic and unexpected variations for this planet with Hubble and Spitzer. With Webb we will reveal these variations in significantly greater detail to understand the physical processes that are responsible.”
An exoplanet about ten times Jupiter’s mass located some 330 light years from Earth. X-ray: NASA/CXC/SAO/I.Pillitteri et al; Optical: DSS; Illustration: NASA/CXC/M.Weiss
For their third observation, the team will be attempting to observe a transiting planet directly. This is very challenging, seeing as how the star’s light is much brighter and therefore obscures the faint light being reflected off the planet’s atmosphere. One method for addressing this is to measure the light coming from a star when the planet is visible, and again when it disappears behind the star.
By comparing the two measurements, astronomers can calculate how much light is coming from the planet alone. This technique works best for very hot planets that glow brightly in infrared light, which is why they selected WASP-18b for this observation – a hot Jupiter that reaches temperatures of around 2,900 K (2627 °C; 4,800 °F). In the process, they hope to determine the composition of the planet’s smothering stratosphere.
In the end, these observations will help test the abilities of the JWST and calibrate its instruments. The ultimate goal will be to examine the atmospheres of potentially-habitable exoplanets, which in this case will include rocky (aka. “Earth-like”) planets that orbit low mass, dimmer red dwarf stars. In addition to being the most common star in our galaxy, red dwarfs are also believed to be the most likely place to find Earth-like planets.
NASA’s James Webb Telescope, shown in this artist’s conception, will provide more information about previously detected exoplanets. Beyond 2020, many more next-generation space telescopes are expected to build on what it discovers. Credit: NASA
“TESS should locate more than a dozen planets orbiting in the habitable zones of red dwarfs, a few of which might actually be habitable. We want to learn whether those planets have atmospheres and Webb will be the one to tell us. The results will go a long way towards answering the question of whether conditions favorable to life are common in our galaxy.”
The James Webb Space Telescope will be the world’s premier space science observatory once deployed, and will help astronomers to solve mysteries in our Solar System, study exoplanets, and observe the very earliest periods of the Universe to determine how its large-scale structure evolved over time. For this reason, its understandable why NASA is asking that the astronomical community be patient until they are sure it will deploy successfully.
When the payoff is nothing short of ground-breaking discoveries, it’s only fair that we be willing to wait. In the meantime, be sure to check out this video about how scientists study exoplanet atmospheres, courtesy of the Space Telescope Science Institute:
Artist's concept of the Kepler mission with Earth in the background. Credit: NASA/JPL-Caltech
The Kepler space telescope has had a relatively brief but distinguished career of service with NASA. Having launched in 2009, the space telescope has spent the past nine years observing distant stars for signs of planetary transits (i.e. the Transit Method). In that time, it has been responsible for the detection of 2,650 confirmed exoplanets, which constitutes the majority of the more than 38oo planets discovered so far.
Earlier this week, the Kepler team was notified that the space telescope’s fuel tank is running very low. NASA responded by placing the spacecraft in hibernation in preparation for a download of its scientific data, which it collected during its latest observation campaign. Once the data is downloaded, the team expects to start its last observation campaign using whatever fuel it has left.
Since 2013, Kepler has been conducting its “Second Light” (aka. K2) campaign, where the telescope has continued conducting observations despite the loss of two of its reaction wheels. Since May 12th, 2018, Kepler has been on its 18th observation campaign, which has consisted of it studying a patch of sky in the vicinity of the Cancer constellation – which it previously studied in 2015.
NASA’s Kepler spacecraft has been on an extended mission called K2 after two of its four reaction wheels failed in 2013. Credit: NASA
In order to send the data back home, the spacecraft will point is large antenna back towards Earth and transmit it via the Deep Space Network. However, the DSN is responsible for transmitting data from multiple missions and time needs to be allotted in advance. Kepler is scheduled to send data from its 18th campaign back in August, and will remain in a stable orbit and safe mode in order to conserve fuel until then.
On August 2nd, the Kepler team will command the spacecraft to awaken and will maneuver the craft to the correct orientation to transmit the data. If all goes well, they will begin Kepler’s 19th observation campaign on August 6th with what fuel the spacecraft still has. At present, NASA expects that the spacecraft will run out of fuel in the next few months.
However, even after the Kepler mission ends, scientists and engineers will continue to mine the data that has already been sent back for discoveries. According to a recent study by an international team of scientists, 24 new exoplanets were discovered using data from the 10th observation campaign, which has brought the total number of Kepler discoveries to 2,650 confirmed exoplanets.
An artist’s conception of how common exoplanets are throughout the Milky Way Galaxy. Image Credit: Wikipedia
In the coming years, many more exoplanet discoveries are anticipated as the next-generation of space telescopes begin collecting their first light or are deployed to space. These include the Transiting Exoplanet Survey Satellite (TESS), which launched this past April, and the James Webb Space Telescope (JWST) – which is currently scheduled to launch sometime in 2021.
However, it will be many years before any mission can rival the accomplishments and contributions made by Kepler! Long after she is retired, her legacy will live on in the form of her discoveries.
In the future, telescopes may consist of distributed arrays rather than single instruments - like NASA's Terrestrial Planet Finder (TPF), a system of space telescopes for detecting extrasolar terrestrial planets. Credit: NASA
These missions will look farther into the cosmos than ever before and help astronomers address questions like how the Universe evolved and if there is life in other star systems. Unfortunately, all these missions have two things in common: in addition to being very large and complex, they are also very expensive. Hence why some scientists are proposing that we rely on more cost-effective ideas like swarm telescopes.
Two such scientists are Jayce Dowell and Gregory B. Taylor, a research assistant professor and professor (respectively) with the Department of Physics and Astronomy at the University of New Mexico. Together, the pair outlined their idea in a study titled “The Swarm Telescope Concept“, which recently appeared online and was accepted for publication by the Journal of Astronomical Instrumentation.
Illustration of NASA’s James Webb Space Telescope. Credits: NASA
As they state in their study, traditional astronomy has focused on the construction, maintenance and operation of single telescopes. The one exception to this is radio astronomy, where facilities have been spread over an extensive geographic area in order to obtain high angular resolution. Examples of this include the Very Long Baseline Array (VLBA), and the proposed Square Kilometer Array (SKA).
In addition, there’s also the problem of how telescopes are becoming increasingly reliant on computing and digital signal processing. As they explain in their study, telescopes commonly carry out multiple simultaneous observation campaigns, which increases the operational complexity of the facility due to conflicting configuration requirements and scheduling considerations.
A possible solution, according to Dowell and Taylor, is to rethink telescopes. Instead of a single instrument, the telescope would consist of a distributed array where many autonomous elements come together through a data transport system to function as a single facility. This approach, they claim, would be especially useful when it comes to the Next Generation Very Large Array (NGVLA) – a future interferometer that will build on the legacy of the Karl G. ansky Very Large Array and Atacama Large Millimeter/submillimeter Array (ALMA). As they state in their study:
“At the core of the swarm telescope is a shift away from thinking about an observatory as a monolithic entity. Rather, an observatory is viewed as many independent parts that work together to accomplish scientific observations. This shift requires moving part of the decision making about the facility away from the human schedulers and operators and transitioning it to “software defined operators” that run on each part of the facility. These software agents then communicate with each other and build dynamic arrays to accomplish the goals of multiple observers, while also adjusting for varying observing conditions and array element states across the facility.”
This idea for a distributed telescope is inspired by the concept of swarm intelligence, where large swarms of robots are programmed to interact with each other and their environment to perform complex tasks. As they explain, the facility comes down to three major components: autonomous element control, a method of inter-element communication, and data transport management.
Of these components, the most critical is the autonomous element control which governs the actions of each element of the facility. While similar to traditional monitoring and control systems used to control individual robotic telescopes, this system would be different in that it would be responsible for far more. Overall, the element control would be responsible for ensuring the safety of the telescope and maximizing the utilization of the element.
“The first, safety of the element, requires multiple monitoring points and preventative actions in order to identify and prevent problems,” they explain. “The second direction requires methods of relating the goals of an observation to the performance of an element in order to maximize the quantity and quality of the observations, and automated methods of recovering from problems when they occur.”
The second component, inter-element communication, is what allows the individual elements to come together to form the interferometer. This can take the form of a leaderless system (where there is no single point of control), or an organizer system, where all of the communication between the elements and with the observation queue is done through a single point of control (i.e. the organizer).
Long Wavelength Array, operated by the University of New Mexico. Credit: phys.unm.edu
Lastly, their is the issue of data transport management, which can take one of two forms based on existing telescopes. These include fully 0ff-line systems, where correlation is done post-observation – used by the Very Long Baseline Array (VLBA) – to fully-connected systems, where correlation is done in real-time (as with the VLA). For the sake of their array, the team emphasized how connectivity and correlation are a must.
After considering all these components and how they are used by existing arrays, Dowell and Taylor conclude that the swarm concept is a natural extension of the advances being made in robotic and thinking telescopes, as well as interferometry. The advantages of this are spelled out in their conclusions:
“It allows for more efficient operations of facilities by moving much of the daily operational work done by humans to autonomous control systems. This, in turn, frees up personnel to focus on the scientific output of the telescope. The swarm concept can also combine the unused resources of the different elements together to form an ad hoc array.”
In addition, swarm telescopes will offer new opportunities and funding since they will consist of small elements that can be owned and operated by different entities. In this way, different organizations would be able to conduct science with their own elements while also being able to benefit from large-scale interferometric observations.
Graphic depiction of Modular Active Self-Assembling Space Telescope Swarms Credit: D. Savransky
This concept is similar to the Modular Active Self-Assembling Space Telescope Swarms, which calls for a swarm of robots that would assemble in space to form a 30 meter (~100 ft) telescope. The concept was proposed by a team of American astronomers led by Dmitri Savransky, an assistant professor of mechanical and aerospace engineering at Cornell University.
This proposals was part of the 2020 Decadal Survey for Astrophysics and was recently selected for Phase I development as part of the 2018 NASA Innovative Advanced Concepts (NIAC) program. So while many large-scale telescopes will be entering service in the near future, the next-next-generation of telescopes could include a few arrays made up of swarms of robots directed by artificial intelligence.
Such arrays would be capable of achieving high-resolution astronomy and interferometry at lower costs, and could free up large, complex arrays for other observations.
Illustration of NASA's James Webb Space Telescope. Credits: NASA
When it is deployed to space, the James Webb Space Telescope (JWST) will be the most powerful and advanced telescope ever deployed. 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 look back at the early Universe, study the Solar System, and help characterize extra-solar planets.
Unfortunately, after many delays, there’s some good news and bad news about this mission. The good news is that recently, the Independent Review Board (IRB) established by NASA to assess the progress on the JWST unanimously decided that work on the space telescope should continue. The bad news is that NASA has decided to push the launch date back again – this time to March 30th, 2021.
As part of their assessment, the IRB was established in April of 2018 to address a range of factors influencing Webb’s schedule and performance. These included the technical challenges and tasks that need to be tackled by its primary contractor (Northrop Grumman) before the mission can launch. A summary of the report’s recommendations, and NASA’s response, can be read here.
The Hubble Space Telescope on the left has a 2.4 meter mirror and the James Webb Space Telescope has a 6.5 meter mirror. LUVOIR, not shown, will dwarf them both with a massive 15 meter mirror. Credit: NASA
In the report, the IRB identified technical issues, which including human errors, that they claim have greatly impacted the development schedule. As they stated in their Overview:
“The observation that there are no small JWST integration and test problems was not initially recognized by the Webb IRB, and this also may be true of others involved with JWST. It is a most important observation that will be apparent in subsequent Findings and Recommendations. It is caused by the complexity and highly integrated nature of the observatory. Specifically, it implies, as an example, that a very small human error or test anomaly can impact the schedule by months and the cost by tens of millions of dollars.”
The anomaly mentioned in the report refers to the “anomalous readings” that were 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 sun shield. In February of 2018, the Government Accountability Office (GAO) issued a report that expressed concerns over further delays and cost overruns. Shortly thereafter, the JWST’s Standing Review Board (SRB) made an independent assessment of the remaining tasks.
The James Webb Space Telescope being placed in the Johnson Space Center’s historic Chamber A on June 20th, 2017. Credit: NASA/JSC
In May of 2018, NASA issued a statement indicating that they now estimated that the launch window would be some time in May 2020. However, they chose to await the findings of the IRB and consider the data from the JWST’s Standing Review Board before making the final determination. The new launch date was set to accommodate environmental testing and work performances challenges on the sunshield and propulsion system.
According to the IRB report, this latest delay will also result in a budget overrun. “As a result of the delay, Webb’s total lifecycle cost to support the March 2021 launch date is estimated at $9.66 billion,” they concluded. “The development cost estimate to support the new launch date is $8.8B (up from the $8B development cost estimate established in 2011).”
As Jim Bridenstine, the NASA Administrator, indicated in a message to the NASA workforce on Wednesday about the report:
“Webb is vital to the next generation of research beyond NASA’s Hubble Space Telescope. It’s going to do amazing things – things we’ve never been able to do before – as we peer into other galaxies and see light from the very dawn of time. Despite major challenges, the board and NASA unanimously agree that Webb will achieve mission success with the implementation of the board’s recommendations, many of which already are underway.”
In the end, the IRB, SRB and NASA are all in total agreement that the James Webb Space Telescope is a crucial mission that must be seen through. In addition to shedding light on a number of mysteries of the Universe – ranging from the earliest stars and galaxies in the Universe to exoplanet habitability – the JWST will also complement and enhance the discoveries made by other missions.
The combined optics and science instruments of NASA’s James Webb Space Telescope being removed from the Space Telescope Transporter for Air, Road and Sea (STTARS) at the Northrop Grumman company headquarters on March 8th, 2018. Credits: NASA/Chris Gunn
These include not only Hubble and Spitzer, but also missions like the Transiting Exoplanet Survey Satellite (TESS), which launched this past April. Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, also issued a statement on the recent report:
“The more we learn more about our universe, the more we realize that Webb is critical to answering questions we didn’t even know how to ask when the spacecraft was first designed. Webb is poised to answer those questions, and is worth the wait. The valuable recommendations of the IRB support our efforts towards mission success; we expect spectacular scientific advances from NASA’s highest science priority.”
The JWST will also be the first telescope of its kind, being larger and more complex than any previous space telescope – so challenges were anticipated from its very inception. In addition, the final phase consists of some of the most challenging work, where the 6.5-meter telescope and science payload element are being joined with the spacecraft element to complete the observatory.
The science team also needs to ensure that the observatory can be folded up to fit inside the Ariane 5 rocket that will launch it into space. They also need to ensure that it will unfold again once it reaches space, deploy its sunshield, mirrors and primary mirror. Beyond that, there are also the technical challenges of building a complex observatory that was created here on Earth, but designed to operate in space.
As a collaborative project between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA), the JWST is also representative of the new era of international cooperation. As such, no one wishes to see the mission abandoned so close to completion. In the meantime, any delays that allow for extra testing will only ensure success in the long run.
Good luck JWST, we look forward to hearing about your first discoveries!
Welcome to the 558th Carnival of Space! The Carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. We have a fantastic roundup today, so now, on to this week’s stories! Continue reading “Carnival of Space #558”
The James Webb Space Telescope inside a cleanroom at NASA’s Johnson Space Center in Houston. Credit: NASA/JSC
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).
NASA’s James Webb Space Telescope sits in Chamber A at NASA’s Johnson Space Center in Houston awaiting the colossal door to close in July 2017 for cryogenic testing. Credits: NASA/Chris Gunn
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.
The sunshield test unit on NASA’s James Webb Space Telescope is unfurled for the first time. Credit: NASA
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:
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Artist conception of the James Webb Space Telescope. Credit: 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.
The JWST’s Optical Telescope element/Integrated Science instrument module (OTIS) undergoing testing at NASA’s Johnson Space Center. Credit: NASA/Desiree Stover
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.”
Each program will rely on the JWST’s suite of four scientific instruments, which have been contributed by NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). These include the the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIRI) developed by the ESA, as well as the Near-Infrared Camera (NIRCam) developed by NASA and the STScI, and the Near-Infrared Imager and Slitless Spectrograph (NIRISS) developed by the CSA.
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.
Once deployed, the JWST will conduct a variety of science missions aimed at improving our understanding of the Universe. Credit: NASA/STScI
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.
Then there’s the Transiting Exoplanet Community Early Release Science Program, which will build on the work of the Hubble, Spitzer, and Kepler space telescopes by conducting exoplanet surveys. Like its predecessors, this will consist of monitoring stars for periodic dips in brightness that are caused by planets passing between them and the observer (aka. Transit Photometry).
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.
Artist’s impression of the planet orbiting a red dwarf star. Credit: ESO/M. Kornmesser
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.
The James Webb Space Telescope’s 18-segment primary mirror, a gold-coated beryllium mirror has a collecting area of 25 square meters. Credit: NASA/Chris Gunn
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!
