22.08.2022

It’s in charge of taking the pretty pictures

I look to the stars, and I see semicolons.Image: NASA, ESA, CSA, and STScI

It turns out that JavaScript, the programming language that web developers and users alike love to complain about, had a hand in delivering the stunning images that the James Webb Space Telescope has been beaming back to Earth. And no, I don’t mean that in some snarky way, like that the website NASA hosts them on uses JavaScript (it does). I mean that the actual telescope, arguably one of humanity’s finest scientific achievements, is largely controlled by JavaScript files. Oh, and it’s based on a software development kit from 2002.

According to a manuscript (PDF) for the JWST’s Integrated Science Instrument Module (or ISIM), the software for the ISIM is controlled by “the Script Processor Task (SP), which runs scripts written in JavaScript upon receiving a command to do so.” The actual code in charge of turning those JavaScripts (NASA’s phrasing, not mine) into actions can run 10 of them at once.

Diagram: NASA

The manuscript and the paper (pdf) “JWST: Maximizing efficiency and minimizing ground systems,” written by the Space Telescope Science Institute’s Ilana Dashevsky and Vicki Balzano, describe this process in great detail, but I’ll oversimplify a bit to save you the pages of reading. The JWST has a bunch of these pre-written scripts for doing specific tasks, and scientists on the ground can tell it to run those tasks. When they do, those JavaScripts will be interpreted by a program called the script processor, which will then reach out to the other applications and systems that it needs to based on what the script calls for. The JWST isn’t running a web browser where JavaScript directly controls the Mid-Infrared Instrument — it’s more like when a manager is given a list of tasks (in this example, the JavaScripts) to do and delegates them out to their team.

Diagram: NASA

The JavaScripts are still very important, though — the ISIM is the collection of instruments that actually take the pictures through the telescope, and the scripts control that process. NASA calls it “the heart of the James Webb Space Telescope.”

It seems a bit odd, then, that it uses such an old technology; according to Dashevsky and Balzano, the language the scripts are written in is called Nombas ScriptEase 5.00e. According to Nombas’ (now-defunct) website, the latest update to ScriptEase 5.00e was released in January 2003 — yes, almost two decades ago. There are people who can vote who weren’t born when the software controlling some of the JWST’s most vital instruments came out.

This knowledge has been bubbling up on the internet in Hacker News and Twitter threads for years, but it still surprised quite a few of us here at The Verge once it actually clicked. At first blush, it just seems odd that such a vital (not to mention expensive) piece of scientific equipment would be controlled by a very old version of a technology that’s not particularly known for being robust.

After thinking about it for a second, though, the software’s age makes a bit more sense — while the JWST was launched in late 2021, the project has been in the works since 1989. When construction on the telescope started in 2004, ScriptEase 5 would’ve only been around two years old, having launched in 2002. That’s actually not particularly old, given that spacecraft are often powered by tried-and-true technology instead of the latest and greatest. Because of how long projects like the JWST take to (literally) get off the ground, things that had to be locked in early on can seem out of date by more conventional standards when launch day rolls around.

It’s worth noting that, like the project itself, these documents that describe the JWST’s JavaScript system are pretty old; the one written by Dashevsky and Balzano is undated but came out in 2006, according to ResearchGate, and the ISIM manuscript is from 2011. (There does appear to have been a version published in 2010, but the one I read cites papers published in 2011.) It’s always possible that NASA could’ve changed the scripting system since then, but that seems like a pretty big undertaking that would’ve been mentioned somewhere. Also, while NASA didn’t reply to The Verge’s request for comment, this JWST documentation page published in 2017 mentions “event-driven science operations,” which is pretty much exactly how the documents describe the JavaScript-based system.

This knowledge base, by the way, also contains a few more details on the telescope’s 68 GB SSD, saying that it can hold somewhere between 58.8 and 65 gigabytes of actual scientific data. Wait, did I forget to mention that? Yes, this telescope’s solid state drive has around the same capacity as the one that was available in the original 2008 MacBook Air.

Anyways, we’re not here to talk about the JWST’s storage. I feel like the big question at this point is why Javascript? Sure, there’s probably a bit more angst about the language now than there was in the time when the project’s engineers were selecting tech for the project, but NASA is famous among some programmers for its strict programming guidelines — what’s the point of going with web-like scripts instead of more traditional code?

Well, NASA’s document says that this way of doing things gives “operations personnel greater visibility, control and flexibility over the telescope operations,” letting them easily change the scripts “as they learn the ramifications and subtleties of operating the instruments.” Basically, NASA’s working with a bunch of files that are written in a somewhat human-readable format — if they need to make changes, they can just open up a text editor, do a bunch of testing on the ground, then send the updated file to the JWST. It’s certainly easier (and therefore likely less error-prone) than if every program was written in arcane code that you’d have to recompile if you wanted to make changes.

Image: Space Telescope Science Institute

If you’re still worried, do note that the Space Telescope Science Institute’s document mentions that the script processor itself is written in C++, which is known for being... well, the type of language you’d want to use if you were programming a spacecraft. And it’s obviously working, right? The pictures are incredible, no matter what kind of code was run to generate them. It is, however, a fun piece of trivia — next time you’re cursing the modern web for being so slow and wishing that someone would just blast JavaScript into space, you can remember that NASA has, in fact, done that.

Quelle: The Verge

----

Update: 23.08.2022

.

Webb’s Jupiter Images Showcase Auroras, Hazes

Webb NIRCam composite image of Jupiter from three filters – F360M (red), F212N (yellow-green), and F150W2 (cyan) – and alignment due to the planet’s rotation. Credit: NASA, ESA, CSA, Jupiter ERS Team; image processing by Judy Schmidt.

With giant storms, powerful winds, auroras, and extreme temperature and pressure conditions, Jupiter has a lot going on. Now, NASA’s James Webb Space Telescope has captured new images of the planet. Webb’s Jupiter observations will give scientists even more clues to Jupiter’s inner life.  

“We hadn’t really expected it to be this good, to be honest,” said planetary astronomer Imke de Pater, professor emerita of the University of California, Berkeley. De Pater led the observations of Jupiter with Thierry Fouchet, a professor at the Paris Observatory, as part of an international collaboration for Webb’s Early Release Science program. Webb itself is an international mission led by NASA with its partners ESA (European Space Agency) and CSA (Canadian Space Agency). “It’s really remarkable that we can see details on Jupiter together with its rings, tiny satellites, and even galaxies in one image,” she said. 

The two images come from the observatory’s Near-Infrared Camera (NIRCam), which has three specialized infrared filters that showcase details of the planet. Since infrared light is invisible to the human eye, the light has been mapped onto the visible spectrum. Generally, the longest wavelengths appear redder and the shortest wavelengths are shown as more blue. Scientists collaborated with citizen scientist Judy Schmidt to translate the Webb data into images. 

In the standalone view of Jupiter, created from a composite of several images from Webb, auroras extend to high altitudes above both the northern and southern poles of Jupiter. The auroras shine in a filter that is mapped to redder colors, which also highlights light reflected from lower clouds and upper hazes. A different filter, mapped to yellows and greens, shows hazes swirling around the northern and southern poles. A third filter, mapped to blues, showcases light that is reflected from a deeper main cloud.  

The Great Red Spot, a famous storm so big it could swallow Earth, appears white in these views, as do other clouds, because they are reflecting a lot of sunlight. 

“The brightness here indicates high altitude – so the Great Red Spot has high-altitude hazes, as does the equatorial region,” said Heidi Hammel, Webb interdisciplinary scientist for solar system observations and vice president for science at AURA. “The numerous bright white ‘spots’ and ‘streaks’ are likely very high-altitude cloud tops of condensed convective storms.” By contrast, dark ribbons north of the equatorial region have little cloud cover.  

In a wide-field view, Webb sees Jupiter with its faint rings, which are a million times fainter than the planet, and two tiny moons called Amalthea and Adrastea. The fuzzy spots in the lower background are likely galaxies “photobombing” this Jovian view.   

“This one image sums up the science of our Jupiter system program, which studies the dynamics and chemistry of Jupiter itself, its rings,and its satellite system,” Fouchet said. Researchers have already begun analyzing Webb data to get new science results about our solar system’s largest planet. 

Data from telescopes like Webb doesn’t arrive on Earth neatly packaged. Instead, it contains information about the brightness of the light on Webb’s detectors. This information arrives at the Space Telescope Science Institute (STScI), Webb’s mission and science operations center, as raw data. STScI processes the data into calibrated files for scientific analysis and delivers it to the Mikulski Archive for Space Telescopes for dissemination. Scientists then translate that information into images like these during the course of their research (here’s a podcast about that). While a team at STScI formally processes Webb images for official release, non-professional astronomers known as citizen scientists often dive into the public data archive to retrieve and process images, too.

Judy Schmidt of Modesto California, a longtime image processor in the citizen science community, processed these new views of Jupiter. For the image that includes the tiny satellites, she collaborated with Ricardo Hueso, a co-investigator on these observations, who studies planetary atmospheres at the University of the Basque Country in Spain.   

Schmidt has no formal educational background in astronomy. But 10 years ago, an ESA contest sparked her insatiable passion for image processing. The “Hubble’s Hidden Treasures” competition invited the public to find new gems in Hubble data. Out of nearly 3,000 submissions, Schmidt took home third place for an image of a newborn star.  

Since the ESA contest, she has been working on Hubble and other telescope data as a hobby. “Something about it just stuck with me, and I can’t stop,” she said. “I could spend hours and hours every day.” 

Her love of astronomy images led her to process images of nebulae, globular clusters, stellar nurseries, and more spectacular cosmic objects. Her guiding philosophy is: “I try to get it to look natural, even if it’s not anything close to what your eye can see.” These images have caught the attention of professional scientists, including Hammel, who previously collaborated with Schmidt on refining Hubble images of comet Shoemaker-Levy 9’s Jupiter impact. 

Jupiter is actually harder to work with than more distant cosmic wonders, Schmidt says, because of how fast it rotates. Combining a stack of images into one view can be challenging when Jupiter’s distinctive features have rotated during the time that the images were taken and are no longer aligned. Sometimes she has to digitally make adjustments to stack the images in a way that makes sense. 

Webb will deliver observations about every phase of cosmic history, but if Schmidt had to pick one thing to be excited about, it would be more Webb views of star-forming regions. In particular, she is fascinated by young stars that produce powerful jets in small nebula patches called Herbig–Haro objects. “I’m really looking forward to seeing these weird and wonderful baby stars blowing holes into nebulas,” she said.  

– Elizabeth Landau, NASA Headquarters 

Quelle: NASA

----

Update: 27.08.2022

.

NASA’s Webb Detects Carbon Dioxide in Exoplanet Atmosphere

NASA’s James Webb Space Telescope has captured the first clear evidence for carbon dioxide in the atmosphere of a planet outside the solar system. This observation of a gas giant planet orbiting a Sun-like star 700 light-years away provides important insights into the composition and formation of the planet. The finding, accepted for publication in Nature, offers evidence that in the future Webb may be able to detect and measure carbon dioxide in the thinner atmospheres of smaller rocky planets.

WASP-39 b is a hot gas giant with a mass roughly one-quarter that of Jupiter (about the same as Saturn) and a diameter 1.3 times greater than Jupiter. Its extreme puffiness is related in part to its high temperature (about 1,600 degrees Fahrenheit or 900 degrees Celsius). Unlike the cooler, more compact gas giants in our solar system, WASP-39 b orbits very close to its star – only about one-eighth the distance between the Sun and Mercury – completing one circuit in just over four Earth-days. The planet’s discovery, reported in 2011, was made based on ground-based detections of the subtle, periodic dimming of light from its host star as the planet transits, or passes in front of the star.

Previous observations from other telescopes, including NASA’s Hubble and Spitzer space telescopes, revealed the presence of water vapor, sodium, and potassium in the planet’s atmosphere. Webb’s unmatched infrared sensitivity has now confirmed the presence of carbon dioxide on this planet as well.

A series of light curves from Webb’s Near-Infrared Spectrograph (NIRSpec) shows the change in brightness of three different wavelengths (colors) of light from the WASP-39 star system over time as the planet transited the star July 10, 2022.

Credits: Illustration: NASA, ESA, CSA, and L. Hustak (STScI); Science: The JWST Transiting Exoplanet Community Early Release Science Team

Download the full-resolution, uncompressed version and supporting visuals from the Space Telescope Science Institute

Filtered Starlight

Transiting planets like WASP-39 b, whose orbits we observe edge-on rather than from above, can provide researchers with ideal opportunities to probe planetary atmospheres.

During a transit, some of the starlight is eclipsed by the planet completely (causing the overall dimming) and some is transmitted through the planet’s atmosphere.

Because different gases absorb different combinations of colors, researchers can analyze small differences in brightness of the transmitted light across a spectrum of wavelengths to determine exactly what an atmosphere is made of. With its combination of inflated atmosphere and frequent transits, WASP-39 b is an ideal target for transmission spectroscopy.

First Clear Detection of Carbon Dioxide

The research team used Webb’s Near-Infrared Spectrograph(NIRSpec) for its observations of WASP-39b. In the resulting spectrum of the exoplanet’s atmosphere, a small hill between 4.1 and 4.6 microns presents the first clear, detailed evidence for carbon dioxide ever detected in a planet outside the solar system.

"As soon as the data appeared on my screen, the whopping carbon dioxide feature grabbed me,” said Zafar Rustamkulov, a graduate student at Johns Hopkins University and member of the JWST Transiting Exoplanet Community Early Release Science team, which undertook this investigation. “It was a special moment, crossing an important threshold in exoplanet sciences.”

No observatory has ever measured such subtle differences in brightness of so many individual colors across the 3 to 5.5-micron range in an exoplanet transmission spectrum before. Access to this part of the spectrum is crucial for measuring abundances of gases like water and methane, as well as carbon dioxide, which are thought to exist in many different types of exoplanets.

“Detecting such a clear signal of carbon dioxide on WASP-39 b bodes well for the detection of atmospheres on smaller, terrestrial-sized planets,” said Natalie Batalha of the University of California at Santa Cruz, who leads the team.

Understanding the composition of a planet’s atmosphere is important because it tells us something about the origin of the planet and how it evolved. “Carbon dioxide molecules are sensitive tracers of the story of planet formation,” said Mike Line of Arizona State University, another member of this research team. “By measuring this carbon dioxide feature, we can determine how much solid versus how much gaseous material was used to form this gas giant planet. In the coming decade, JWST will make this measurement for a variety of planets, providing insight into the details of how planets form and the uniqueness of our own solar system.”

A transmission spectrum of the hot gas giant exoplanet WASP-39 b captured by Webb’s Near-Infrared Spectrograph (NIRSpec) July 10, 2022, reveals the first clear evidence for carbon dioxide in a planet outside the solar system. This is also the first detailed exoplanet transmission spectrum ever captured that covers wavelengths between 3 and 5.5 microns.

Credits: Illustration: NASA, ESA, CSA, and L. Hustak (STScI); Science: The JWST Transiting Exoplanet Community Early Release Science Team

Download the full-resolution, uncompressed version and supporting visuals from the Space Telescope Science Institute

Early Release Science

This NIRSpec prism observation of WASP-39 b is just one part of a larger investigation that includes observations of the planet using multiple Webb instruments, as well as observations of two other transiting planets. The investigation, which is part of the Early Release Science program, was designed to provide the exoplanet research community with robust Webb data as soon as possible.

“The goal is to analyze the Early Release Science observations quickly and develop open-source tools for the science community to use,” explained Vivien Parmentier, a co-investigator from Oxford University. “This enables contributions from all over the world and ensures that the best possible science will come out of the coming decades of observations.”

Natasha Batalha, co-author on the paper from NASA's Ames Research Center, adds that “NASA's open science guiding principles are centered in our Early Release Science work, supporting an inclusive, transparent, and collaborative scientific process."

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

Quelle: NASA

----

Update: 31.08.2022

.

Webb telescope spots CO₂ on exoplanet for first time: What it means for finding alien life

Report heralds what’s to come from the landmark observatory, which is set to explore 76 worlds during its first year.

WASP-39b orbits closely to its star, making it a hot exoplanet (artist’s rendering shown).Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

The James Webb Space Telescope — already famous for its mesmerizing images of the cosmos— has done it again. The telescope has captured the first unambiguous evidence of carbon dioxide in the atmosphere of a planet outside the Solar System.

The finding not only provides tantalizing hints about how the exoplanet formed, it is also a harbinger for what’s to come as Webb studies more and more alien worlds. It was reported in a manuscript on the preprint server arXiv¹, ahead of peer review, and is expected to publish in Nature in the coming days. (Nature’s news team is independent of its journals team.)

Although the plotted data that led to the discovery lack the lustre of Webb’s previous images — which showed galaxies locked in a cosmic dance and radiant clouds in a stellar nursery— they still prompted Jessie Christiansen, an astronomer at the NASA Exoplanet Science Institute at Caltech in Pasadena, to describe them as “gorgeous”.

The plot, or spectrum, reveals detailed information about the atmosphere of the exoplanet WASP-39b, called a ‘hot Jupiter’ by scientists because it is slightly wider in diameter than Jupiter but orbits its star much more closely than Mercury orbits the Sun, making it unbearably hot. The planet, which is over 200 parsecs from Earth, was initially discovered during ground-based observations² and later detected by NASA’s Spitzer Space Telescope, operational between 2003 and 2020. Data from the latter suggested³ that WASP-39b’s atmosphere might contain carbon dioxide, but they were inconclusive.

Then came Webb. For a little more than eight hours on 10 July, the infrared telescope observed the planet move across the face of its star. As it did, starlight shone through the planet’s atmosphere where various molecules absorbed specific wavelengths of infrared light. Astronomers wondered whether carbon dioxide would show up as a telltale blip in the spectrum. “And there it was — just jumping off of the computer screen,” says Natalie Batalha, an astronomer at the University of California at Santa Cruz (UCSC), who leads Webb’s Transiting Exoplanet Early Release Science team.

Batalha wasn’t alone. When Christiansen, who is not part of the team, saw the data, she gasped. “I was like ‘oh there it is,’” she says. “We’ve had hints of it before, but this is the first time it’s really been a ‘punch in the face’ kind of detection.”

Mysterious origins

The result has bolstered confidence that Webb is going to be revolutionary for exoplanet research. In the first year of its operation alone, the telescope is commissioned to observe 76 exoplanets, but the final tally could fall in the hundreds. It will gaze through the atmospheres of gas giants and small, rocky worlds that could be like Earth. “My very first thought when I saw that signal was ‘wow, this is going to work,’” Batalha says.

But the finding of carbon dioxide is also impressive on its own. “From a science standpoint, it’s extremely exciting,” says Jonathan Fortney, the director of the Other Worlds Laboratory at UCSC and a co-author on the paper. It’s safe to expect that a planet like Jupiter, which formed out of the same disk of material as its star, would have roughly the same chemical makeup as that star. But that clearly isn’t the case in our Solar System, nor is it true for WASP-39b. The exoplanet’s strong carbon dioxide signal suggests that it is enriched with elements heavier than hydrogen and helium, which typically make up stars. The question is why?

“That’s where the story starts to get interesting,” Batalha says. It’s possible that when WASP-39b was young, it was bombarded with comets and asteroids, which could have delivered heavier elements such as carbon and oxygen. Interestingly, the exoplanet appears to have the same amounts of heavy elements as Saturn, which astronomers also think underwent a violent youth.

Or the answer might be that WASP-39b formed from materials in the cold outer reaches of its planetary system, then migrated inward. At its final resting spot, it snuggled up to its host star, which could have blasted away some of the hydrogen in the exoplanet’s atmosphere — concentrating heavier elements to make it appear richer in carbon dioxide. Fortney, Batalha and their colleagues are currently working on four papers that will analyse the planet’s spectrum in significantly more detail and probe these possibilities further.

“It’s like archaeology,” Batalha says. “You’re trying to build up a big story — and you’re using the molecules themselves, as tracers of that story.”

The building blocks of life

Spotting carbon dioxide in a planet’s atmosphere is a stepping stone towards detecting life beyond Earth. Of course astronomers don’t expect that WASP-39b is capable of hosting life — it is far too close to its star. They don’t even expect the Webb telescope to definitely find life on another planet. But using Webb to detect carbon dioxide helps lay the foundation for future discoveries.

Astronomers think that a mixture of carbon dioxide and methane in a planet’s atmosphere could be an indicator of life — a so-called biosignature. So WASP-39b’s signal is “halfway to a good biosignature”, Christiansen says. Batalha’s team built a model predicting that the planet’s atmosphere also contains water, carbon monoxide and hydrogen sulfide — but little methane.

Ultimately, the detection of life will probably require an even more advanced observatory than Webb. But, Batalha says, “this is a really important phase that we need to pass through to be ready for that technology in the future”.

Quelle: nature

----

Update: 1.09.2022

.

Remarkable new image of Phantom Galaxy taken by Webb shows power compared to Hubble

The center of the galaxy is usually clouded by gas, which Webb can pass through.

Officials have released a remarkable new image of the Phantom Galaxy -- about 32 million light-years away from Earth -- taken by the James Webb Space Telescope.

Published first by the European Space Agency, which has been collaborating with NASA on the Webb telescope, the image shows the galaxy -- located in the Pisces constellation -- in great detail.

Also known as Messier 74, the Phantom Galaxy, with its two well-defined spiral arms, falls under a class known as a "grand design spiral."

The galaxy has low surface brightness, making it hard to see and requiring clear, dark skies to do so. However, Webb's sharp lens have captured the clearest image of the galaxy's features.

"These spiral arms are traced by blue and bursts of pink, which are star-forming regions," NASA wrote in a social media post. "A speckled cluster of young stars glow blue at the very heart of the galaxy."

It also provides an unobstructed view of the star cluster at the center of the galaxy, without it being obscured by gas. The Webb telescope can past through gas and dust, which can appear opaque to the human eye.

"The addition of crystal-clear Webb observations at longer wavelengths will allow astronomers to pinpoint star-forming regions in the galaxies, accurately measure the masses and ages of star clusters, and gain insights into the nature of the small grains of dust drifting in interstellar space," the ESA said.

In the NASA post, there are also differences seen in the way the Webb telescope captured the Phantom Galaxy compared to the Hubble telescope.

The Webb telescope is an infrared telescope, meaning it uses infrared radiation to detect objects in space.

It can observe celestial bodies, such as stars, nebulae and planets, that are too cool or too faint to be observed in visible light -- that is, what's visible to humans.

By comparison, the Hubble telescope sees visible light, ultraviolet radiation and near-infrared radiation.

While Hubble did manage to capture many of the same star-forming regions and young stars, the images are not as clear as the one captured by Webb.

The Webb telescope was launched last December and NASA and ESA began releasing images from the new technology in July.

Quelle: abcNews