Tag: JWST

What the JWST is Learning About Exoplanet Atmospheres

We are now well into the era of exoplanet atmospheres, of measurements made possible by the James Webb Space Telescope.  While prior observatories could detect some chemicals in exoplanet atmospheres,  the limits were substantial. This is an artist’s impression of a hot Jupiter with a thick atmosphere transiting its host star. (NASA, ESA, and G. Bacon (STScI)

The James Webb Space Telescope is beginning to reveal previously unknowable facts about the composition of exoplanets — about the presence or absence of atmospheres around the exoplanets and the makeup of any atmospheres that are detected.

The results have been coming in for some months and they are a delight to scientists.  And as with most things about exoplanets, the results are not always what were expected.

For instance, gas giant planets  orbiting our Sun show a clear pattern; the more massive the planet, the lower the percentage of “heavy” elements (anything other than hydrogen and helium) in the planet’s atmosphere.

The James Webb Space Telescope is returning insights into the atmospheres of exoplanets that scientists have long dreamed about obtaining. Some are predicting a new era in exoplanet research. (NASA)

But out in the galaxy, the atmospheric compositions of giant planets do not fit the solar system trend, an international team of astronomers has found.

Researchers discovered that the atmosphere of exoplanet HD149026b, a “hot jupiter” given the name “Smertrios” that orbits a Sun-like star, is super-abundant in the heavier elements carbon and oxygen – far above what scientists would expect for a planet of its mass.

In its “early release” program for exoplanet results, JWST also observed WASP-39 b, a “hot Saturn” (a planet about as massive as Saturn but in an orbit tighter than Mercury) orbiting a star some 700 light-years away.

The atmosphere around the planet provided the first detection in an exoplanet atmosphere of sulfur dioxide (SO2), a molecule produced from chemical reactions triggered by high-energy light from the planet’s parent star.

The Trappist-1 system –seven Earth-sized planets orbiting a red dwarf star only 40 light-years away — is another subject of great interest and JWST has provided some exciting results there too.

While the first Trappist-1 planet studied — the one nearest to the star — apparently has no atmosphere, JWST was able to in effect take the planet’s temperature.  The telescope captured thermal signatures from the planet, which is another first.

When starlight passes through a planet’s atmosphere, certain parts of the light are absorbed by the atmosphere’s elements.

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The Amazing Unfurling Of The James Webb Space Telescope

The last view of the JWST and its unfurled solar arrays after it separated from the Ariane 5 launch vehicle and started it’s month-long and extraordinarily complicated deployment. (NASA)

Over the next three weeks-plus, the James Webb Space Telescope will play out an unfurling and deployment in deep space unlike anything this world has seen before.

It took decades to perfect the observatory — a segmented telescope on a heat shield  the length of a tennis court that was squeezed for launch into a rocket payload compartment less than 30 feet in diameter.  The unfurling has begun and will continue over 25 more days, with 50 major deployments and 178 release mechanisms to set the pieces free.

The process has been likened to the undoing of an origami creation, or like the opening of a massive, many-featured Swiss army knife but without a human to pull the parts out.

Adding to the stress of these days,  the JWST will be much further out into space than the Hubble Space Telescope, which is in a very close orbit around the Earth at an altitude of about 340 miles.  The JWST will be over 930,000 miles away from Earth at the stable orbital point called the second Lagrange point 2 (L2) — way too far away for any manual fixes or upgrades like the ones accomplished by astronauts for the Hubble.

Four days after liftoff, the observatory has unfurled some of its solar panels, has deployed some of the pallet that will hold the sunshield and has extended the tower assembly about 6 feet from its storage space.   Here is a video from the Goddard Space Flight Center illustrating all the steps needed to make JWST whole:

 

And here is a more detailed depiction of the many stages of deployment, what is being deployed and how.

JWST will  have the largest telescope mirror ever sent into space — 21 feet in diameter compared with the Hubble’s 8-foot diameter.  Because it is so large, it had to be divided into 18 hexagonal segments of the lightweight element beryllium, each one roughly the size of a coffee table. Together, the segments must align almost perfectly, moving in alignment within a fraction of a wavelength of light.

Webb mission systems engineer Mike Menzel, of NASA’s Goddard Space Flight Center, said in a deployment-explaining video called “29 Days on the Edge” that every single releases and deployment must work.… Read more

The WFIRST Space Observatory Becomes the Nancy Grace Roman Space Telescope. But Will it Ever Fly?

An artist’s rendering of NASA’s Wide Field Infrared Survey Telescope (WFIRST), now  the Nancy Grace Roman Space Telescope, which will search for exoplanets that are small rocky as well as Neptune sized at a greater distance from their host stars than currently possible.  It will also study multiple cosmic phenomena, including dark energy and other theorized Einsteinian phenomena. (NASA’s Goddard Space Flight Center)

Earlier last week, NASA put out a release alerting journalists to  “an exciting announcement about the agency’s Wide Field Infrared Survey Telescope (WFIRST) mission.”

Given the controversial history of the project — the current administration has formally proposed cancelling it for several years and the astronomy community (and Congress) have been keep it going — it seemed to be a  newsworthy event, maybe a breakthrough regarding an on-again, off-again very high profile project.

And since WFIRST was the top large mission priority of the National Academies of Sciences some years ago — guidance that NASA almost always follows — the story could reflect some change in the administration’s approach to the value of long-established scientific norms.  Plus, it could mean that a space observatory with cutting-edge technology for identifying and studying exoplanets and for learning much more about dark matter and Einsteinian astrophysics might actually be launched in the 2020s.

But instead of a newsy announcement about fate of the space telescope, what NASA disclosed was that the project had been given a new name — the Nancy Grace Roman space telescope.

As one of NASA’S earliest hired and highest-ranking women, Roman spent 21 years at NASA developing and launching space-based observatories that studied the sun, deep space, and Earth’s atmosphere. She most famously worked to develop the concepts behind the Hubble Space Telescope, which just spent its 30th year in orbit.

This is a welcome and no doubt deserving honor.  But it will be much less of an honor if the space telescope is never launched into orbit.  And insights into the fate of WFIRST (the Nancy Grace Roman Space Telescope) are what really would constitute “an exciting announcement.”

What’s going on?

Nancy Grace Roman at NASA’s Goddard Space Flight Centre in the early 1970s (NASA)

 

I have no special insights, but I think that one of the scientists on the NASA Science Live event was probably on to something when she said:

“I find it tremendously exciting that the observatory is being  renamed,”  said Julie McEnery, deputy project scientist for the (now) NASA Roman mission.  … Read more

NASA’s Planet-Hunter TESS Has Just Been Launched to Check Out the Near Exoplanet Neighborhood

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A SpaceX Falcon 9 rocket transporting the TESS satellite lifts off from launch complex 40 at the Cape Canaveral Air Force Station in Cape Canaveral, Fla., Wednesday, April 18, 2018. The space telescope will survey almost the entire sky, staring at the brightest, closest stars in an effort to find any planets that might be encircling them. (AP Photo/John Raoux)

On January 5, 2010, NASA issued  landmark press release : the Kepler Space Telescope had discovered its first five new extra-solar planets.

The previous twenty years had seen the discovery of just over 400 planets beyond the solar system. The majority of these new worlds were Jupiter-mass gas giants, many bunched up against their star on orbits far shorter than that of Mercury. We had learnt that our planetary system was not alone in the Galaxy, but small rocky worlds on temperate orbits might still have been rare.

Based on just six weeks of data, these first discoveries from Kepler were also hot Jupiters; the easiest planets to find due to their large size and swiftly repeating signature as they zipped around the star. But expectations were high that this would be just the beginning.

“We expected Jupiter-size planets in short orbits to be the first planets Kepler could detect,” said Jon Morse, director of the Astrophysics Division at NASA Headquarters at the time the discovery was announced. “It’s only a matter of time before more Kepler observations lead to smaller planets with longer period orbits, coming closer and closer to the discovery of the first Earth analog.”

Morse’s prediction was to prove absolutely right. Now at the end of its life, the Kepler Space Telescope has found 2,343 confirmed planets, 30 of which are smaller than twice the size of the Earth and in the so-called “Habitable Zone”, meaning they receive similar levels of insolation –the amount of solar radiation reaching a given area–to our own planet.

Yet, the question remains: were any of these indeed Earth analogs?

In just a few decades, thanks to Kepler, the Hubble Space Telescope and scores of astronomers at ground-based observatories, we have gone from suspecting the presence of exoplanets to knowing there are more exoplanets than stars in our galaxy. (NASA/Ames Research Station; Jessie Dotson and Wendy Stenzel)

It was a question that Kepler was not equipped to answer. Kepler identifies the presence of a planet by looking for the periodic dip in starlight as a planet passes across the star’s surface.… Read more

The Very Influential Natalie Batalha

Natalie Batalha, project scientist for the Kepler mission and a leader of NASA’s NExSS initiative on exoplanets, was just selected as one of Time Magazine’s 100 most influential people in the world. (NASA, TIME Magazine.)

I’d like to make a slight detour and talk not about the science of exoplanets and astrobiology, but rather a particular exoplanet scientist who I’ve had the pleasure to work with.

The scientist is Natalie Batalha, who has been lead scientist for NASA’s landmark Kepler Space Telescope mission since soon after it launched in 2009, has serves on numerous top NASA panels and boards, and who is one of the scientists who guides the direction of this Many Worlds column.

Last week, Batalha was named by TIME Magazine as one of the 100 most influential people in the world. This is a subjective (non-scientific) calculation for sure, but it nonetheless seems appropriate to me and to doubtless many others.

Batalha and the Kepler team have identified more than 2500 exoplanets in one small section of the distant sky, with several thousand more candidates awaiting confirmation.  Their work has once and for all nailed the fact that there are billions and billions of exoplanets out there.

“NASA is incredibly proud of Natalie,” said Paul Hertz, astrophysics division director at NASA headquarters, after the Time selection was announced.

“Her leadership on the Kepler mission and the study of exoplanets is helping to shape the quest to discover habitable exoplanets and search for life beyond the solar system. It’s wonderful to see her recognized for the influence she has had on the world – and on the way we see ourselves in the universe.”

And William Borucki, who had the initial idea for the Kepler mission and worked for decades to get it approved and then to manage it, had this to say about Batalha:

“She has made major contributions to the Kepler Mission throughout its development and operation. Natalie’s collaborative leadership style, and expert knowledge of the population of exoplanets in the galaxy, will provide guidance for the development of successor missions that will tell us more about the habitability of the planets orbiting nearby stars.”

Batalha has led the science mission of the Kepler Space Telescope since it launched in 2009. (NASA)

As a sign of the perceived importance of exoplanet research, two of the other TIME influential 100 are discoverers of specific new worlds.  They are Guillem Anglada-Escudé (who led a team that detected a planet orbiting Proxima Centauri) and Michael Gillon (whose team identified the potentially habitable planets around the Trappist-1 system.)… Read more

With the Main JWST Mirror Completed, Scientists Focus On How To Best and Most Fairly Use It Once In Space

Engineers conduct a white light inspection on NASA's James Webb Space Telescope in the clean room at NASA's Goddard Space Flight Center, Greenbelt, Maryland. Credits: NASA/Chris Gunn

Engineers conduct a white light inspection on NASA’s James Webb Space Telescope in the clean room at NASA’s Goddard Space Flight Center, Greenbelt, Maryland. (NASA/Chris Gunn)

Recent word that the giant mirror of the James Webb Space Telescope is essentially complete is a cause for celebration, a milestone in the long march toward launching what will be the most powerful astronomical instrument ever.  NASA Administrator Charlie Bolden made the announcement at the Goddard Space Flight Center, with senior project scientist John Mather declaring that “we’re opening up a whole new territory of astronomy.”

Although liftoff isn’t scheduled until two years from now, the mirror’s completion has led to an intensifying of the far less public but also essential task of determining how precisely the JWST will be used.

This is a major issue because the observatory will be far more complicated with many more moving parts for astronomers than the Hubble Space Telescope and other predecessors, and a significant amount of the learning about how to make observations can’t be done until JWST is already in space.

But more pressing still is the fact that “JW” (as it is now commonly called) will fly for a limited time, and as of now cannot be repaired or upgraded once in space because it will be too far away.

So while astronomers and the public have grown accustomed to long-lived observatories like the Hubble and Spitzer space telescopes — which have been revolutionizing astronomy for decades now — JW has a planned mission duration of just five years. Should the instruments continue working after that, the observatory will nonetheless run out of necessary fuel in 10 years.

Especially for exoplanet astronomers who often have to focus on a particular star and planet over a substantial time, this means they need to learn the JWST ropes fast or miss out on a scientific opportunity of a lifetime.

Natalie Batalha, a member of the JWST Science Advisory Committee and project scientist for the Kepler mission, said that the logic of  the traditional proposal cycles and proprietary periods “threatens to stall the release of potentially important technical information keeping data out of the public domain until the five year nominal mission is well underway.”

“Because of the finite lifetime of JWST, we have an urgency here that we didn’t have with Hubble,” she told me.

“The JWST Science Advisory Committee recognized the need to get data into the hands of community scientists as early as possible to take full advantage of this so valuable but limited opportunity.”… Read more

Out Of The Darkness

Simulation of the "Dark Ages," a period between 380,000 years and 4 million years after the Big Bang. The universe was made up primarily of hydrogen in a neutral state, which did not easily connect with any other particles. NASA/WMAP

Simulation of the “Dark Ages” of the universe, a period predicted by theorists to have lasted as long as several hundred million years after the Big Bang.  The first hydrogen atoms in the universe had not yet coalesced into stars and galaxies. (NASA/WMAP)

Before there were planets in our solar system, there was a star that would become our sun.  Before there was a sun, there were older stars and exoplanets throughout the galaxies.

Before there were galaxies with stars and exoplanets, there were galaxies with stars and no planets.  Before there were galaxies without planets, there were massive singular stars.

And before that, there was darkness for more than 100 million years after the Big Bang — a cosmos without much, or at times any, light.

So how did the lights get turned on, setting the stage for all that followed?  Scientists have many theories but so far only limited data.

In the coming years, that is likely to change substantially.

First, the James Webb Space Telescope, scheduled to launch in 2018, will be able to look back at distant galaxies and stars that existed in small or limited numbers during the so called Dark Ages.  They gradually became more prevalent and then suddenly (in astronomical terms) became common.  Called the epoch of cosmic “reionization,” this period is an essential turning point in the evolution of the cosmos.

Less well known but also about to begin pioneering work into how and when the lights came on will be an international consortium led by a team at the University of California, Berkeley. Unlike the space-based JWST,  this effort will use an array of radio telescopes under construction in the South African desert.  The currently small array will expand quickly now thanks in large part to a $9.6 million grant recently announced from the National Science Foundation.

Named the Hydrogen Epoch of Reionization Array (HERA), the project will focus especially on the billion-year process that changed the fundamental particle physics of the universe to allow stars, galaxies and their light burst out like spring flowers after a long winter.  But unlike the JWST, which will be able to observe faint and very early individual galaxies and stars, HERA will be exploring the early universe as a near whole.

 

Before stars and galaxies became common, the universe went through a long period of darkness and semi-darkness, but ended with the Epoch of Reionization. (S.G. Dorgovski & Digital Media Center, Caltech.)

Before stars and galaxies became common, the universe went through a long period of darkness and semi-darkness, but ended with the “Epoch of Reionization.”

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