Hubble Space Telescope Archives

January 17, 2018 by Matt Williams

James Webb Wraps up 3 Months in the Freezer. It’s Ready for Space

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).

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:

Further Reading: ArsTechnica, NASA

December 15, 2017December 15, 2017 by Matt Williams

Are Little Blue Dots in the Hubble Frontier Fields Precursors to Globular Clusters?

The massive galaxy cluster Abell 370 as seen by Hubble Space Telescope in the final Frontier Fields observations. The lensing effect reveals details about a supernova in the distant universe. Credit: NASA/ESA/HFF

In 2012, the Hubble Space Telescope Frontier Fields program (aka. Hubble Deep Fields Initiative 2012) officially kicked off. The purpose of this project was to study the faintest and most distant galaxies in the Universe using the gravitational lensing technique, thus advancing our knowledge of early galaxy formation. By 2017, the Frontier Field program wrapped up, and the hard work of analyzing all the data it collected began.

One of the more interesting finds within the Frontier Fields data has been the discovery of low mass galaxies with high star formation rates. After examining the “parallel fields” for Abell 2744 and MACS J0416.1-2403 – two galaxy clusters studied by the program – a pair of astronomers noted the presence of what they refer to as “Little Blue Dots” (LBDs), a finding which has implications for galaxy formation and globular clusters.

The study which details their findings recently appeared online under the title “Little Blue Dots in the Hubble Space Telescope Frontier Fields: Precursors to Globular Clusters?“. The study team consisted of Dr. Debra Meloy Elmegreen – a professor of astronomy at Vassar College – and Dr. Bruce G. Elmegreen, an astronomer with the IBM Research Division at the T.J. Watson Research Center in Yorktown Heights.

*The galaxy clusters Abell 2744, MACS J0416.1-2403, MACS J0717.5+3745, MACS J1149.5+2223, Abell S1063, Abell 370. Credit: NASA, ESA, STScI, and the HFF team*

To put it simply, the Frontier Fields program used the Hubble Space Telescope to observe six massive galaxy clusters at optical and near-infrared wavelengths – with its Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3), respectively. These massive galaxies were used to magnify and stretch images of remote galaxies located behind them which were otherwise too faint for Hubble to see directly (aka. gravitational lensing).

While one of these Hubble cameras would look at a galaxy cluster, the other would simultaneously view an adjacent patch of sky. These adjacent patches are known as “parallel fields”, otherwise faint regions that provide some of the deepest looks into the early Universe. As Dr. Bruce Elmegreen told Universe Today via email:

“The purpose of the HFF program is to take deep images of 6 regions of the sky where there are clusters of galaxies, because these clusters magnify background galaxies through the gravitational lens effect. In this way, we can see further than just with direct imaging of the sky alone. Many galaxies have been studied using this magnification technique. The clusters of galaxies are important because they are big mass concentrations which make strong gravitational lenses.”

This six galaxy clusters used for the sake of the project included Abell 2744, MACS J0416.1-2403 and their parallel fields, the latter of which were the focal point in this study. These and the other clusters were used to find galaxies that existed just 600 to 900 million years after the Big Bang. These galaxies and their respective parallels had already been cataloged using computer algorithms that automatically found galaxies in the images and determined their properties.

*Images of the MACS J0416.1–2403 and Abell 2744 galaxy clusters, taken as part of the Hubble Frontier Fields program. Credit: NASA/ESA/HST Frontier Fields team (STScI)*

As the research duo go on to explain in their study, recent large-scale deep surveys have enabled studies of smaller galaxies at higher redshifts. These include “green peas” – luminous, compact and low mass galaxies with high specific star formation rates – and even lower-mass “blueberries”, small starburst galaxies that are a faint extension of the green peas that also show intense rates of star formation.

Using the aforementioned catalogues, and examining the parallel fields for Abell 2744 and MACS J0416.1-2403, the team went looking for other examples of low-mass galaxies with high star formation rates. The purpose of this was to measure the properties of these dwarf galaxies, and to see if any of their positions accorded with where globular clusters are known to have formed.

What they found was what they referred to as “Little Blue Dots” (LBSs), which are even lower-mass versions of “blueberries”. As Dr. Debra Elmegreen told Universe Today via email:

“When I was examining the images (there are about 3400 galaxies detected in each field), I noticed occasional galaxies that appeared as little blue dots, which was very intriguing because of Bruce’s previous theoretical work on dwarf galaxies. The published catalogs included redshifts and star formation rates and masses for each galaxy, and it turns out the little blue dots are low mass galaxies with very high star formation rates for their mass.”

*Close-up view of a HFF parallel field, showing a LBD (upper right). Credit: Debra & Bruce Elmegreen*

These galaxies didn’t show structure, so Debra and Bruce stacked the images of galaxies into 3 different ranges of redshift (which worked out to about 20 galaxies each) to create deeper images. “Still they showed no structure or faint extended outer disk,” said Debra, “so they are at the limit of resolution, with average sizes of 100-200 parsecs (about 300-600 light years) and masses of a few million times the mass of our sun.”

In the end, they determined that within these LBDs, star formation rates were very high. They also noted that these dwarf galaxies were very young, being less than 1% the age of the Universe at the time that they were observed. “So the tiny galaxies just formed,: said Bruce, “and their star formation rates are high enough to account for the globular clusters, maybe one in each LBD, when the star bursts in them wind down after a few tens of million years.”

Debra and Bruce Elmegreen are no strangers to high redshift galaxies. Back in 2012, Bruce published a paper that suggested that the globular clusters that orbit the Milky Way (and most other galaxies) formed in dwarf galaxies during the early Universe. These dwarf galaxies would have since been acquired by larger galaxies like our own, and the clusters are essentially their remnants.

Globular clusters are essentially massive star clusters that orbit around the Milky Way Halo. They are typically around 1 million Solar masses and are made up of stars that are very old – somewhere on the order of 10 to 13 billion years. Beyond the Milky Way, many appear in common orbits and in the Andromeda Galaxy, some even appear connected by a stream of stars.

*The three groups of LBDs, where the dwarf galaxies were stacked based on their redshift. Credit: Debra & Bruce Elmegreen*

As Bruce explained, his is a compelling argument for the theory that globular clusters formed from dwarf galaxies in the early Universe:

“This suggests that the metal-poor globular clusters are the dense remnants of little galaxies that got captured by bigger galaxies, like the Milky Way, and ripped apart by tidal forces. This idea for the origin of halo globular clusters goes back several decades… It would be only the metal-poor one that are like this, which are about half the total, because dwarf galaxies are metal poor compared to big galaxies, and they were also more metal poor in the early universe.”

This study has many implications for our understanding of how the Universe evolved, which was the chief aim of the Hubble Frontier Fields program. By examining objects in the early Universe, and determining their properties, scientists are able to determine how the structures that we are familiar with today – i.e. stars, galaxies, clusters, etc. – truly came from.

These same studies also allow scientists to make educated guesses about where the Universe is going and what will become of those same structures millions or even billions of years from now. In short, knowing where we’ve been lets us predict where we are headed!

Further Reading: arXiv

December 3, 2017December 4, 2017 by Matt Williams

A New Survey Takes the Hubble Deep Field to the Next Level, Analyzing Distance and Properties of 1,600 Galaxies

Images from the Hubble Ultra Deep Field (HUDF). Credit: NASA/ESA/S. Beckwith (STScI)/HUDF Team

Since its deployment in 1990, the Hubble Space Telescope has given us some of the richest and most detailed images of our Universe. Many of these images were taken while observing a patch of sky located in the Fornax constellation between September 2003 and January 2004. This region, known as the Hubble Ultra Deep Field (HUDF), contains an estimated 10,000 galaxies, all of which existed roughly 13 billion years ago.

Looking to this region of space, multiple teams of astronomers used the MUSE instrument on the ESO’s Very Large Telescope (VLT) to discover 72 previously unseen galaxies. In a series of ten recently released studies, these teams indicate how they measured the distance and properties of 1600 very faint galaxies in the Ultra Deep Field, revealing new information about star formation and the motions of galaxies in the early Universe.

The original HUDF images, which were published in 2004, were a major milestone for astronomy and cosmology. The thousands of galaxies it observed were dated to less than just a billion years after the Big Bang, ranging from 400 to 800 million years of age. This area was subsequently observed many times using the Hubble and other telescopes, which has resulted in the deepest views of the Universe to date.

One such telescope is the European Southern Observatory‘s (ESO) Very Large Telescope, located in the Paranal Observatory in Chile. Intrinsic to the studies of the HUDF was the Multi Unit Spectroscopic Explorer (MUSE), a panoramic integral-field spectrograph operating in the visible wavelength range. It was the data accumulated by this instrument that allowed for 72 new galaxies to be discovered from this tiny area of sky.

The MUSE HUDF Survey team, which was led by Roland Bacon of the Centre de recherche astrophysique de Lyon (CRAL) and the National Center for Scientific Research (CNRS), included members from multiple European observatories, research institutes and universities. Together, they produced ten studies detailing the precise spectroscopic measurements they conducted of 1600 HUDF galaxies.

This was an unprecedented accomplishment, given that this is ten times as many galaxies that have had similar measurements performed on them in the last decade using ground-based telescopes. As Bacon indicated in an ESO press release:

“MUSE can do something that Hubble can’t — it splits up the light from every point in the image into its component colors to create a spectrum. This allows us to measure the distance, colors and other properties of all the galaxies we can see — including some that are invisible to Hubble itself.”

The galaxies detected in this survey were also 100 times fainter than any galaxies studied in previous surveys. Given their age and their very dim and distant nature, the study of these 1600 galaxies is sure to add to any already very richly-observed field. This,in turn, can only deepen our understanding of how galaxies formed and evolved during the past 13 billions years.

The 72 newly-discovered galaxies that the survey observed are known as Lyman-alpha emitters, a class of galaxy that is extremely distant and only detectable in Lyman-alpha light. This form of radiation is emitted by excited hydrogen atoms, and is thought to be the result of ongoing star formation. Our current understanding of star formation cannot fully explain these galaxies, and they were not visible in the original Hubble images.

Thanks to MUSE’s ability to disperse light into its component colors, these galaxies became more apparent. As Jarle Brinchmann – an astronomer at the University of Leiden and the University of Porto’s (CAUP) Institute of Astrophysics and Space Sciences, and the lead author of one of the papers – described the results of the survey:

“MUSE has the unique ability to extract information about some of the earliest galaxies in the Universe — even in a part of the sky that is already very well studied. We learn things about these galaxies that is only possible with spectroscopy, such as chemical content and internal motions — not galaxy by galaxy but all at once for all the galaxies!”

Another major finding of this survey was the systematic detection of luminous hydrogen halos around galaxies in the early Universe. This finding is expected to give astronomers a new and promising way to study how material flowed in and out of early galaxies, which was central to early star formation and galactic evolution. The series of studies produced by Bacon and his colleagues also indicate a range of other possibilities.

These include studying the role faint galaxies played during cosmic reionization, the period that took place between 150 million to billion years after the Big Bang. It was during this period, which followed the “dark ages” (380 thousand to 150 million years ago) that the first stars and quasars formed and sent ionizing radiation throughout the early Universe. And as Roland Bacon explained, the best may yet be to come:

“Remarkably, these data were all taken without the use of MUSE’s recent Adaptive Optics Facility upgrade. The activation of the AOF after a decade of intensive work by ESO’s astronomers and engineers promises yet more revolutionary data in the future.”

Even before Einstein proposed his groundbreaking Theory of General Relativity – which established that space and time are inextricably linked – scientists have understood that probing deeper into the cosmic field is to also probe farther back in time. The farther we are able to see, the more we are able to learn about how the Universe evolved over the course of billions of years.

Further Reading: ESO

September 24, 2017September 24, 2017 by Matt Williams

Hubble Spots Unique Object in the Main Asteroid Belt

Artist’s impression shows the binary asteroid 288P, located in the Main Asteroid Belt between the planets Mars and Jupiter. Credit: ESA/Hubble, L. Calçada.

In 1990, the NASA/ESA Hubble Space Telescope was deployed into Low Earth Orbit (LEO). As one of NASA’s Great Observatories – along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope – this instrument remains one of NASA’s larger and more versatile missions. Even after twenty-seven years of service, Hubble continues to make intriguing discoveries, both within our Solar System and beyond.

The latest discovery was made by a team of international astronomers led by the Max Planck Institute for Solar System Research. Using Hubble, they spotted a unique object in the Main Asteroid Belt – a binary asteroid known as 288P – which also behaves like a comet. According to the team’s study, this binary asteroid experiences sublimation as it nears the Sun, which causes comet-like tails to form.

The study, titled “A Binary Main-Belt Comet“, recently appeared in the scientific journal Nature. The team was led by Jessica Agarwal of the Max Planck Institute for Solar System Research, and included members from the Space Telescope Science Institute, the Lunar and Planetary Laboratory at the University of Arizona, the Johns Hopkins University Applied Physics Laboratory (JHUAPL), and the University of California at Los Angeles.

Using the Hubble telescope, the team first observed 288P in September 2016, when it was making its closest approach to Earth. The images they took revealed that this object was not a single asteroid, but two asteroids of similar size and mass that orbit each other at a distance of about 100 km. Beyond that, the team also noted some ongoing activity in the binary system that was unexpected.

As Jessica Agarwal explained in a Hubble press statement, this makes 288P the first known binary asteroid that is also classified as a main-belt comet. “We detected strong indications of the sublimation of water ice due to the increased solar heating – similar to how the tail of a comet is created,” she said. In addition to being a pleasant surprise, these findings are also highly significant when it comes to the study of the Solar System.

Since only a few objects of this type are known, 288P is an extremely important target for future asteroid studies. The various features of 288P also make it unique among the few known wide asteroid binaries in the Solar System. Basically, other binary asteroids that have been observed orbited closer together, were different in size and mass, had less eccentric orbits, and did not form comet-like tails.

The observed activity of 288P also revealed a great deal about the binary asteroids past. From their observations, the team concluded that 288P has existed as a binary system for the past 5000 years and must have accumulated ice since the earliest periods of the Solar System. As Agarwal explained:

“Surface ice cannot survive in the asteroid belt for the age of the Solar System but can be protected for billions of years by a refractory dust mantle, only a few meters thick… The most probable formation scenario of 288P is a breakup due to fast rotation. After that, the two fragments may have been moved further apart by sublimation torques.”

*Image depicting the two areas where most of the asteroids in the Solar System are found: the Main Asteroid Belt and the Trojans. Credit: ESA/Hubble, M. Kornmesser*

Naturally, there are many unresolved questions about 288P, most of which stem from its unique behavior. Given that it is so different from other binary asteroids, scientists are forced to wonder if it merely coincidental that it presents such unique properties. And given that it was found largely by chance, it is unlikely that any other binaries that have similar properties will be found anytime soon.

“We need more theoretical and observational work, as well as more objects similar to 288P, to find an answer to this question,” said Agarwal. In the meantime, this unique binary asteroid is sure to provide astronomers with many interesting opportunities to study the origin and evolution of asteroids orbiting between Mars and Jupiter.

In particular, the study of those asteroids that show comet-like activity (aka. main-belt comets) is crucial to our understanding of how the Solar System formed and evolved. According to contrasting theories of its formation, the Asteroid Belt is either populated by planetesimals that failed to become a planet, or began empty and gradually filled with planetesimals over time.

In either case, studying its current population can tell us much about how the planets formed billions of years ago, and how water was distributed throughout the Solar System afterwards. This, in turn, is crucial to determining how and where life began to emerge on Earth, and perhaps elsewhere!

Be sure to check out this animation of the 288P binary asteroid too, courtesy of the ESA and Hubble:

Further Reading: Hubble, Nature

September 15, 2017September 15, 2017 by Matt Williams

Hubble Spots Pitch Black Hot Jupiter that “Eats Light”

Illustration showing one of the darkest known exoplanets - an alien world as black as fresh asphalt - orbiting a star like our Sun. The day side of the planet, called WASP-12b, eats light rather than reflects it into space. Credit: NASA, ESA, and G. Bacon (STScI)

The study of extra-solar planets has revealed discoveries that have confounded expectations and boggled the mind! Whether it’s Super-Earths that become diamond planets, multiple rocky planets orbiting closely together, or “Hot Jupiters” with traces of gaseous metal in their atmospheres, there’s been no shortage of planets out there for which there is no comparison here in the Solar System.

In this respect, WASP-12b is in good company. This Hot-Jupiter, located in a star system 1400 light years from Earth in the direction of the Auriga constellation, was recently studied by a team of astronomers using the Hubble Space Telescope. Due to the particular nature of its atmosphere, which absorbs the vast majority of light it receives instead of reflecting it, this planet appeared pitch black when observed by the Hubble team.

The study which details their findings, “The Very Low Albedo of WASP-12b from Spectral Eclipse Observations with Hubble“, was recently published in The Astrophysical Journal. Led by Taylor Bell, a researcher at the Institute for Research on Exoplanets (IREx) at McGill University, the team consulted data from the Hubble’s Space Telescope Imaging Spectrograph (STIS) to observe WASP-12b during an optical eclipse.

*WASP-12b orbits so close to its star that it is heated to a record-breaking 2500°C. Credit: ESA/C Carreau*

Like all Hot Jupiters, WASP-12b is similar in mass to Jupiter (1.35 to 1.43 Jupiter masses) and orbits very close to its star. At a distance of just 3.4 million km (2.115 million mi), or 0.0229 AU, it takes a little over a day to complete a single orbit. Because of its proximity, one side of the planet is constantly facing towards it’s sun – i.e. it is tidally locked with its star.

Because of its orbit, temperatures on the day side of the planet are estimated to reach as high as 2811 K (2538 °C; 4600 °F). It is because of these extreme temperatures that most molecules are unable to survive on the day side of the planet, so clouds cannot form to reflect light back into space. As a result, most incoming light penetrates deep into the planet’s atmosphere, where it is absorbed by hydrogen atoms and converted into heat energy.

This was what Bell and his team noticed as they observed the planet passing behind its star (aka. an optical eclipse). Using the STIS, they monitored the system for any dips in starlight, which would indicate how much reflected light was being given off by the planet. However, their observations did not detect reflected light, which indicated that the sun-facing side was absorbing most of the light it was receiving.

As Bell explained in a NASA press statement, this was quite the unusual find: “We did not expect to find such a dark exoplanet,” he said. “Most hot Jupiters reflect about 40 percent of starlight.” However, observations conducted of the night side of the planet show that things are quite different there. On this side, temperatures are about 1366 K (1093 °C; 2000 °F) cooler, which allows water vapor and clouds to form.

*An artist’s impression of WASP 12-b being slowly consumed as a result of its ridiculously tight orbit around its star. Credit: NASA.*

Back in 2013, scientists working with the HST detected traces of water vapor in the atmosphere (and possible traces of clouds as well) while studying the day/night boundary. As Bell indicated, this new research just goes to show just how diverse this type of gas giant can be:

“This new Hubble research further demonstrates the vast diversity among the strange population of hot Jupiters. You can have planets like WASP-12b that are 4,600 degrees Fahrenheit and some that are 2,200 degrees Fahrenheit, and they’re both called hot Jupiters. Past observations of hot Jupiters indicate that the temperature difference between the day and night sides of the planet increases with hotter day sides. This previous research suggests that more heat is being pumped into the day side of the planet, but the processes, such as winds, that carry the heat to the night side of the planet don’t keep up the pace.”

Since its discovery in 2008, several telescopes have studied WASP-12b, including Hubble, NASA’s Spitzer Space Telescope, and NASA’s Chandra X-ray Observatory. Previous observations by Hubble’s Cosmic Origins Spectrograph (COS) also revealed that the planet may be losing size and mass due to super-heated material from its atmosphere slowly being accreted onto the star.

This is just the latest find in a slew that has confounded scientists expectations about exoplanets. The more we come to learn about the nature and diversity of these distant worlds, the more tantalizing they seem and the more appealing the prospect of exploring them directly someday becomes!

Further Reading: NASA, IREx, Astrophysical Journal Letters

September 12, 2017 by Matt Williams

Galaxies Swell due to Explosive Action of New Stars

Artist’s impression of a disk galaxy transforming in to an elliptical galaxy. Stars are actively formed in the massive reservoir of dust and gas at the center of the galaxy. Credit: NAOJ

In 1926, famed astronomer Edwin Hubble developed his morphological classification scheme for galaxies. This method divided galaxies into three basic groups – Elliptical, Spiral and Lenticular – based on their shapes. Since then, astronomers have devoted considerable time and effort in an attempt to determine how galaxies have evolved over the course of billions of years to become these shapes.

One of th most widely-accepted theories is that galaxies changed by merging, where smaller clouds of stars – bound by mutual gravity – came together, altering the size and shape of a galaxy over time. However, a new study by an international team of researchers has revealed that galaxies could actually assumed their modern shapes through the formation of new stars within their centers.

The study, titled “Rotating Starburst Cores in Massive Galaxies at z = 2.5“, was recently published in the Astrophysical Journal Letters. Led by Ken-ichi Tadaki – a postdoctoral researcher with the Max Planck Institute for Extraterrestrial Physics and the National Astronomical Observatory of Japan (NAOJ) – the team conducted observations of distant galaxies in order to get a better understanding of galactic metamorphosis.

Evolution diagram of a galaxy. First the galaxy is dominated by the disk component (left) but active star formation occurs in the huge dust and gas cloud at the center of the galaxy (center). Then the galaxy is dominated by the stellar bulge and becomes an elliptical (or lenticular) galaxy. Credit: NAOJ

This involved using ground-based telescopes to study 25 galaxies that were at a distance of about 11 billion light-years from Earth. At this distance, the team was seeing what these galaxies looked like 11 billion years ago, or roughly 3 billion years after the Big Bang. This early epoch coincides with a period of peak galaxy formation in the Universe, when the foundations of most galaxies were being formed. As Dr. Tadaki indicated in a NAOJ press release:

“Massive elliptical galaxies are believed to be formed from collisions of disk galaxies. But, it is uncertain whether all the elliptical galaxies have experienced galaxy collision. There may be an alternative path.”

Capturing the faint light of these distant galaxies was no easy task and the team needed three ground-based telescopes to resolve them properly. They began by using the NAOJ’s 8.2-m Subaru Telescope in Hawaii to pick out the 25 galaxies in this epoch. Then they targeted them for observations with the NASA/ESA Hubble Space Telescope (HST) and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

Whereas the HST captured light from stars to discern the shape of the galaxies (as they existed 11 billion years ago), the ALMA array observed submillimeter waves emitted by the cold clouds of dust and gas – where new stars are being formed. By combining the two, they were able to complete a detailed picture of how these galaxies looked 11 billion years ago when their shapes were still evolving.

*Observation images of a galaxy 11 billion light-years away. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Tadaki et al.*

What they found was rather telling. The HST images indicated that early galaxies were dominated by a disk component, as opposed to the central bulge feature we’ve come to associate with spiral and lenticular galaxies. Meanwhile, the ALMA images showed that there were massive reservoirs of gas and dust near the centers of these galaxies, which coincided with a very high rate of star formation.

To rule out alternate possibility that this intense star formation was being caused by mergers, the team also used data from the European Southern Observatory’s Very Large Telescope (VLT) – located at the Paranal Observatory in Chile – to confirm that there were no indications of massive galaxy collisions taking place at the time. As Dr. Tadaki explained:

“Here, we obtained firm evidence that dense galactic cores can be formed without galaxy collisions. They can also be formed by intense star formation in the heart of the galaxy.”

These findings could lead astronomers to rethink their current theories about galactic evolution and howthey came to adopt features like a central bulge and spiral arms. It could also lead to a rethink of our models regarding cosmic evolution, not to mention the history of own galaxy. Who knows? It might even cause astronomers to rethink what might happen in a few billion years, when the Milky Way is set to collide with the Andromeda Galaxy.

As always, the further we probe into the Universe, the more it reveals. With every revelation that does not fit our expectations, our hypotheses are forced to undergo revision.

Further Reading: ALMA, Astrophysical Journal Letters

August 31, 2017June 20, 2020 by Matt Williams

Hubble Spots First Indications of Water on TRAPPIST-1s Planets

This artist’s impression shows the view from the surface of one of the planets in the TRAPPIST-1 system. A powerful laser beacon using current and near-future technology could send a signal strong enough to be detected by any alien astronomers here. Credit: NASA/ESA/HST

In February of 2017, astronomers from the European Southern Observatory (ESO) announced the discovery of seven rocky planets around the nearby star of TRAPPIST-1. Not only was this the largest number of Earth-like planets discovered in a single star system to date, the news was also bolstered by the fact that three of these planets were found to orbit within the star’s habitable zone.

Since that time, multiple studies have been conducted to ascertain the likelihood that these planets are actually habitable. Thanks to an international team of scientists who used the Hubble Space Telescope to study the system’s planets, we now have the first clues as to whether or not water (a key ingredient

Continue reading “Hubble Spots First Indications of Water on TRAPPIST-1s Planets”

August 9, 2017August 11, 2017 by Ken Kremer

Sunshield Layers Installed on NASA’s James Webb Space Telescope as Mirror Cryo Cooling Testing Commences

All 5 layers of the Webb telescope sunshield installed at Northrop Grumman's clean room in Redondo Beach, California. The five sunshield membrane layers are each as thin as a human hair. Credits: Northrop Grumman Corp.

The complex multilayered sunshield that will protect the delicate optics and state of the art infrared science instruments of NASA’s James Webb Space Telescope (JWST) is now fully installed on the spacecraft bus in California, completing another major milestone on the path to launch, NASA announced.

Meanwhile a critical cryogenic cooling test of Webb’s mirrors and science instrument bus has commenced inside a giant chamber at NASA’s Johnson Space Center in Texas, marking another major milestone as the mammoth telescope comes together after years of development.

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 telescopes groundbreaking tennis court sized 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.

“The sunshield layers work together to reduce the temperatures between the hot and cold sides of the observatory by approximately 570 degrees Fahrenheit,” according to NASA. “Each successive layer of the sunshield is cooler than the one below.”

The painstaking work to integrate the five sunshield membranes was carried out in June and July by engineers and technicians working at the Northrop Grumman Corporation facility in Redondo Beach, California.

“All five sunshield membranes have been installed and will be folded over the next few weeks,” said Paul Geithner, deputy project manager – technical for the Webb telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.

Deployment tests of the folded sunshield start in August.

Webb’s four research instruments cannot function without the essential cooling provided by the sunshield deployment.

Northrop Grumman designed the Webb telescope’s optics and spacecraft bus for NASA’s Goddard Space Flight Center in Greenbelt, Maryland, which manages Webb.

Two sides of the James Webb Space Telescope (JWST). Credit: NASA

“This is a huge milestone for the Webb telescope as we prepare for launch,” said Jim Flynn, Webb sunshield manager, Northrop Grumman Aerospace Systems.

“The groundbreaking tennis court sized sunshield will shield the optics from heat and assist in providing the imaging of the formation of stars and galaxies more than 13.5 billion years ago.”

The 18-segment gold coated primary mirror of NASA’s James Webb Space Telescope is raised into vertical alignment in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on Nov. 2, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com

Webb is designed to look at the first light of the Universe and will be able to peer back in time to when the first stars and first galaxies were forming. It will also study the history of our universe and the formation of our solar system as well as other solar systems and exoplanets, some of which may be capable of supporting life on planets similar to Earth.

After successfully passing a rigorous series of vibration and acoustic environmental tests earlier this year at NASA Goddard in March, the mirror and instrument assembly was shipped to NASA Johnson in May for the cryo cooling tests.

“Those tests ensured Webb can withstand the vibration and noise created during the telescope’s launch into space. Currently, engineers are analyzing this data to prepare for a final round of vibration and acoustic testing, once Webb is joined with the spacecraft bus and sunshield next year,” says NASA.

The cryogenic cooling test will last 100 days and is being carried out inside the giant thermal vacuum known as Chamber A at the Johnson Space Center in Houston.

“A combination of liquid nitrogen and cold gaseous helium will be used to cool the telescope and science instruments to their operational temperature during high-vacuum operations,” said Mark Voyton, manager of testing effort, who works at the NASA Goddard Space Flight Center in Greenbelt, Maryland.

Next year, the tennis-court sized sunshield and spacecraft bus will be combined to make up the entire observatory.

The first layer of the Webb telescope sunshield installed at Northrop Grumman’s clean room in Redondo Beach, California. Credits: Northrop Grumman Corp.

The Webb Telescope is a joint international collaborative project between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

Assembly of the Webb telescope is currently on target and slated to launch on an ESA Ariane V booster from the Guiana Space Center in Kourou, French Guiana in October 2018.

NASA and ESA are currently evaluating a potential launch scheduling conflict with ESA’s BepiColombo mission to Mercury.

Technicians work on the James Webb Space Telescope in the massive clean room at NASA’s Goddard Space Flight Center, Greenbelt, Maryland, on Nov. 2, 2016, as the completed golden primary mirror and observatory structure stands gloriously vertical on a work stand, reflecting incoming light from the area and observation deck. Credit: Ken Kremer/kenkremer.com

Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Artist’s concept of the James Webb Space Telescope (JWST) with Sunshield at bottom. Credit: NASA/ESA

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Learn more about the upcoming SpaceX Dragon CRS-12 resupply launch to ISS on Aug. 14, ULA Atlas TDRS-M NASA comsat on Aug. 18, 2017 Solar Eclipse, NASA missions and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Aug 11-14: “SpaceX CRS-12 and CRS-11 resupply launches to the ISS, Inmarsat 5, BulgariaSat 1 and NRO Spysat, EchoStar 23, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, ULA Atlas/John Glenn Cygnus launch to ISS, SBIRS GEO 3 launch, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

July 27, 2017August 13, 2020 by Matt Williams

Hubble Sees Tiny Phobos Orbiting Mars

While photographing Mars, NASA’s Hubble Space Telescope captured a cameo appearance of the tiny moon Phobos on its trek around the Red Planet. Credit: NASA/Hubble/Goddard

Mars’ moon Phobos is a pretty fascinating customer! Compared to Mars’ other moon Deimos, Phobos (named after the Greek personification of fear) is the larger and innermost satellite of the Red Planet. Due to its rapid orbital speed, the irregularly-shaped moon orbits Mars once every 7 hours, 39 minutes, and 12 seconds. In other words, it completes over three orbits of Mar within a single Earth day.

It’s not too surprising then that during a recent observation of Mars with the Hubble space telescope, Phobos chose to photobomb the picture! It all took place in May of 2016, when while Mars was near opposition and Hubble was trained on the Red Planet to take advantage of it making its closest pass to Earth in over a decade. The well-timed sighting also led to the creation of a time-lapse video that shows the moon’s orbital path.

June 22, 2017June 23, 2017 by Matt Williams

Hubble Finds a Dead Galaxy that was Finished Making Stars Just a Few Billion Years After the Big Bang

Artist's Concept of Milky Way vs Galaxy MACS2129-1. Credit: hubblesite.org

Thanks to recent improvements in space-based and ground-based telescopes, astronomers have been able to probe deeper into the Universe than ever before. By looking billions of years back in time, we are able to test our theories about the history of galactic formation and evolution. Unfortunately, studying the very early Universe is a daunting task, and one that is beyond the capabilities of our current instruments.

But by combining the power of the Hubble Space Telescope with a technique known as gravitational lensing, a team of astronomers made the first discovery of a compact galaxy that stopped making stars just a few billion years after the Big Bang. The discovery of such a galaxy existing so early in the Universe is unprecedented and represents a major challenge to \theories of how massive galaxies form and evolve.

Their findings were reported in a study titled “A Massive, Dead Disk Galaxy in the Early Universe“, which appeared in the June 22 issue of the journal Nature. As is indicated in the study, the team relied on data from Hubble which they combined with gravitational lensing – where a massive cluster of galaxies magnifies and stretches images of more distant galaxies beyond them – to study the distant galaxy known as MACS 2129-1.

*Image of the Galaxy Cluster MACS J2129-0741, as part of CLASH. Credit: hubblesite.org*

What they found was completely unexpected. Given the age of the galaxy – dated to just three billion years after the Big Bang – they expected to see a chaotic ball of stars that were forming due to early galaxies merging. Instead, they noticed that the galaxy, which was disk-shaped (like the Milky Way), was effectively dead – meaning that star formation had already ceased within it.

This was a surprise, seeing as how astronomers did not expect to see this so early in the Universe. What’s more, it was the first time that direct evidence has been obtained that shows how at least some of the earliest “dead” galaxies in the Universe evolved from disk-shaped objects to become the giant elliptical galaxies that we regularly see in the Universe today.

As Sune Toft – a researcher from the Dark Cosmology Center at the Niels Bohr Institute and the lead author on the study – explained, this may force a rethink of how galaxies evolved in the early Universe:

“This new insight may force us to rethink the whole cosmological context of how galaxies burn out early on and evolve into local elliptical-shaped galaxies, Perhaps we have been blind to the fact that early “dead” galaxies could in fact be disks, simply because we haven’t been able to resolve them.”

In previous studies, it was assumed that distant dead galaxies were similar in structure to the local elliptical galaxies they eventually evolved into. Prior to this study, confirmation of this hypothesis was not possible since current instruments are not powerful enough to see that far into space. But by combining the power of gravitational lensing with Hubble’s high resolution, Toft and his team were able to see this dead galaxy clearly.

*Galaxy Cluster MACS J2129-0741 and Lensed Galaxy MACS2129- Credit: hubblesite.org*

Combining rotational velocity measurements from the ESO’s Very Large Telescope (VLT) with archival data from the Cluster Lensing And Supernova survey with Hubble (CLASH), they were able to determine the size of the galaxy, mass, and age as well as its (defunct) rate of star formation. Ultimately, they found that the remote galaxy is three times as massive as the Milky Way, though only half its size, and is spinning more than twice as fast.

Why this galaxy stopped forming stars is still unknown, and will require follow-up surveys using more sophisticated instruments. But in the meantime, there are some possible theories. For instance, it could be the result of an active galactic nucleus, where a supermassive black hole at the center of MACS 2129-1 inhibited star formation by heating the galaxy’s gas and expelling it from the galaxy.

Or it may be the result of cold gas being streamed into the galaxy’s center where it was rapidly heated and compressed, thereby preventing it from cooling and forming star-forming clouds. But when it comes to how these types of early, dead galaxies could have led to the elliptical galaxies we see today, Toft and his colleagues think they know the answer. As he explained, it could be through mergers:

“If these galaxies grow through merging with minor companions, and these minor companions come in large numbers and from all sorts of different angles onto the galaxy, this would eventually randomize the orbits of stars in the galaxies. You could also imagine major mergers. This would definitely also destroy the ordered motion of the stars.”

In the coming years, Toft and his team hope to take advantage of the James Webb Telescope (which will be launching in 2018) to search for more early dead galaxies, in the hopes that it can shed light on the unresolved questions this discover raises. And with the ability to probe deeper into space, astronomers anticipate that a great deal more will be revealed about the early Universe.

Further Reading: Hubblesite, Nature