US Postal Service Celebrates NASA’s Webb Telescope With New Postal Stamp

The U.S. Postal Service will issue a stamp celebrating NASA’s new James Webb Space Telescope, the largest, most powerful, and most complex science telescope ever put in space. The stamp, which features an illustration of the observatory, will be dedicated in a ceremony Thursday, Sept. 8, at the Smithsonian’s National Postal Museum in Washington.

“When anyone who uses these stamps looks at this telescope, I want them to see what I see: its incredible potential to reveal new and unexpected discoveries that help us understand the origins of the universe, and our place in it,” said NASA Associate Administrator Bob Cabana. “This telescope is the largest international space science program in U.S. history, and I can’t wait to see the scientific breakthroughs it will enable in astronomy.”

Webb, a mission led by NASA in partnership with ESA (European Space Agency) and CSA (Canadian Space Agency), launched Dec. 25, 2021, from Europe’s Spaceport in French Guiana. Over the following months, Webb traveled to its destination nearly one million miles (1.5 million kilometers) away from Earth, underwent weeks of complex deployments to unfold into its final configuration, and prepared its mirrors and science instruments to capture never-before-seen views of the universe.

The U.S. Postal Service will issue a stamp highlighting NASA’s James Webb Space Telescope on Sept. 8, 2022. U.S. Postal Service Art Director Derry Noyes designed the stamp using existing art by James Vaughan and an image provided by NASA and the Space Telescope Science Institute.
Credits: U.S. Postal Service

NASA released Webb’s first full-color images and spectra July 12 – providing a first look at the observatory’s powerful capabilities. The U.S. Postal Service stamp honors these achievements as Webb continues its mission to explore the unknown in our universe and study every phase in cosmic history.

“I am excited to add this beautiful stamp to our collection, as we watch from the ground as humanity’s newest and most capable telescope unlocks the greatest secrets of our cosmos that have been waiting to be revealed since the beginning of time,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “The Webb Telescope represents the start to a new era of what we can accomplish for the benefit of all.”

The stamp features an artist’s digital illustration of Webb against a background of stars. The selvage around each set of stamps showcases a sharp image of a star, captured while setting up the telescope in space to confirm precise alignment of Webb’s 18 hexagonal mirror segments.

The U.S. Postal Service’s first day of issue event is free and open to the public on Thursday, Sept. 8, at 11 a.m. EDT at the National Postal Museum. NASA Associate Administrator Bob Cabana; Lee Feinberg, Webb optical telescope element manager at NASA’s Goddard Space Flight Center; and Erin Smith, Webb deputy observatory project scientist at NASA Goddard will be among the speakers providing remarks.

NASA/Photo: Nasa.gov

To follow along with NASA’s Webb Telescope as it begins its mission to unfold the infrared universe, visit:

https://www.nasa.gov/webb

The James Webb Space Telescope is the world’s premier infrared 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 CSA (Canadian Space Agency).

30 Doradus: Thousands of stunning young stars in “cosmic tarantula”captured by James Webb telescope

Thousands of never-before-seen young stars spotted in a stellar nursery called 30 Doradus, captured by NASA’s James Webb Space Telescope, called Tarantula Nebula owing to its appearance in dusty filaments.

The nebula has long been a favorite for astronomers studying star formation and the  Webb has been revealing beautiful distant background galaxies, as well as the detailed structure and composition of the nebula’s gas and dust ever since it’s started capturing the deep space.

At only 161,000 light-years away in the Large Magellanic Cloud galaxy, the Tarantula Nebula is the largest and brightest star-forming region in the Local Group, the galaxies nearest our Milky Way. It is home to the hottest, most massive stars known. Astronomers focused three of Webb’s high-resolution infrared instruments on the Tarantula. Under the lens of Webb’s Near-Infrared Camera (NIRCam), the region resembles a burrowing tarantula’s home, lined with its silk.

The nebula’s cavity centered in the image above has been hollowed out by blistering radiation from a cluster of massive young stars, which sparkle pale blue in the image. Only the densest surrounding areas of the nebula resist erosion by these stars’ powerful stellar winds, forming pillars that appear to point back toward the cluster. These pillars contain forming protostars, which will eventually emerge from their dusty cocoons and take their turn shaping the nebula.

Caption: Nestled in the center of the Tarantula Nebula in the Large Magellanic Cloud is the largest star yet discovered, astronomers have produced the sharpest image ever of this star.  Photo:Observatory/NOIRLab/NSF/AURA Acknowledgment

Webb’s Near-Infrared Spectrograph (NIRSpec) caught one very young star doing precisely emerging out of the dust. Astronomers previously thought this star might be a bit older and already in the process of clearing out a bubble around itself. However, NIRSpec showed that the star was only just beginning to emerge from its pillar and still maintained an insulating cloud of dust around itself. Without Webb’s high-resolution spectra at infrared wavelengths, this episode of star formation-in-action could not have been revealed.

The region takes on a different appearance when viewed in the longer infrared wavelengths detected by Webb’s Mid-infrared Instrument (MIRI). The hot stars fade, and the cooler gas and dust glow. Within the stellar nursery clouds, points of light indicate embedded protostars, still gaining mass.

While shorter wavelengths of light are absorbed or scattered by dust grains in the nebula, and therefore never reach Webb to be detected, longer mid-infrared wavelengths penetrate that dust, ultimately revealing a previously unseen cosmic environment.

Caption: NASA’s James Webb Space Telescope

One of the reasons the Tarantula Nebula is interesting to astronomers is that the nebula has a similar type of chemical composition as the gigantic star-forming regions observed at the universe’s “cosmic noon,” when the cosmos was only a few billion years old and star formation was at its peak. Star-forming regions in our Milky Way galaxy are not producing stars at the same furious rate as the Tarantula Nebula, and have a different chemical composition.

Caption: In this mosaic image displays the Tarantula Nebula star, including tens of thousands of never-before-seen young stars that were previously shrouded in cosmic dust. The most active region appears to sparkle with massive young stars, appearing pale blue./Photo:NASA

This makes the Tarantula the closest (i.e., easiest to see in detail) example of what was happening in the universe as it reached its brilliant high noon. Webb will provide astronomers the opportunity to compare and contrast observations of star formation in the Tarantula Nebula with the telescope’s deep observations of distant galaxies from the actual era of cosmic noon.

 

 

 

 

 

 

First underground radar images from Mars Perseverance rover reveal some surprises

Key takeaways:

  • Roving the Red Planet. Perseverance landed on Mars in February 2021 and has been gathering data on the planet’s geology and climate and searching for signs of ancient life.​​​​​​
  • What lies beneath. The rover’s subsurface radar experiment, co-led by UCLA’s David Paige, has returned images showing unexpected variations in rock layers beneath the Jezero crater.
  • Probing the past. The variations could indicate past lava flows or possibly a river delta even older than the one currently being explored on the crater floor.

After a tantalizing year-and-a-half wait since NASA’s Mars Perseverance rover touched down on our nearest planetary neighbor, new data is arriving — and bringing with it a few surprises.

The rover, which is about the size of car and carries seven scientific instruments, has been probing Mars’ 30-mile-wide Jezero crater, once the site of a lake and an ideal spot to search for evidence of ancient life and information about the planet’s geological and climatic past.

Rendering of Perseverance, whose RIMFAX technology is exploring what lies beneath the Martian surface. Photo: NASA/JPL/Caltech/FFI

In a paper published today in the journal Science Advances, a research team led by UCLA and the University of Oslo reveals that rock layers beneath the crater’s floor, observed by the rover’s ground-penetrating radar instrument, are unexpectedly inclined. The slopes, thicknesses and shapes of the inclined sections suggest they were either formed by slowly cooling lava or deposited as sediments in the former lake.

Perseverance is currently exploring a delta on the western edge of the crater, where a river once fed the lake, leaving behind a large deposit of dirt and rocks it picked up along its course. As the rover gathers more data, the researchers hope to clear up the complex history of this part of the Red Planet.

“We were quite surprised to find rocks stacked up at an inclined angle,” said David Paige, a UCLA professor of Earth, planetary and space sciences and one of the lead researchers on the Radar Imager for Mars Subsurface Experiment, or RIMFAX. “We were expecting to see horizontal rocks on the crater floor. The fact that they are tilted like this requires a more complex geologic history. They could have been formed when molten rock rose up towards the surface, or, alternatively, they could represent an older delta deposit buried in the crater floor.”

Paige said that most of the evidence gathered by the rover so far points to an igneous, or molten, origin, but based on the RIMFAX data, he and the team can’t yet say for certain how the inclined layers formed. RIMFAX obtains a picture of underground features by sending bursts of radar waves below the surface, which are reflected by rock layers and other obstacles. The shapes, densities, thicknesses, angles and compositions of underground objects affect how the radar waves bounce back, creating a visual image of what lies beneath.

During Perseverance’s initial 3-kilometer traverse, the instrument has obtained a continuous radar image that reveals the electromagnetic properties and bedrock stratigraphy — the arrangement of rock layers — of Jezero’s floor to depths of 15 meters, or about 49 feet. The image reveals the presence of ubiquitous layered rock strata, including those that are inclined at up to 15 degrees. Compounding the mystery, within those inclined areas are some perplexing highly reflective rock layers that in fact tilt in multiple directions.

“RIMFAX is giving us a view of Mars stratigraphy similar to what you can see on Earth in highway road cuts, where tall stacks of rock layers are sometimes visible in a mountainside as you drive by,” Paige explained. “Before Perseverance landed, there were many hypotheses about the exact nature and origin of the crater floor materials. We’ve now been able to narrow down the range of possibilities, but the data we’ve acquired so far suggest that the history of the crater floor may be quite a bit more complicated than we had anticipated.”

The data collected by RIMFAX will provide valuable context to rock samples Perseverance is collecting, which will eventually be brought back to Earth.

“RIMFAX is giving us the backstory of the samples we’re going to analyze. It’s exciting that the rover’s instruments are producing data and we’re starting to learn, but there’s a lot more to come,” Paige said. “We landed on the crater floor, but now we’re driving up on the actual delta, which is the main target of the mission. This is just the beginning of what we’ll hopefully soon know about Mars.”

The paper, “Ground penetrating radar observations of subsurface structures in the floor of Jezero crater, Mars,” is one of three simultaneously published papers discussing some of the first data from Perseverance.

Explore the Solar System With NASA’s New, Improved 3D ‘Eyes’

The agency’s newly upgraded “Eyes on the Solar System” visualization tool includes Artemis I’s trajectory along with a host of other new features.

NASA has revamped its “Eyes on the Solar System” 3D visualization tool, making interplanetary travel easier and more interactive than ever. More than two years in the making, the update delivers better controls, improved navigation, and a host of new opportunities to learn about our incredible corner of the cosmos – no spacesuit required. All you need is a device with an internet connection.

 Trace the course Artemis I will take to lunar orbit, or touch down with Perseverance during its harrowing entry, descent, and landing on the Red Planet. Learn the basics about dwarf planets or the finer points of gas giants, and ride alongside no fewer than 126 space missions past and present. You can even follow the paths of spacecraft and celestial bodies as far back as 1949 and as far into the future as 2049.

While you’re at it, you can rotate objects, compare them side by side, and even modulate the perspective as well as the lighting. The visuals are striking. This latest version of “Eyes” also lets you scroll through rich interactive journeys, including Voyager’s Grand Tour of Jupiter, Saturn, Uranus, and Neptune.

“The beauty of the new browser-based ‘Eyes on the Solar System’ is that it really invites exploration. You just need an internet connection, a device that has a web browser, and some curiosity,” said Jason Craig, the producer of the “Eyes” software at NASA’s Jet Propulsion Laboratory.

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.

NASA Prepares Webb Telescope /NASA

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.”

NASA hopes to Launch Artemis I Moon Mission on Sept 3

NASA will target Saturday, Sept. 3 at 2:17 p.m. EDT, the beginning of a two-hour window, for the launch of Artemis I, the first integrated test of NASA’s Orion spacecraft, Space Launch System (SLS) rocket, and the ground systems at the agency’s Kennedy Space Center in Florida.

Mission managers met Tuesday to discuss data and develop a forward plan to address issues that arose during an Aug. 29 launch attempt for the flight test. During that launch attempt, teams were not able to chill down the four RS-25 engines to approximately minus 420 degrees F, with engine 3 showing higher temperatures than the other engines. Teams also saw a hydrogen leak on a component of the tail service mast umbilical quick disconnect, called the purge can, and managed the leak by manually adjusting propellant flow rates.

Artemis I launch on Aug 27, 2022 / NASA

In the coming days, teams will modify and practice propellant loading procedures to follow a procedure similar to what was successfully performed during the Green Run at NASA’s Stennis Space Center in Mississippi. The updated procedures would perform the chilldown test of the engines, also called the kick start bleed test, about 30 to 45 minutes earlier in the countdown during the liquid hydrogen fast fill liquid phase for the core stage.

Teams also are configuring platforms at Launch Pad 39B to enable engineers access to the purge can on the tail service mast umbilical. Once access is established, technicians will perform assessments and torque connection points where necessary.

Meteorologists with the U.S. Space Force Space Launch Delta 45 predict favorable weather conditions for Saturday. While rain showers are expected, they are predicted to be sporadic during the launch window.

The mission management team will reconvene Thursday to review data and overall readiness.

Sharpest image ever of universe’s most massive known star

By harnessing the capabilities of the 8.1-meter Gemini South telescope in Chile, which is part of the International Gemini Observatory operated by NSF’s NOIRLab, astronomers have obtained the sharpest image ever of the star R136a1, the most massive known star in the Universe. Their research, led by NOIRLab astronomer Venu M. Kalari, challenges our understanding of the most massive stars and suggests that they may not be as massive as previously thought.

Astronomers have yet to fully understand how the most massive stars — those more than 100 times the mass of the Sun — are formed. One particularly challenging piece of this puzzle is obtaining observations of these giants, which typically dwell in the densely populated hearts of dust-shrouded star clusters. Giant stars also live fast and die young, burning through their fuel reserves in only a few million years. In comparison, our Sun is less than halfway through its 10 billion year lifespan. The combination of densely packed stars, relatively short lifetimes, and vast astronomical distances makes distinguishing individual massive stars in clusters a daunting technical challenge.

By pushing the capabilities of the Zorro instrument on the Gemini South telescope of the International Gemini Observatory, operated by NSF’s NOIRLab, astronomers have obtained the sharpest-ever image of R136a1 — the most massive known star. This colossal star is a member of the R136 star cluster, which lies about 160,000 light-years from Earth in the center of the Tarantula Nebula in the Large Magellanic Cloud, a dwarf companion galaxy of the Milky Way.

Previous observations suggested that R136a1 had a mass somewhere between 250 to 320 times the mass of the Sun. The new Zorro observations, however, indicate that this giant star may be only 170 to 230 times the mass of the Sun. Even with this lower estimate, R136a1 still qualifies as the most massive known star.

Astronomers are able to estimate a star’s mass by comparing its observed brightness and temperature with theoretical predictions. The sharper Zorro image allowed NSF’s NOIRLab astronomer Venu M. Kalari and his colleagues to more accurately separated the brightness of R136a1 from its nearby stellar companions, which led to a lower estimate of its brightness and therefore its mass.

Our results show us that the most massive star we currently know is not as massive as we had previously thought,” explained Kalari, lead author of the paper announcing this result. “This suggests that the upper limit on stellar masses may also be smaller than previously thought.

This result also has implications for the origin of elements heavier than helium in the Universe. These elements are created during the cataclysmicly explosive death of stars more than 150 times the mass of the Sun in events that astronomers refer to as pair-instability supernovae. If R136a1 is less massive than previously thought, the same could be true of other massive stars and consequently pair instability supernovae may be rarer than expected.

The star cluster hosting R136a1 has previously been observed by astronomers using the NASA/ESA Hubble Space Telescope and a variety of ground-based telescopes, but none of these telescopes could obtain images sharp enough to pick out all the individual stellar members of the nearby cluster.

Gemini South’s Zorro instrument was able to surpass the resolution of previous observations by using a technique known as speckle imaging, which enables ground-based telescopes to overcome much of the blurring effect of Earth’s atmosphere [1]. By taking many thousands of short-exposure images of a bright object and carefully processing the data, it is possible to cancel out almost all this blurring [2]. This approach, as well as the use of adaptive optics, can dramatically increase the resolution of ground-based telescopes, as shown by the team’s sharp new Zorro observations of R136a1 [3].

This result shows that given the right conditions an 8.1-meter telescope pushed to its limits can rival not only the Hubble Space Telescope when it comes to angular resolution, but also the James Webb Space Telescope,” commented Ricardo Salinas, a co-author of this paper and the instrument scientist for Zorro. “This observation pushes the boundary of what is considered possible using speckle imaging.

We began this work as an exploratory observation to see how well Zorro could observe this type of object,” concluded Kalari. “While we urge caution when interpreting our results, our observations indicate that the most massive stars may not be as massive as once thought.

Zorro and its twin instrument `Alopeke are identical imagers mounted on the Gemini South and Gemini North telescopes, respectively. Their names are the Hawaiian and Spanish words for “fox” and represent the telescopes’ respective locations on Maunakea in Hawai‘i and on Cerro Pachón in Chile. These instruments are part of the Gemini Observatory’s Visiting Instrument Program, which enables new science by accommodating innovative instruments and enabling exciting research. Steve B. Howell, current chair of the Gemini Observatory Board and senior research scientist at the NASA Ames Research Center in Mountain View, California, is the principal investigator on both instruments.

Gemini South continues to enhance our understanding of the Universe, transforming astronomy as we know it. This discovery is yet another example of the scientific feats we can accomplish when we combine international collaboration, world-class infrastructure, and a stellar team,” said NSF Gemini Program Officer Martin Still.

Sunday May 6: Solar Storm to cause Mobile, TV, Tech Blackout on Earth?

US space agency NASA has informed that a solar storm brewing on Sun is flaring up splitting huge sun storms which may reach earth on Sunday, May 6. It said a coronal hole or sun spot has opened up releasing huge swarm of cosmic rays which may take 8 minutes to reach earth.

The space weather watching unit of National Oceanic and Atmospheric Administration (NOAA) said the solar tsunami can create an aurora or polar lights when it hits earth. Astronomers have estimated that three such solar storms are likely to reach earth on May 6, to be precise, the Indian Ocean and India is very much within the target area.

The storm classified as G-1 or ‘minor’ is the biggest since 2004 and it could trigger sparks and melt soil on Moon, while its impact on Earth is still not comprehended by astronomers but similar storms had apparently given birth to origin of life on earth.

A section of scientists warned that the solar storms on Sunday could be severe enough to disrupt communications, satellite-based GPS, flaring up magnetic field around electricity power stations or transmitters. A partial tech blackout is likely to disrupt the Internet-based communications, they added.

Effects on Earth?

Since the severity has been classified as low by NOAA, it may cause voltage fluctuations in electricity supply or even cause power failures for now. However, the US Space Weather Prediction Center (SWPC) has issued a storm alert on Sunday and Monday stating that the solar storm could cause a “high stream of activity” that is characteristic to any G1-class storm. The gigantic coronal hole in the sun’s surface was captured today by NASA’s Solar Dynamics Observatory (SDO), said SWPC.

G1 (Minor) geomagnetic storm watches have been issued for 06 and 07 May 2018 due to the anticipated effects of a negative polarity coronal hole high speed stream… Aurora may be visible at high latitudes, that is, northern tier of the US such as northern Michigan and Maine,” said SWPC in a statement.

Meanwhile, conspiracy theorists woke up to the situation to claim that these disruptions are due to the effect of an approaching Nibiru planet which is lurking in the vicinity of our solar system. David Meade, its proponent, has repeated that the next seven years will witness tribulation with many more calamities. NASA has denied these claims as Internet Hoax, though.

50-Year-Cycle?

 

Researchers have long announced that a storm is likely to come and the most intense solar flare may reach earth in maximum fifty years. It is not sure whether the Sunday storm was the one or not.

Mausumi Dikpati of the National Center for Atmospheric Research (NCAR), who’s been working on these storms for decades, predicted that the next solar storm will be a stronger one. “The next sunspot cycle will be 30% to 50% stronger than the previous one,” she said a few years ago. It can produce a burst of solar activity second only to the historic Solar Max of 1958.

Earlier, such intense solar storms had been observed in 1805 and 1958 but with no mobiles and magnetic power lines, the disruption was not detectable as clearly as it would today when auroras and cell technology will showcase the real impact.

According to solar physicist David Hathaway of the National Space Science and Technology Center (NSSTC), a typical sunspot exists for just a few weeks. When it decays, it leaves behind a ‘corpse’ of weak magnetic fields.

Whether the big Doomsday is Sunday or not will be known sooner. For now, a storm is coming and how big will it be remains a major question.

‘Seeing’ the other side of our galaxy

Astronomers have successfully traced a spiral arm on the far side of our Galaxy, an accomplishment that provides new insights into the structure of the Milky Way. Efforts to observe the far side of our Galaxy have been hampered by the vast distance and interstellar dust that blocks optical light from those regions. Here, Alberto Sanna and colleagues used radio interferometry with the Very Long Baseline Array to trace the motions of methanol and water molecules associated with a high-mass star-forming region on the far side of the Milky Way. Using the data, they were able to locate the Scutum-Centaurus spiral arm as it passes around the far side of the Galaxy and trace the arm through almost a complete rotation. The authors note that their data suggest that the pitch angle of the spiral arm (a measure of how tight the spiral is) may vary along its length. Their observations provide a record-breaking use of parallax, the apparent motion of distant objects as the Earth orbits the Sun, to measure the distance of stars. They also verify a new method of inferring distances on the far side of our Galaxy.