Formation of Massive Star Caught in the Act with Magnetic Field Mapping

by Anashe Bandari

Catching a massive star in the early stages of formation is a rare event in astronomy, making it an exciting moment to study. A group of researchers took advantage of the discovery of one youthful star and used the Stratospheric Observatory for Infrared Astronomy (SOFIA) to reveal the magnetic processes that allow such a massive star to form.

Composite image of BYF 73 with magnetic fields overlayed.
The magnetic field orientations of BYF 73, as derived from SOFIA data, are overlain on a composite image of the region taken by the Spitzer Space Telescope and Anglo-Australian Telescope. The circled areas are locations of protostars in the region identified by ALMA and the Gemini Observatory. These studies help astronomers uncover the relationship between magnetism and gravity in star formation. Credit: NASA/Spitzer/SOFIA/ALMA/Gemini/AAT/Barnes et al.

The stellar nursery where the action is taking place, called BYF 73, is not your typical star-forming cloud. It’s relatively small, but at its central core is a young star that holds the record for the highest known rate of protostellar mass accretion, the process by which a growing star accumulates mass from its surrounding material.

Using SOFIA and another observatory – the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile – Peter Barnes, a research scientist at the Space Science Institute in Boulder, Colorado, and his team examined the magnetic fields within this cloud amid ongoing star formation. Studying the orientation of magnetic fields can shed light on their role in massive-star formation, a long-standing question. Massive stars form through a different process from their more average counterparts, relying on an ongoing exchange of material with their environment, rather than accreting mass from a surrounding disk of matter.

Birth of a “Masquerading Monster”

Previous ALMA research had shown that within the core of BYF 73 lies a “masquerading monster:” a single protostar, MIR 2, which is about 1,300 times the Sun’s mass and responsible for about half of the region’s power output. These ALMA values place MIR 2 in the very early stages of massive star formation, with an age of around 40,000 years — on human timescales, it began forming sometime after the arrival of humans to Australia.

“It’s exciting because MIR 2 seems to be so young, and massive stars evolve very quickly by astronomical standards and are very rare, making their early stages easy to miss,” said Barnes.

Data from SOFIA and ALMA both offer high resolution and sensitivity in their respective wavelength ranges, allowing Barnes and his team to map the polarization of dust grains in BYF 73. This helped the researchers determine the relationship between the cloud’s magnetic field and gas density – and what that might mean for the formation of MIR 2.

When Gravity Takes Over

The researchers found that both the strength of the magnetic field and density of the gas are on the higher end of the range typical for star-forming clouds, but the relationship between the two scales is as expected. This means what’s happening in BYF 73 isn’t necessarily something unique — it just happens to be massive, and its monstrous density compared to its small size may help astronomers uncover a threshold necessary for gravity to take over and allow stars to form.

Gravity is the sole force responsible for forming stars, but the unusually strong magnetic field in BYF 73 could be acting in opposition, preventing lower-mass stars from forming until gravity becomes strong enough to form a monster.

“The original discovery of the massive inflow of material [onto MIR 2] was very exciting, since so few examples were known for higher-mass protostars. From that point on, BYF has been the gift that keeps on giving,” Barnes said.

MIR 2 is still in the very early stages of forming a massive star, and the synergies between SOFIA and ALMA’s magnetic field studies have helped clarify the factors at play in the process.

“Without their discoveries, BYF 73, and MIR 2 within it, would still be real head-scratchers,” said Barnes.

SOFIA was a joint project of NASA and the German Space Agency at DLR. DLR provided the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley managed the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft was maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014 and concluded its final science flight on Sept. 29, 2022.

SOFIA’s Final Flight

SOFIA is on its way to a new “forever home” at the Pima Air & Space Museum in Tucson. Today, SOFIA took off for the last time from NASA’s Armstrong Flight Research Center in Palmdale, California. The pilots performed one last flyby of the area with a wing tilt to acknowledge everyone in the community who has supported and worked on SOFIA. The aircraft will land in Tucson, at the Davis-Monthan Air Force Base, where it will undergo final preparations before it is towed to the museum to eventually be on display to the public.

Composite image of SOFIA aircraft with Orion magnetic fields in the background and a swoosh depicting various mission patches. At the bottom are thumbnails of significant SOFIA science images.
With its observations, SOFIA’s traveled throughout the universe, and the aircraft traveled the world. SOFIA temporarily changed its home of operations 17 times after achieving “first light” to observe time-sensitive phenomena and parts of the sky not readily observable from its home base in Palmdale, California. SOFIA observed a wide variety of objects in our solar system, our galaxy, and beyond. Credit: NASA/SOFIA

“The SOFIA mission may have ended, but the future is bright,” said Dr. Naseem Rangwala, the SOFIA project scientist at NASA’s Ames Research Center in California’s Silicon Valley. “SOFIA has made numerous and significant contributions to astrophysics and will continue to do so as our scientific community finds new and creative ways to analyze SOFIA data in the archive.”

SOFIA is a modified Boeing 747SP jet that was operated out of Armstrong. The SOFIA mission’s operations ended on Sept. 29, 2022 , but the team of incredible and diligent pilots and mechanics continued to support SOFIA as it prepared to go to its new home.

SOFIA is part of NASA’s legacy of airborne astronomy. Building on the successes of the Galileo I aboard a Learjet and the Kuiper Airborne Observatory, SOFIA was developed to provide the astrophysical community unprecedented access to the mid- and far-infrared wavelengths of light. This part of the electromagnetic spectrum is difficult to observe from Earth’s surface, because water in the atmosphere blocks mid- and far-infrared light from reaching the ground. SOFIA, flying above 99.9% of water in the atmosphere, could make observations of a wide variety of phenomena, from to cosmic magnetic fields.

In fact, SOFIA revolutionized the study of cosmic magnetic fields in astrophysics. Other observatories, like ESA’s (European Space Agency’s) Planck space observatory, could also detect polarized light and learn how these invisible forces affect galaxies. SOFIA, however, allowed scientists to make observations on much smaller scales. With the HAWC+ instrument, SOFIA probed dark rivers of material, called filaments, where stars start to form. They investigated the “bones” in galactic arms and caught the aftermath of galactic mergers. SOFIA also studied our galaxy and closest galactic companions, the Magellanic clouds.

SOFIA observed cosmic bubbles and how groups of massive stars trigger star formation or quench it, in some cases. SOFIA also could study molecules, making the first-ever detection of helium hydride, the first type of molecule that ever formed in the universe. SOFIA also turned its gaze on things much closer to home, like Venus’s atmosphere, comets, Pluto, and the Moon.

As the aircraft heads off to the Pima Air & Space Museum, the SOFIA leadership team at NASA would like to share some thoughts:

“We want to express our gratitude to everyone, both our U.S. and German colleagues, who, over the years, developed, tested, and operated the observatory at Ames and Armstrong. It has been an incredible team effort to create and operate the world’s largest airborne observatory. None of this would have been possible without the community of scientists who have used and supported SOFIA over the years. We look forward to hearing everything the SOFIA scientific community learns as we go on. It is with heartfelt thanks that we at NASA say goodbye to SOFIA. We are sad to see you go but so happy to have worked with the SOFIA team.”

SOFIA was a joint project of NASA and the German Space Agency at DLR. DLR provided the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley managed the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft was maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014 and concluded its final science flight on Sept. 29, 2022.

No Phosphine on Venus, According to SOFIA

by Anashe Bandari

Venus is considered Earth’s twin in many ways, but, thanks to the Stratospheric Observatory for Infrared Astronomy (SOFIA), one difference now seems clearer: Unlike Earth, Venus does not have any obvious phosphine.

The planet Venus with a spectra laid over it
The spectral data from SOFIA overlain atop this image of Venus from NASA’s Mariner 10 spacecraft is what the researchers observed in their study, showing the intensity of light from Venus at different wavelengths. If a significant amount of phosphine were present in Venus’s atmosphere, there would be dips in the graph at the four locations labeled “PH3,” similar to but less pronounced than those seen on the two ends. Credit: Venus: NASA/JPL-Caltech; Spectra: Cordiner et al.

Phosphine is a gas found in Earth’s atmosphere, but the announcement of phosphine discovered above Venus’s clouds made headlines in 2020. The reason was its potential as a biomarker. In other words, phosphine could be an indicator of life. Though common in the atmospheres of gas planets like Jupiter and Saturn, phosphine on Earth is associated with biology. Here, it’s formed by decaying organic matter in bogs, swamps, and marshes.

“Phosphine is a relatively simple chemical compound — it’s just a phosphorus atom with three hydrogens — so you would think that would be fairly easy to produce. But on Venus, it’s not obvious how it could be made,” said Martin Cordiner, a researcher in astrochemistry and planetary science at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

There may be other potential ways to form phosphine on a rocky planet, like through lightning or volcanic activity, but none of these apply if there simply isn’t any phosphine on Venus. And according to SOFIA, there isn’t.

Following the 2020 study, a number of different telescopes conducted follow-up observations to confirm or refute the finding. Cordiner and his team followed suit, using SOFIA in their search.

The recently retired SOFIA was a telescope on an airplane and, over the course of three flights in November 2021, it looked for hints of phosphine in Venus’s sky. Thanks to its operation from Earth’s sky, SOFIA could perform observations not accessible from ground-based observatories. Its high spectral resolution also enabled it to be sensitive to phosphine at high altitudes in Venus’s atmosphere, about 45 to 70 miles (about 75 to 110 kilometers) above the ground — the same region as the original finding — with spatial coverage across Venus’s entire disk.

The researchers didn’t see any sign of phosphine. According to their results, if there is any phosphine present in Venus’s atmosphere at all, it’s a maximum of about 0.8 parts phosphine per billion parts everything else, much smaller than the initial estimate.

Pointing SOFIA’s telescope at Venus was a challenge in and of itself. The window during which Venus could be observed was short, about half an hour after sunset, and the aircraft needed to be in the right place at the right time. Venus also goes through phases similar to the Moon, making it difficult to center the telescope on the planet. Add in its proximity to the Sun in the sky — which the telescope must avoid — and the situation quickly became tense.

“You don’t want sunlight accidentally coming in and shining on your sensitive telescope instruments,” Cordiner said. “The Sun is the last thing you want in the sky when you’re doing these kinds of sensitive observations.”

Despite the fact the group did not find phosphine after the stressful observations, the study was a success. Along with complementary data from other observatories that vary in the depths they probe within Venus’s atmosphere, the SOFIA results help build the body of evidence against phosphine anywhere in Venus’s atmosphere, from its equator to its poles.

SOFIA was a joint project of NASA and the German Space Agency at DLR. DLR provided the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley managed the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft was maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014 and concluded its final science flight on Sept. 29, 2022.

Magnetic Fields Help Black Holes Reach Deeper Into Galaxies

by Anashe Bandari

Black holes potentially have an even larger influence on the galaxies around them than we thought. And the Stratospheric Observatory for Infrared Astronomy (SOFIA) provided a new way to look at their impact.

Active galactic nuclei (AGN) — the central region of a galaxy, which houses its supermassive black hole — are classified by how strong of a jet they produce, shooting matter away at near light speed. Since the jets are mostly visible at radio wavelengths, they are described as either radio loud or radio quiet.

Artist’s conception of Cygnus A, surrounded by the torus of dust and debris with jets launching from its center
Artist’s conception of Cygnus A, surrounded by the torus of dust and debris with jets launching from its center. Magnetic fields are illustrated trapping dust near the supermassive black hole at the galaxy’s core. This initial study motivated the larger comparison of radio loudness to polarization and was included in the composite data set. Credit: NASA/SOFIA/Lynette Cook

“We see that some AGN have very powerful radio jets and some don’t, even though all AGN are intrinsically the same — they all have a supermassive black hole in the center and accrete mass,” said Enrique Lopez-Rodriguez, a research scientist at Stanford University’s Kavli Institute for Particle Astrophysics and Cosmology and lead author on the new SOFIA finding. “We don’t understand why some of them are so powerful, and some of them are not.”

Now, using SOFIA, Lopez-Rodriguez and his team have found that the polarization of infrared light from AGN also increases with their radio loudness, providing a new way to study black hole characteristics.

Motivated by the 2018 SOFIA discovery that the infrared light from the strongest known radio-loud AGN, Cygnus A, was highly polarized, the researchers developed a follow-up observation program with SOFIA to determine whether there’s a relationship between infrared polarization and radio loudness, and if so, why. They looked at the magnetic fields of a total of nine AGN, four of them radio loud and five radio quiet.

From SOFIA observations of light polarization, astronomers can deduce the structure of the magnetic field in the region. In the AGN sample Lopez-Rodriquez and his team studied, these polarizations show that in radio-loud AGN — AGN with strong jets — there’s a donut-shaped magnetic field perpendicular to the jets, along the equator of the AGN. That only radio-loud AGN have such a strong toroidal magnetic field indicates that the field is helping to transfer energy inward, feeding the black hole with matter coming from the host galaxy. The stronger the jets, the stronger the magnetic field, and the more energy there is in the system.

The group was surprised by the strength of the result.

“We were hoping for it, but we weren’t expecting such a nice correlation,” Lopez-Rodriguez said. “There’s so much physics behind it that we don’t understand, and future hydromagnetic models are required.”

Though a lot of science behind these objects remains unexplained, the result implies that black holes are potentially affecting galaxy evolution and jet production quite a bit more than astronomers previously realized. While astronomers typically consider gravity as the only force influencing supermassive black holes, this work shows that magnetic fields can aid in bridging the interface between black holes and matter in their host galaxy. With the help of these magnetic fields, black holes can impact not only the matter immediately around them, but can also work at even larger distances within the galaxy.

SOFIA was a joint project of NASA and the German Space Agency at DLR. DLR provided the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley managed the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft was maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014 and concluded its final science flight on Sept. 29, 2022.

SOFIA Spies a New Type of Stellar Outburst

by Anashe Bandari

Astronomers using SOFIA, the Stratospheric Observatory for Infrared Astronomy, discovered something unique: a new type of stellar outburst that had never been seen before in the type of system under study. Through some scientific detective work, they were able to identify the characteristics that made this outburst different, placing it in its own brand-new category.

In what is known as a classical nova, a white dwarf – the dense remnant of a star in the final stage of its evolution – accumulates material from a nearby Sun-like companion star. The material absorbed from the companion star builds up on the surface of the white dwarf, until extreme pressures and densities cause a nuclear explosion, ejecting the material from the surface of the white dwarf. This creates a bright burst of light that lasts a few weeks to a few months, sometimes even years. Together, the pair of stars is called a cataclysmic variable.

Artist’s rendition of a cataclysmic variable in which a white dwarf (white/blue) is accreting material from its nearby Sun-like companion (yellow).
Caption: Artist’s rendition of a cataclysmic variable in which a white dwarf (white/blue) is accreting material from its nearby Sun-like companion (yellow). The material forms a disk around the white dwarf until an instability causes an explosion and a bright outburst of light, known as a nova. Credit: NASA/SOFIA/L. Proudfit

In contrast, a dwarf nova happens in the same kind of system as a classical nova, but for a different reason. This type of nova occurs when the disc around the white dwarf becomes unstable causing an outburst that is much less powerful and bright than a classical nova. These outbursts last only a few days, but happen more frequently.

The cataclysmic variable SOFIA observed – V1047 Cen, a white dwarf and its Sun-like companion – erupted as a classical nova in 2005 (Nova Centauri 2005). But 14 years later, in April 2019, the system slowly started to re-brighten.

On days 88 and 89 after V1047 Cen began to brighten again, a team of researchers led by Dr. Elias Aydi, an astronomer at Michigan State University, used the FORCAST camera aboard SOFIA to analyze the system. They initially thought the re-brightening was indicative of a dwarf nova, but, unlike dwarf novae, this one kept going for quite a while.

“The thing about dwarf novae is they usually happen relatively quickly. The majority of them tend to rise to peak quickly and then decline quickly, they don’t spend a lot of time at the peak,” Aydi said. As far as we know, the longest dwarf nova cases have been around 100 days. V1047 Cen went on for 400. “If this was a dwarf nova, it would be a record-breaking one.”

Understanding the temperature of the gas around the system is typically an important clue as to what is going on. In this case, the researchers used the SOFIA spectra to reveal the temperature, which showed heating as a result of the outburst, helping to prove it was more than a typical dwarf nova.

With features inconsistent with both classical novae and dwarf novae, the astronomers tried to come up with an alternate explanation for this unusual event.

“We were like, ‘There’s something really interesting here, and we need to try to explain it,’” Aydi said.

Supplementing the SOFIA data, the group also conducted observations using nearly a dozen other instruments, covering much of V1047 Cen’s 400-day event. Taken together, the data started to make more sense, and they realized they had come across something unique – a new type of stellar outburst that had never been seen before in this type of system. The discovery uncovers new scenarios that can take place in these types of cataclysmic variables.

“It’s definitely not a classical nova, but definitely something more than a dwarf nova. It’s something in between, and likely a combination of different processes or outbursts,” Aydi said.

Such combinations of outburst are often referred to as combination novae and have been observed to take place in systems that feature a white dwarf and a giant companion star, but there’s no evidence of a giant star in V1047 Cen — if there were, we would be able to see it. Instead of a giant star, the white dwarf in V1047 Cen has a Sun-like companion. In addition, the observed characteristics of the outburst are not exactly like those seen in combination novae. This makes the 2019 outburst of V1047 Cen quite an exotic one — the first of its kind ever to be seen in a cataclysmic variable system that has undergone a recent classical nova eruption.

Finding out what caused this outburst is key to understanding V1047 Cen, and potentially other similarly unusual outbursts that might be discovered in the future. One of the primary steps will be determining how quickly the white dwarf and its Sun-like companion are orbiting their center of mass, which will require additional observations.

SOFIA was a joint project of NASA and the German Space Agency at DLR. DLR provided the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley managed the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft was maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014 and concluded its final science flight on Sept. 29, 2022.

Twisted Magnetic Fields Can Reveal How Protobinary Systems, Tatooine Planets Form

by Anashe Bandari

Tatooine is real.

Well, sort of.

Circumbinary planets – planets that orbit around two stars, like the fictional Star Wars planet Tatooine and its two suns – exist in the universe, and are sometimes referred to as Tatooine planets. Systems in which two stars rotate around each other, called binary star systems, are incredibly common, comprising over half the stars in the Milky Way galaxy. But how does a binary system like this happen?

Researchers using the Stratospheric Observatory for Infrared Astronomy (SOFIA) saw a twisted magnetic field around a protobinary star system, a very young binary star system that is still growing. This provides a hint about how the system came to be.

As stars begin to form, they obtain most of their material from a disk of dust and gas surrounding them. A larger envelope of matter surrounds and feeds the disk. From here, binaries can emerge in one of two ways – far apart, where they grow in the envelope, or much closer to one another, where they form in the disk.

There’s a caveat, though: binaries that form in the envelope can move closer to each other over time, so even if they look near to one another now, they were not necessarily always that way.

That’s where magnetic fields come in.

In a recent study, SOFIA observations – supported by data from the Atacama Large Millimeter Array (ALMA), the Pico dos Dias Observatory, and archival data from the Herschel Space Observatory – found the magnetic field in the star-forming cloud Lynds 483 (L483) is oriented east-to-west in its outer regions, but twists 45 degrees counter-clockwise toward its center. ALMA confirmed that L483 contains two protostars and Herschel provided information about some of the region’s physical properties, while SOFIA and Pico dos Dias traced the magnetic field’s shape.

A subset of polarization vectors are overlain atop a Spitzer Space Telescope image of Lynds 483.
A subset of polarization vectors are overlain atop a Spitzer Space Telescope image of Lynds 483. The SOFIA data is shown in red, and the orange vectors were obtained by Pico dos Dias Observatory. The green vectors show data obtained by SHARC C-II Polarimeter at the Caltech Submillimeter Observatory in previous work, shown here as a comparison of scales. Near the center of the image is a small yellow dot indicating the location of the binary protostars. The combined fields show a twist as they approach the protostellar envelope, though they are parallel on larger scales. Credit: L483: NASA/JPL-Caltech/J. Tobin; Vectors: Cox et al. 2022, Chapman et al. 2013

“If we back up a little bit, we think these protostars formed far away, migrated, and twisted up their field in the process of coming toward each other,” said Erin Cox, a postdoctoral associate at Northwestern University in Evanston, Illinois, who led the study.

Because stars and their planets form around the same time, figuring out how the protobinary came together tells astronomers about the types of planets it can harbor.

“If we understand how the protobinary stars formed, we will get a better understanding of how much stuff is in the disk, which is the material that provides the planets with their masses,” Cox said. “We want to understand what our starting mass budget is for these planets.”

For example, the protobinaries’ inward migration can enhance the motion of the gas and dust around them, ejecting them out of the system. If too much material gets blown out, only Earth-like rocky planets can potentially form, rather than gas giants, like Jupiter.

Being able to see these magnetic fields helps decipher the formation of binary systems and, in turn, their associated Tatooine planets.

SOFIA is a joint project of NASA and the German Space Agency at DLR. DLR provides the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014, and the mission will conclude no later than Sept. 30, 2022. SOFIA will continue its regular operations until then.

SOFIA Finds More Water in the Moon’s Southern Hemisphere

by Anashe Bandari

In 2020, researchers using the Stratospheric Observatory for Infrared Astronomy (SOFIA) announced they had discovered water on the sunlit surface of the Moon. Now, they’ve confirmed it – and found even more.

The image shows flux data obtained by SOFIA’s FORCAST instrument overlaid on an orthographic projection of the Moon
The image shows flux data obtained by SOFIA’s FORCAST instrument overlaid on an orthographic projection of the Moon, creating a map of water abundances in the Moretus Crater region. Surface lunar features are clearly visible within the flux data. In this image, lighter colors correspond to a higher flux, and darker corresponds to a lower flux. Credit: Honniball et al. and Applied Coherent Technology Corp. The Moon reference image is constructed using the LRO-WAC albedo mosaic.

The team of researchers led by Casey Honniball, a postdoctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, found molecular water in the Moretus Crater region, located near the Moon’s Clavius Crater, where the original finding took place. This confirmation that water is indeed present outside of Permanently Shadowed Regions on the Moon’s southern hemisphere allowed the researchers to begin decoding where this water comes from. Additionally, with the new observations, the researchers were able to create a map of the water abundances in the crater, which they could not do for the Clavius Crater due to insufficient data. Because the Moretus study included a much larger number of observations, the map helped determine that the abundance of water on the Moon varies with both temperature and latitude – in particular, there is more water at the poles and at lower temperatures.

“Water on the Moon is exciting because it allows us to study the processes that occur not only on the Moon, but also on other airless bodies. It is of extreme importance as a resource for human exploration,” said Honniball. “If you can find [sufficiently] large concentrations of water on the surface of the Moon – and learn how it’s being stored and what form it’s in – you can learn how to extract it and use it for breathable oxygen or rocket fuel for a more sustainable presence.”

When looking at the Moon, it is, in general, difficult to differentiate between water and hydroxyl – a molecule composed of oxygen bound to a single hydrogen atom (OH), as opposed to water’s two hydrogen atoms (H2O). With its Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST), SOFIA can look at 6.1-micron emission features from the Moon, a wavelength of emission unique to water. And by flying above 99% of the water vapor in Earth’s atmosphere, SOFIA can see what ground-based telescopes cannot.

Because SOFIA is capable of distinguishing water from hydroxyl, the astronomers found evidence for a theory about how water came to be on the Moon in the first place, ruling out several previous hypotheses.

“The Moon is constantly being bombarded by solar wind, which is delivering hydrogen to the lunar surface,” Honniball said. “This hydrogen interacts with oxygen on the lunar surface to create hydroxyl.”

Then, when the Moon is hit by micrometeorites – which happens surprisingly often – the high temperature of the impact causes two hydroxyl molecules to combine, leaving behind a water molecule and an extra oxygen atom. A lot of this water is likely lost to space, while some is trapped within glass formed on the Moon’s surface by the impact.

More SOFIA data about lunar water is forthcoming: The group made additional observations to understand how water varies with the Moon’s latitude, composition, and temperature to corroborate the strong indications of increased water toward the poles in the current work.

NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) will arrive on the South Pole of the Moon in late 2024 to map water in different forms and other volatiles. The SOFIA observations provide an idea of how one form of water is distributed in sunlit regions, helping to place VIPER’s future measurements into a broader context.

SOFIA is a joint project of NASA and the German Space Agency at DLR. DLR provides the telescope, scheduled aircraft maintenance, and other support for the mission. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. SOFIA achieved full operational capability in 2014, and the mission will conclude no later than Sept. 30, 2022. SOFIA will continue its regular operations until then.

SOFIA Returns from New Zealand Deployment

The Stratospheric Observatory for Infrared Astronomy (SOFIA) has returned to its usual base of operations after a month of science observations in the Southern Hemisphere. The observatory was temporarily based out of Christchurch International Airport in New Zealand.

SOFIA is seen in front of Building 703 with crew going down the stairs
The Stratospheric Observatory for Infrared Astronomy (SOFIA) returns to NASA’s Armstrong Flight Research Center Building 703 on Aug. 11 after a productive month of science flights out of Christchurch International Airport in New Zealand. Credit: NASA/Joshua Fisher

SOFIA arrived Thursday, Aug. 11 at NASA Armstrong Flight Research Center’s Building 703 in Palmdale, California, and plans to resume science flights Monday, Aug. 22.

SOFIA had been scheduled to remain longer in New Zealand before severe weather caused damage to the aircraft, requiring the mission to adjust its science observation plans and cancel the remainder of the deployment. During its time in the Southern Hemisphere, SOFIA observed and studied a wide range of celestial objects and phenomena, like cosmic magnetic fields, the structure of the Milky Way, and the origin of cosmic rays.

An inspection and assessment of the aircraft determined SOFIA may safely return to science flights for the remainder of the mission, following minor repairs and a safety checkout flight conducted in New Zealand. The mission will conclude no later than Sept. 30.

SOFIA Adjusts Science Planning Following Damage to Aircraft

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is adjusting its science observation plans and canceling the remainder of its Southern Hemisphere deployment following damage to the aircraft caused by severe weather on Monday, July 18. SOFIA is currently operating out of Christchurch International Airport in New Zealand to better observe celestial objects in the southern skies.

SOFIA at Christchurch Airport, NZ at night
SOFIA at Christchurch International Airport, New Zealand. Credit: NASA/SOFIA/G. Perryman

The SOFIA team has determined the needed repairs will take at least three weeks, eliminating the possibility of conducting the remaining science observation flights that were planned from New Zealand through August 7.

SOFIA arrived in New Zealand on June 18 and had a successful and productive month of science flights. Using two instruments, HAWC+ and GREAT, SOFIA observed and studied a wide range of celestial objects and phenomena, like cosmic magnetic fields, structure of the Milky Way, and the origin of cosmic rays.

During the deployment, the SOFIA team also took part in multiple outreach events, sharing information about the observatory and its science with students in grades K-12, youth groups, museum attendees, and members of the aerospace industry.

The aircraft will return to its usual base of operations in Palmdale, California, and resume science flights after repairs are complete.

SOFIA Down for Maintenance in Christchurch

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is down for maintenance after being damaged by a storm that affected the area around Christchurch International Airport in New Zealand on Monday, July 18.

During the severe weather event, high winds caused the stairs outside the aircraft to shift, causing light damage to the front of the aircraft, as well as the stairs themselves. There were no injuries to any staff. The aircraft damage is being assessed, repair plans are moving forward, and new stairs are being delivered. During this time, the mission’s science observation schedule will be reassessed, as SOFIA is unable to continue normal operations until the repairs are complete and stairs are available.

SOFIA currently is operating out of Christchurch International Airport to better observe celestial objects in the Southern Hemisphere. Updates to the status of SOFIA will be shared once available.