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.

Orion’s Veil Comes Out of Its Shell

by Anashe Bandari

Orion’s Veil might be breaking.

Within the Orion Nebula is a massive set of stars known as the Trapezium stars. The winds from the Trapezium stars blow a bubble of dust and gas in the area in front of them, called Orion’s Veil. The majority of Orion’s Veil is sparse, with most of its gas lying in the bubble’s wall. The wall, or Orion’s Veil shell, is about a light-year thick and expanding toward us – and recent observations by the Stratospheric Observatory for Infrared Astronomy (SOFIA) German REceiver for Astronomy at Terahertz Frequencies (GREAT) have identified some unexpected features in it.

A 3D model of the Orion Nebula shows Orion’s Veil shell as a bluish gas surrounding the nebula depicted in red and yellow
A 3D model of the Orion Nebula shows Orion’s Veil shell as a bluish gas surrounding the nebula depicted in red and yellow. Researchers using SOFIA found a protrusion in the shell, which could allow gas and dust to escape beyond the shell. Credit: NASA, ESA, Frank Summers (STScI), Greg T. Bacon (STScI), Lisa Frattare (STScI), Zolt G. Levay (STScI), K. Litaker (STScI). Acknowledgment: Axel Mellinger, Robert Gendler, Rogelio B. Andreo

“The bubble – with a diameter of approximately seven light-years – should be an almost sphere-like structure, but we found a protrusion in its northwestern part,” said Ümit Kavak, a postdoctoral researcher at SOFIA based out of NASA’s Ames Research Center in California’s Silicon Valley, who is the lead author on a recent paper describing the studies.

The SOFIA observations show ionized carbon emission in this protrusion, which Kavak used to determine its size, structure, and how it is expanding, in hopes of uncovering its origins and future.

Shaped like a “U” lying on its side, the protrusion extends well beyond Orion’s Veil shell. It is a likely spot for the shell to pierce, and the protrusion’s chimney-like top seems to imply it already has.

Infrared image of Orion Nebula with curved and dashed lines over it showing outflows, rims, lobes, shells, and protrusion along with location of Trapezium stars.
Schematic picture of the protrusion (green lines, center right) and outflows of ionized carbon extending beyond the protrusion — where the shell has likely been pierced — overlaid on a Wide-field Infrared Survey Explorer image of the region. Credit: NASA/JPL-Caltech/WISE Team; Kavak et al.

“When you breach the Veil shell, you effectively start stirring a cosmic soup of gas and dust by adding turbulence,” Kavak said.

“This isn’t the most appetizing soup, but it’s one of the ways to form new stars or limit future star formation,” added Alexander Tielens, a researcher at Leiden University and another author on the paper.

This turbulence affects the density, temperature, and chemistry of its surrounding region, which may ultimately lead to the creation or destruction of star formation sites.

The group also identified a second, weaker protrusion, which they plan to investigate further in a future publication. Together, these protrusions affect the entire morphology of the Orion Nebula.

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, including science flights and a deployment to New Zealand this summer.

Returning to New Zealand: SOFIA Travels to Christchurch for a Seventh and Final Time

By Maggie McAdam

After a two-year hiatus, SOFIA has returned to Christchurch, New Zealand, for a long deployment. About once a year, SOFIA temporarily moves its operating home to better observe celestial objects in the Southern Hemisphere.

SOFIA at Christchurch International Airport
SOFIA taxiing on the ramp at Christchurch International Airport in 2017. Image Credit: NASA/SOFIA/Waynne Williams

There is always a high demand from the SOFIA scientific community to observe the southern skies, and SOFIA has been working to meet those needs. This year, we already deployed once to Santiago, Chile, for a quick, two-week deployment to observe the Large Magellanic Cloud. Now SOFIA is heading back to New Zealand for the seventh and final time.

“We are thrilled to be returning to Christchurch to continue to study and discover the infrared universe,” said Naseem Rangwala, the SOFIA project scientist.

SOFIA has made 12 deployments over its operational lifetime, generally leaving Palmdale, California, to observe celestial objects and phenomena not visible from its home skies. We observed occultations in Florida and New Zealand, as well as atomic oxygen in Earth’s atmosphere, stellar feedback, and magnetic fields from German soil.

Christchurch is often SOFIA’s home-away-from-home when deploying overseas. This time, SOFIA plans to conduct 32 flights to observe a wide range of celestial objects and phenomena, like cosmic magnetic fields, stellar feedback, and cosmic rays, using two instruments, HAWC+ and GREAT.

Probing the Magnetic Universe

Milky Way galactic center, looking like a band of red clouds against a starry background.
While in New Zealand, SOFIA will observe magnetic fields in our galaxy, the Milky Way, pictured here from a previous study with another SOFIA instrument. Image credit: NASA/SOFIA/JPL-Caltech/ESA/Herschel.

Sticking relatively close to our cosmic home, SOFIA will start by investigating our galaxy, the Milky Way. A team of researchers is mapping the magnetic fields within the Milky Way’s central regions. These data will complement a previous Legacy Program that made mid-infrared images of the Milky Way. This work is similar to other cosmic magnetic field studies that map the shape and strength of this invisible force in other galaxies. SOFIA can detect cosmic magnetic fields on many scales, including star formation scales, especially along filaments.

SOFIA will also be looking at magnetic fields in filaments of material in our galaxy. These filaments are thread-like structures full of cold gas and dust. Most stars form in these dark rivers of material. A team of scientists will be investigating how magnetic fields play a role in star formation in filaments.

Stars Blowing Bubbles and a Barometer for Cosmic Rays

Deployment crew and staff stand in front of the SOFIA aircraft, all wearing neon yellow high-vis vests and jackets.
SOFIA in Christchurch, New Zealand, during its 2019 deployment with the staff and crew of the observatory. Image credit: NASA/Waynne Williams.

After HAWC+ finishes up probing the magnetic universe, SOFIA’s operations team will swap the instrument for the German PI-led GREAT instrument. GREAT does a wide variety of studies including looking at stellar feedback – how some stars can affect the regions around them. Young massive stars create huge winds that blow out into the surrounding dusty material, sometimes blowing celestial bubbles. As they do this, the stellar winds plow into the material and sometimes can trigger or quench star formation. Scientists want to understand when and why star formation is turned on or off.

GREAT, like the radio in your car, can be tuned to be sensitive to specific signals. During the New Zealand deployment, it will be set to register hydride molecules. These molecules were some of the first types that formed in our universe, and, even now, they are sometimes created in other environments. When scientists detect hydrides, they can use them as sensitive barometers for the presence of cosmic rays, high energy particles that travel close to the speed of light.

Hydride molecules form in very specific circumstances, and, usually, scientists can determine their production rate. At the same time, these molecules are quite delicate and can easily be destroyed by passing cosmic rays. Understanding the balance between their production and destruction can provide clues to the abundance of cosmic rays.

Scientists have measured the cosmic rays produced by our Sun and understand them very well, but do not fully understand cosmic rays that originate from outside our solar system. Using hydride molecules, researchers will investigate how abundant cosmic rays are in environments outside our solar system.

A Strong Finish

Arc-shaped patch with gold border and SOFIA text in gold with the telescope mirror in place of the O. The patch reads "New Zealand 2022, NASA, DLR, USRA, DSI" and shows SOFIA flying over New Zealand with the Milky Way and the fours stars of the Southern Cross constellation in the background sky.
2022 Deployment patch graphic. Image credit: NASA/SOFIA/Cheryse Triano.

Many of the key celestial objects for astronomers, like the center of the Milky Way, are either visible only from the Southern Hemisphere or more easily observed from these latitudes. Three years after SOFIA achieved first light in 2010, the observatory made its first trip to New Zealand. Now, nine years later and with six previous trips to Christchurch, this will be SOFIA’s last international deployment.

NASA and DLR recently announced the conclusion of the SOFIA mission. SOFIA will operate for the rest of fiscal year 2022, before entering an orderly shutdown process on October 1, 2022.

“We are committed to delivering a strong finish for this unique astrophysics mission, from a place of strength and pride, by giving our scientific community as much data as possible from the Southern Hemisphere,” Dr. Rangwala said. Moving forward, SOFIA’s data will be available in NASA’s public archives for astronomers worldwide to use.

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.