Illuminating Research: UCLA's Contributions to Understanding Space Weather and Light Pollution

The University of California, Los Angeles (UCLA) has emerged as a leading institution in researching phenomena ranging from space weather and its effects on Earth to the impact of artificial light on coastal ecosystems. Through innovative projects, dedicated faculty, and student involvement, UCLA is advancing our understanding of the complex interactions between our planet, the sun, and human activities.

HARP Project: Unveiling Plasma Waves Through Citizen Science

As civilization becomes increasingly reliant on satellite technology, we have also become increasingly vulnerable to disruptions caused by solar activity. In response to this growing concern, an international team led by researchers from UCLA and the Space Science Institute (SSI) has launched a groundbreaking project called Heliophysics Audified: Resonances in Plasmas, or HARP. This project invites the public to join NASA scientists in the search for space weather signals, specifically magnetic vibrations around Earth called plasma waves.

Plasma waves arise when charged particles from the sun impact Earth’s magnetic field, causing it to vibrate or resonate, unleashing radiation that can potentially damage spacecraft. On the brighter side, plasma waves can also generate the beautiful northern and southern lights. These waves, invisible to cameras, can influence the formation of the aurora, causing pulsating and shimmering regions to appear when charged particles impact Earth’s upper atmosphere, making it glow.

The HARP project utilizes a web app that converts satellite magnetic data into sounds, allowing users to listen to and classify the data. Studies show that people's eyes and ears in combination are better at finding hidden wave patterns than using computer algorithms or eyes alone. Users are greeted with a brief tutorial, where they listen to the satellite data simultaneously while viewing it in a spectrogram, a graph of frequency and intensity vs. time. NASA's five THEMIS satellites, launched in 2007 to study how energy in Earth’s magnetic field powers the aurora, provide the data for this project. In 2011, two of the probes were sent to study space weather around the moon and renamed ARTEMIS.

Mike Hartinger, principal investigator at SSI and a researcher in the UCLA Department of Earth, Planetary, and Space Sciences (EPSS), explains that Earth’s magnetic field and plasma waves are invisible to cameras. Plasmas are charged particles that emanate from the sun, which blows a solar wind in continuous streams and explosive eruptions. When the solar wind impacts Earth’s magnetic field, different types of plasma waves can form, analogous to vibrations formed by different musical instruments.

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HARP expands upon a pilot project in the UK led by team member Martin Archer of Imperial College London, in which high school students found a new complex pattern of plasma waves and became co-authors in a peer-reviewed journal publication. The project aims to incorporate more types of plasma waves throughout the solar system by adding other heliophysics satellites and data sources.

ELFIN: A Student-Led CubeSat Mission

UCLA has been at the forefront of space weather research for decades, with a legacy of building magnetic sensors and managing missions to study plasma waves around Earth, the moon, Mars, and on Jupiter’s moon, Europa. Five years ago, a group of UCLA undergrads came together with a common goal - to build a small satellite and launch it into space. Although UCLA has been building space instruments for NASA and other international space missions for more than 40 years, and members of its faculty have been critical contributors to space science, the Experimental Lunar Far-side Interferometer (ELFIN) is the first satellite mission built, managed and operated entirely at UCLA. The ELFIN mission exemplifies UCLA's commitment to hands-on learning and innovation in space exploration. The two micro-satellites, each weighing about eight pounds and roughly the size of a loaf of bread, help scientists better understand magnetic storms in near-Earth space. These storms are a typical form of “space weather” that is induced by solar activity, including flares and violent solar eruptions.

Margaret Kivelson, UCLA professor emeritus of space physics, explains that magnetic storms are not just interesting space phenomena; they can energize electrons to high energies that can damage or even destroy orbiting satellites we depend on for GPS, communications and weather monitoring. They can also enhance space electrical currents which flow onto Earth, and could damage the power grid. Currently, scientists’ ability to accurately model and predict space weather is in its infancy, just like meteorology was at the turn of the last century.

Vassilis Angelopoulos, a UCLA space physicist who got his doctorate at UCLA and serves as ELFIN’s principal investigator, notes that the aurora is sort of a TV screen that shows us what happens out in space. ELFIN aims to observe the complex sequence whereby magnetic storms form waves near Earth, accelerating and forcing electrons to fall into the atmosphere, while a network of all-sky cameras across North America captures the resulting brightening of the auroral lights.

CubeSats fill this need because of their compact size, relative affordability ($300,000 compared to several hundred million dollars for a typical research satellite), and how quickly a team can go from prototyping to launch compared to standard-sized satellites. Angelopoulos emphasizes that CubeSats are ideal because they create an environment where students from all walks of life, from all disciplines, can come together and practice what they’ve learned during their formal education in the context of a realistic environment. This is exactly what academia, industry and research organizations around the country need - and they tell us that.

Artinger, a transfer student who graduated from Orange Coast College in 2016, plans to become a community college professor and can’t wait to use her ELFIN experience to inspire a new generation of students. Ethan Tsai learned about ELFIN when he was a UCLA sophomore. Despite having no background in space science, the former physics major started to work on simple tasks and gained the necessary skills to become the project’s attitude determination and control subsystem lead.

Understanding Space Waves and Solar Wind

UCLA researchers are also making significant contributions to understanding the behavior of space waves and their impact on the solar wind. Scientists have discovered a new way for different types of waves in space to work together, to heat and accelerate particles in the solar wind. Using NASA's Magnetospheric Multiscale spacecraft and computer simulations, UCLA researchers found that large-scale magnetic waves (~2000km), known as Alfvén waves, can generate smaller-scale sound-like waves (50-1500m) that heat particles to high temperatures. This process occurs near boundaries in space where different plasma environments meet, such as at Earth's magnetopause - the outer edge of our planet's magnetic shield.

This finding solves a long-standing puzzle about how energy moves between different scales in space plasmas and how particles are heated in these environments. It's similar to how ocean waves can create smaller ripples that eventually break and heat the water. The discovery helps explain how streaming particles from the Sun- the solar wind- are heated as they travel through space. This process of energy transfer can occur at other astrophysical settings, from the Sun's atmosphere to fusion devices on Earth. This improved understanding could help scientists better predict space weather and advance the development of fusion energy.

Xin An, a researcher in the Earth, Planetary, and Space Sciences department, emphasizes the importance of investigating the nature of these particles, since plasma wave heating can impact our satellite technology and astronauts, who are especially more vulnerable on the moon, outside of our planet’s protective magnetic bubble.

SDPI: Streamlining Space Payload Integration

UCLA’s ELFIN student team, part of the Experimental Space Physics (ESP) lab of Professor Vassilis Angelopoulos, is one of the three finalists winning the 2024 NASA TechLeap Prize, a challenge to develop interface systems that easily integrate diverse space payloads onto flight vehicles.

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The Experimental Space Physics lab focuses on in situ measurements of plasma, particles, and fields in near-Earth space. The sizable undergraduate student portion of the lab is led by Project Manager Ethan Tsai, who previously oversaw the successful completion of the NASA ELFIN CubeSat mission. Sophie Ye, a graduating senior, will lead the focused undergraduate team's development of the UCLA Software-Defined Payload Interface (SDPI), which leverages previous flight experience and synergizes well with future EPSS ambitions for spaceflight.

Mentored by graduate students and engineering staff at EPSS, the SDPI team aims to reduce the cost and complexity of integrating scientific payloads into orbital vehicles and lunar landers which solves a key bottleneck in the performing scientific investigations in space. Their proposal for the Software-Defined Payload Interface (SDPI) is powered by a flight-proven ARM/FPGA System-on-Chip and provides customers with fleixbile user interface that allows for the configuration of communication and power interfaces for seamless integration into a wide range of space applications.

Recognizing Leadership in Heliophysics

Vassilis Angelopoulos has received the NASA Outstanding Public Leadership Medal for 2024. The Agency Honor Awards are NASA’s most prestigious form of recognition and are presented to individuals and teams who have distinguished themselves by making outstanding contributions to the Agency’s mission. Professor Angelopoulos is receiving the Public Leadership Medal in recognition of his outstanding leadership generating cutting edge Heliophysics research and educating, cultivating, and inspiring a new generation of heliophysicists.

Vassilis Angelopoulos has been a professor in the UCLA Earth, Planetary and Space Sciences Department and Institute of Geophysics and Planetary Physics since 2007. His primary areas of scientific research are how particles are accelerated in Earth's magnetosphere, how the upper atmosphere and ionosphere respond to space currents, and how the lunar environment is affected by its interaction with the solar wind. As Principal Investigator of NASA’s THEMIS and ARTEMIS missions, he led the development of the associated five satellites and twenty ground-based observatories. At UCLA he proposed, oversaw the development, successful launch, and operation of the two ELFIN CubeSats until their deorbit in September 2022.

Unraveling the Mysteries of STEVE

Citizen scientist photo of STEVE, providing researchers with unprecedented detail of its fine structure. The image was selected as the cover of the Journal of Geophysics Research. A recent article published in Science News details the captivating yet mysterious phenomenon known as STEVE (Strong Thermal Emission Velocity Enhancement), a rare sky glow observed by citizen scientists like Alan Dyer in rural Alberta, Canada. Unlike traditional auroras, STEVE appears as a ribbon of mauve closer to the equator and exhibits unique characteristics.

Dyer's high-resolution footage of STEVE provided scientists, particularly THEMIS researcher Toshi Nishimura from Boston University, with unprecedented details. Scientists have been grappling with the enigmatic nature of STEVE since its introduction to the scientific community in 2016. While initially thought to be related to auroras, STEVE's distinct purple hue and different behavior have raised numerous questions about its origins and underlying mechanisms. Recent observations suggest a connection between STEVE and another atmospheric phenomenon called stable auroral red (SAR) arcs, indicating a complex interplay of factors contributing to STEVE's appearance.

Further complicating the understanding of STEVE is the discovery of its association with green stripes known as the "picket fence," which was initially mistaken for a type of aurora. However, detailed analysis suggests that the picket fence's green glow may stem from different processes than traditional auroras, possibly involving atmospheric electric fields. Computer modeling and proposed rocket missions aim to shed light on these phenomena and confirm the existence of such electric fields.

NASA's upcoming missions, including the Geospace Dynamics Constellation mission, hold promise for gathering more data to elucidate the mysteries surrounding STEVE and related atmospheric phenomena. Despite the challenges, citizen scientists like Dyer remain instrumental in capturing observations of STEVE from the ground, contributing valuable data that continue to puzzle and intrigue researchers in the field of space physics.

Investigating the Rayleigh-Taylor Instability

Artist rendition of the Rayleigh-Taylor Instability at Earth's Magnetopause, when the solar wind dynamic pressure suddenly drops. The magnetopause, the outermost edge that our planet's intrinsic magnetic field reaches, is always in motion. The macroscopic acceleration at the magnetopause is sometimes as large as a few km/s2. Theoretically, such an acceleration of the boundary can facilitate an instability in the motion of the interface, the Rayleigh-Taylor (R-T) instability. Such an instability can, in turn, cause a transfer of plasma across the magnetopause, from solar wind into near-Earth space.

If the resulting particles are sufficiently energetic, operations of many satellites in space can be threatened. However, details of how the instability operates at the magnetopause have been neither verified nor observed in spacecraft observations. Recent measurements from NASA's THEMIS mission indicate that the R-T instability can be excited at the magnetopause, and many details of the instability, including those of its electric field and plasma transport across the magnetopause, appear to be verified in those observations.

Space Waves and Geomagnetic Activity

More accurate space-weather predictions and safer satellite navigation through radiation belts could someday result from new insights into “space waves,” researchers at Embry-Riddle Aeronautical University reported. The simulation (right) shows the Earth’s magnetic environment during the equinox and the solstice. As the solar wind - a flow of particles from the Sun - hits the Earth’s magnetic environment, it can create breaking waves known as Kelvin-Helmholtz waves. This occurs more often during the equinoxes due to the orientation of the Sun’s and Earth’s magnetic fields (left). These breaking waves, known as Kelvin-Helmholtz waves, occur at the boundary between the solar wind and the Earth’s magnetic shield.

As plasma or solar wind streams from the Sun at speeds up to 1 million miles per hour, it pushes energy, mass and momentum toward the planet’s magnetic shield. It also whips up space waves. Fast-moving solar wind can’t pass directly through the Earth’s magnetic shield, so it thunders along the magnetosphere, propelling Kelvin-Helmholtz waves with massive peaks up to 15,000 kilometers (km) high and 40,000 km long.

Through these waves, solar wind plasma particles can propagate into the magnetosphere, leading to variations in radiation belt fluxes of energetic particles-regions of dangerous radiation-that may affect astronaut safety and satellite communications. On the ground, these events can impact power grids and Global Positioning Systems. Describing the properties of space waves and the mechanisms that cause them to intensify is key to understanding and forecasting space weather.

Light Pollution Along the Southern California Coast

Beyond space weather, UCLA researchers are also investigating the impact of artificial light on coastal ecosystems. A UCLA-led study has quantified, for the first time, how much of that light is too much for the Western snowy plover, a small shorebird, and the California grunion, a fish.

Researchers used satellite images and ground-based measurements to build a detailed map of light pollution along a 0.9 mile-wide strip of coast stretching from about 6.2 miles north of the northern Ventura County line to 6.2 miles south of the southern Orange County line.

Travis Longcore, an associate adjunct professor at the UCLA Institute of Environment and Sustainability and the study’s senior author, notes that he doesn’t like to sleep with a streetlight shining in his eyes, and other species can’t pull down shades to cope. Plovers and grunion avoid areas illuminated by artificial light, likely because there is an increased risk that they will be targeted or caught by predators. Environmental scientists have long advised that controlling light pollution, especially at night, is critical for preserving threatened species.

The researchers calculated that grunion runs, the animals’ periodic mating rituals that occur at high tide, declined significantly in areas with more than 100 millilux of light - roughly the brightness on the beach from a full moon in a clear sky. Ariel Levi Simons said local officials and property owners should minimize the amount of light that reaches beaches and other sensitive habitats by reducing direct glow and dimming their lights.

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