SETI Institute's Allen Telescope Array Unveils Space Distortion Through Pulsar Scintillation
Mountain View, CA, December 10, 2025 -- A groundbreaking study led by the SETI Institute has revealed the intricate dance of space distortion, using the Allen Telescope Array (ATA) to observe pulsar PSR J0332+5434. Over a period of 10 months, the team meticulously measured the pulsar's radio signal, which 'twinkles' as it traverses the vast interstellar expanse between the star and Earth. This phenomenon, known as scintillation, was found to exhibit slow, significant changes in its pattern over time.
Pulsars, the remnants of massive stars, emit radio waves with remarkable precision. Their high rotation speeds and immense density make them invaluable tools for scientists. By employing sensitive radio telescopes, researchers can measure the exact arrival times of pulses, searching for patterns that may indicate phenomena like low-frequency gravitational waves. However, the interstellar gas plays a mischievous role, scattering the pulsar's radio waves and causing delays in pulse reception.
The 'twinkling' of pulsar radio waves, akin to starlight in Earth's atmosphere, creates a mesmerizing display of bright and dim patches across various radio frequencies. This scintillation is not static; it evolves as the pulsar, gas, and Earth move in relation to each other. The twinkling delays the pulses, and the extent of scintillation directly correlates with the delay. By monitoring a nearby pulsar frequently, the team observed these shifting patterns, translating them into minute timing delays.
Grayce Brown, a SETI Institute intern and project leader, emphasized the significance of these findings, stating, 'Pulsars are incredible tools that offer profound insights into the universe and our stellar neighborhood.' The study's results not only contribute to pulsar science but also benefit other fields of astronomy, including SETI. All radio signals passing through the interstellar medium experience scintillation, and noticeable scintillation can aid SETI scientists in distinguishing between human-made radio signals and those from other star systems.
The ATA's observations, utilizing a wide range of radio frequencies and frequent, short sessions, revealed a scintillation bandwidth that changed noticeably over timescales from days to months. The study also introduced a novel, robust method to estimate scintillation's increase with radio frequency, utilizing the ATA's wide frequency range. Dr. Sofia Sheikh, a co-author and Technosignature Research Scientist at the SETI Institute, praised the ATA's design, stating, 'It is ideally suited for studying pulsar scintillation due to its wide bandwidths and long-term commitment capabilities.'
This research provides a unique window into pulsars, Earth, and the space between them, enabling scientists to better differentiate radio frequency interference from potential artificial signals. The findings are published in a paper available at doi: 10.3847/1538-4357/ae0fff.
About the SETI Institute
Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization dedicated to leading humanity's quest to understand the origins and prevalence of life and intelligence in the universe. With expertise in the physical and biological sciences, data analytics, machine learning, and advanced signal detection technologies, the Institute collaborates with industry, academia, and government agencies, including NASA and NSF.
Contact: Rebecca McDonald, Director of Communications, SETI Institute
