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Hybrid orbiting starshade paired with large ground-based telescopes to observe Earth-like exoplanets. Credit: Ahmed Soliman
Finding Earth-like planets orbiting sun-like stars and identifying signs of life such as oxygen or water is a major goal in astronomy and a key interest for the public. Addressing this challenge speaks directly to one of humanity's most fundamental questions: Are we alone in the universe? However, these planets are about 10 billion times dimmer than their stars in visible light, making direct detection extremely challenging.
Space telescopes such as the James Webb Space Telescope and the upcoming Nancy Grace Roman Space Telescope use internal coronagraphs to block starlight, but they cannot reach the contrast needed to detect habitable Earth-like worlds.
Ground-based telescopes also face limitations from atmospheric turbulence and instrumental contrast.
A hybrid observatory combining a space-based starshade with large ground telescopes (NASA NIAC HOEE study) can overcome these limits and enable new science.
The starshade blocks starlight and forms a deep shadow above Earth's atmosphere, while the large apertures of ground telescopes provide the angular resolution and sensitivity needed to directly detect and characterize Earth-like exoplanets.
In the study, carried out with my outstanding team, including Nobel laureates John C. Mather (PI of HOEE) and Michel Mayor (discovered the first exoplanet orbiting a sun-like star)—we analyzed the performance of this hybrid observatory with the Extremely Large Telescope (ELT), Thirty Meter Telescope (TMT), and Giant Magellan Telescope (GMT).
Our results show that this approach can achieve the imaging contrast necessary to directly observe Earth-like exoplanets.
The key challenge in enabling this concept is the effect of Earth's atmosphere, which can blur captured images. Our paper presents a detailed foundational analysis of this challenge and demonstrates how this concept can be used to observe Earth-like exoplanets with ELT through Earth's atmosphere.
We highlight the crucial role of ELT adaptive optics in achieving clear observations. As a proof of concept, we demonstrate the detectability of the full solar system—from Venus to Saturn, as well as key biosignatures of life, such as oxygen and water, under moderate weather conditions.
Our findings are published in Nature Astronomy, titled "The observation of Earth-like exoplanets with ground-based telescopes and a shared orbiting starshade" and our paper was selected for the journal March cover.
This paper provides a stepping stone toward building, testing, and advancing our NASA NIAC HOEE concept into a space mission. This concept can observe about many times faster because it uses a ground telescope roughly six times larger than NASA's Habitable World Observatory, providing a new window to observe habitable exoplanets from our own planet, Earth.
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Publication details Ahmed Soliman et al, The observation of Earth-like exoplanets with ground-based telescopes and a shared orbiting starshade, Nature Astronomy (2026). DOI: 10.1038/s41550-026-02787-9 Journal information: Nature Astronomy
Ahmed is a scientist and technologist at Jet Propulsion Laboratory NASA/Caltech. He has received his Ph.D. from California Institute of Technology—Caltech in 2023.
— Source: Phys.org (https://phys.org/news/2026-03-earth-exoplanets-planet.html)
