NASA's Starshade to Enable Direct Imaging of Earth-like Exoplanets
NASA is advancing a hybrid telescope concept, known as the Hybrid Observatory for Earth-like Exoplanets (HOEE), to directly image rocky exoplanets. This innovative approach involves an orbital starshade working in conjunction with next-generation extremely large ground-based optical telescopes.
The starshade, a 50-meter diameter structure with 48 petals, will orbit approximately 175,000 kilometers from Earth. It is designed to suppress starlight before it reaches the atmosphere, enhancing the telescopes' ability to capture clear images of distant planets. Initial operations are expected to commence with the European Southern Observatory’s Extremely Large Telescope by 2030.
Targeting stellar systems within 20 light-years, the HOEE aims to detect Earth analogs in under a minute and perform high-fidelity optical spectroscopy to identify potential biosignatures like nitrogen and oxygen emissions. The project is estimated to cost in the billion-dollar range, with the starshade's inflatable structure keeping its launch mass under 1,500 kilograms.
Supported by NASA's NIAC program, the concept has undergone extensive modeling, demonstrating its feasibility with adaptive optics on ground telescopes mitigating atmospheric turbulence effectively. This system could transform ground telescopes into powerful exoplanet imagers, capable of detecting molecular signatures such as water and oxygen.