Could a unique rectangular telescope be the key to discovering Earth 2.0? A new study proposes that to resolve nearby Earth-like exoplanets, a rectangular telescope may outperform traditional circular designs.
According to astrophysicist Heidi Newberg of Rensselaer Polytechnic Institute, a telescope similar in size to the James Webb Space Telescope (JWST) but with a one by 20 meter (65.6 by 3.3 foot) rectangular mirror could detect planets orbiting sun-like stars. Unlike JWST’s 6.5-meter circular mirror, this alternative shape maximizes efficiency for exoplanet imaging.
The National Academies’ Astronomy and Astrophysics Decadal Survey prioritizes developing a telescope capable of imaging Earth-size planets in habitable zones. While current proposals envision an eight-meter circular aperture, Newberg argues that a rectangular design could achieve similar goals at lower cost.
The telescope must observe light at 10 microns, the infrared wavelength at which water vapor emits. While JWST’s MIRI can detect this, its mirror is too small to resolve Earth-sized planets 30 light-years away. A 20-meter aperture would be required, but engineering such a large circular telescope is prohibitively complex and costly.
An interferometer using multiple small telescopes has also been proposed, but its precise alignment needs present major technological challenges. In contrast, a rectangular telescope would be simpler, cheaper, and more efficient. Although its collecting area would be smaller than JWST’s, its design ensures optimal orientation toward target exoplanets.
Newberg’s team estimates that with this design, astronomers could detect half of all existing Earth-like planets orbiting sun-like stars within 30 light-years in less than three years. With around 69 nearby sun-like stars and nearly 300 M dwarfs within that distance, the telescope could potentially identify about 30 promising Earth analogs.
A paper describing this groundbreaking rectangular telescope concept was published on September 1 in Frontiers in Astronomy and Space Sciences.
With this proposal, the idea of a rectangular telescope Earth 2.0 is no longer just theoretical — it could soon redefine humanity’s search for another habitable world.
