Rectangular Telescope Design Could Offer the Best Way to Find Earth-Like Planets

The James Webb Space Telescope (JWST) has already captured some incredible images of our universe, with some game-changing insights to boot. But researchers at New York’s Rensselaer Polytechnic Institute believe the observatory would be capable of even more if it had been designed differently. Published Sunday in Frontiers in Astronomy and Space Science, their new study posits that a rectangular telescope with a long, narrow mirror might be the best way to find Earth-like planets.
Authored by Heidi Newberg, a professor of astrophysics, the study suggests that utilizing a telescope with a rectangular mirror would capture nearly half of all Earth-like planets orbiting Sun-like stars within 30 light-years of Earth.
Newberg explains that planets that are Earth-like in size and have liquid water give off the most light at wavelengths around the width of a human hair. To image that effectively, a telescope designed like Webb would have to be over 20 meters in diameter; the Webb has a diameter of just 6.5 meters.
Newberg proposes stretching that mirror out horizontally rather than making it circular. This would allow for the kind of light collection it needs to image those sorts of planets without turning into an impossibly large mirror, which we simply cannot create with current technologies within a reasonable budget.
“We show that it is possible to find nearby, Earth-like planets orbiting sun-like stars with a telescope that is about the same size as the James Webb Space Telescope, operating at roughly the same infrared wavelength as JWST, with a mirror that is a one by 20 meter [65.6 by 3.3 foot] rectangle instead of a circle 6.5 meters [21.3 feet] in diameter,” Newberg said in a news release.
Newberg claims that with such a telescope, scientists could discover a massive quantity of Earth-like exoplanets in just a few years.
Although this isn’t the only idea for imaging planets of this size and type, many of them require leaps in technologies that aren’t yet viable, making them more costly and even improbable with the current level of technological development. Others are incredibly expensive. Newberg’s solution is both feasible and potentially more affordable, since it would ultimately be smaller than Webb.
Admittedly, Webb cost somewhere around $10 billion, so perhaps this isn’t as small an ask as she’s suggesting.
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