A team of astronomers from Ohio State University (OSU) has found that the development of next-generation telescopes could allow scientists to observe weather phenomena on distant exoplanets, providing new insights into the possibility of extraterrestrial life. The Extremely Large Telescope (ELT), Giant Magellan Telescope (GMT) and Thirty Meter Telescope (TMT) are expected to be the largest ground-based telescopes ever built and surpass the capabilities of the James Webb Space Telescope (JWST).
Michael Plummer, a graduate student in OSU’s Department of Astronomy and lead author of the study, explained that studying the atmospheres of other objects outside our solar system not only gives us information about how Earth’s atmosphere might behave, but also allows scientists to scale these concepts to explore potentially habitable planets.
Next-generation telescopes will allow astronomers to use Doppler imaging, a revolutionary technique that can recreate two-dimensional maps of an object’s surface, to accurately measure the magnetism and chemical composition of ultracold space objects with temperatures below 2,700 K. This category includes brown dwarfs (BDs), very low-mass stars (VLMs) and even some exoplanets.
The ability to detect the magnetic field is crucial for assessing a planet’s suitability for life, as it is essential for sustaining life on a planet, especially in small star systems. Previously, experts have developed a publicly available analysis code, Imber, to model and infer the presence of surface irregularities such as magnetic starspots, cloud systems, and other atmospheric phenomena such as hurricanes.
In the present study, the experts used this technique to evaluate the science capabilities of various ELT instruments – the consortium’s Large Earth Finder (GMT/GCLEF), the Mid-Infrared ELT Imager and Spectrograph (ELT/METIS), and the TMT Multipurpose Diffraction-limited High Resolution Infrared Spectrograph (MODHIS) – to detect surface variations of six space objects. These objects included the star Trappist-1, a known seven-planet system located about 40 light-years from Earth, two brown dwarfs and three exoplanets.
The analysis showed that although the tilt of Trappist-1’s star makes it difficult for all three instruments to distinguish the starspots, the next-generation ELT and TMT telescopes can provide high-resolution observations of brown dwarfs and exoplanets in a single rotation. In contrast, the GMT instruments required several rounds of observations to detect irregularities on the surface of exoplanets.
Plummer said his technique has already piqued the interest of astronomers seeking to identify or confirm the presence of planetary bodies using the radial velocity method, a way of detecting exoplanets by determining the slight gravitational influence of space objects on the stars around which they orbit. “The more we learn about other Earth-like planets, the more these discoveries will advance Earth science. Our work is particularly well suited to help make such observations in the real world,” Plummer concluded.
