High-tech telescopes search for chemicals essential to life on Earth. A new study suggests that a new generation of advanced telescopes could sharpen the search for potential extraterrestrial life by examining the atmospheres of nearby exoplanets.

In a new article published recently Astronomy MagazineIt describes how a team of astronomers from Ohio State University tested the ability of future telescopes to detect chemical signatures of oxygen, carbon dioxide, methane and water on 10 rocky exoplanets. These elements are also biological signatures found in Earth’s atmosphere and can provide important scientific evidence for the existence of life.

Potential biosignatures on exoplanets

The study found that these telescopes were highly adept at detecting the presence of potential biosignatures for Proxima Centauri b and GJ 887 b, two of the closest worlds. Of these two findings, only Proxima Centauri b indicates that the machines can detect carbon dioxide if it is present. Although no exoplanets have been found that exactly match the initial conditions of life on Earth, this study suggests that, if examined in more detail, such unique Super-Earths (planets larger than Earth but smaller than Neptune) may be suitable targets for the future. is showing. research missions

Visualization methods and tool testing

To advance the search for habitable planets, the study’s lead author, Huihao Zhang, a senior astronomer at Ohio State, and colleagues also sought to determine the performance of specialized imaging instruments such as the James Webb Space Telescope (JWST) and other Extremely Large Space Telescopes. Telescopes (ELTs) such as the European Extremely Large Telescope, the Thirty Meter Telescope, and the Giant Magellanic Telescope image exoplanets directly.

“Not every planet is amenable to direct imaging, but the simulations therefore give us a rough idea of ​​what ELTs can offer and the promise they have to offer when built,” Zhang said.

A direct method of imaging exoplanets involves using a coronagraph, or starshade, to block the light of the host star; This allows scientists to capture a faint image of the new world in orbit. But locating them this way can be difficult and time-consuming, so the researchers aimed to see how well ELTs could perform this task. To do this, they tested the ability of each telescope’s instruments to distinguish cosmic background noise from the planetary noise they aimed to capture when detecting biosignatures; The higher this ratio, called the signal-to-noise ratio, the easier it is to detect and analyze the planet’s wavelength.

The results showed that the direct imaging mode of one of the European ELT instruments, called the mid-infrared ELT Imager and Spectrograph, gave better results for three planets (GJ 887 b, Proxima b and Wolf 1061 c) in detecting the presence of methane. The high angular resolution monolithic optical and near-infrared integrated field spectrograph could detect methane, carbon dioxide, oxygen, and water but required significantly longer exposure times.

Zhang also said the findings compare favorably with JWST’s current capabilities in space, as they include instruments that will have to study the chemical turbidity of Earth’s atmosphere to advance the search for space life.

Comparative analysis of space and ground telescopes

“It’s hard to say whether space telescopes are better than ground-based telescopes because they are different,” he said. “They have different environments, different places, and their observations have different effects.”

In this case, the results showed that although GJ 887 b is one of the most suitable targets for direct ELT imaging, its location and size lead to a particularly high signal-to-noise ratio for some transiting planets such as TRAPPIST-1. In his system, JWST methods for studies of planetary atmospheres are better suited for their detection than direct images from ELTs on Earth.

Future directions and the importance of modeling

The actual performance of future astronomical instruments may still surprise scientists because the study used more conservative assumptions about the data, Zhang said. Besides subtle contrasts in performance, these powerful technologies serve to expand our understanding of the universe and are intended to complement each other, said Ji Wang, an assistant professor of astronomy at Ohio State and co-author of the study. Therefore, he said, there is a need for studies like this that evaluate the limitations of these technologies.

“The importance of simulation cannot be overstated, especially for multibillion-dollar missions,” Wang said. “People need to not only build the hardware, but also model the performance very tightly and be ready to deliver great results.”

Since ELT is unlikely to be completed by the end of this decade, the researchers’ next steps will focus on modeling how well future ELT instruments will probe the intricacies of the overwhelming evidence for life on our own planet.

“We want to see to what extent we can study our atmosphere down to the smallest detail and how much information we can extract from it,” Wang said. “Because if we can’t answer questions about the habitability of Earth’s atmosphere, we can’t answer questions around other planets.”