Researchers from the Institute of Astrophysics and Space Sciences at the Lisbon Astronomical Observatory have developed a method for studying the atmospheres of small exoplanets located in other star systems. This technique is based on observations of Venus during its transit across the Sun as seen from Earth. The study was published in the journal Atmosphere.
Current methods are effective for analyzing the hot atmospheres of giant worlds close to their stars, but are less suitable for assessing the gaseous environments of smaller bodies like Earth and Venus.
In their research, the team analyzed a rare dataset collected on June 5 and 6, 2012, when Venus last crossed the Sun's disk in this century. During such transits, planets leave imprints of their presence in the stellar radiation as it travels to Earth, including signals from the atmospheric molecules of these worlds. This information provides astronomers with insights into the composition of the gas envelopes of transiting planets.
The team applied the new methods to the transit data of Venus and confirmed the feasibility of using this approach for analyzing the atmospheres of small rocky exoplanets similar to Venus.
According to the researchers, their methodology can be utilized with new astronomical instruments expected to become operational in the 2030s.
Previously, astronomers determined that life similar to that on Earth never existed on Venus.