James Webb Telescope to Reveal Secrets of Potentially Habitable Exoplanet Trappist-1e

Artist's conception of TRAPPIST-1 e, a potentially habitable exoplanet that orbits a nearby star.

Credits: NASA

April 25, 2023

Trappist-1e is one of the seven exoplanets that orbit the ultra-cool dwarf star Trappist-1, which is located approximately 39.6 light-years away in the constellation Aquarius. Trappist-1e has been the subject of much interest among astronomers since it was discovered in 2017, as it is located within the habitable zone of its host star, making it a potentially habitable world. In this article, we will explore what we currently know about Trappist-1e and what the upcoming James Webb Space Telescope observations may reveal about this promising exoplanet.

What is Trappist-1e?

Trappist-1e is a rocky exoplanet that is slightly larger than Earth, with a radius estimated to be 0.92 times that of our planet. It orbits its host star at a distance of approximately 0.029 astronomical units (AU), which is closer than Mercury orbits the Sun, but due to the lower luminosity of its host star, Trappist-1e receives a similar amount of energy from its star as Earth does from the Sun. Trappist-1e completes one orbit around its host star in just 6.1 Earth days, making its year much shorter than ours.

What makes Trappist-1e potentially habitable?

The habitable zone of a star is the region around it where conditions are just right for liquid water to exist on the surface of an orbiting planet. This is considered to be a key factor in the potential for life to exist on a planet. Trappist-1e is located within the habitable zone of its host star, which means that it is possible that it could have liquid water on its surface.

However, being in the habitable zone is not enough to make a planet habitable. There are many other factors that must be considered, such as the composition of the planet's atmosphere and the presence of a magnetic field to protect it from the harsh stellar winds of its host star. We currently do not have enough information about Trappist-1e to determine whether it has these factors, but upcoming observations with the James Webb Space Telescope may help to answer these questions.

What can we learn from the James Webb Space Telescope observations?

The James Webb Space Telescope (JWST) is a large, infrared telescope that was launched in late 2021. It is designed to study the early universe, the formation of galaxies, stars, and planetary systems, as well as the atmospheres of exoplanets. The JWST will be able to observe Trappist-1e and its host star in great detail, providing valuable information about the planet's atmosphere, temperature, and potential for habitability.

One of the key instruments on the JWST that will be used to study Trappist-1e is the Near Infrared Spectrograph (NIRSpec). NIRSpec is designed to measure the spectra of light from distant objects, allowing astronomers to study the chemical composition and temperature of planetary atmospheres. By analyzing the light that passes through Trappist-1e's atmosphere during a transit, astronomers can learn about the planet's composition and atmospheric properties, including the presence of water vapor, methane, and other gases that could be indicative of life.

Another instrument on the JWST that will be used to study Trappist-1e is the Mid-Infrared Instrument (MIRI). MIRI is designed to study the mid-infrared light emitted by objects in space, which is particularly useful for studying the thermal properties of exoplanets. By measuring the thermal emission from Trappist-1e, astronomers can determine the planet's temperature, which can provide insights into its potential for habitability. In addition to these instruments, the JWST also has a high-resolution camera called the Near Infrared Camera (NIRCam), which will be used to study the surface features of Trappist-1e. NIRCam can detect light in the near-infrared range, which can penetrate through the thick clouds that may be present in the atmosphere of Trappist-1e. By studying the surface features of the planet, astronomers can learn about its geological history and potential for life.

One of the challenges in studying exoplanets like Trappist-1e is the fact that they are extremely far away and appear as faint dots of light in telescopes. To overcome this, astronomers use a technique called transit spectroscopy, which involves observing the planet as it passes in front of its host star. During a transit, some of the star's light passes through the planet's atmosphere, leaving a signature that can be analyzed to determine the planet's atmospheric properties. The JWST will be able to study the atmospheres of exoplanets in much greater detail than any other telescope before it, and it is expected to revolutionize our understanding of exoplanet atmospheres and potential for habitability. Trappist-1e is a particularly promising target for the JWST, as it is one of the most potentially habitable exoplanets discovered so far.

What have we learned about Trappist-1e so far?

While we currently do not have enough information about Trappist-1e to determine whether it is habitable, we have learned a lot about its properties since its discovery in 2017. In addition to its location within the habitable zone of its host star, we know that Trappist-1e is rocky and slightly larger than Earth. We also know that it likely has a thick atmosphere, as all of the planets in the Trappist-1 system appear to have a similar composition.

One of the most intriguing aspects of Trappist-1e is the fact that it is part of a system of seven exoplanets, all of which are located within the habitable zone of their host star. This makes the Trappist-1 system one of the most exciting places to search for life beyond our solar system.

Conclusion

Trappist-1e is a promising exoplanet that is located within the habitable zone of its host star, making it a potentially habitable world. While we currently do not have enough information to determine whether it is habitable, upcoming observations with the James Webb Space Telescope may provide valuable insights into its potential for life.

The JWST is a powerful tool that will allow astronomers to study exoplanets in unprecedented detail, and Trappist-1e is one of the most exciting targets for its observations. By studying the planet's atmosphere, surface features, and thermal properties, astronomers may be able to determine whether Trappist-1e is habitable, and potentially even detect signs of life beyond our solar system.