Data is coming in from the Transiting Exoplanet Survey Satellite, known as TESS for short. It is the most powerful telescope ever deployed to look for planets orbiting other stars. Over two years, TESS can cover all 360 degrees of sky visible from Earth’s orbit. Our previous satellite called Kepler could only scan a small segment of the sky. Already Tess has identified over 300 probable exoplanets including one named HD 21749b which has the lowest known temperature for a planet orbiting a bright nearby star. (“Nearby” being 53 light-years away.)
The problem with this is that what astronomers consider “cool” is not cool from our standpoint. The surface temperature of HD 21749b is 150 degrees Celsius, which is way too hot for liquid water. (Water boils at 100 degrees Celsius.) A year on that planet equals 36 Earth days as it makes a complete orbit around its star. Most of the other exoplanets found at this time are vastly hotter than HD 21749b.
Astronomers have found other planetary systems, but they again have properties that would preclude any kind of life. Some of them have a planetary density equal to that of pure water. Some have orbits that are highly eccentric. Pi Mensae b, for example, has an orbit that varies widely. Its closest distance to its star approximately equals the distance from Earth to our Sun. The longest distance is similar to Jupiter’s distance from the Sun.
All of this continues to tell us that Earth is a unique planet orbiting a unique star. It is possible that those stars with exoplanets are undergoing an evolutionary process that could result in Earth-like planets billions of years from now. As we study them, we are learning more and more about what God did to create the “heaven and the earth.” God’s power and design become more amazing to us as we learn more about the universe. The more we learn, the more we see what Frank C. Baxter, who hosted the old Bell System Science TV Series, called “the wonder-working hand that has gone before us.”
–John N. Clayton © 2019