The quest to find an Earth-like planet capable of supporting advanced life will not be fulfilled simply by discovering a planet approximating the mass of Earth that orbits its star at a distance that would permit surface liquid water to exist. Astronomers are finally recognizing the futility of this search.
Water is abundant in the universe. In fact, in the most likely scenario for an Earth-sized planet with an Earth-like rotation, it would contain over two hundred times as much surface water as Earth—making it a permanent water world. In order to support advanced life, a planet's surface must possess both landmasses and oceans. Additionally, both the landmasses and the oceans must cover a large fraction of the planet's surface.
Acknowledging that a planet capable of supporting advanced life must possess these features, two different teams of astronomers have made measurements and simulations that demonstrate the feasibility of detecting such "Earth-like" planets using existing technology. A team of American astronomers (including an astronomer who once wrote an article for one of RTB's magazines) used measurements from the Deep Impact spacecraft to treat Earth as if it were an extrasolar planet.1
Deep Impact's primary purpose is to make the most detailed studies to date of the chemical and physical properties of comets. The spacecraft has already completed a flyby and the release of an impact probe on the comet Tempel 1. It is now headed toward the comet Hartley 2. Deep Impact, however, is not limited to studying comets. Its design permits astronomers to use it to observe transits and eclipses of extrasolar gas giant planets. The above-mentioned American team used the distant satellite to observe Earth.
The team successfully detected the rotation rate of our planet by measuring variations in Earth's reflectivity. Depending on the wavelength over which they observed, they detected reflectivity variations that ranged from 15 to 30 percent. They determined that the spectral and spatial distributions of the differences in Earth's reflectivity corresponded to cloud-free continents and oceans. Based on their measurements, the researchers concluded that "time-resolved broadband observations taken by a large space-based coronagraphic telescope" should be able to infer the existence of water oceans and continents on extrasolar planets.2
Their study was complemented by a separate analysis performed by two astronomers at the University of Colorado. The Colorado team used computer simulations to determine whether or not the New Worlds Observatory would be able to detect continents and oceans on extrasolar planets.3 The New Worlds Observatory is a planned NASA project to put a telescope in space designed to block the light of a star in order to observe its orbiting planets. Such a light blocker also could be easily installed on the James Webb Space Telescope, scheduled for launch in 2014. The Colorado team determined that such telescopes could detect the presence of oceans and continents on extrasolar planets if: (1) the extrasolar planet was not too far away (closer to Earth than fifty light-years away); (2) observations at crescent phases in high inclination systems were available; and (3) the planet's average cloud coverage is lower than that on Earth.
Though not minimizing the difficulty of actually observing the presence of continents and oceans on extrasolar planets, both teams showed it will be feasible to do so in the near future. Such observations will test an important feature of the RTB creation model.4 That model predicts that nothing less than the direct intervention of a supernatural, super-intelligent Being can explain the positions, sizes, heights, depths, and long-term stability of Earth's continents and oceans and that all these features are fundamental requirements for the existence of advanced life.
Given that God has chosen to create advanced physical life on only one planet in the universe (apparently only one such planet is necessary for God to achieve all the biblically mentioned purposes for creating the universe5), the RTB creation model predicts that Earth alone will manifest continents and oceans with all the features that advanced life requires. By contrast, scientists holding to a nontheistic perspective predict the opposite. They predict that many such planets will be found. It will not be long before astronomical measurements prove which model is correct and which models are wrong.
- Nicolas B. Cowan et al., "Alien Maps of an Ocean-Bearing World," Astrophysical Journal 700 (August 1, 2009): 915-23.
Cowan et al., 915.
P. H. H. Oakley and W. Cash, "Construction of an Earth Model: Analysis of Exoplanet Light Curves and Mapping the Next Earth with the New Worlds Observer," Astrophysical Journal 700 (August 1, 2009): 1428-39.
Hugh Ross, More Than a Theory (Grand Rapids: Baker, 2009).
Hugh Ross, Why the Universe Is the Way It Is (Grand Rapids: Baker, 2008).