There seems to be another recently discovered habitable zone requirement. I’ve added a 10th position in the list below.
NASA loosely describes (screenshot) the water habitable zone as “the right distance and temperature for liquid water to exist. The key … is a planetary surface where the water could pool.” This entails that “the size and composition of both planets and stars are critical to habitability.” And specifically, as it relates to stars, time plays and important factor, “Big bright stars burn out far more quickly than their more modest counterparts.” Planetary distance, temperature, star type, and time play a role in making a planet habitable.
But apparently there is more to the story, and as of today, there are at least eight additional “stories.” There may be as many as eight more planetary requirements needed for life to survive, let alone get started, than just the aforementioned criteria.
Here is a list of eight (now nine) more zones that may be necessary for life:
2. Planetary Obliquity Habitable Zone — Gregory S. Jenkins, “Global Climate Model High-Obliquity Solutions to the Ancient Climate Puzzles of the Faint-Young Sun Paradox and Low-Altitude Proterozoic Glaciation,” Journal of Geophysical Research: Atmospheres 105 (March 2000): 7357-70.
3. Ozone Habitable Zone — Antígona Segura et al., “Ozone Concentrations and Ultraviolet Fluxes on Earth-Like Planets Around Other Stars” Volume: 3 Issue 4: July 5, 2004.
4. Photosynthetic Habitable Zone (and Tectonics) — N.H. Sleep “Tectonics and the photosynthetic habitable zone” American Geophysical Union, Fall Meeting 2009, abstract #B11E-03.
5. Astrosphere Habitable Zone — David S. Smith and John M. Scalo, “Habitable Zones exposed: Astrosphere Collapse Frequency as a Function of Stellar Mass,” Astrobiology 9 (September 2009): 673-81.
6. Ultraviolet Habitable Zone — Jianpo Guo et al., “Habitable Zones and UV Habitable Zones around Host Stars” 5 Mar 2010.
7. Tidal Habitable Zone — R. Heller, J. Leconte, and R. Barnes, “Tidal Obliquity Evolution and Potentially Habitable Planets” Astronomy and Astrophysics 528 (April 2011): id. A27.
8. Planetary Rotation Rate Habitable Zone — Jun Yang et al., “Strong Dependence on the Inner edge of the Habitable Zone on Planetary Rotation Rate,” Astrophysics Journal Letters 787 (May 2014): L2.
9. Electric Wind — Glyn Collinson et al., “The Electric Wind of Venus: A Global and Persistent ‘Polar Wind’-Like Ambipolar Electric Field Sufficient for the Direct Escape of Heavy Ionospheric Ions: Venus Has Potential,” Geophysical Research Letters 43 (June 2016): 5926–34, doi:10.1002/2016GL068327.
10. Planet Obliquity and Orbital Eccentricity (Added on 11/22/18) — Russell Deitrick et al., “Exo-Milankovitch Cycles. I. Orbits and Rotation States,” The Astronomical Journal, Volume 155, Number 2: January 16, 2018.
Hugh Ross expounds on this discovery here: Exoplanets’ Climate Instabilities Reveal Earth’s Fine-Tuning.
So what do these additional habitable zones mean? It means that the Water Habitable Zone isn’t enough for life. And from what Dr. Hugh Ross has said, “the only known planet that resides in all eight (leaving out Electric Wind) of these habitable zones is Earth.”2.
We live on a very special planet.