Corrigendum: Living at the Extremes: Extremophiles and the Limits of Life in a Planetary Context

Abstract

In the original article, there was a mistake in the legend for Table 4 as published. The legend in Table 4 is missing two parentheses around “Poly.” The correct legend appears below. “Table 4. Examples of notable (Poly)extremophiles and their physiological requirements.” Additionally, there was a mistake in Table 3 and Table 5 as published. In Table 3, the lowest temperature listed for Planococcus halocryophilus Or1 is “−18°C.” It should be “−15°C” instead. In addition, the pH range is “nr” but should be “6–11” instead. In the temperature column, 37 is bold type, but this should be regular type. Table 3 Limits of life as identified by (poly)extremophilic organisms in pure cultures. Strain Domain Extremophile Type Isolation ecosystem Temperature ( ° C) pH Pressure (Mpa) Salinity (%) Water activity (a w ) References Picrophilus oshimae KAW 2/2 Archaea Hypercidophile Hot springs, Solfataras 47–65 (60) a −0.06–1.8 (0.7) nr 0–20 nr Schleper et al., 1995, 1996 Serpentinomonas sp. B1 Bacteria Alkaliphile Serpentinizing system (water) 18–37 (30) 9–12.5 (11) nr 0–0.5 (0) nr Suzuki et al., 2014 Methanopyrus kandleri 116 Archaea Hyperthemophile Deep-sea hydrothermal vent 90–122 (105) (6.3–6.6) 0.4–40 0.5–4.5 (3.0) nr Takai et al., 2008 Planococcus halocryophilus Or1 Bacteria Halopsychrophile Sea ice core −15–37 (25) 6–11 (7–8) nr 0–19 (2) nr Mykytczuk et al., 2012, 2013 Halarsenatibacter silvermanii SLAS-1 Bacteria Haloalkaliphile Soda lake 28–55 (44) 8.7–9.8 (9.4) nr 20–35 (35) nr Oremland et al., 2005 Thermococcus piezophilus CDGS Archaea Piezothermophile Deep-sea hydrothermal vent 60–95 (75) 5.5–9 (6) 0.1–125 (50) 2–6 (3) nr Dalmasso et al., 2016 Haloarchaeal strains GN-2 and GN-5 Archaea Xerophile Solar salterns (brine) nr nr nr nr 0.635 Javor, 1984 a Data presented as range (optimum) for each parameter. nr, not reported in the original publication. Current limits are highlighted in bold. Table 5 Boundary conditions for different planetary bodies of astrobiological interest (compared to Earth), split into atmosphere, surface, and subsurface layers. Planetary body Type Layer Temperature (°C) pH Pressure (MPa) Salinity (% NaCl) Geochemistry References Earth Planet Atmosphere −100 – 40 Neutral, local acidic conditions possible due to volcanism and human activities 0.0001 – 0.1 0 78% N2, 21% O2, 9340 ppm Ar, 400 ppm CO2 18.2 ppm Ne, 5.2 ppm He, 1.7 ppm CH4, 1.1 ppm Kr, 0.6 ppm H2, variable H2 Hans Wedepohl, 1995; McDonough and Sun, 1995; Wayne, 2000 Surface −98.6 – 464 −3.6 – 13.3 0.003 – 112 0 – saturation Soils and sediments of varying lithologies, siliceous crust, ranging from mafic to felsic composition. Extensive ocean (70% planet surface), with 4,000 m average depth, 4°C and 3.5% average temperature and salinity respectively Subsurface 3.25 – <400 ~1 – 12.8 <800 0.05 – saturation Soils and sediments of varying lithologies, siliceous crust, ranging from mafic to felsic composition, ultramafic mantle Venus Planet Atmosphere −40 – 482 a 0 b 0.1 – 9.3 c nr 96.5% CO2, 3.5% N2; small quantities of CO, SO2, HCl, HF, HDO, and H2O; H2SO4 condensates Cockell, 1999; Basilevsky and Head, 2003; Schulze-Makuch et al., 2004; Lang and Hansen, 2006; Bertaux et al., 2007; Airey et al., 2017 Surface 377 – 482 nr 4.5 – 9.3 c nr Rocks are similar to tholeiitic and alkaline basalts; no liquid water Subsurface nr nr nr nr Fluid channels; volcanism Mars Planet Atmosphere −138 – 35 d nr 0.0001–0.0009 nr 95.3% CO2, 2.7% N2, 1.6% Ar, 0.13% O2, 0.08% CO; trace amounts of H2O, NO, Ne, Kr, Xe Varnes et al., 2003; Fairén et al., 2004; Nicholson and Schuerger, 2005; Hecht et al., 2009; Smith et al., 2009; Johnson et al., 2011; Jones et al., 2011; Michalski et al., 2013; Longstaff, 2014; Wordsworth, 2016; Sinha et al., 2017; NASA, 2018 Surface −138 – 30 7.7 e 0.0004–0.0009 5.2–5.8 Basaltic, Fe-/Mg-rich phyllosilicates, perchlorate salts, Al-rich clays, sulfates, chlorides, calcite, and silicas; potential cryosphere Subsurface 55 g 4.96–9.13 h 10–303 g Cl-rich brines Potential groundwater; basalt crust; possible serpentinization Enceladus Icy moon Plume jets 0 ~8.5 – 9 High velocity jets > 0.5 90–99% H2O, ≤ 0.61–4.27% N2, 0.3–5.3% CO2, 0.1–1.68% CH4, 0.4–0.9% NH3, 0.4–39% H2, trace amounts of hydrocarbons; high mass organic cations, silicates, sodium, potassium, carbonates Gioia et al., 2007; Postberg et al., 2009, 2018; Waite et al., 2009; Zolotov et al., 2011; Glein et al., 2015; Holm et al., 2015; Hsu et al., 2015; Taubner et al., 2018 Icy shell (~10 km thick) −233 – −23 nr nr May have ammonia brine pockets May have tectonics Subsurface global ocean (~0–170 km depth) <90 8.5 – 12.2 k 1 – 8 0.45 – <4 Possible serpentinization Titan Icy moon Atmosphere −183 – −73 j nr > 0.01 – 0.15 nr 98.4% N2, 1.4% CH4, 0.2% H2, trace hydrocarbons and organics; 95% N2, 5% CH4, 0.1% H2; ~50 ppmv CO and ~15 ppbv CO2; C2H3CN; clouds Fulchignoni et al., 2005; de Kok et al., 2007; Norman, 2011; Baland et al., 2014; Mastrogiuseppe et al., 2014; Mitri et al., 2014; Sohl et al., 2014; Jennings et al., 2016; McKay, 2016; Mitchell and Lora, 2016; Brassé et al., 2017; Cordier et al., 2017 Surface −183 – −179 nr 0.15–0.35 i nr Lakes and sea have CH4, C2H4, and dissolved nitrogen; dunes of solid organic material; low-latitude deserts and high-latitude moist climates Subsurface −18 11.8 l 50–300 m Likely dense subsurface ocean (≤ 1,350 kg m−3) suggesting high salinity CH4 and C2H6 Ceres Dwarf planet Atmosphere nr nr nr nr Transient atmosphere with possible water vapo Fanale and Salvail, 1989; Zolotov, 2009, 2017; Küppers et al., 2014; Hayne and Aharonson, 2015; Neveu and Desch, 2015; Hendrix et al., 2016; Villarreal et al., 2017; Vu et al., 2017; Castillo-Rogez et al., 2018; McCord and Castillo-Rogez, 2018; McCord and Zambon, 2019 Surface (−157– −30) n 9.7–11.3 n nr <10 n Surface clays; (Mg, Ca)-carbonates; (Mg, NH4)-phyllosilicates; Fe-rich clays; salt deposits; chloride salts; water-rock interactions; brucite and magnetite; sulfur species and graphitized carbon; localized Na-carbonates (e.g.,Na2CO3), NH4Cl, NH4HCO3 Subsurface −143 – −93° o Likely alkaline <140 – 200 p Potentially has briny or NH3-rich subsurface liquid Active water/ice-driven subsurface processes Europa Icy moon Atmosphere (tenuous) nr nr 0.1−12 – 1−12 nr Ion sputtering of the surface; potential water plumes; O2; trace amounts of sodium and potassium Spencer et al., 1999; Chyba and Phillips, 2001; Marion et al., 2005; McGrath et al., 2009; Zolotov and Kargel, 2009; Travis et al., 2012; Cassidy et al., 2013; Muñoz-Iglesias et al., 2013; Kattenhorn and Prockter, 2014; Soderlund et al., 2014; Hand and Carlson, 2015; Kimura and Kitadai, 2015; Noell et al., 2015; Vance et al., 2016; Teolis et al., 2017; Zhu et al., 2017; Jones et al., 2018; Martin and McMinn, 2018; Pavlov et al., 2018 Surface (icy shell) −187 - −141 nr 0.1−12 May be saline, as delivered to the surface from a salty ocean, may have brine or salt inclusions H2O2, H2SO4, CO2; salts concentrated in cracks; oxidants and simple organics; potentially MgSO4, Na2SO4, Na2CO3, may have gas inclusions; may have tectonics Subsurface ocean Daily inundation of seawater at T = −4 – 0 Potential for wide range q 0.1 – 30 r <3.5 Likely contains Mg2+, SO 4 2 - , Na+, Cl−; oxidants and simple organics The observed or putative geochemistry as well as other potential influences are also listed. a Thermosphere can be as cold as −173°C (Bertaux et al., 2007); the upper-to-middle cloud layers are between −40 and 60°C (Cockell, 1999). b Acid concentration in upper cloud layer is 81%, in lower layers up to 98% (Cockell, 1999). c Up to 11 MPa in a deep depression (Basilevsky and Head, 2003). d Summer air temperatures on Mars near the equator can reach a maximum of 35°C (Longstaff, 2014). e Measured by the Phoenix Mars Lander Wet Chemistry Laboratory at the northern plains of the Vastitas Borealis (Hecht et al., 2009). f Liquid water may have had water activity > 0.95 (Fairén et al., 2009). g Calculated temperature at a depth of 1–30 km (Jones et al., 2011; Sinha et al., 2017); at a depth ~310 km, the calculated temperature is <427°C (Jones et al., 2011); the Martian core has temperature 1527°C (Longstaff, 2014). h Calculated groundwater pH (Varnes et al., 2003). i Calculated pressure at Titan's large sea, Ligeia Mare, is 0.20–0.35 MPa (Cordier et al., 2017). j Tropospheric temperature can be −193°C; 80% of incident sunlight is absorbed by Titan's atmosphere, suggesting that there are greenhouse and antigreenhouse effects (Mitchell and Lora, 2016). k The subsurface ocean on Enceladus could also have pH range 10.8–13.5 (Glein et al., 2015). l Calculated ocean pH with 5 wt% NH3 (Brassé et al., 2017). m Calculated pressure for the subsurface ocean with thickness 100 km and outer shell thickness 40–170 km (Baland et al., 2014); 800 MPa at the mantle ice shell-core boundary (Sohl et al., 2014). n Calculated surface temperatures, illuminated surfaces can have temperature < -173°C (Hayne and Aharonson, 2015); calculated pH and salinity for bright deposits in Occator crater (Zolotov, 2017); temperature for bright deposits in Occator crater might reach < -0.2°C (Zolotov, 2017). o Internal temperature might reach 77°C (McCord and Sotin, 2005). p Ceres' center pressure (Zolotov, 2009). q Acid brine may result from hydrothermal systems and be enriched with sulfuric acid (Kargel et al., 2000); neutral brine may occur as leachate from chondritic material and be enriched with magnesium sulfate (Kargel et al., 2000; Pasek and Greenberg, 2012); alkaline brine may occur in areas with natron (Na2 CO 3 . 10H2O), produced from the venting of CO2 from aqueous reservoirs (Langmuir, 1971; Millero and Rabindra, 1997). r At the base of a 100 km Europan ocean, the pressure is calculated to be 146 MPa (Marion et al., 2005). In Table 5, the atmosphere entry for Earth > Atmosphere > Geochemistry is listed as “8.1% N2,” but the actual composition of Earth's atmosphere is “78% N2.” The corrected Table 3 and Table 5 appear below. Lastly, there is a grammatical error in the original article. A correction has therefore been made to the section Can Life Originate, Evolve, or Survive on Other Planetary Bodies? , paragraph five: “Solar and galactic cosmic rays (high-energy particles with energies from 10 MeV to >10 GeV) present challenges to life on the surface and near-surface of Mars and other planetary bodies. However, any subsurface aquifer deeper than a few meters would be protected from damaging radiation. Dartnell et al. (2007) calculated the galactic cosmic ray dosage rates and the corresponding survival times (which they defined as a million-fold decrease in cell number) of characteristic microbes at different depths in Mars's subsurface. At the surface, E. coli has a survival time of 1,200 years, while at 20-m depth, that survival time jumps to 1.5 × 108 years. Compared to E. coli, D. radiodurans has survival times an order of magnitude longer. These survival times are, in fact, lower limits in light of recent measurements by the Radiation Assessment Detector onboard the Mars Science Laboratory (Hassler et al., 2014), which found that the actual dose rate at Gale Crater (76 mGy year−1) is a factor of 2 lower than that modeled by Dartnell et al. (2007).” The authors apologize for these errors and state that they do not change the scientific conclusions of the article in any way. The original article has been updated.