The Sirens of Mars

by Sarah Stewart Johnson

  CRYSTALLINE FORM OF RUST Bruce Murray, quoted in Jennifer Vaughn, “Mars, Old and New: A Personal View by Bruce Murray,” The Planetary Society (September 3, 2013). Hematite (Fe2O3) appears red in its fine-grained form and gray in its coarse-grained form. Signatures of coarse-grained gray hematite in orbital infrared spectrometry data were what drove the decision to land at Merdiani Planum.

  BEGAN CLAPPING The recounting of this moment, as well as many others in the early days of the Mars Exploration Rover mission, are encapsulated in Steve Squyres’s wonderful firsthand account: Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet, p. 292.

  FELT COMPLETELY DISORIENTED Ibid., p. 292.

  “WELCOME TO MERIDIANI” Ibid., p. 293.

  ADVOCATED FOR MERIDIANI Ibid., p. 307.

  “HOLY SMOKES” Ibid., pp. 293–294; misunderstanding the expression, Korea’s major afternoon daily ran with the headline, THE SECOND MARS ROVER LANDS, SEEING MYSTERIOUS SMOKE.

  “HOLE IN ONE” Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet, p. 294.

  BARELY ANKLE-HIGH Marcus Y. Woo, “Roving on Mars,” Engineering and Science, 72 (2), (2009) pp. 12–20.

  WERE DUBBED “BLUEBERRIES” “Martian ‘Blueberries,’ ” NASA Science Mars Exploration Program (Jan. 27, 2015).

  “FREAKY LITTLE HEMATITE BALLS” Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet, p. 300.

  SUGGESTING THAT THE HEMATITE HAD FORMED Marjorie A Chan, Brenda Beitler, W. T. Parry, Jens Ormö, and Goro Komatsu, “A Possible Terrestrial Analogue for Haematite Concretions on Mars,” Nature, 429, no. 6993 (2004); Scott M. McLennan, J. F. Bell III, W. M. Calvin, P. R. Christensen, BC D. Clark, P. A. De Souza, J. Farmer et al., “Provenance and Diagenesis of the Evaporite-Bearing Burns Formation, Meridiani Planum, Mars,” Earth and Planetary Science Letters, 240, no. 1 (2005), pp. 95–121; W. M. Calvin, et al., “Hematite Spherules at Meridiani: Results from MI, Mini-TES, and Pancam,” Journal of Geophysical Research: Planets, 113, no. E12 (2008).

  MAGNESIUM SULFATE EVERYWHERE Henry Bortman, “Evidence of Water Found on Mars,” Astrobiology Magazine (March 3, 2004).

  SULFATE MINERAL JAROSITE G. Klingelhöfer, R. Van Morris, B. Bernhardt, C. Schröder, D. S. Rodionov, P. A. De Souza, A. Yen, et al., “Jarosite and Hematite at Meridiani Planum from Opportunity’s Mössbauer Spectrometer,” Science, 306, no. 5702 (2004), pp. 1,740–1,745.

  HIGHLY ACIDIC CONDITIONS This would have been a welcome development to Roger Burns, an MIT geologist, who proposed a model of acid weathering of the iron-rich basalts on Mars long before anyone else; see: Roger Burns and Duncan Fisher, “Rates of Oxidative Weathering on the Surface of Mars,” Journal of Geophysical Research, 98 (1993). For this reason, the evaporite-bearing Burns formation at Meridiani was named in his honor. Acidic waters also help explain the mystery of why so few chalky carbonates had been detected on the planet’s surface, as carbonates do not precipitate out of solution at low pH.

  “RIVER OF FIRE” Linda A. Amaral Zettler, Felipe Gómez, Erik Zettler, Brendan G. Keenan, Ricardo Amils, and Mitchell L. Sogin, “Microbiology: Eukaryotic Diversity in Spain’s River of Fire,” Nature, 417, no. 6885 (2002), p. 137.

  LAYERS OF ROCK OVERLAPPING J. P. Grotzinger, R. E. Arvidson, J. F. Bell III, W. Calvin, B. C. Clark, D. A. Fike, M. Golombek, et al., “Stratigraphy and Sedimentology of a Dry to Wet Eolian Depositional System, Burns Formation, Meridiani Planum, Mars,” Earth and Planetary Science Letters, 240, no. 1 (2005), pp. 11–72; McLennan, et al., “Provenance and Diagenesis of the Evaporite-Bearing Burns Formation, Meridiani Planum, Mars,” Earth and Planetary Science Letters.

  LIGHTHEARTEDNESS INSTANTLY RETURNED The team was broken into scientific areas of expertise—one for geology, one for atmospheric science, etc.—not into teams based on the rover’s seven instruments. As I’d later realize, that was a deliberate decision made to dissolve rivalries among those who’d worked in small groups for years to build a particular piece of hardware. Instead of competing for time and power to be dedicated to their beloved technology during SOWG, the theme groups had to argue the merits of the larger scientific goals.

  CRACK NAMED ANATOLIA “Press Release Images: Opportunity: A Puzzling Crack,” NASA Mars Exploration Rovers (April 6, 2004).

  CRATER NAMED FRAM S. W. Squyres, et al., “Overview of the Opportunity Mars Exploration Rover Mission to Meridiani Planum: Eagle Crater to Purgatory Ripple,” Journal of Geophysical Research, 111 (2006), p. 4.

  THE ROUTE TO ENDURANCE The convention soon became to name craters after famous ships of exploration: Fram was the ship that transported Amundsen’s crew to Antarctica, where they first successfully reached the South Pole; Endurance was the name of Shackleton’s ship that was crushed in the ice; and Endeavor was the name of the ship that took James Cook on his voyage to New Zealand and Australia. The team joked that if Opportunity ever reached Endeavor Crater, only a few graduate students would remain, just as only a few crew members managed to avoid malaria and dysentery on Cook’s voyage. Even Eagle fit the convention, as it was also the name of the famous spacecraft that delivered Neil Armstrong and Buzz Aldrin to the surface of the moon.

  “FIRST NAVCAM FRAME” Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet, p. 335.

  DRIVEN AND DRIVEN Ibid., p. 334.

  A NEW MAP Bruce C. Heezen and Marie Tharp, “World Ocean Floor Panorama,” full color, painted by H. Berann, Mercator projection, scale 1, no. 23,230,300 (1977).

  SAGAN BARELY SET FOOT Steve went on to work closely with other Cornell professors, including Joseph Veverka (his scientific advisor), Arthur Bloom, Steven Ostro, and William Travers, as well as Gene Shoemaker at USGS and several members of the Voyager imaging team. Steven Squyres, “The Morphology and Evolution of Ganymede and Callisto,” Cornell PhD thesis (1981).

  STIPPLED WITH BLUEBERRIES David R. Williams, “Mars Rover ‘Opportunity’ Images,” NASA Goddard Space Flight Center (June 16, 2004).

  COLUMBIA HILLS The Columbia Hills were named after the space shuttle Columbia, which disintegrated as it reentered Earth’s atmosphere in 2003, killing the crew. The seven peaks are named for the seven individual astronauts.

  WEST SPUR OF HUSBAND HILL Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet, pp. 351–354.

  UNCOVERED TRACES OF HEMATITE Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet, pp. 351–354, 362–363.

  CHEMICAL ENRICHMENTS Douglas Wayne Ming, David W. Mittlefehldt, Richard Van Morris, D. C. Golden, Ralf Gellert, Albert Yen, Benton C. Clark, et al., “Geochemical and Mineralogical Indicators for Aqueous Processes in the Columbia Hills of Gusev Crater, Mars,” Journal of Geophysical Research: Planets, 111, no. E2 (2006).

  WERE CALLED “VUGS” Squyres, Steven W., John P. Grotzinger, Raymond E. Arvidson, J. F. Bell, Wendy Calvin, Philip R. Christensen, Benton C. Clark, et al., “In Situ Evidence for an Ancient Aqueous Environment at Meridiani Planum, Mars,” Science, 306, no. 5702 (2004), pp. 1,709–1,714; Kenneth E. Herkenhoff, S. W. Squyres, R. Arvidson, D. S. Bass, J. F. Bell, Pernille Bertelsen, B. L. Ehlmann, et al., “Evidence from Opportunity’s Microscopic Imager for Water on Meridiani Planum,” Science, 306, no. 5702 (2004), pp. 1,727–1,730.

  LAST FEATURES TO FORM McLennan, et al, “Provenance and Diagenesis of the Evaporite-Bearing Burns Formation, Meridiani Planum, Mars,” Earth and Planetary Science Letters.

  WATER TABLE HAD RISEN S. W. Squyres and Andrew H. Knoll, Sedimentary Geology at Meridiani Planum, Mars (Houston: Gulf Professional Publishing, 2005), p. 68; J. P. Grotzinger, “Depositional Model for the Burns Formation, Meridiani Planum,” Seventh International Conference on Mars (2007).

  SEE OUR TRACKS NASA/JPL/MSSS, “Opportunity Tracks Seen From Orbit,” NASA Science Mars Explorati
on Program (Jan. 24, 2005).

  “FOLLOW THE WATER” “Fourth Planet from the Sun,” NASA Mars Exploration Program.

  JAROSITE THAT OPPORTUNITY HAD FOUND The Mössbauer spectrometer on the rover’s arm was designed specifically to look at different types of iron minerals, which could help tease apart past environmental conditions, given that iron rusts in the presence of water and oxygen.

  HIGHLY ACIDIC WATER Peter Cogram, “Jarosite,” in Reference Module in Earth Systems and Environmental Sciences, Scott A. Elias, et al., eds. (ScienceDirect, 2018). While high concentrations of potassium ions, for instance, can also lead to jarosite formation at higher pH, the surface chemistry supported an acidic interpretation.

  EVEN EUKARYOTES Amaral Zettler, Gómez, Zettler, Keenan, Amils, and Sogin, “Microbiology: Eukaryotic Diversity in Spain’s River of Fire,” Nature.

  UNDER WAY FOR SCIENCE Nicholas J. Tosca, Andrew H. Knoll, and Scott M. McLennan, “Water Activity and Challenge for Life on Early Mars,” Science, 320, no. 5880 (2008), pp. 1,204–1,207.

  SOY SAUCE J. E. Henney, C. L. Taylor, and C. S. Boon, eds., “Preservation and Physical Property Roles of Sodium in Foods,” in Strategies to Reduce Sodium Intake in the United States (Washington, D.C.: National Academies Press, 2010).

  CALLED THE CLUSTERS “DAISIES” “Daisy Found on ‘Route 66’,” Mars Exploration Rovers Spirit Press Release Image, NASA/JPL/Cornell (April 17, 2004).

  IT REMINDED ME OF Joseph von Littrow’s proposed fiery canals in the Sahara, Carl Friedrich Gauss’s triangle of wheat in Siberia, and Charles Cros’s mirrors across Europe have been cited more than a dozen times in recent years, though it is not clear whether these proposals were genuine, speculative, or mere rumors. That these stories circulated in the eighteenth and nineteenth centuries, however, points to a preoccupation during that era with signaling to extraterrestrial beings that the Earth was inhabited by intelligent life-forms (in 1900, a prize of 100,000 francs—the “Prix Pierre Guzman”—was even set up by the French Académie des Sciences for the first person to communicate with a celestial object other than Mars—Mars was excluded because it was considered to be sufficiently well known, and therefore not a difficult enough challenge). Jeff Greenwald, “Who’s Out There?” Discover (April 1, 1999); Michael J. Crowe, The Extraterrestrial Life Debate, 1750–1900 (Mineola, N.Y.: Dover Publications, 2011), p. 205; Hans Zappe, Fundamentals of Micro-Optics, 1st ed. (Cambridge University Press, 2010), p. 298; Willy Ley, Rockets, Missiles, and Space Travel (New York: Viking Press, 1958); Frank Drake, “A Brief History of SETI,” Third Decennial US–USSR Conference on SETI—ASP Conference Series, 47 (1993), pp. 11–18; Michael Carroll, Earths of Distant Suns (Göttingen, Germany: Copernicus), pp. 14–15; Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences, 131 (1900), p. 1,147.

  CAVE OF SWIMMERS Gilf Kebir, László E. de Almásy, Récentes Explorations dans le Désert Libyque (1932–1936), E. and R. Schindler pour la Société Royale de Géographie d’Égypte, 1936.

  Chapter 9: In Aeternum

  “ROAD OF BONES” Marcus Warren, “ ‘Road of Bones’ Where Slaves Perished,” The Telegraph (London: Aug. 10, 2002).

  GATHER BLUEBERRIES Quoted in Kristofor Minta and Herbert Pföstl, To Die No More (New York: Blind Pony Books, 2008), originally from Catherine Merridale, Night of Stone: Death and Memory in Twentieth Century Russia (New York: Penguin Books, 2002), p. 300.

  IN THE 1990S Eske Willerslev, et al., “Diverse Plant and Animal Genetic Records from Holocene and Pleistocene Sediments,” Science, 300, no. 5,620 (2003), pp. 791–795 (see also “Sample Information” and “Stratigraphic Information” in “Supporting Material”).

  DICE-SIZED CUBES Carl Zimmer, “Eske Willerslev Is Rewriting History with DNA,” The New York Times (May 16, 2016).

  FROZEN WATER I. Mitrofanov, et al., “Maps of Subsurface Hydrogen from the High Energy Neutron Detector, Mars Odyssey,” Science, 297, no. 5,578 (2002), pp. 78–81.

  IN 2001 BY A NASA ORBITER This was NASA’s Mars Odyssey mission, which launched in April of 2001 and arrived that October.

  NEWLY FORMED GROUP Eske continues to do pioneering work in evolutionary genetics; he is now at the University of Copenhagen, where he leads the Center for GeoGenetics.

  ONCE DISAPPEARED Zimmer, “Eske Willerslev Is Rewriting History with DNA,” The New York Times.

  CONTAMINATION WAS SUCH Most genomics labs were awash in tiny strands of DNA—exponentially copied target molecules that would waft out of strips of plastic tubes as they clicked open. To work with such lean samples—where there was low signal to noise—we needed to transfer our sealed DNA extractions to another building before we amplified them and began our analyses.

  SØREN KIERKEGAARD’S GRAVE Joakim Garff, translated by Bruce H. Kirmmse, Søren Kierkegaard: A Biography (Princeton, N.J.: Princeton University Press, 2000), p. 811.

  300,000 YEARS Sarah S. Johnson, et al., “Ancient Bacteria Show Evidence of DNA Repair,” Proceedings of the National Academy of Sciences, 104 (36) (2007), pp. 14,401–14,405.

  THE ENTIRE PHYLOGENIC TREE Rod Pyle, Destination Mars: New Explorations of the Red Planet (Amherst, N.Y.: Prometheus Books, 2012), p. 248.

  ASSESS ITS BIOLOGICAL POTENTIAL The official objectives of the mission were to 1) study the history of water in the Martian arctic and 2) search for evidence of a habitable zone and assess the biological potential of the ice-soil boundary. “Mars Phoenix Lander Overview,” NASA.

  MYTHICAL ARABIAN BIRD Herodotus, Histories, trans. George Rawlinson (The Internet Classics Archive), II.

  RECYCLED HARDWARE AND SOFTWARE Pyle, Destination Mars: New Explorations of the Red Planet, p. 231.

  SHOESTRING BUDGET “NASA’s Phoenix Mars Mission Gets Thumbs Up for 2007 Launch,” NASA press release (June 2, 2005).

  FIRST SCOUT MISSION “Phoenix Mars Scout,” NASA Facts, NASA JPL.

  RUN AND OPERATED Pyle, Destination Mars: New Explorations of the Red Planet, p. 230.

  PULSE THRUSTERS D. H. Plemmons, et al., “Effects of the Phoenix Lander Descent Thruster Plume on the Martian Surface,” Journal of Geophysical Research, 113 (2008).

  ALMOST ALL THE SUCCESSFUL MISSIONS An exception includes the Viking 2 lander, which touched down at 48 degrees north latitude.

  CANADA’S NORTHWEST TERRITORIES “Frequently Asked Questions,” Phoenix Mars Mission, the University of Arizona.

  SLOW IT DOWN Eric Hand, “Mars exploration: Phoenix: a race against time,” Nature (Dec. 10, 2008).

  JUST BENEATH THE SURFACE W. C Feldman, W. V. Boynton, R. L. Tokar, T. H. Prettyman, O. Gasnault, S. W. Squyres, R. C. Elphic, et al., “Global Distribution of Neutrons from Mars: Results from Mars Odyssey,” Science, 297, no. 5578 (2002), pp. 75–78; I. Mitrofanov, D. Anfimov, A. Kozyrev, M. Litvak, A. Sanin, V. Tret’yakov, A. Krylov, et al., “Maps of Subsurface Hydrogen from the High Energy Neutron Detector, Mars Odyssey.” Science, 297, no. 5578 (2002), pp. 78–81.

  A FIERY MURAL Angela Poulson, “UA Art Class About to Complete Giant Phoenix Mars Mission Mural,” UA News (Dec. 1, 2006).

  REHEARSING A PRESS CONFERENCE Pyle, Destination Mars: New Explorations of the Red Planet, p. 249.

  VACCINE FOR YELLOW FEVER Joe Bargmann, “Spacemen,” The Washington Post Magazine (Sept. 28, 2008).

  A TWITTER ACCOUNT Alexis Madrigal, “Wired Science Scores Exclusive Twitter Interview with the Phoenix Mars Lander,” Wired (May 30, 2008).

  140-CHARACTER LIMIT Ibid.

  “VEGAS SLOT MACHINE” Ibid.

  MARS RECONNAISSANCE ORBITER The Mars Reconnaissance Orbiter was a NASA orbital mission that launched in 2005 and arrived in 2006. The mission has mapped the presence of clays, carbonates, and chlorides, determined the volume of water ice in the northern polar cap, and collected arrestingly detailed images of features like recurring slope lineae with its High Resolutio
n Imaging Science Experiment (HiRISE) camera. The orbiter remains active today and is a key telecommunications link for rover surface operations.

  PHOTOGRAPH OF PHOENIX John Mahoney, “Mars Reconnaissance Orbiter Captures Images of Phoenix Lander’s Descent,” Popular Science (May 27, 2008).

  SIX AND A HALF SECONDS Ivan Semeniuk, “First Phoenix Images Reveal ‘Quilted’ Martian Terrain,” New Scientist (May 26, 2008).

  PIROUETTE AS IT OPENED Emily Lakdawalla, “Phoenix Has Landed!” The Planetary Society (May 25, 2008).

  “CHEERS! TEARS!!” Madrigal, “Wired Science Scores Exclusive Twitter Interview with the Phoenix Mars Lander,” Wired.

  MULTIPLE CAMERAS ON PHOENIX Peter H. Smith, “Introduction to Visions of Mars,” The Planetary Society (Feb. 14, 2007).

  INTERSECTING POLYGONS Michael T. Mellon, Michael C. Malin, Raymond E. Arvidson, Mindi L. Searls, Hanna G. Sizemore, Tabatha L. Heet, Mark T. Lemmon, H. Uwe Keller, and John Marshall, “The Periglacial Landscape at the Phoenix Landing Site,” Journal of Geophysical Research: Planets, 114, no. E1 (2009).

  REPEATED EXPANSION AND CONTRACTION Ivan Semeniuk, “First Phoenix Images Reveal ‘Quilted’ Martian Terrain,” New Scientist (May 26, 2008).

  “POLYGONS WITHIN POLYGONS WITHIN POLYGONS” Ivan Semeniuk, “Mars Scientists Ponder Polygon Mystery,” New Scientist (May 27, 2008).

  FROM THE UNIVERSITY OF MICHIGAN That team member was Nilton Rennó, a professor of climate and space sciences and engineering at the University of Michigan.

  WATER DROPLETS Kenneth Chang, “Blobs in Photos of Mars Lander Stir a Debate: Are They Water?” The New York Times (March 16, 2009); N. Rennó, et al., Lunar and Planetary Science Conference, 40 (2009); Nilton O. Rennó, Brent J. Bos, David Catling, Benton C. Clark, Line Drube, David Fisher, Walter Goetz, et al., “Possible Physical and Thermodynamical Evidence for Liquid Water at the Phoenix Landing Site,” Journal of Geophysical Research: Planets, 114, no. E1 (2009).