dark earths: initial goals for interstellar exploration

Dark Earths: Initial Goals for Interstellar Exploration T .M. Eubanks, Asteroid Initiatives LLC, Clifton, Virginia ([email protected]) Abstract Submitted to the 65th International Astronautical Congress Session D4.4 Strategies for Rapid Implementation of Interstellar Missions: Precursors and Beyond Gravitational microlensing surveys have revealed the existence of a substantial and widespread population of “nomadic” planets, bodies not in orbit around any star. Nomadic Jupiter-mass objects are apparently more common than main sequence stars, immediately implying that there should be one or more Jupiter-mass nomadic objects closer to us than any stellar system. The microlensing results also reveal that the mass spectrum of these objects follows power laws such that smaller nomadic planets should be more common that Jupiter-sized bodies. Strigari et al. (2012) extrapolated these power laws to estimate that there could be as many as 1000 Earth-mass, and 100,000 Lunar-mass, nomadic bodies per main sequence star. Interstellar nomadic planets, if they can be found close to the Sun, would offer compelling destinations for initial interstellar missions. Wit h the Strigari et al. population estimates, the nearest “dark Moon” could be within 0.1 light years (ly), the nearest “dark Earth” 0.5 ly, and the nearest “dark Jupiter” 3 ly, of the Solar System. Theoretical analysis also indicates that Earth-sized and larger nomadic planets, although likely very cold on the surface or at the top of their atmosphere, should have sufficient sources of internal heat to support biospheres for durations comparable to the age of the solar system. Nearby nomadic planets within a few tenths of a ly of the solar system, potentially possessing biospheres and much easier to reach than the nearest stellar systems, are likely to be the natural targets for early interstellar missions, if they can be found. An immediate goal of interstellar exploration should thus be to find the dark nomadic planets within 1/2 ly of the Earth. These bodies would be typically too close to be detected with gravitational microlensing, but could be detected via stellar transits and confirmed with the ALMA interferometer, which is sensitive to cold body thermal emissions at millimeter and sub-millimeter wavelengths.

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Abstract Submitted to the 65th International Astronautical Congress

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5/27/2018 Dark Earths: Initial Goals for Interstellar Exploration

Dark Earths: Initial Goals for Interstellar Exploration

T.M. Eubanks, Asteroid Initiatives LLC, Clifton, Virginia([email protected])

Abstract Submitted to the 65th International Astronautical Congress

Session D4.4 Strategies for Rapid Implementation of Interstellar Missions: Precursorsand Beyond

Gravitational microlensing surveys have revealed the existence of a substantial andwidespread population of nomadic planets, bodies not in orbit around any star.Nomadic Jupiter-mass objects are apparently more common than main sequence stars,immediately implying that there should be one or more Jupiter-mass nomadic objects

closer to us than any stellar system. The microlensing results also reveal that the massspectrum of these objects follows power laws such that smaller nomadic planets shouldbe more common that Jupiter-sized bodies. Strigari et al. (2012) extrapolated thesepower laws to estimate that there could be as many as 1000 Earth-mass, and 100,000Lunar-mass, nomadic bodies per main sequence star.

Interstellar nomadic planets, if they can be found close to the Sun, would offercompelling destinations for initial interstellar missions. With the Strigari et al. populationestimates, the nearest dark Moon could be within 0.1 light years (ly), the nearest darkEarth 0.5 ly, and the nearest dark Jupiter 3 ly, of the Solar System. Theoreticalanalysis also indicates that Earth-sized and larger nomadic planets, although likely very

cold on the surface or at the top of their atmosphere, should have sufficient sources ofinternal heat to support biospheres for durations comparable to the age of the solarsystem.

Nearby nomadic planets within a few tenths of a ly of the solar system, potentiallypossessing biospheres and much easier to reach than the nearest stellar systems, arelikely to be the natural targets for early interstellar missions, if they can be found. Animmediate goal of interstellar exploration should thus be to find the dark nomadicplanets within 1/2 ly of the Earth. These bodies would be typically too close to bedetected with gravitational microlensing, but could be detected via stellar transits andconfirmed with the ALMA interferometer, which is sensitive to cold body thermal

emissions at millimeter and sub-millimeter wavelengths.
mailto:[email protected]:[email protected]
5/27/2018 Dark Earths: Initial Goals for Interstellar Exploration