Abstract
The Laser Astrometric Test of Relativity (LATOR) is an experiment designed to test the metric nature of gravitation—a fundamental postulate of the Einstein’s general theory of relativity. The key element of LATOR is a geometric redundancy provided by the long-baseline optical interferometry and interplanetary laser ranging. By using a combination of independent time-series of gravitational deflection of light in the immediate proximity to the Sun, along with measurements of the Shapiro time delay on interplanetary scales (to a precision respectively better than 0.1 picoradians and 1 cm), LATOR will significantly improve our knowledge of relativistic gravity and cosmology. The primary mission objective is i) to measure the key post-Newtonian Eddington parameter γ with accuracy of a part in 109. \(\frac{1}{2}(1-\gamma)\) is a direct measure for presence of a new interaction in gravitational theory, and, in its search, LATOR goes a factor 30,000 beyond the present best result, Cassini’s 2003 test. Other mission objectives include: ii) first measurement of gravity’s non-linear effects on light to ∼0.01% accuracy; including both the traditional Eddington β parameter and also the spatial metric’s 2nd order potential contribution (never measured before); iii) direct measurement of the solar quadrupole moment J 2 (currently unavailable) to accuracy of a part in 200 of its expected size of ≃ 10 − 7; iv) direct measurement of the “frame-dragging” effect on light due to the Sun’s rotational gravitomagnetic field, to 0.1% accuracy. LATOR’s primary measurement pushes to unprecedented accuracy the search for cosmologically relevant scalar-tensor theories of gravity by looking for a remnant scalar field in today’s solar system. We discuss the science objectives of the mission, its technology, mission and optical designs, as well as expected performance of this experiment. LATOR will lead to very robust advances in the tests of fundamental physics: this mission could discover a violation or extension of general relativity and/or reveal the presence of an additional long range interaction in the physical law. There are no analogs to LATOR; it is unique and is a natural culmination of solar system gravity experiments.
Similar content being viewed by others
References
Anderson, J.D., Williams, J.G.: Long-range tests of the equivalence principle. Class. Quantum Gravity 18, 2447 (2001)
Anderson, J.D., Lau, E.L., Turyshev, S.G., Williams, J.G., Nieto, M.M.: Recent results for solar-system tests of general relativity. BAAS 34, 833 (2002)
Bean, R., Carroll, S.M., Trodden, M.: Insights into dark energy: interplay between theory and observation (2005). astro-ph/0510059
Bennett, C.L., Halpern, M., Hinshaw, G., Jarosik, N., Kogut, A., Limon, M., Meyer, S.S., Page, L., Spergel, D.N., Tucker, G.S., Wollack, E., Wright, E.L., Barnes, C., Greason, M.R., Hill, R.S., Komatsu, E., Nolta, M.R., Odegard, N., Peirs, H.V., Verde, L., Weiland, J.L., [i.e. WMAP Science Team]: First year Wilkinson Microwave Anisotropy Probe (WMAP) observations: preliminary maps and basic results. Astrophys. J. Suppl. 148, 1 (2003). astro-ph/0302207
Bertolami, O., Páramos, J.: The pioneer anomaly in the context of the braneworld scenario. Class. Quantum Gravity 21, 3309 (2004) gr-qc/0310101
Bertolami, O., Páramos, J.: Astrophysical constraints on scalar field models. Phys. Rev. D71, 023521 (2004). astro-ph/0408216
Bertolami, O., Páramos, J., Turyshev, S.G.: General theory of relativity: will it survive the next decade? In: Proc. 359th WE-Heraeus Seminar: Lasers, Clock, and Drag-free: Technologies for Future Exploration in Space and Gravity Tests. University of Bremen, ZARM, Bremen, Germany, 30 May–1 June 2005. “Lasers, Clocks, and Drag-Free: Exploration of Relativistic Gravity in Space.” H. Dittus, C. Laemmerzahl, S. Turyshev, editors. (Springer Verlag, 2006), pp. 27–67 (2006), gr-qc/0602016
Bertotti, B., Iess, L., Tortora, P.: A test of general relativity using radio links with the Cassini spacecraft. Nature 425, 374 (2003)
de Bernardis, P., Ade, P.A.R., Bock, J.J., Bond, J.R., Borrill, J., Boscaleri, A., Coble, K., Crill, B.P., De Gasperis, G., Farese, P.C., Ferreira, P.G., Ganga, K., Giacometti, M., Hivon, E., Hristov, V.V., Iacoangeli, A., Jaffe, A.H., Lange, A.E., Martinis, L., Masi, S., Mason, P.V., Mauskopf, P.D., Melchiorri, A., Miglio, L., Montroy, T., Netterfield, C.B., Pascale, E., Piacentini, F., Pogosyan, D., Prunet, S., Rao, S., Romeo, G., Ruhl, J.E., Scaramuzzi, F., Sforna, D., Vittorio, N.: A flat universe from high-resolution maps of the cosmic microwave background radiation. Nature 404, 955 (2000)
Capozziello, S., Troisi, A.: PPN-limit of fourth order gravity inspired by scalar-tensor gravity. Phys. Rev. D72, 044022 (2005). astro-ph/0507545
Carroll S.M.: The cosmological constant. Living Rev. Rel. 4, 1 (2001). astro-ph/0004075
Carroll, S.M., Hoffman, M., Trodden, M.: Can the dark energy equation-of-state parameter w be less than − 1? Phys. Rev. D68, 023509 (2003). astro-ph/0301273
Carroll, S.M., Duvvuri, V., Trodden, M., Turner, M.: Is cosmic speed-up due to new gravitational physics? Phys. Rev. D70, 043528 (2004). astro-ph/0306438
Carroll, S.M., De Felice, A., Duvvuri, V., Easson, D.A., Trodden, M., Turner M.S.: The cosmology of generalized modified gravity models (2005). astro-ph/0410031
Carroll, S.M.: Is our universe natural? (2005). hep-th/0512148
Damour, T., Nordtvedt, K.L., Jr.: General relativity as a cosmological attractor of tensor scalar theories. Phys. Rev. Lett. 70, 2217 (1993)
Damour, T., Nordtvedt, K.L., Jr.: Tensor-scalar cosmological models and their relaxation toward general relativity. Phys. Rev. D48, 3436 (1993)
Damour, T., Polyakov, A.M.: String theory and gravity. Gen. Relativ. Gravit. 26, 1171 (1994)
Damour, T., Polyakov, A.M.: The string dilaton and a least coupling principle. Nucl. Phys. B423, 532 (1994)
Damour, T., Esposito-Farese, G.: Testing gravity to second post-Newtonian order: a field-theory approach. Phys. Rev. D53, 5541 (1996a). gr-qc/9506063
Damour, T., Esposito-Farese, G.: Tensor-scalar gravity and binary pulsar experiments. Phys. Rev. D54, 1474 (1996b). gr-qc/9602056
Damour, T., Esposito-Farese, G.: Gravitational-wave versus binary-pulsar tests of strong-field gravity. Phys. Rev. D58, 042001 (1998). gr-qc/9803031
Damour T., Taylor J.H.: Strong-field tests of relativistic gravity and binary pulsars. Phys. Rev. D45, 1840 (1992)
Damour, T., Piazza, F., Veneziano, G.: Runaway dilaton and equivalence principle violations. Phys. Rev. Lett. 89, 081601 (2002). gr-qc/0204094
Damour, T., Piazza, F., Veneziano, G.: Violations of the equivalence principle in a dilaton-runaway scenario. Phys. Rev. D66, 046007 (2002). hep-th/0205111
Dvali, G., Gabadadze, G., Porrati, M.: 4D gravity on a brane in 5D Minkowski space. Phys. Lett. B485, 208 (2000). hep-th/0005016
Dvali, G., Gabadadze, G., Porrati, M.: On sub-millimeter forces from extra dimensions. Mod. Phys. Lett. A15, 1717 (2000). hep-ph/0007211
Dvali, G., Gruzinov, A., Zaldarriaga, M.: The accelerated universe and the moon. Phys. Rev. D68, 024012 (2003). hep-ph/0212069
Halverson, N.W., Leitch E.M., Pryke C., Kovac, J., Carlstrom, J.E., Holzapfel, W.L., Dragovan, M., Cartwright, J.K., Mason, B.S., Padin, S., Pearson, T.J., Shepherd, M.C., Readhead, A.C.S.: DASI first results: a measurement of the cosmic microwave background angular power spectrum. Astrophys. J. 568, 38 (2002). astro-ph/0104489
Lange, Ch., Camilo, F., Wex, N., Kramer, M., Backer, D.C., Lyne, A.G. Doroshenko, O.: Precision timing measurements of PSR J1012+5307. Mon. Not. R. Astron. Soc. 326, 274 (2001)
Lebach, D.E., Corey, B.E., Shapiro, I.I., Ratner, M.I., Webber, J.C., Rogers, A.E.E., Davis, J.L. Herring, T.A.: Measurement of the solar gravitational deflection of radio waves using very-long-baseline interferometry. Phys. Rev. Lett. 75, 1439 (1995)
Netterfield, C.B., Ade, P.A.R., Bock, J.J., Bond, J.R., Borrill, J., Boscaleri, A., Coble, K., Contaldi, C.R., Crill, B.P., de Bernardis, P., Farese, P., Ganga, K., Giacometti, M., Hivon, E., Hristov, V.V., Iacoangeli, A., Jaffe, A.H., Jones, W.C., Lange, A.E., Martinis, L., Masi, S., Mason, P., Mauskopf, P.D., Melchiorri, A., Montroy, T., Pascale, E., Piacentini, F., Pogosyan, D., Pongetti, F., Prunet, S., Romeo, G., Ruhl, J.E., Scaramuzzi, F. [i.e. Boomerang Collaboration]: A measurement by BOOMERANG of multiple peaks in the angular power spectrum of the cosmic microwave background. Astrophys. J. 571, 604 (2002). astro-ph/0104460
Nordtvedt, K.L., Jr.: Probing gravity to the 2nd post-Newtonian order and to one part in 107 using the Sun. ApJ 320, 871 (1987)
Nordtvedt, K.L., Jr.: Significance of ‘second-order’ light propagation experiments in the solar system. Class. Quantum Gravity 13, A11 (1996)
Nordtvedt, K.L., Jr.: Lunar laser ranging—a comprehensive probe of post-Newtonian gravity (2003). gr-qc/0301024
Peebles, P.J.E., Ratra, B.: The cosmological constant and dark energy. Rev. Mod. Phys. 75, 599 (2003). astro-ph/0207347
Peacock, J.A., et al.: A measurement of the cosmological mass density from clustering in the 2dF galaxy redshift survey. Nature 410, 169 (2001)
Perlmutter, S., Aldering, G., Goldhaber, G., Knop, R.A., Nugent, P., Castro, P.G., Deustua, S., Fabbro, S., Goobar, A., Groom, D.E., Hook, I.M., Kim, A.G., Kim, M.Y., Lee, J.C., Nunes, N.J., Pain, R., Pennypacker, C.R., Quimby, R., Lidman, C., Ellis, R.S., Irwin, M., McMahon, R.G., Ruiz-Lapuente, P., Walton, N., Schaefer, B., Boyle, B.J., Filippenko, A.V., Matheson, T., Fruchter, A.S., Panagia, N., Newberg, H.J.M., Couch, W.J. [i.e. Supernova Cosmology Project Collaboration]: Measurements of omega and lambda from 42 high-redshift supernovae. Astrophys. J. 517, 565 (1999). astro-ph/9812133
Pitjeva, E.V.: Relativistic effects and solar oblateness from radar observations of planets and spacecraft. Astron. Lett. 31, 340 (2005)
Plowman, J.E., Hellings, R.W.: LATOR covariance analysis. Class. Quantum Gravavity 23, 309 (2006). gr-qc/0505064
Reasenberg, R.D., Shapiro, I.I., MacNeil, P.E., Goldstein, R.B., Breidenthal, J.C., Brenkle, J.P., Cain, D.L., Kaufman, T.M., Komarek, T.A., Zygielbaum, A.I.: Viking relativity experiment: verification of signal retardation by solar gravity. ApJ Lett. 234, L219 (1979)
Robertson, D.S., Carter, W.E., Dillinger, W.H.: A new measurement of solar gravitational deflection of radio signals using VLBI. Nature 349, 768 (1991)
Riess, A.G., Filippenko, A.V., Challis, P., Clocchiatti, A., Diercks, A., Garnavich, P.M., Gilliland, R.L., Hogan, C.J., Jha, S., Kirshner, R., Leibundgut, B., Phillips, M.M., Reiss, D., Schmidt, B.P., Schommer, R.A., Smith, R.C., Spyromilio, J., Stubbs, C., Suntzeff, N.B., Tonry, J.: Observational evidence from supernovae for an accelerating universe and a cosmological constant. [i.e., Supernova Search Team Collaboration] Astron. J. 116, 1009 (1998)
Shapiro, I.I., Counselman, C.C., III, King, R.W.: Verification of the principle of equivalence for massive bodies. Phys. Rev. Lett. 36, 555 (1976)
Shapiro, I.I., Reasenberg, R.D., MacNeil, P.E., Goldstein, R.B., Brenkle, J.P., Cain, D.L., Komarek, T., Zygielbaum, A.I., Cuddihy, W.F., Michael, W.H., Jr.: The viking relativity experiment. JGR 82, 4329 (1977)
Shapiro, S.S., Davis, J.L., Lebach, D.E., Gregory, J.S.: Measurement of the solar gravitational deflection of radioWaves using geodetic very-long-baseline interferometry data, 1979–1999. Phys. Rev. Lett. 92, 121101 (2004)
Taylor, J.H., Wolszczan, A., Damour, T., Weisberg, J.M.: Experimental constraints on strong-field relativistic gravity. Nature 355, 132 (1992)
Tonry, J.L., Schmidt, B.P., Barris, B., Candia, P., Challis, P., Clocchiatti, A., Coil, A.L., Filippenko, A.V., Garnavich, P., Hogan, C., Holland, S.T., Jha, S., Kirshner, R.P., Krisciunas, K., Leibundgut, B., Li, W., Matheson, T., Phillips, M.M., Riess, A.D., Schommer, R., Smith, R.C., Sollerman, J., Spyromilio, J., Stubbs, C.W., Suntzeff, N.B.: Cosmological results from high-z supernovae. Astrophys. J. 594, 1–24 (2003). astro-ph/0305008
Turyshev, S.G., Shao, M., Nordtvedt, K.L., Jr.: The Laser Astrometric Test of Relativity (LATOR) mission. Class. Quantum Gravity 21, 2773 (2004). gr-qc/0311020
Turyshev, S.G., Shao, M., Nordtvedt, K.L., Jr.: Experimental design for the LATOR mission. Int. J. Mod. Phys. D13, 2035 (2004). gr-qc/0410044
Turyshev, S.G., Shao, M., Nordtvedt, K.L., Jr.: Optical design for the Laser Astrometric Test of Relativity. In: Proc. The XXII Texas Symposium on Relativistic Astrophysics. Stanford University, 13–17 December 2004, eConf C041213 #0306 (2004). gr-qc/0502113
Turyshev, S.G., Shao, M., Nordtvedt, K.L., Jr.: Science, technology and mission design for the Laser Astrometric Test of Relativity mission. 359th WE-heraeus Seminar: Lasers, Clock, and Drag-free: Technologies for Future Exploration in Space and Gravity Tests. University of Bremen, ZARM, Bremen, Germany, 30 May–1 June 2005. In: Dittus, H., Laemmerzahl, C., Turyshev, S. (eds.) Lasers, Clocks, and Drag-free: Technologies for Future Exploration in Space and Tests of Gravity: Proceedings, pp. 429-493. Springer Verlag (2006). arXiv:gr-qc/0601035
Turyshev, S.G., Israelsson, U.E., Shao, M., Yu, N., Kusenko, A., Wright, E.L., Everitt, C.W.F., Kasevich, M., Lipa, J.A., Mester, J.C., Reasenberg, R.D., Walsworth, R.L., Ashby, N., Gould, H., Paik, H.J.: Space-based research in fundamental physics and quantum technologies. Int. J. Mod. Phys. D 16(12a), 1879–1925 (2007). arXiv:0711.0150 [gr-qc]
Turyshev S. G.: Experimental tests of general relativity. Annu. Rev. Nucl. Part. Sci. 58, 207–248 (2008). arXiv:0806.1731 [gr-qc]
Will, C.M.: Theory and experiment in gravitational physics. Cambridge: Cambridge University Press (1993)
Will, C.M.: The confrontation between general relativity and experiment. Liv. Rev. Relativity 9 (2006). gr-qc/0510072
Williams, J.G., Turyshev, S.G., Boggs, D.H.: Progress in lunar laser ranging tests of relativistic gravity. Phys. Rev. Lett. 93, 261101 (2004) gr-qc/0411113
Acknowledgements
The work described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Turyshev, S.G., Shao, M., Nordtvedt, K.L. et al. Advancing fundamental physics with the Laser Astrometric Test of Relativity. Exp Astron 27, 27 (2009). https://doi.org/10.1007/s10686-009-9170-9
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s10686-009-9170-9
Keywords
- Fundamental physics
- Tests of general relativity
- Scalar-tensor theories
- Modified gravity
- Interplanetary laser ranging
- Optical interferometry
- Picometer-class metrology
- LATOR