Institution
Jet Propulsion Laboratory
Facility•La Cañada Flintridge, California, United States•
About: Jet Propulsion Laboratory is a facility organization based out in La Cañada Flintridge, California, United States. It is known for research contribution in the topics: Mars Exploration Program & Telescope. The organization has 8801 authors who have published 14333 publications receiving 548163 citations. The organization is also known as: JPL & NASA JPL.
Topics: Mars Exploration Program, Telescope, Galaxy, Coronagraph, Planet
Papers published on a yearly basis
Papers
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TL;DR: The IAU/IAG Working Group on cartographic coordinates and rotational elements of the planets and satellites revises tables giving the directions of the north poles of rotation and the prime meridians of the asteroids as discussed by the authors.
Abstract: Every three years the IAU/IAG Working Group on cartographic coordinates and rotational elements of the planets and satellites revises tables giving the directions of the north poles of rotation and the prime meridians of the planets, satellites, and asteroids. Also presented are revised tables giving their sizes and shapes. Changes since the previous report are summarized in the Appendix.
526 citations
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TL;DR: In this article, the authors presented new limits on an isotropic stochastic gravitational wave background (GWB) using a six pulsar dataset spanning 18 yr of observations from the 2015 European Pulsar Timing Array data release.
Abstract: We present new limits on an isotropic stochastic gravitational-wave background (GWB) using a six pulsar dataset spanning 18 yr of observations from the 2015 European Pulsar Timing Array data release Performing a Bayesian analysis, we fit simultaneously for the intrinsic noise parameters for each pulsar, along with common correlated signals including clock, and Solar System ephemeris errors, obtaining a robust 95$\%$ upper limit on the dimensionless strain amplitude $A$ of the background of $A<30\times 10^{-15}$ at a reference frequency of $1\mathrm{yr^{-1}}$ and a spectral index of $13/3$, corresponding to a background from inspiralling super-massive black hole binaries, constraining the GW energy density to $\Omega_\mathrm{gw}(f)h^2 < 11\times10^{-9}$ at 28 nHz We also present limits on the correlated power spectrum at a series of discrete frequencies, and show that our sensitivity to a fiducial isotropic GWB is highest at a frequency of $\sim 5\times10^{-9}$~Hz Finally we discuss the implications of our analysis for the astrophysics of supermassive black hole binaries, and present 95$\%$ upper limits on the string tension, $G\mu/c^2$, characterising a background produced by a cosmic string network for a set of possible scenarios, and for a stochastic relic GWB For a Nambu-Goto field theory cosmic string network, we set a limit $G\mu/c^2<13\times10^{-7}$, identical to that set by the {\it Planck} Collaboration, when combining {\it Planck} and high-$\ell$ Cosmic Microwave Background data from other experiments For a stochastic relic background we set a limit of $\Omega^\mathrm{relic}_\mathrm{gw}(f)h^2<12 \times10^{-9}$, a factor of 9 improvement over the most stringent limits previously set by a pulsar timing array
526 citations
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01 Nov 2013TL;DR: A generic framework, dubbed MultiSensor-Fusion Extended Kalman Filter (MSF-EKF), able to process delayed, relative and absolute measurements from a theoretically unlimited number of different sensors and sensor types, while allowing self-calibration of the sensor-suite online online is presented.
Abstract: It has been long known that fusing information from multiple sensors for robot navigation results in increased robustness and accuracy. However, accurate calibration of the sensor ensemble prior to deployment in the field as well as coping with sensor outages, different measurement rates and delays, render multi-sensor fusion a challenge. As a result, most often, systems do not exploit all the sensor information available in exchange for simplicity. For example, on a mission requiring transition of the robot from indoors to outdoors, it is the norm to ignore the Global Positioning System (GPS) signals which become freely available once outdoors and instead, rely only on sensor feeds (e.g., vision and laser) continuously available throughout the mission. Naturally, this comes at the expense of robustness and accuracy in real deployment. This paper presents a generic framework, dubbed MultiSensor-Fusion Extended Kalman Filter (MSF-EKF), able to process delayed, relative and absolute measurements from a theoretically unlimited number of different sensors and sensor types, while allowing self-calibration of the sensor-suite online. The modularity of MSF-EKF allows seamless handling of additional/lost sensor signals during operation while employing a state buffering scheme augmented with Iterated EKF (IEKF) updates to allow for efficient re-linearization of the prediction to get near optimal linearization points for both absolute and relative state updates. We demonstrate our approach in outdoor navigation experiments using a Micro Aerial Vehicle (MAV) equipped with a GPS receiver as well as visual, inertial, and pressure sensors.
521 citations
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TL;DR: High-resolution Galileo spacecraft images of Europa are presented, in which evidence for mobile ‘icebergs’ is found and the detailed morphology of the terrain strongly supports the presence of liquid water at shallow depths below the surface, either today or at some time in the past.
Abstract: Ground-based spectroscopy of Jupiter's moon Europa, combined with gravity data, suggests that the satellite has an icy crust roughly 150 km thick and a rocky interior In addition, images obtained by the Voyager spacecraft revealed that Europa's surface is crossed by numerous intersecting ridges and dark bands (called lineae) and is sparsely cratered, indicating that the terrain is probably significantly younger than that of Ganymede and Callisto It has been suggested that Europa's thin outer ice shell might be separated from the moon's silicate interior by a liquid water layer, delayed or prevented from freezing by tidal heating; in this model, the lineae could be explained by repetitive tidal deformation of the outer ice shell However, observational confirmation of a subsurface ocean was largely frustrated by the low resolution (>2 km per pixel) of the Voyager images Here we present high-resolution (54 m per pixel) Galileo spacecraft images of Europa, in which we find evidence for mobile 'icebergs' The detailed morphology of the terrain strongly supports the presence of liquid water at shallow depths below the surface, either today or at some time in the past Moreover, lower-resolution observations of much larger regions suggest that the phenomena reported here are widespread
521 citations
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San Diego State University1, Harvard University2, University of California, Santa Cruz3, University of Florida4, Ames Research Center5, Villanova University6, Georgia State University7, Massachusetts Institute of Technology8, Search for extraterrestrial intelligence9, San Jose State University10, Katholieke Universiteit Leuven11, University of Texas at Austin12, University of Copenhagen13, Niels Bohr Institute14, NASA Exoplanet Science Institute15, Jet Propulsion Laboratory16, Space Telescope Science Institute17, University of California, Berkeley18, Tel Aviv University19, Las Cumbres Observatory Global Telescope Network20, University of California, Santa Barbara21, Fermilab22
TL;DR: The observed rate of circumbinary planets in this sample implies that more than ∼1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.
Abstract: Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars (binaries). Although long anticipated the existence of a ‘circumbinary planet’ orbiting such a pair of normal stars was not definitively established until the discovery of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary planets: Kepler-34 (AB)b and Kepler-35 (AB)b, referred to here as Kepler-34 b and Kepler-35 b, respectively. Each is a low-density gas-giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289 days, whereas Kepler-35 b orbits a pair of smaller stars (89% and 81% of the Sun’s mass) every 131 days. The planets experience large multi-periodic variations in incident stellar radiation arising from the orbital motion of the stars. The observed rate of circumbinary planets in our sample implies that more than ~1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.
520 citations
Authors
Showing all 9033 results
Name | H-index | Papers | Citations |
---|---|---|---|
B. P. Crill | 148 | 486 | 111895 |
George Helou | 144 | 662 | 96338 |
H. K. Eriksen | 141 | 474 | 104208 |
Charles R. Lawrence | 141 | 528 | 104948 |
W. C. Jones | 140 | 395 | 97629 |
Gianluca Morgante | 138 | 478 | 98223 |
Jean-Paul Kneib | 138 | 805 | 89287 |
Kevin M. Huffenberger | 138 | 402 | 93452 |
Robert H. Brown | 136 | 1174 | 79247 |
Federico Capasso | 134 | 1189 | 76957 |
Krzysztof M. Gorski | 132 | 380 | 105912 |
Olivier Doré | 130 | 427 | 104737 |
Mark E. Thompson | 128 | 527 | 77399 |
Clive Dickinson | 123 | 501 | 80701 |
Daniel Stern | 121 | 788 | 69283 |