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Thermophysical Modeling of 99942 Apophis: Estimations of Surface Temperature During the April 2029 Close Approach
Apophis T–9 Years 2020 (LPI Contrib. No. 2242) 2069.pdf THERMOPHYSICAL MODELING OF 99942 APOPHIS: ESTIMATIONS OF SURFACE TEMPERATURE DURING THE APRIL 2029 CLOSE APPROACH. K. C. Sorli1 and P. O. Hayne1, 1Laboratory for Atmospheric and Space Physics – University of Colorado Boulder, CO 80303 ([email protected]) Introduction: The April 13, 2029 close approach purposes of calculating temperatures and thermal IR of the ~350-meter asteroid 99942 Apophis offers an fluxes. Our predictions for surface temperatures and unprecedented opportunity to observe a large near-Earth dynamical effects will be directly testable during the asteroid in detail with ground-based observatories. As Janus mission, with an anticipated launch date of 2022. one of the best-studied hazardous objects, with Though the model was constructed with the intent of additional near-miss flybys in coming decades, it is categorizing binary thermal and dynamical behaviors, crucial to planetary defense to understand its properties including binary YORP [5][6], it is easily adaptable to and potential perturbations to its orbit. solitary asteroids. Apophis has been the subject of extensive study, and This model begins by coupling a 1-d thermophysical will continue to be so for years to come. This existing model [7] to a 3-d shape model and computing facet-by- knowledge and the promise of new data makes it an facet temperatures of the surface and near subsurface excellent candidate for modeling subject to during the time period of Apophis’s 2029 close observational constraints. The 2029 close approach will approach. To calculate temperatures, the model is given have a sizable amplifying effect on Apophis’ orbital information about the incoming solar flux on each facet uncertainty, so small dynamical perturbations will be as a function of solar distance and is set to equilibrate required to understand both the conditions of the 2029 for 1 year to allow for subsurface temperature settling. -
An Estimate of the Flux of Apophis-Particle Meteors at Earth
Apophis T–9 Years 2020 (LPI Contrib. No. 2242) 2075.pdf An Estimate of the Flux of Apophis-Particle Meteors at Earth 1 1 2 Robert Melikyan , Beth Ellen Clark , Carl Hergenrother 1 D epartment of Physics and Astronomy, Ithaca College, Ithaca, NY, USA. 2 L unar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA. Near-Earth asteroid (99942) Apophis is meteoroid stream is propagated between 1900 - predicted to make a close encounter with Earth 2029 using an Apophis ephemeris that places the on April 13, 2029. This close encounter will asteroid at its most likely position for the 2029 bring Apophis within 6 Earth radii from our encounter. Unlike most meteoroid stream geocenter providing an excellent opportunity to evolution studies, our simulations release study and observe the asteroid and any particles from Apophis at a regular (~weekly) subsequent effects of the interaction. Here, we rate around its entire orbit, consistent with the bring to your attention the possibility that the Bennu observations. passage of Apophis will not be the only event worth observing. We predict a rain of Apophis Assuming similar particle production meteors that may be detectable to Earth’s meteor mechanisms at Apophis as observed at Bennu, monitoring systems. Apophis could be producing on order of 104 grams of material continuously throughout its NASA’s OSIRIS-REx mission has orbit. Of that material, we assume 30% will recently shown that near-Earth asteroid (101955) escape on hyperbolic trajectories [6]. This Bennu has been continuously producing results in roughly 3500 grams of new material 4 cm-sized ejecta at rates of ~10 grams per orbit entering the Apophis meteoroid stream annually. -
Small Satellite Rendezvous and Characterization of Asteroid 99942 Apophis
SSC09-IV-3 Small Satellite Rendezvous and Characterization of Asteroid 99942 Apophis James Chartres Carnegie Mellon Innovations Laboratory, Carnegie Mellon University Silicon Valley Small Spacecraft Office, NASA Ames Research Center Building 202, Moffett Field, CA 94035; (650) 604-6347 [email protected] David Dunham, Bobby Williams Space Navigation and Flight Dynamics, KinetX, Inc. 2050 E. ASU Circle, Suite 107, Tempe, AZ 85284; (480) 829-6600 [email protected], [email protected] Anthony Genova, Anthony Colaprete, Ronald Johnson, Belgacem Jaroux Small Spacecraft Office, NASA Ames Research Center Building 202, Moffett Field, CA 94035; (650) 604-6347, (650) 604-2918, (650) 604-6699, (650) 604-6312 [email protected], [email protected], [email protected], [email protected] ABSTRACT The Measurement and Analysis of Apophis Trajectory (MAAT) concept study investigated a low-cost characterization mission to the asteroid 99942 Apophis that leverage small spacecraft architectures and technologies. The mission goals were to perform physical characterization and improve the orbital model. The MAAT mission uses a small spacecraft free flyer and a bi-propellant transfer stage that can be incorporated as a secondary payload on Evolved Expendable Launch Vehicles (EELVs), Atlas V or Delta IV launches. Using the innovative secondary architecture allows the system to be launched on numerous GTO or LTO opportunities such as NASA science missions or commercial communication satellites. The trajectory takes advantage of the reduced Delta-V requirement during the 2012- 2015 time frame, with a large flexible launch opportunity, from January to November 2012 and heliocentric injection occurs in April 2013. -
Radar Images Provide Details on Halloween Asteroid 4 November 2015
Radar images provide details on Halloween asteroid 4 November 2015 California, to transmit high-power microwaves toward the asteroid. The signal bounced off the asteroid, and its radar echoes were received by the National Radio Astronomy Observatory's (NRAO) 100-meter (330-foot) Green Bank Telescope in West Virginia. The radar images achieve a spatial resolution as fine as 13 feet (4 meters) per pixel. The radar images were taken as the asteroid flew past Earth on October 31 at 1 p.m. EDT at about 1.3 lunar distances (300,000 miles, or 480,000 kilometers) from Earth. Asteroid 2015 TB145 is spherical in shape and approximately 2,000 feet (600 meters) in diameter. "The radar images of asteroid 2015 TB145 show Asteroid 2015 TB145 is depicted in eight individual radar portions of the surface not seen previously and images collected on Oct. 31, 2015 between 5:55 a.m. PDT (8:55 a.m. EDT) and 6:08 a.m. PDT (9:08 a.m. reveal pronounced concavities, bright spots that EDT). At the time the radar images were taken, the might be boulders, and other complex features that asteroid was between 440,000 miles (710,000 could be ridges," said Lance Benner of NASA's Jet kilometers) and about 430,000 miles (690,000 Propulsion Laboratory in Pasadena, California, who kilometers) distant. Asteroid 2015 TB145 safely flew past leads NASA's asteroid radar research program. Earth on Oct. 31, at 10:00 a.m. PDT (1 p.m. EDT) at "The images look distinctly different from the about 1.3 lunar distances (300,000 miles, 480,000 Arecibo radar images obtained on October 30 and kilometers). -
User Provided Data Product Upload of Herschel/PACS Near-Earth Asteroid Observations (Release Note)
Small Bodies: Near and Far NEA HSA UPDP upload User Provided Data Product upload of Herschel/PACS near-Earth asteroid observations (release note) Small Bodies: Near and Far; 687378 – SBNAF – RIA Cs. Kiss1, T.G. M¨uller2, and the SBNAF team 1Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege 15-17, H-1121 Budapest, Hungary 2Max-Planck-Institut f¨ur extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching, Germany Version 1.0 (as of December 29, 2016) Contents 1 Introduction 2 2 Herschel Space Observatory 2 3 Near-Earth asteroid observations 2 4 Data reduction and calibration 3 5Results 3 5.1 (101955) Bennu . 5 5.2 175706 (1996 FG 3) . 5 5.3 308635 (2005 YU 55) . 5 5.4 (162173) Ryugu . 6 5.5 (99942) Apophis . 6 References 7 Appendix 8 Summary of uploaded data products . 8 Summary of additional FITS keywords . 11 Page 1 Small Bodies: Near and Far NEA HSA UPDP upload 1 Introduction SMALL BODIES: NEAR AND FAR is a Horizon 2020 project (project number: 687378) that addresses critical points in reconstructing physical and thermal properties of near- Earth, main-belt, and trans-Neptunian objects (see the project webpage for details: http://www.mpe.mpg.de/ tmueller/sbnaf/). One of the goals of the SBNAF project is to produce a set of high-quality data products for Herschel observations of Solar System objects for an upload to the Herschel Science Archive (HSA). These new products will then be available for the entire scientific community, in parallel to the standard pipeline-processed Herschel archive data. -
The Atlantic Online | June 2008 | the Sky Is Falling | Gregg Easterbrook
The Atlantic Online | June 2008 | The Sky Is Falling | Gregg Easter... http://www.theatlantic.com/doc/print/200806/asteroids Print this Page Close Window JUNE 2008 ATLANTIC MONTHLY The odds that a potentially devastating space rock will hit Earth this century may be as high as one in 10. So why isn’t NASA trying harder to prevent catastrophe? BY GREGG EASTERBROOK The Sky Is Falling Image credit: Stéphane Guisard, www.astrosurf.com/sguisard ALSO SEE: reakthrough ideas have a way of seeming obvious in retrospect, and about a decade ago, a B Columbia University geophysicist named Dallas Abbott had a breakthrough idea. She had been pondering the craters left by comets and asteroids that smashed into Earth. Geologists had counted them and concluded that space strikes are rare events and had occurred mainly during the era of primordial mists. But, Abbott realized, this deduction was based on the number of craters found on land—and because 70 percent of Earth’s surface is water, wouldn’t most space objects hit the sea? So she began searching for underwater craters caused by impacts VIDEO: "TARGET EARTH" rather than by other forces, such as volcanoes. What she has found is spine-chilling: evidence Gregg Easterbrook leads an illustrated that several enormous asteroids or comets have slammed into our planet quite recently, in tour through the treacherous world of space rocks. geologic terms. If Abbott is right, then you may be here today, reading this magazine, only because by sheer chance those objects struck the ocean rather than land. Abbott believes that a space object about 300 meters in diameter hit the Gulf of Carpentaria, north of Australia, in 536 A.D. -
Head-On Impact Deflection of Neas: a Case Study for 99942 Apophis
Planetary Defense Conference 2007, Wahington D.C., USA, 05-08 March 2007 (c) 2007 by the authors Head-On Impact Deflection of NEAs: A Case Study for 99942 Apophis Bernd Dachwald∗ and Ralph Kahle† German Aerospace Center (DLR), 82234 Wessling, Germany Bong Wie‡ Arizona State University, Tempe, AZ 85287, USA Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029- encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. -
Spex Upgrade for the IRTF
SpeX Upgrade for the IRTF 1. Overview and Motivation The objective of this proposal is to upgrade the NASA Infrared Telescope Facility (IRTF) 0.8–5.5 µm medium-resolution spectrograph, SpeX, with a higher performance near-infrared array and modern array controller. The upgrade will help keep SpeX scientifically productive as it moves into its second decade of operation by improving sensitivity and wavelength coverage, and reducing operational risk by replacing its obsolete array controller. This will involve replacing the current Aladdin 3 1024x1042 InSb array with a 2048x2048 Hawaii 2RG (H2RG) array and the ten-year-old Digital Signal Processor-based (DSP) array controller with an off-the-shelf configurable controller developed for the Pan-STARRS Project. The Motorola DSPs used in the original controller are no longer made and the continued functioning of the controller (and therefore SpeX) depends on the decreasing supply of spare DSP boards we hold (two). With the improvement in read noise, dark current and short wavelength QE (<1.2 µm) through the use of the H2RG array, the gain in sensitivity averages 0.75 magnitudes (or a factor of three in speed) in the short wavelength (0.8-2.5 µm) observing modes, while the larger format and smaller pixels increases simultaneous wavelength coverage and sampling (for better airglow emission line subtraction and telluric absorption feature division) in all observing modes. Apart from a new detector mount and wiring, no other changes to the cryostat are required. The optics are unchanged. To carry out the upgrade SpeX would be off the telescope for one observing semester (six months). -
Detecting the Yarkovsky Effect Among Near-Earth Asteroids From
Detecting the Yarkovsky effect among near-Earth asteroids from astrometric data Alessio Del Vignaa,b, Laura Faggiolid, Andrea Milania, Federica Spotoc, Davide Farnocchiae, Benoit Carryf aDipartimento di Matematica, Universit`adi Pisa, Largo Bruno Pontecorvo 5, Pisa, Italy bSpace Dynamics Services s.r.l., via Mario Giuntini, Navacchio di Cascina, Pisa, Italy cIMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Lille, 77 av. Denfert-Rochereau F-75014 Paris, France dESA SSA-NEO Coordination Centre, Largo Galileo Galilei, 1, 00044 Frascati (RM), Italy eJet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, 91109 CA, USA fUniversit´eCˆote d’Azur, Observatoire de la Cˆote d’Azur, CNRS, Laboratoire Lagrange, Boulevard de l’Observatoire, Nice, France Abstract We present an updated set of near-Earth asteroids with a Yarkovsky-related semi- major axis drift detected from the orbital fit to the astrometry. We find 87 reliable detections after filtering for the signal-to-noise ratio of the Yarkovsky drift esti- mate and making sure the estimate is compatible with the physical properties of the analyzed object. Furthermore, we find a list of 24 marginally significant detec- tions, for which future astrometry could result in a Yarkovsky detection. A further outcome of the filtering procedure is a list of detections that we consider spurious because unrealistic or not explicable with the Yarkovsky effect. Among the smallest asteroids of our sample, we determined four detections of solar radiation pressure, in addition to the Yarkovsky effect. As the data volume increases in the near fu- ture, our goal is to develop methods to generate very long lists of asteroids with reliably detected Yarkovsky effect, with limited amounts of case by case specific adjustments. -
The Case of 99942 Apophis (2004 MN4) Steven R
Asteroids, Comets, Meteors Proceedings IAU Symposium No. 229, 2005 c 2006 International Astronomical Union D. Lazzaro, S. Ferraz-Mello & J.A. Fern´andez, eds. doi:10.1017/S1743921305006769 Potential impact detection for Near-Earth asteroids: the case of 99942 Apophis (2004 MN4) Steven R. Chesley Jet Propulsion Laboratory, Pasadena, CA 91109, USA email: [email protected] Abstract. Orbit determination for Near-Earth Asteroids presents unique technical challenges due to the imperative of early detection and careful assessment of the risk posed by specific Earth close approaches. This article presents a case study of asteroid 99942 Apophis, a 300-400 meter object that, for a short period in December 2004, held an impact probability of more than 2% in 2029. Now, with an orbit based on radar ranging and more than a year of optical observations, we can confidently say that it will pass safely by the Earth in 2029, although at a distance of only about six Earth radii from the geocenter. However, the extremely close nature of this encounter acts to obscure the trajectory in subsequent years, when resonant returns to the vicinity of the Earth are possible. In particular, an impact possibility in the year 2036 has a roughly 5% probability of persisting through the very favorable 2013 radar and optical observing apparition. In the event that the 2036 potential impact has not been eliminated by 2013, a precise characterization of the Yarkovsky accelerations acting on the asteroid may become an important part of the orbit estimation and impact prediction problem. Even so, the sixteen years available to effect a deflection from 2013 until 2029, after which the problem would become intractable, are sufficient to respond to the threat should a deflection effort become warranted. -
Halloween Asteroid a Treat for Radar Astronomers 22 October 2015, by Dc Agle
Halloween asteroid a treat for radar astronomers 22 October 2015, by Dc Agle Center, this is the closest currently known approach by an object this large until asteroid 1999 AN10, at about 2,600 feet (800 meters) in size, approaches at about 1 lunar distance (238,000 miles from Earth) in August 2027. "The trajectory of 2015 TB145 is well understood," said Paul Chodas, manager of the Center for Near Earth Object Studies at NASA's Jet Propulsion Laboratory, Pasadena, California. "At the point of closest approach, it will be no closer than about 300,000 miles—480,000 kilometers or 1.3 lunar distances. Even though that is relatively close by celestial standards, it is expected to be fairly faint, so night-sky Earth observers would need at least a small telescope to view it." This is a graphic depicting the orbit of asteroid 2015 TB145. The asteroid will safely fly past Earth slightly The gravitational influence of the asteroid is so farther out than the moon's orbit on Oct. 31 at 10:05 a.m. small it will have no detectable effect on the moon Pacific (1:05 p.m. EDT and 17:05 UTC). Credit: NASA/JPL-Caltech or anything here on Earth, including our planet's tides or tectonic plates. The Center for NEO Studies at JPL is a central NASA scientists are tracking the upcoming node for NEO data analysis in NASA's Near-Earth Halloween flyby of asteroid 2015 TB145 with Object Observation Program and a key group several optical observatories and the radar involved with the international collaboration of capabilities of the agency's Deep Space Network astronomers and scientists who keep watch on the at Goldstone, California. -
Cfht-Um-Neos (Wainscoat).Key
The search for Near Earth Objects — how CFHT is helping Richard Wainscoat University of Hawaii, Institute for Astronomy Near Earth Objects Defined as objects that have perihelion less than 1.3 Astronomical Units May be asteroids or comets Largest risk is from asteroids (but impacts can be predicted well in advance Comets on elliptical orbits will have higher impact velocities, and there would be less warning time Near Earth Objects Earth impact from an asteroid (or comet) is the only natural disaster that can be prevented Pan-STARRS (on Haleakala, Maui) is helping to find dangerous asteroids and comets that may hit Earth in the future MegaCam on CFHT is being used to get rapid additional observations of these objects to characterize their orbits and size NASA funding NASA now funds Near Earth Object discovery and characterization $50 million per year The Chelyabinsk meteorite helped increase funding Operation of Pan-STARRS is funded by the NASA Near Earth Object Observation program NASA has also provided funds to help finish Pan- STARRS2 NASA funding Nearly all discovery and confirmation of Near Earth Objects comes from US-operated telescopes The major discovery telescopes were all built for other purposes All NEO discovery telescopes are threatened by light pollution There is much poorer coverage of the southern hemisphere February 15, 2013 Chelyabinsk meteorite Approximately 18 meters in diameter Approximately 9,100 tonnes 19 km/s impact velocity Exploded at an altitude of 23 km Glancing trajectory resulted in a high altitude explosion;