DOCSLIB.ORG

Arizona-Based Astronomers Characterize One of the Smallest Known Asteroids

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Arizona-Based Astronomers Characterize One of the Smallest Known Asteroids PRESS RELEASE FOR IMMEDIATE RELEASE: 30 November 2016 ***Contact details appear below*** Arizona-based Astronomers Characterize One of the Smallest Known Asteroids A team of astronomers have obtained observations of the smallest asteroid –with a diameter of only two meters (six feet)—ever characterized in detail. The asteroid, named 2015 TC25, is also one of the brightest near-Earth asteroids ever discovered, reflecting 60 percent of the sunlight that falls on it. Discovered by the University of Arizona’s Catalina Sky Survey last October, 2015 TC25 was studied extensively by a team led by Vishnu Reddy, an assistant professor at the University of Arizona's Lunar and Planetary Laboratory. Other participating institutions include Lowell Observatory and Northern Arizona University. The team used four Earth-based telescopes for the study, published this month in The Astronomical Journal. Reddy argues that new observations from the NASA Infrared Telescope Facility and Arecibo Planetary Radar show that 2015 TC25's surface is similar to a rare type of highly reflective meteorite called aubrites. Aubrites consist of very bright minerals, mostly silicates, that formed in an oxygen-free, basaltic environment at very high temperatures. Only one out of every 1,000 meteorites that fall to Earth belong to this class. "This is the first time we have optical, infrared, and radar data on such a small asteroid, which is essentially a meteoroid," said Reddy. "You can think of it as a meteorite floating in space that hasn't hit the atmosphere and made it to the ground—yet." “2015 TC25 is one of the five smallest Near-Earth Objects ever observed to measure rotation rate” says Audrey Thirouin from Lowell Observatory. Thanks to coordinated observations with Lowell’s 4.3-meter Discovery Channel Telescope, the NASA Infrared Telescope Facility, and the Magdalena Ridge Observatory 2.4-meter telescope, the team found that 2015 TC25 is a fast rotator with a rotational period of only 2.23 minutes and an irregular shape. Small near-Earth asteroids such as 2015 TC25 are in the same size range as meteorites that fall to Earth. Astronomers discover them frequently, but not very much is known about them as they are difficult to characterize. By studying such objects in more detail, astronomers hope to better understand the parent bodies from which these meteorites originate. Asteroids are remaining fragments from the formation of the solar system that mostly orbit the Sun between the orbits of Mars and Jupiter today. Near-Earth asteroids are a subset that cross Earth's path. So far, more than 15,000 near-Earth asteroids have been discovered. As far as the little asteroid's origin is concerned, Reddy believes it likely was chipped off by another impacting rock from its parent, 44 Nysa, a main belt asteroid large enough to cover most of Los Angeles. "Being able to observe small asteroids like this one is like looking at samples in space before they hit the atmosphere and make it to the ground," Reddy say. "It also gives us a first look at their surfaces in pristine condition before they fall through the atmosphere." “It’s especially important to study the physical properties of small nearEarth asteroids because of the threats these objects pose to us,” says Stephen Tegler, coauthor of the study and a professor in the Department of Physics and Astronomy at Northern Arizona University “The meteoroid that caused injuries and damage in Chelyabinsk, Russia in 2013 was less than 20 meters in diameter.” Participating institutions/facilities in this project include the University of Hawaii/NASA IRTF, USRA/Arecibo Planetary Radar, New Mexico Institute of Mining and Technology/Magdalena Ridge Observatory, Northern Arizona University, and Lowell Observatory/Discovery Channel Telescope. Reference: “Physical Characterization of ~2-Meter Diameter Near-Earth Asteroid 2015 TC25: A Possible Boulder from E-type Asteroid (44) Nysa" by Vishnu Reddy et al, 2016, The Astronomical Journal [http://aj.aas.org, Paper: http://tinyurl.com/hhgrlm3]. Thirouin's research on 2015 TC25 is funded by the Mission Accessible Near-Earth Objects Survey (MANOS) awarded by the NASA's Near-Earth Object Observations program. Media Contact Kevin Schindler, Lowell Observatory (928) 607-1974 [email protected] Science Contact Audrey Thirouin, Lowell Observatory [email protected] ### About Lowell Observatory Lowell Observatory is a private, non-profit research institution founded in 1894 by Percival Lowell. The Observatory has been the site of many important discoveries including the detection of the large recessional velocities (redshift) of galaxies by Vesto Slipher in 1912-1914 (a result that led ultimately to the realization the universe is expanding), and the discovery of Pluto by Clyde Tombaugh in 1930. Today, Lowell's 14 astronomers use ground-based telescopes around the world, telescopes in space, and NASA planetary spacecraft to conduct research in diverse areas of astronomy and planetary science. The Observatory welcomes about 80,000 visitors each year to its Mars Hill campus in Flagstaff, Arizona for a variety of tours, telescope viewing, and special programs. Lowell Observatory currently operates four research telescopes at its Anderson Mesa dark sky site east of Flagstaff and the 4.3-meter Discovery Channel Telescope near Happy Jack, Arizona. .
Load more

Recommended publications
  • Pluto's Long, Strange History — in Pictures : Nature News & Comment
    Pluto's long, strange history — in pictures Nature marks the 85th anniversary of the dwarf planet's discovery. Alexandra Witze 18 February 2015 Even at a distance of 5 billion kilometres, Pluto has entranced scientists and the public back on Earth. Nature looks at the history of this enigmatic world, which in July will get its first close-up visit by a spacecraft. First glimpse Lowell Observatory 18 February 1930: Farmer-turned-astronomer Clyde Tombaugh (pictured), aged 24, discovers Pluto while comparing photographic plates of the night sky at Lowell Observatory in Flagstaff, Arizona. The discovery, announced on 13 March 1930, is the culmination of observatory founder Percival Lowell’s obsessive quest to find a ‘Planet X’, the existence of which was suspected based on perturbations in Neptune’s orbit. Name game Galaxy Picture Library 1 May 1930: The Lowell Observatory announces that its favoured name for the discovery is Pluto, suggested by 11-year-old Venetia Burney (pictured) from Oxford, UK, after the Roman god of the underworld. Venetia later becomes the namesake of a student-built dust counter on NASA's New Horizons spacecraft, which is currently on its way to Pluto. Pair bond US Naval Observatory 22 June 1978: James Christy and Robert Harrington, of the US Naval Observatory's Flagstaff Station, discover Pluto’s largest moon, Charon. It is visible as a bulge (at top in left image) that regularly appears and disappears in observational images as the two bodies orbit their mutual centre of gravity1. The moon is so large relative to Pluto that the two are sometimes referred to as a binary planet.
    [Show full text]
  • Lessons from Recent Flybys
    Real-&me Characterizaon of Hazardous Asteroids: Lessons from Recent Flybys Vishnu Reddy Planetary Science Ins&tute Tucson, Arizona Contributors • Juan Sanchez, Ma Izawa (PSI) • Audrey Thirouin, Nick Moskovitz (Lowell) • Eileen and Bill Ryan (MRO) • Ed Rivera-Valen&n, Patrick Taylor, Jim Richardson (Arecibo) • Stephen Teglar (NAU) • Ed Clous (University of Winnipeg) 2015 TC25 • Oct. 11th 2015 06:56 UTC object (WT19969) discovered by Catalina Sky Survey, Tucson (703) • Oct. 11th 2015 08:09 UTC object followed up by Magdalena Ridge Observatory, New Mexico (H01) • Oct. 11th 2015 15:01 UTC object followed up by Bisei Spaceguard Center, Japan (300) • Oct. 11th 2015 21:12 UTC object followed up by Italian amateurs from Farra d'Isonzo (595) • Oct. 11th 2015 21:52 UTC object (WT19969) is designated 2015 TC25 and MPEC-T61 is issued 2015 TC25 • Absolute Magnitude (H) :29.5; Size: 2-7 meters • Closest approach: Oct. 13, 2015 07:26 UTC • Distance: 111,000 km 2015 TC25 • Characterizaon • Photometry • Spectroscopy • Radar • Science Quesons: • What is the spin rate of the object? • What is the composi&on of the object? 2015 TC25 Discovery Channel Telescope (4.2 meter) Observer: S. Teglar 10.1 hours NASA IRTF (3 meter) Observer: Reddy/Sanchez MRO, (2 meter) Observer: B. Ryan/E. Ryan 2015 TC25 Oct. 12, 2015 22:00 UTC Rotates once 10 hours aer MPEC in 134 seconds • Only 4 NEAs in this size range have lightcurves. • 2015 TC25 has the second fastest rotaon. • 2010 WA rotates once every 30 seconds. 2015 TC25 10.1 hours gemini North (8 meter) NASA IRTF (3 meter) Observer: Mokovitz Observer: Reddy/Sanchez 2015 TC25 goldstone Radar Arecibo Radar 2015 TC25 Rock vs.
    [Show full text]
  • Pluto and Charon
    National Aeronautics and Space Administration 0 300,000,000 900,000,000 1,500,000,000 2,100,000,000 2,700,000,000 3,300,000,000 3,900,000,000 4,500,000,000 5,100,000,000 5,700,000,000 kilometers Pluto and Charon www.nasa.gov Pluto is classified as a dwarf planet and is also a member of a Charon’s orbit around Pluto takes 6.4 Earth days, and one Pluto SIGNIFICANT DATES group of objects that orbit in a disc-like zone beyond the orbit of rotation (a Pluto day) takes 6.4 Earth days. Charon neither rises 1930 — Clyde Tombaugh discovers Pluto. Neptune called the Kuiper Belt. This distant realm is populated nor sets but “hovers” over the same spot on Pluto’s surface, 1977–1999 — Pluto’s lopsided orbit brings it slightly closer to with thousands of miniature icy worlds, which formed early in the and the same side of Charon always faces Pluto — this is called the Sun than Neptune. It will be at least 230 years before Pluto history of the solar system. These icy, rocky bodies are called tidal locking. Compared with most of the planets and moons, the moves inward of Neptune’s orbit for 20 years. Kuiper Belt objects or transneptunian objects. Pluto–Charon system is tipped on its side, like Uranus. Pluto’s 1978 — American astronomers James Christy and Robert Har- rotation is retrograde: it rotates “backwards,” from east to west Pluto’s 248-year-long elliptical orbit can take it as far as 49.3 as- rington discover Pluto’s unusually large moon, Charon.
    [Show full text]
  • Characterization of Temporarily Captured Minimoon 2020 CD₃ By
    Draft version August 13, 2020 Typeset using LATEX preprint style in AASTeX62 Characterization of Temporarily-Captured Minimoon 2020 CD3 by Keck Time-resolved Spectrophotometry Bryce T. Bolin,1, 2 Christoffer Fremling,1 Timothy R. Holt,3, 4 Matthew J. Hankins,1 Tomas´ Ahumada,5 Shreya Anand,6 Varun Bhalerao,7 Kevin B. Burdge,1 Chris M. Copperwheat,8 Michael Coughlin,9 Kunal P. Deshmukh,10 Kishalay De,1 Mansi M. Kasliwal,1 Alessandro Morbidelli,11 Josiah N. Purdum,12 Robert Quimby,12, 13 Dennis Bodewits,14 Chan-Kao Chang,15 Wing-Huen Ip,15 Chen-Yen Hsu,15 Russ R. Laher,2 Zhong-Yi Lin,15 Carey M. Lisse,16 Frank J. Masci,2 Chow-Choong Ngeow,15 Hanjie Tan,15 Chengxing Zhai,17 Rick Burruss,18 Richard Dekany,18 Alexandre Delacroix,18 Dmitry A. Duev,6 Matthew Graham,1 David Hale,18 Shrinivas R. Kulkarni,1 Thomas Kupfer,19 Ashish Mahabal,1, 20 Przemyslaw J. Mroz,´ 1 James D. Neill,1 Reed Riddle,21 Hector Rodriguez,22 Roger M. Smith,21 Maayane T. Soumagnac,23, 24 Richard Walters,1 Lin Yan,1 and Jeffry Zolkower18 1Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, U.S.A. 2IPAC, Mail Code 100-22, Caltech, 1200 E. California Blvd., Pasadena, CA 91125, USA 3University of Southern Queensland, Computational Engineering and Science Research Centre, Queensland, Australia 4Southwest Research Institute, Department of Space Studies, Boulder, CO-80302, USA 5Department of Astronomy, University of Maryland, College Park, MD 20742, USA 6Division of Physics, Mathematics and Astronomy, California Institute of
    [Show full text]
  • PLUTO: a New Way to Explore the Planets
    Q)mft version 4.1 ************************************** PLUTO: A New Way To Explore the Planets By Richard Shope and Jackie Giuliano ***** ********************************* he Pluto Fast Flyby Mission is an exciting adventure beginning (he next century with a new wuy to explore the planets, The Pluto Preproject Team at the Jet Propulsion 1,aboratory is leading the effort to design and build two spacecraft equipped with @ components atthe cutting edgeof advanced technology. ‘I’he proposed odyssey inthe first years of the ncw century will be achieved through the combined efforts of American and Russian project teams, and perhaps using Russian launch vehicles known as Protons. After seven to nine years in flight, these two innovative, cost-effective spacecraft will provide us the first ever view of the last unexplored planetary system: the mysterious planet Pluto and its enigmatic moon, Charon. The video “Ot(t of the Darkness: Mis- sion 7b Plu[o” (JPI. AVC-94- 164) provides an overview of this mission and an opportu- nity to involve your students in the challenges of such an ambitious endeavor. uL’k, vNk’k, uEu, N,k’LElkk L,uNk’Hk’L,&,k,kluE~NkL~ L’EURL, U kN vL Involve your students in ~k ku’ the thrill of discoveiy! ~ k u uk’k L,vk L’k, kQLl&kp Qlkk Llkkkl Qkklukk, ~x~, ~~ ~,~~~~~ The Pluto Fast Flyby video affords an opportunity for the teacher and student to ex- plore many concepts. These curriculum guides The cost-e ftlcient Pluto Fast Flyby spacecraft have been designed to provide the teacher at encountering Pluto and its moon Charon.
    [Show full text]
  • 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.
    [Show full text]
  • Asteroid Observations with the Hubble Space Telescope? FGS??
    A&A 401, 733–741 (2003) Astronomy DOI: 10.1051/0004-6361:20030032 & c ESO 2003 Astrophysics Asteroid observations with the Hubble Space Telescope? FGS?? II. Duplicity search and size measurements for 6 asteroids P. Tanga1;3, D. Hestroffer2;???, A. Cellino3,M.Lattanzi3, M. Di Martino3, and V. Zappal`a3 1 Laboratoire Cassini, Observatoire de la Cˆote d’Azur, BP 4229, 06304 Nice, France 2 IMCCE, UMR CNRS 8028, Paris Observatory, 77 Av. Denfert Rochereau 75014 Paris, France 3 INAF, Osservatorio Astronomico di Torino, Strada Osservatorio 20, 10025 Pino Torinese (TO), Italy Received 19 August 2002 / Accepted 9 December 2002 Abstract. We present the results of the observations of five Main Belt asteroids and one Trojan obtained using the Fine Guidance Sensors (FGS) of the Hubble Space Telescope. For each object, estimates of the spin axis orientation, angular size and overall shape, as well as possible indications of a binary structure, are derived. This enables the computation of new physical ephemerides. While the data concerning (63) Ausonia are clearly compatible with a three-axis ellipsoidal model, other objects show more complex shapes. (15) Eunomia, (43) Ariadne and (44) Nysa could in fact be double asteroids, or highly irregular bodies. The data concerning (624) Hektor are not conclusive as to its supposed binary nature, even if they agree with the signal of a single body. The results presented here strongly support the outstanding capabilities of the FGS for asteroid measurements, provided that the observations are performed over a sufficient time interval. Key words. minor planets, asteroids – methods: observational 1. Introduction their large maximum amplitudes, the light–curves of the se- lected targets are generally compatible with the behavior ex- The HST/FGS astrometer has already been successfully used pected for couples of bodies having overall rubble pile inter- in the past to derive angular diameters and flattenings of nal structures, for which equilibrium shapes can be expected Mira stars (Lattanzi et al.
    [Show full text]
  • LOWELL OBSERVATORY in Flagstaff Embodies the Legacy of Arizona's VISIONARY ASTRONOMER
    dby eSALLY BsENFORtD /iphontographsaby DAVItD Hi. SMoITH n PERCIVAL LOWELL NEVER CONSIDERED 1966, Lowell Observatory was registered as a LOWELL himself a dreamer. A stargazer, perhaps, but National Historic Landmark. Today, professional OBSERVATORY never a dreamer. and amateur stargazers go to the observatory, In the summer of 1894, Lowell thought he one of the world’s largest, privately operated, in Flagstaff had proof that intelligent life existed on Mars. nonprofit astronomical research observatories. The Harvard-educated mathematician, who Lowell’s 24-inch Clark refractor telescope, Embodies hailed from Boston blue-blooded society, spent which he used for his Mars observations, now the Legacy of night after night perched on a lonely serves as an instrument for public viewing. ponderosa pine-studded mesa above Flagstaff, Even in the 21st century, Lowell seems to Arizona’s gazing through a telescope at Mars, taking oversee the operation as he peers from a large notes and making calculations. By the end of painting that hangs in the observatory’s Steele VISIONARY summer, Lowell decided he had enough Visitor Center lobby. Hand on hip and staring ASTRONOMER information to publish his findings. straight into the future, Lowell stands amid Lowell never proved his theory of life on modern-day and historical space observational Mars, but such theories sparked a firestorm devices. The center serves as the entry point of controversy about Martians, adding a for all observatory programs, telescopes and fascination with space to the developing literary exhibits. People come to learn the observatory’s genre of science fiction. Author H.G. Wells history and for a chance to look through published his novel War of the Worlds in 1898 Lowell’s telescopes.
    [Show full text]
  • Pluto and Its Cohorts, Which Is Not Ger Passing by and Falling in Love So Much When Compared to the with Her
    INTERNATIONAL SPACE SCIENCE INSTITUTE SPATIUM Published by the Association Pro ISSI No. 33, March 2014 141348_Spatium_33_(001_016).indd 1 19.03.14 13:47 Editorial A sunny spring day. A green On 20 March 2013, Dr. Hermann meadow on the gentle slopes of Boehnhardt reported on the pre- Impressum Mount Etna and a handsome sent state of our knowledge of woman gathering flowers. A stran- Pluto and its cohorts, which is not ger passing by and falling in love so much when compared to the with her. planets in our cosmic neighbour- hood, yet impressively much in SPATIUM Next time, when she is picking view of their modest size and their Published by the flowers again, the foreigner returns gargantuan distance. In fact, ob- Association Pro ISSI on four black horses. Now, he, serving dwarf planet Pluto poses Pluto, the Roman god of the un- similar challenges to watching an derworld, carries off Proserpina to astronaut’s face on the Moon. marry her and live together in the shadowland. The heartbroken We thank Dr. Boehnhardt for his Association Pro ISSI mother Ceres insists on her return; kind permission to publishing Hallerstrasse 6, CH-3012 Bern she compromises with Pluto allow- herewith a summary of his fasci- Phone +41 (0)31 631 48 96 ing Proserpina to living under the nating talk for our Pro ISSI see light of the Sun during six months association. www.issibern.ch/pro-issi.html of a year, called summer from now for the whole Spatium series on, when the flowers bloom on the Hansjörg Schlaepfer slopes of Mount Etna, while hav- Brissago, March 2014 President ing to stay in the twilight of the Prof.
    [Show full text]
  • More Than a One-Hit Wonder. Falk, Dan Astronomy. Feb2006, Vol. 34 Issue 2, P40-45
    More than a one-hit wonder. Falk, Dan Astronomy. Feb2006, Vol. 34 Issue 2, p40-45 Famous for discovering Pluto, Clyde Tombaugh reached far beyond the planets Clyde Tombaugh's life instantly changed when he discovered Pluto in 1930. Just 24 years old, and with only a high-school diploma, Tombaugh spotted the missing "Planet X." Shortly thereafter, he was awarded a scholarship for his scientific work and returned to school to earn bachelor's and master's degrees in astronomy. Now, 100 years after his birth, both amateur and professional astronomers celebrate this astronomy great. The day he discovered Pluto began like any other during the previous few months. Tombaugh had not been able to observe the night before because of the Moon's glare. So on February 18, 1930, he "blinked" two photographic plates from January 23 and 29. He would work for a half hour, then rest his eyes and brain for the same time, and return to blinking. The task required intense concentration. And at about 4 o'clock in the afternoon on a cold, wintry day in Flagstaff, Arizona, he found it. For 45 minutes, he checked his plates and examined another from January 21. Once Tombaugh was 100-percent positive he had found it, he reported the news to his boss. Twenty- five years of astronomers' searching was over. Finding a path Clyde William Tombaugh (1906-1997) was born in Streator, Illinois, and moved to Kansas at the age of 16 when his parents began farming in the small town of Burdett. Tombaugh would have been the quintessential American farm boy were it not for his fascination -- one might say, obsession -- with astronomy.
    [Show full text]
  • Asteroid Photometric and Polarimetric Phase Curves: Joint Linear-Exponential Modeling
    Meteoritics & Planetary Science 44, Nr 12, 1937–1946 (2009) Abstract available online at http://meteoritics.org Asteroid photometric and polarimetric phase curves: Joint linear-exponential modeling K. MUINONEN1, 2, A. PENTTILÄ1, A. CELLINO3, I. N. BELSKAYA4, M. DELBÒ5, A. C. LEVASSEUR-REGOURD6, and E. F. TEDESCO7 1University of Helsinki, Observatory, Kopernikuksentie 1, P.O. BOX 14, FI-00014 U. Helsinki, Finland 2Finnish Geodetic Institute, Geodeetinrinne 2, P.O. Box 15, FI-02431 Masala, Finland 3INAF-Osservatorio Astronomico di Torino, strada Osservatorio 20, 10025 Pino Torinese, Italy 4Astronomical Institute of Kharkiv National University, 35 Sumska Street, 61035 Kharkiv, Ukraine 5IUMR 6202 Laboratoire Cassiopée, Observatoire de la Côte d’Azur, BP 4229, 06304 Nice, Cedex 4, France 6UPMC Univ. Paris 06, UMR 7620, BP3, 91371 Verrières, France 7Planetary Science Institute, 1700 E. Ft. Lowell Road, Tucson, Arizona 85719, USA *Corresponding author. E-mail: [email protected] (Received 01 April, 2009; revision accepted 18 August 2009) Abstract–We present Markov-Chain Monte-Carlo methods (MCMC) for the derivation of empirical model parameters for photometric and polarimetric phase curves of asteroids. Here we model the two phase curves jointly at phase angles գ25° using a linear-exponential model, accounting for the opposition effect in disk-integrated brightness and the negative branch in the degree of linear polarization. We apply the MCMC methods to V-band phase curves of asteroids 419 Aurelia (taxonomic class F), 24 Themis (C), 1 Ceres (G), 20 Massalia (S), 55 Pandora (M), and 64 Angelina (E). We show that the photometric and polarimetric phase curves can be described using a common nonlinear parameter for the angular widths of the opposition effect and negative-polarization branch, thus supporting the hypothesis of common physical mechanisms being responsible for the phenomena.
    [Show full text]
  • Percival Lowell Society: Joe Sims Wanted to Be an Astronomer, Maybe Even Belt Asteroids, and Neos
    THE LOWELL EXPANDING OUR UNIVERSE OBSERVER The quarterly newsletter of Lowell Observatory Issue 98 Fall 2013 (Right) Nick Moskovitz poses in front Nick Moskovitz of the SOAR 4-m telescope on Cerro Pachon in Chile, where he was Coming to Lowell observing near-Earth asteroids. The by Tom Vitron figure below illustrates the sheer size of various NEOs. The meteor from the Chelyabinsk event was only slightly smaller than the DCT dome, On February 15th, Earth and more than three times as large witnessed two close-up Near-Earth Object as “Big Red”, Percival Lowell’s 1911 (NEO) events, a predicted nearby pass and Model Y Stevens-Duryea touring the Chelyabinsk, Siberia event. Questions car. The Barringer Meteor created Meteor Crater in Arizona, whereas arose immediately: were the two events the Tunguska Comet explosion was related? What kind of meteor was seen the largest impact event on or near brilliantly exploding in the numerous car Earth in recorded history, occurring dashboard videos from Siberia? When the in 1908 near the Podkamennaya world went looking for answers, one of the Tunguska River in Siberia. leading experts quoted was astronomer Nick Moskovitz of MIT, who will be joining Lowell in 2014. “I was at Kitt Peak [National Observatory near Tucson] to see the flyby as we had one chance to try to see it well,” recounts Dr. Moskovitz. “We had some interviews that night about the flyby and [the interviewers] started asking about Chelyabinsk. I hadn’t heard much yet. We were able to see news about the event more 100m 56.3m 50m 18.9m 17m 12.8m 4.9m closely in the night.
    [Show full text]