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We report radar observations of Apophis obtained during the 2012−2013 apparition. We observed Apophis on fourteen days at Goldstone (8560 MHz, 3.5 cm) and on five days at Arecibo (2380 MHz, 12.3 cm) between 2012 December 21 to 2013 March 16. Closest approach occurred on January 9 at a distance of 0.097 au. We obtained relatively weak echo power spectra and delay-Doppler images. The highest range resolution...
We report radar observations of near-Earth asteroid (469896) 2005 WC1 that were obtained at Arecibo (2380 MHz, 13 cm) and Goldstone (8560 MHz, 3.5 cm) on 2005 December 14–15 during the asteroid's approach within 0.020 au The asteroid was a strong radar target. Delay-Doppler images with resolutions as fine as 15 m/pixel were obtained with 2 samples per baud giving a correlated pixel resolution of 7...
We report radar and optical photometric observations of near-Earth asteroid (214869) 2007 PA8 obtained during October 2–November 13, 2012. We observed 2007 PA8 on sixteen days with Goldstone (8560MHz, 3.5cm) and on five days with the 0.6m telescope at Table Mountain Observatory. Closest approach was on November 5 at a distance of 0.043au. Images obtained with Goldstone's new chirp system achieved...
We report radar observations of near-Earth Asteroid (NEA) 2003 MS2 with Goldstone (8560MHz, 3.5cm) on June 28, 29, and July 4, 2003, shortly after the asteroid’s discovery. Delay-Doppler images with resolutions as fine as 19m/pixel reveal an unusually angular object with pronounced facets. The longest sequence of images was obtained on July 4 when the asteroid rotated ∼140deg in 2.7h. During this...
We present the numerically integrated orbits of Pluto’s satellites. The orbits have been fit to a data set that includes Earth-based and Hubble Space Telescope (HST) astrometry of Charon, Nix, Hydra, Kerberos, and Styx, as well as the lightcurves from the Pluto–Charon mutual events. We also report new, 2010–2012 HST astrometry of all satellites including recently discovered Styx plus a pre-discovery...
We observed near-Earth Asteroid (162421) 2000 ET70 using the Arecibo and Goldstone radar systems over a period of 12days during its close approach to the Earth in February 2012. We obtained continuous wave spectra and range-Doppler images with range resolutions as fine as 15m. Inversion of the radar images yields a detailed shape model with an effective spatial resolution of 100m. The asteroid has...
We report radar, photometric, and spectroscopic observations of near-Earth Asteroid (136617) 1994 CC. The radar measurements were obtained at Goldstone (8560MHz, 3.5cm) and Arecibo (2380MHz, 12.6cm) on 9days following the asteroid’s approach within 0.0168AU on June 10, 2009. 1994 CC was also observed with the Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes (PROMPT) on May 21 and...
We observed the near-Earth ASTEROID 2008 EV5 with the Arecibo and Goldstone planetary radars and the Very Long Baseline Array during December 2008. EV5 rotates retrograde and its overall shape is a 400±50m oblate spheroid. The most prominent surface feature is a ridge parallel to the asteroid’s equator that is broken by a concavity about 150m in diameter. Otherwise the asteroid’s surface is notably...
Arecibo (2380MHz, 12.6cm) and Goldstone (8560MHz, 3.5cm) delay-Doppler radar images obtained in July and August of 2000 reveal that 4486 Mithra is an irregular, significantly bifurcated object, with a central valley ∼380m deep and a long axis potentially exceeding 2km. With its bimodal appearance, Mithra is a strong candidate for a contact binary asteroid. Sequences of Goldstone images spanning up...
Near–Earth Asteroid 4660 Nereus has been identified as a potential spacecraft target since its 1982 discovery because of the low delta-V required for a spacecraft rendezvous. However, surprisingly little is known about its physical characteristics. Here we report Arecibo (S-band, 2380-MHz, 13-cm) and Goldstone (X-band, 8560-MHz, 3.5-cm) radar observations of Nereus during its 2002 close approach....
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