S-band Spotlight

Arecibo Planetary Radar Returns to Action with Images of Asteroid 3200 Phaethon!

After several months of downtime in the aftermath of Hurricane Maria, the Arecibo Observatory Planetary Radar returned to normal operation providing the best images to date of near-Earth asteroid 3200 Phaethon, which is thought to be the parent body for the Geminid meteor shower. The radar images, which are subtle at available resolution, reveal the asteroid is spheroidal in shape and has a large concavity at least several hundred meters in extent near the leading edge and a conspicuous dark, circular feature near one of the poles. For more information, see our press release here.

About Us


The Planetary Radar Science group is a department of the Arecibo Observatory, which is an NSF facility operated under cooperative agreement by the University of Central Florida, Yang Enterprises, and la Universidad Metropolitana (UMET). The Arecibo Observatory Planetary Radar program is fully funded by NASA's Near-Earth Object Observations program.

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Recently Observed Objects


For media inquiries, please contact our USRA communications lead, Dr. Edgard G. Rivera-Valentin

All observations in 2018 - most recent first

(469737) 2005 NW44
(441987) 2010 NY65
(467309) 1996 AW1
2018 LK
2015 DP155
2018 EJ4
1999 FN19
2014 WG365
(68347) 2001 KB67
(66391) 1999 KW4
(96590) 1998 XB
2018 DH1
2018 FB
2018 FH1
2013 RZ73 - detected, but data corrupted
2017 VR12
2018 DT
(311554) 2006 BQ147
3752 Camillo
2018 BH3
(505657) 2014 SR339
2018 BM5
(306383) 1993 VD
2018 AJ
2018 BT1 - taken from NEO Confirmation Page as ZBA33FE!
2018 AV2
2006 WE4
(438017) 2003 YO3
2017 XT61

Past Observations

Upcoming Radar Targets

The following table includes targets with submitted observing proposals. It is not comprehensive for targets of opportunity, especially newly discovered asteroids. For possible targets of opportunity and long-term future radar targets, updated daily, see: All asteroids visible today (SNR > 2/day), this month (SNR > 2/day), and in the next five years (SNR > 100/day). Note that these tables inevitably include objects that are currently "lost," often suggested by "1d" in the Type column, which stands for "one apparition with a days-long arc," so observer beware!

Object Dates Expected
H mag Request Optical
Request Optical
Request Optical
(68347) 2001 KB67 May 26-31 High-res Imaging Y 19.9 Y Y PHA, period unknown
(66391) 1999 KW4 May 25-01 High-res Imaging Y 16.5 Y Y BINARY, PHA, 2.8-h period
2015 DP155 Jun 08-13 High-res Imaging 21.6 Y Y PHA, NHATS, period unknown
(441987) 2010 NY65 Jun 19-29 High-res Imaging Y 21.5 Y Y PHA, 5.0-h period
1627 Ivar Jul 05-13 Imaging Y 13.2 Y 4.8-h period
398188 Agni Jul 23-01 High-res Imaging Y 19.5 Y Y PHA, 22-h period
2015 FP118 Aug 24-13 High-res Imaging 19.3 0.25 deg Y Y PHA, period unknown
(144332) 2004 DV24 Sep 13-15 High-res Imaging Y 16.5 Y Y PHA, period unknown
2002 VE68 Nov 07-11 High-res Imaging Y 20.5 Y Y PHA, 13.5-h period
(163899) 2003 SD220 Dec 18-22 High-res Imaging 17.3 Y PHA, NHATS, 285-h period
2016 AZ8 Jan 02-05 High-res Imaging 21.1 Y Y PHA, NHATS, period unknown
2004 XP14 Jan 03-07 High-res Imaging 19.7 Y Y PHA, 100-h(?) period

Requests for Optical Observations:

Astrometry: optical astrometry is specifically requested for objects with plane-of-sky pointing uncertainties of tens of arcseconds or more. Optical observers are asked to submit astrometry to the Minor Planet Center as soon as possible after observations.

Lightcurves: optical lightcurves and period estimates are specifically requested for objects that will produce high-resolution images (i.e., possible shape models), for targets of IRTF thermal-infrared observations, for candidate binary asteroids, and for potential human-exploration targets. Lightcurve observers are asked to relay period estimates to the radar team to help with the planning of radar observations. During the analysis and modeling process, the radar team may request to use available lightcurve data.

Characterization: optical characterization refers to spectra and colors, which are most important for targets of IRTF thermal observations, for completeness of the strongest radar targets, for candidate binary asteroids, and for potential human-exploration targets. Optical observers are asked to relay probable spectral-class information to the radar team to compare with characteristics suggested by radar.

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