1999 DJ4 Planning
Background
1999 DJ4 was discovered by Spacewatch on October 23, 2001. It will approach within
0.0586 AU (23 lunar distances) on April 20, 2004. Its absolute magnitude of 18.4
suggests that it is within a factor of two of about 800 meters in diameter. Binzel et al.
(2004, submitted for publication) report that 1999 DJ4 is an Sq-type object.
On 2004 April 8, Pravec et al. announced in IAU Circular #8316 that 1999 DJ4 is a
binary system with an orbital period of 17.72 hours. Pravec et al. obtained a
small lightcurve amplitude (~0.1 mag) for the primary, suggesting that its shape is approximately
spheroidal.
1999 DJ4 will be a moderately strong Goldstone radar target. We expect to image it with
range resolutions up to about 75 m/pixel (0.5 usec). This should be adequate to detect the
secondary.
Due to its size and the proximity of its orbit to that of Earth, 2001 US16 has been
classified as a "Potentially Hazardous Asteroid" by the International
Astronomical Union's Minor Planet Center.
These will be combined Goldstone and Arecibo observations. Arecibo observations are
scheduled on April 14-17 and Goldstone observations are scheduled on April 23-24 when
the asteroid is too far south for Arecibo to track.
Orbital and Physical Characteristics
orbit type Apollo
semimajor axis 1.851 AU
eccentricity 0.483
inclination 9.16°
perihelion distance 0.957 AU
aphelion distance 2.745 AU
absolute magnitude (H) 18.4
diameter unknown
rotation period
primary 2.514 hours
secondary 17.72 hours
pole direction unknown
lightcurve amplitude 0.1 magnitudes (primary)
spectral class Sq (Binzel et al. 2004, submitted)
Last updated: 2004 April 20
Discovery
Discovery Announcement
M.P.E.C. 1999-D21 Issued 1999 Feb. 26, 17:03 UT
The Minor Planet Electronic Circulars contain information on unusual
minor planets and routine data on comets. They are published
on behalf of Commission 20 of the International Astronomical Union by the
Minor Planet Center, Smithsonian Astrophysical Observatory,
Cambridge, MA 02138, U.S.A.
BMARSDEN@CFA.HARVARD.EDU or GWILLIAMS@CFA.HARVARD.EDU
URL http://cfa-www.harvard.edu/iau/mpc.html ISSN 1523-6714
1999 DJ4
Observations:
J99D04J* C1999 02 24.35637 14 24 34.85 +20 03 37.2 17.6 704
J99D04J C1999 02 24.36669 14 24 39.04 +20 03 15.7 17.4 704
J99D04J C1999 02 24.37701 14 24 43.14 +20 02 53.3 17.8 704
J99D04J C1999 02 24.38733 14 24 47.26 +20 02 32.1 17.6 704
J99D04J C1999 02 24.39768 14 24 51.37 +20 02 09.6 17.8 704
J99D04J C1999 02 25.02891 14 29 15.79 +19 38 31.4 16.5 R 046
J99D04J C1999 02 25.02993 14 29 16.24 +19 38 27.8 046
J99D04J C1999 02 25.03078 14 29 16.61 +19 38 26.1 046
J99D04J C1999 02 25.03163 14 29 16.96 +19 38 24.2 046
J99D04J C1999 02 25.08304 14 29 38.02 +19 36 28.6 16.6 R 118
J99D04J C1999 02 25.08752 14 29 39.85 +19 36 18.3 118
J99D04J C1999 02 25.08963 14 29 40.70 +19 36 13.6 118
J99D04J C1999 02 25.30639 14 31 14.03 +19 28 02.8 15.5 R 758
J99D04J C1999 02 25.30820 14 31 14.80 +19 27 59.2 15.5 R 758
J99D04J C1999 02 25.30993 14 31 15.39 +19 27 55.4 15.4 R 758
J99D04J C1999 02 25.31161 14 31 16.14 +19 27 51.0 15.3 R 758
J99D04J C1999 02 25.31341 14 31 16.97 +19 27 46.4 15.3 R 758
J99D04J C1999 02 25.37108 14 31 41.71 +19 25 26.8 17.2 704
J99D04J C1999 02 25.37242 14 31 42.18 +19 25 23.6 17.3 704
J99D04J C1999 02 25.37382 14 31 42.87 +19 25 21.0 17.0 704
J99D04J C1999 02 25.37521 14 31 43.41 +19 25 17.4 704
J99D04J C1999 02 25.37660 14 31 44.04 +19 25 14.1 17.7 704
J99D04J C1999 02 25.37799 14 31 44.64 +19 25 12.2 704
J99D04J C1999 02 25.37939 14 31 45.14 +19 25 07.7 704
J99D04J C1999 02 25.38078 14 31 45.73 +19 25 03.7 17.4 704
J99D04J C1999 02 25.38217 14 31 46.31 +19 25 02.3 17.4 704
J99D04J C1999 02 25.38356 14 31 46.93 +19 24 58.1 704
J99D04J C1999 02 25.38496 14 31 47.49 +19 24 54.5 17.4 704
J99D04J C1999 02 25.38635 14 31 48.11 +19 24 53.1 704
J99D04J C1999 02 25.38770 14 31 48.53 +19 24 47.5 704
J99D04J C1999 02 25.38909 14 31 49.16 +19 24 42.4 704
J99D04J C1999 02 25.39048 14 31 49.82 +19 24 41.3 704
J99D04J C1999 02 25.39890 14 31 52.06 +19 24 28.2 15.6 R 758
J99D04J C1999 02 25.40066 14 31 52.79 +19 24 24.7 15.7 R 758
J99D04J C1999 02 25.40243 14 31 53.62 +19 24 19.6 15.9 R 758
J99D04J C1999 02 25.40447 14 31 54.41 +19 24 14.9 15.5 R 758
J99D04J C1999 02 25.40623 14 31 55.07 +19 24 11.9 15.6 R 758
J99D04J C1999 02 25.69809 14 34 02.49 +19 12 25.2 17.0 V 900
J99D04J C1999 02 25.71283 14 34 08.70 +19 11 49.6 900
J99D04J C1999 02 25.91801 14 35 38.80 +19 03 12.5 587
J99D04J C1999 02 25.91972 14 35 39.60 +19 03 10.0 587
J99D04J C1999 02 25.92563 14 35 42.14 +19 02 55.6 587
J99D04J C1999 02 25.94873 14 35 51.94 +19 01 59.6 16.2 R 118
J99D04J C1999 02 25.95009 14 35 52.51 +19 01 56.3 118
J99D04J C1999 02 25.95245 14 35 53.55 +19 01 50.3 118
J99D04J C1999 02 25.95741 14 35 55.71 +19 01 38.1 118
J99D04J C1999 02 25.97894 14 36 05.10 +19 00 47.9 108
J99D04J C1999 02 25.98079 14 36 06.18 +19 00 41.1 108
J99D04J C1999 02 25.98322 14 36 06.94 +19 00 38.6 108
J99D04J C1999 02 25.99035 14 36 10.12 +19 00 20.8 16.8 V 108
J99D04J C1999 02 26.34083 14 38 43.53 +18 45 55.9 15.5 R 758
J99D04J C1999 02 26.34443 14 38 45.12 +18 45 46.1 15.8 R 758
J99D04J C1999 02 26.34612 14 38 45.87 +18 45 42.3 15.7 R 758
J99D04J C1999 02 26.34778 14 38 46.62 +18 45 37.7 15.7 R 758
J99D04J C1999 02 26.39049 14 39 04.89 +18 43 48.5 15.5 R 758
J99D04J C1999 02 26.39142 14 39 05.15 +18 43 47.1 15.5 R 758
J99D04J C1999 02 26.39236 14 39 05.36 +18 43 45.1 15.7 R 758
J99D04J C1999 02 26.39330 14 39 05.66 +18 43 42.9 15.7 R 758
J99D04J C1999 02 26.39778 14 39 08.96 +18 43 19.7 16.5 V 713
J99D04J C1999 02 26.41565 14 39 16.59 +18 42 35.4 16.2 V 713
Observer details:
046 Klet. Observers M. Tichy, Z. Moravec. Measurer M. Tichy. 0.57-m f/5.2
reflector + CCD.
108 Montelupo. Observers M. Tombelli, A. Boattini, L. Tesi, S. Bartolini,
G. Forti. Measurers M. Tombelli, A. Boattini, L. Tesi, D. Guidetti,
G. Forti, E. Masotti. 0.30-m f/5.7 Schmidt-Cassegrain + CCD.
118 Modra. Observers L. Kornos, J. Toth. 0.6-m f/5.5 reflector + CCD.
587 Sormano. Observers F. Manca, P. Ghezzi. 0.5-m reflector + CCD.
704 Lincoln Laboratory ETS, New Mexico. Observers M. Blythe, F. Shelly,
M. Bezpalko. Measurers J. Stuart, H. Viggh, R. Sayer. 1.0-m f/2.15
reflector + CCD.
713 Thornton. Observer R. A. Koff. 0.20-m f/10 Schmidt-Cassegrain + CCD.
758 BCC Observatory, Cocoa. Observer I. P. Griffin. 0.30-m f/5 Maksutov
+ CCD.
900 Moriyama. Observer Y. Ikari. 0.25-m f/6.3 reflector + CCD.
Orbital elements:
1999 DJ4 PHA 0.030D
Epoch 1999 Feb. 11.0 TT = JDT 2451220.5 Williams
M 335.12309 (2000.0) P Q
n 0.40406931 Peri. 197.49123 -0.79525134 +0.60389610
a 1.8120304 Node 19.95043 -0.53573502 -0.65848094
e 0.4728430 Incl. 9.05676 -0.28383674 -0.44912399
P 2.44 H 17.7 G 0.15
From 53 observations 1999 Feb. 24-26.
Ephemeris:
1999 DJ4 a,e,i = 1.81, 0.47, 9 q = 0.9552
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
1999 02 21 14 02.74 +21 48.9 0.222 1.130 124.7 46.0 16.4
1999 02 26 14 36.20 +19 00.4 0.193 1.101 120.8 50.5 16.2
1999 03 03 15 15.92 +14 47.9 0.169 1.074 115.3 56.5 16.0
1999 03 08 16 02.03 +08 54.7 0.152 1.049 108.1 64.0 16.0
1999 03 13 16 53.09 +01 32.5 0.143 1.027 99.4 72.7 16.1
1999 03 18 17 45.82 -06 20.5 0.143 1.007 90.6 81.2 16.3
1999 03 23 18 36.25 -13 26.2 0.152 0.990 83.1 88.1 16.7
1999 03 28 19 21.47 -18 57.2 0.168 0.976 77.7 92.7 17.1
1999 04 02 20 00.43 -22 50.0 0.189 0.965 74.3 94.8 17.4
1999 04 07 20 33.46 -25 23.7 0.213 0.959 72.5 95.2 17.7
.
.
.
Gareth V. Williams (C) Copyright 1999 MPC M.P.E.C. 1999-D21
SNR Calculation
HMag: 18.0
Diameter: 0.79 km (Assumes an S-class optical albedo)
Period: 4 (an educated guess)
The SNR estimates below adopt RA, DEC, and delta at 00:00 UTC on each date; actual
view periods may differ.
------------GOLDSTONE---------- -------------ARECIBO-----------
Max Max
Dat Run UTC Dat Run UTC
Date RA Decl Delta Runs SNR SNR Window Runs SNR SNR Window
2004 4 9 94 33 0.084 246 46 3 19:06-30:48 40 741 135 20:36-22:30
2004 4 10 92 31 0.080 252 54 4 19:00-30:30 47 980 157 20:18-22:23
2004 4 11 90 29 0.077 257 64 4 18:53-30:11 53 1239 183 20:00-22:18
2004 4 12 88 27 0.074 262 75 5 18:48-29:53 59 1533 213 19:41-22:11
2004 4 13 86 24 0.071 267 88 6 18:41-29:30 64 1860 246 19:23-22:06
2004 4 14 83 21 0.068 270 102 7 18:36-29:11 67 2206 283 19:11-21:53
2004 4 15 81 18 0.065 272 117 8 18:30-28:48 70 2562 322 18:53-21:36
2004 4 16 78 15 0.063 272 132 9 18:23-28:23 70 2879 362 18:41-21:23
2004 4 17 76 11 0.061 271 146 10 18:18-28:00 68 3111 400 18:36-21:06
2004 4 18 73 7 0.060 267 156 11 18:18-27:36 62 3158 433 18:30-20:41
2004 4 19 70 3 0.059 260 162 11 18:11-27:11 50 2787 455 18:30-20:11
2004 4 20 67 -1 0.059 251 162 11 18:06-26:41 26 1530 317 18:41-19:23
2004 4 21 64 -5 0.059 240 156 11 18:06-26:11 0 0 0 -
2004 4 22 61 -9 0.059 226 144 11 18:06-25:41 0 0 0 -
2004 4 23 58 -13 0.060 210 128 10 18:06-25:11 0 0 0 -
2004 4 24 55 -17 0.061 193 110 9 18:06-24:36 0 0 0 -
2004 4 25 52 -20 0.063 175 91 8 18:06-24:00 0 0 0 -
2004 4 26 49 -24 0.065 157 74 7 18:11-23:23 0 0 0 -
Arecibo SNRs DO NOT reflect current system sensitivity (transmitter power ~700 kW).
Goldstone Track Assignments
UT UT Duration
DOY Date TX Window PDT TX Window (hh:mm)
--- ---- --------- ------------- -------
114 Apr 23 1805-1940 1105-1240 1:35
115 Apr 24 1820-2000 1120-1300 1:40
Scheduled Arecibo Tracks
------------------------
UT UT Duration
DOY Date TX Window PST TX Window AST TX Window (hh:mm)
--- ---- --------- ------------- ------------- --------
105 Apr 14 1856-2143 1156-1443 1456-1743 2:47
106 Apr 15 1844-2128 1144-1428 1444-1728 2:44
107 Apr 16 1834-2109 1134-1409 1434-1709 2:35
108 Apr 17 1826-2046 1126-1346 1426-1646 2:20
Arecibo images
April 14 horizontal collage
April 15 horizontal collage
April 16 horizontal collage
April 14 vertical collage
April 15 vertical collage
April 16 vertical collage
Sky Motion
Uncertainties
From Horizons: 2004 April 1, JPL solution #71, # obs: 477 (1999-2004)
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2004-Apr-09 00:00 94.19097 33.35047 0.0838906755 1.56955713 0.06 0.20 0.001024
2004-Apr-10 00:00 92.26870 31.41156 0.0803297459 1.75269046 0.05 0.18 0.001004
2004-Apr-11 00:00 90.24435 29.26484 0.0769230407 1.95673588 0.05 0.19 0.000979
2004-Apr-12 00:00 88.11411 26.89064 0.0736985270 2.18203517 0.06 0.22 0.000949
2004-Apr-13 00:00 85.87530 24.27109 0.0706875881 2.42767540 0.08 0.27 0.000912
2004-Apr-14 00:00 83.52662 21.39222 0.0679249066 2.69090216 0.10 0.34 0.000870
2004-Apr-15 00:00 81.06852 18.24671 0.0654479898 2.96649541 0.12 0.42 0.000820
2004-Apr-16 00:00 78.50346 14.83716 0.0632961933 3.24626173 0.14 0.50 0.000764
2004-Apr-17 00:00 75.83628 11.17950 0.0615091271 3.51888999 0.16 0.59 0.000701
2004-Apr-18 00:00 73.07441 7.30576 0.0601244161 3.77046310 0.19 0.67 0.000633
2004-Apr-19 00:00 70.22799 3.26522 0.0591749482 3.98583595 0.21 0.75 0.000563
2004-Apr-20 00:00 67.30994 -0.87689 0.0586859566 4.15081767 0.23 0.83 0.000495
2004-Apr-21 00:00 64.33575 -5.04382 0.0586724568 4.25469298 0.25 0.90 0.000436
2004-Apr-22 00:00 61.32317 -9.15417 0.0591376114 4.29230036 0.27 0.96 0.000395
2004-Apr-23 00:00 58.29165 -13.13001 0.0600724278 4.26491705 0.28 1.01 0.000377
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Jon Giorgini (2004 April 6):
With 498 usable observations spanning 1999-Feb-24 to 2004-Apr-2,
1999 DJ4 solution #74 was computed. 3-sigma uncertainties are as
tabulated below.
Date__(UT)__HR:MN POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
----------------- ---------- --------- --------- ------------
2004-Apr-09 00:00 1.33171257 0.05 0.18 0.000921
2004-Apr-10 00:00 1.48911679 0.05 0.17 0.000904
2004-Apr-11 00:00 1.66498696 0.05 0.18 0.000883
2004-Apr-12 00:00 1.85973950 0.06 0.22 0.000858
2004-Apr-13 00:00 2.07272872 0.07 0.26 0.000828
2004-Apr-14 00:00 2.30173423 0.09 0.32 0.000792
2004-Apr-15 00:00 2.54240916 0.11 0.39 0.000750
2004-Apr-16 00:00 2.78782044 0.13 0.46 0.000703
2004-Apr-17 00:00 3.02829392 0.15 0.54 0.000649
2004-Apr-18 00:00 3.25182149 0.17 0.61 0.000592
Close Approaches
Close-approach results (distance < 0.1 AU):
Date (CT) Body CA Dist MinDist MaxDist Vrel TCA3Sg Nsigs P_i/p
---------------------- ----- ------- ------- ------- ------ ------ ------ -------
A.D. 1399 Mar 16.55398 Earth .043280 .036683 .059599 9.922 7243.2 4.20E5 .000000
A.D. 1404 Apr 29.57827 Earth .095620 .084984 .108681 9.667 7376.5 3.91E5 .000000
A.D. 1467 Apr 09.25023 Earth .058199 .051388 .067117 9.201 6872.7 3.62E5 .000000
A.D. 1530 Apr 08.67887 Earth .056836 .052523 .061775 9.166 3808.8 3.60E5 .000000
A.D. 1588 Mar 30.64278 Earth .033195 .033132 .033268 9.676 192.40 3.63E5 .000000
A.D. 1651 Apr 17.64751 Earth .055164 .054784 .055547 9.133 291.64 3.50E5 .000000
A.D. 1709 Apr 24.18030 Earth .068638 .068324 .068954 9.187 260.21 3.96E5 .000000
A.D. 1762 Mar 21.09820 Earth .068334 .067947 .068721 11.057 88.83 4.79E5 .000000
A.D. 1767 May 07.36316 Earth .090023 .089854 .090192 9.270 139.29 4.14E5 .000000
A.D. 1825 Apr 13.26486 Earth .045115 .044903 .045328 9.240 145.04 3.45E5 .000000
A.D. 1878 Mar 27.22529 Earth .042840 .042692 .042988 10.425 47.48 3.54E5 .000000
A.D. 1883 May 12.94079 Earth .098620 .098534 .098707 9.305 69.87 4.27E5 .000000
A.D. 1941 Apr 03.99706 Earth .026324 .026324 .026324 9.748 2.17 3.10E5 .000000
A.D. 2004 Apr 20.53404 Earth .058646 .058646 .058646 9.070 0.32 4.16E5 .000000
A.D. 2057 Mar 22.02197 Earth .084555 .084548 .084561 11.718 1.25 3.80E5 .000000
A.D. 2062 May 04.98723 Earth .086451 .086449 .086453 9.076 1.90 4.40E5 .000000
A.D. 2120 Apr 28.66124 Earth .074238 .074229 .074247 8.999 6.82 3.92E5 .000000
A.D. 2173 Mar 22.62169 Earth .091830 .091788 .091871 12.028 6.54 3.34E5 .000000
A.D. 2178 May 05.49977 Earth .087256 .087241 .087270 9.062 12.61 4.40E5 .000000
A.D. 2236 Apr 19.34131 Earth .053094 .053039 .053149 9.147 31.34 3.14E5 .000000
A.D. 2289 Apr 07.34199 Earth .016837 .016774 .016904 9.781 80.57 1.84E5 .000000
A.D. 2337 Mar 28.41315 Earth .065652 .049719 .081592 11.448 2842.9 2.28E5 .000000
Setups
CW Setup for the first track
TX polarization RCP
RCV polarization LCP
Frequencies: 2
Dwell: 20 seconds
Bandwidth: 4000 Hz
Sampling interval: 2500 x 0.1 usec
VME FFT for PSD files: 1024 for 3.906-Hz resolution
Possible ranging setups:
---------------------------------------------------------------------------
127 x 64 10-usec single sample
baud 10 usec
code 127
gates 127
FFT 64
CLT 11
ncoh 2
bandwidth 394 Hz
resolution 6.15 Hz
TXOFF +60 Hz -> echo will be centered at +9.75 bins or in bin 32+10 = 42
incoh sums 64 => 10.4 sec/record
---------------------------------------------------------------------------
127 x 64 11-usec single sample, 5.6-Hz resolution.
baud 11 usec
code 127
gates 127
PRP 1397
FFT 64
CLT 11
ncoh 2
bandwidth 357.9 Hz
resolution 5.59 Hz
TXOFF TBD
-------------------------------------------------------------------------
127 x 64 11-usec single sample, 11.2-Hz resolution
baud 11 usec
code 127
gates 127
PRP 1397
FFT 64
CLT 11
ncoh 1
bandwidth 715.8 Hz
resolution 11.2 Hz
TXOFF +60 -> echo would be centered at +5 bins w/perfect ephemeris
-------------------------------------------------------------------------
127 x 64 7-usec single sample
------------------------------
baud 7 usec
code 127
gates 127
PRP 889
FFT 64
CLT 11
ncoh 1
bandwidth 1124.9 Hz
resolution 17.6 Hz
TXOFF +60 -> echo would be centered at +3.4 bins w/perfect ephemeris
-------------------------------------------------------------------------
127 x 64 1-usec single sample
------------------------------
baud 1 usec
code 127
gates 127
PRP 127
FFT 64
CLT 13 & 14, about evenly divided
ncoh 15
bandwidth 525 Hz
resolution 8.2 Hz
TXOFF +50 -> echo would be centered at +6.1 bins w/perfect ephemeris
-------------------------------------------------------------------------------
0.125-usec ranging
------------------
setup JX1XS001
baud 0.125 usec
code 127
gates 127
FFT 64
ncoh 1968
bandwidth 32.008 Hz
resolution 0.5001 Hz
TXOFF 6 Hz = 12 cells, => cell 44
incoh sums 4 looks=> 8 sec/record => expect records per run ~ RTT/8
CLT gate 34.8
_____________________________________________________________________
POSSIBLE RANGING SETUPS: (code=127, FFT=64, single-pol'n)
These are from JX, w/ max-band (min-acc) options from Ray Jurgens.
Currently configured for 5-sec records.
_______________________________________________________________________
Setup Baud RP 1-acc 1-acc
usec m usec band res acc band res
_______________________________________________________________________
JX1XS110 11.000 1650 1397.0 715.8 11.2 2 358 5.6
JX1XS070 7.000 1050 889.0 1124.9 17.6 3 375 5.9
JX1XS020 2.000 300 254.0 3937.0 61.5 12 328 5.1
4 984 15.4
JX1XS010 1.000 150 127.0 7874.0 123.0 41 192 3.0
8 984 15.4
JX1XS005 0.500 75 63.5 15748.0 246.1 123 128 2.0
15 1050 16.4
JX1XS002 0.250 37.5 31.75 31496.1 492.1 492 64 1.0
30 1050 16.4
JX1XS001 0.125 18.75 15.875 62992.1 984.3 1970 32 0.5
60 1050 16.4
____________________________________________________________________
Instructions
NOTE: Data should be moved to the appropriate subdirectories in
stealth:/export/data0/rosema/1999DJ4/raw/
1999 DJ4 POINTING:
OSOD and initial predicts will be set-up at
Goldstone on stealth:
/export/data2/osod/ops/1999dj4/PRDX.OUT.s??
/PUNCH.OUT.s??
/EPH.OUT.s??
NOT AVAILABLE YET
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
NOT AVAILABLE YET
PRDX.OUT.s??
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
NOT AVAILABLE YET
GOLDSTONE MASTERLOG
MASTERLOG
==============================================================================
RCV
file setup runs start -stop osod OFFSET TX Poln
------------------------------------------------------------------------------
April 23
------------------------------------------------------------------------------
April 24
==============================================================================
Dr. Lance A. M. Benner | PHONE: (818) 354-7412
Mail Stop 300-233 | FAX: (818) 354-9476
Jet Propulsion Laboratory | email: lance@reason.jpl.nasa.gov
Pasadena, CA 91109-8099 | Plan: To live long and prosper
Asteroid Radar Astronomy