Goldstone Radar Observations Planning: 162173 Ryugu
...We will provide background information later... The 2020 Earth flyby is the closest by this asteroid until 2033 when it will approach within 0.0474 au.
Orbital and Physical Characteristics Name Ryugu Asteroid number 162173 Provisional designation 1999 JU3 Discoverer LINEAR Discovery date 1999 May 10 Close approach distance 0.0605 au (23.5 lunar distances or about 9 million km) Close approach date 2020 Dec 29 Orbit type Apollo semimajor axis 1.1896 au eccentricity 0.190 inclination 5.9 deg Orbital period 1.297 years perihelion distance 0.963 au aphelion distance 1.416 au MOID 0.000354 au absolute magnitude (H) 19.3 diameter 0.9 km optical albedo 0.04 rotation period 7.63 h lightcurve amplitude ...need to dig this out... pole direction (lambda, beta) = (178, -87) deg spectral class C PHA? Yes Last update: 2020 December 15
Goldstone Radar Data from Near-Earth Asteroid (162173) Ryugu
Echo power spectrum from Ryugu obtained on December 14, 2020. The resolution is 0.5 Hz.
Ryugu (1999 JU3) https://www.minorplanetcenter.net/mpec/J99/J99J33.html
Goldstone SNRs Assumptions: D = 0.9 km, P = 7.6326 h, OC albedo = 0.1, pole = (178, -87), Ptx = 450 kW w DOY start date window RA, dec dist delta runs SNR/day SNR/run 46 314-315 2020 Nov 09-10 21:48-08:23 339, +21 0.112 +30 170 31 3 46 315-316 2020 Nov 10-11 21:46-08:17 339, +20 0.111 +29 171 32 3 46 316-317 2020 Nov 11-12 21:44-08:11 339, +19 0.110 +28 172 34 3 46 317-318 2020 Nov 12-13 21:42-08:06 339, +19 0.108 +28 173 35 3 46 318-319 2020 Nov 13-14 21:40-08:00 339, +18 0.107 +27 175 37 3 46 319-320 2020 Nov 14-15 21:38-07:55 339, +17 0.105 +26 176 39 3 46 320-321 2020 Nov 15-16 21:37-07:49 339, +16 0.104 +26 177 41 3 47 321-322 2020 Nov 16-17 21:35-07:43 340, +15 0.103 +25 178 42 3 47 322-323 2020 Nov 17-18 21:34-07:38 340, +15 0.101 +24 179 45 4 47 323-324 2020 Nov 18-19 21:33-07:32 340, +14 0.100 +23 180 47 4 47 324-325 2020 Nov 19-20 21:32-07:27 340, +13 0.099 +22 182 49 4 47 325-326 2020 Nov 20-21 21:31-07:21 340, +12 0.097 +22 183 52 4 47 326-327 2020 Nov 21-22 21:30-07:16 340, +11 0.096 +21 184 54 4 47 327-328 2020 Nov 22-23 21:30-07:11 341, +10 0.094 +20 185 57 4 48 328-329 2020 Nov 23-24 21:29-07:05 341, +10 0.093 +19 186 60 5 48 329-330 2020 Nov 24-25 21:29-07:00 341, +9 0.092 +18 187 63 5 Overlaps WJ16 for 10 minutes 48 330-331 2020 Nov 25-26 21:29-06:54 341, +8 0.090 +17 188 66 5 48 331-332 2020 Nov 26-27 21:29-06:49 342, +7 0.089 +16 189 70 5 THANKSGIVING 48 332-333 2020 Nov 27-28 21:29-06:43 342, +6 0.088 +15 190 74 6 48 333-334 2020 Nov 28-29 21:29-06:38 342, +5 0.086 +14 191 77 6 48 334-335 2020 Nov 29-30 21:30-06:32 343, +4 0.085 +13 192 82 6 49 335-336 2020 Nov 30-01 21:31-06:26 343, +2 0.084 +11 192 86 7 49 336-337 2020 Dec 01-02 21:32-06:21 344, +1 0.082 +10 193 91 7 49 337-338 2020 Dec 02-03 21:33-06:15 344, 0 0.081 +9 193 95 7 49 338-339 2020 Dec 03-04 21:35-06:09 344, -1 0.080 +8 193 100 8 49 339-340 2020 Dec 04-05 21:36-06:03 345, -2 0.079 +6 194 110 8 49 340-341 2020 Dec 05-06 21:39-05:56 345, -4 0.077 +5 193 110 9 49 341-342 2020 Dec 06-07 21:41-05:50 346, -5 0.076 +4 193 120 9 50 342-343 2020 Dec 07-08 21:44-05:43 346, -6 0.075 +2 192 120 10 50 343-344 2020 Dec 08-09 21:47-05:36 347, -8 0.074 +1 191 130 10 50 344-345 2020 Dec 09-10 21:50-05:29 347, -9 0.073 -1 190 130 11 50 345-346 2020 Dec 10-11 21:54-05:22 348, -11 0.072 -2 188 140 11 50 346-347 2020 Dec 11-12 21:59-05:14 349, -12 0.070 -4 185 140 12 Scheduled 0320-0510 Dec 12 50 347-348 2020 Dec 12-13 22:04-05:06 349, -14 0.069 -6 182 150 12 50 348-349 2020 Dec 13-14 22:10-04:57 350, -15 0.068 -7 179 150 12 Scheduled 0310-0455 Dec 14 w/Geminids 51 349-350 2020 Dec 14-15 22:16-04:48 350, -17 0.068 -9 174 160 13 51 350-351 2020 Dec 15-16 22:23-04:38 351, -19 0.067 -11 169 160 13 Scheduled 0250-0425 Dec 16 51 351-352 2020 Dec 16-17 22:32-04:28 352, -20 0.066 -13 162 160 14 51 352-353 2020 Dec 17-18 22:41-04:16 353, -22 0.065 -15 155 160 14 Scheduled 0130-0415 Dec 18 51 353-354 2020 Dec 18-19 22:52-04:04 353, -24 0.064 -17 146 160 14 51 354-355 2020 Dec 19-20 23:04-03:49 354, -26 0.064 -19 134 160 14 51 355-356 2020 Dec 20-21 23:19-03:33 355, -28 0.063 -21 121 150 14 52 356-357 2020 Dec 21-22 23:38-03:13 356, -30 0.062 -23 103 140 14 52 358 2020 Dec 23 00:02-02:48 357, -32 0.062 -25 80 120 14 52 359 2020 Dec 24 00:42-02:08 358, -34 0.061 -27 42 89 14 CHRISTMAS EVE We checked to see if Ryugu view periods overlap times scheduled for other objects: the overlap is minimal. RYUGU ARECIBO SNRs Ryugu: D = 0.90 km, P = 7.6326 hr, OC albedo = 0.100, pole = (178, -87) start date window RA, dec dist delta runs SNR/day SNR/run 2020 Oct 04 02:20-03:54 353, +35 0.183 +37 15 35 10 2020 Oct 05 02:13-03:48 353, +35 0.180 +37 15 37 11 2020 Oct 06 02:07-03:42 352, +35 0.177 +37 16 41 11 2020 Oct 07 02:00-03:37 351, +35 0.175 +37 16 43 12 2020 Oct 08 01:53-03:31 351, +35 0.172 +38 17 47 13 2020 Oct 09 01:46-03:26 350, +35 0.170 +38 17 50 13 2020 Oct 10 01:39-03:21 350, +34 0.167 +38 18 55 14 2020 Oct 11 01:32-03:16 349, +34 0.165 +38 19 59 15 2020 Oct 12 01:25-03:11 349, +34 0.163 +38 19 64 16 2020 Oct 13 01:17-03:06 348, +34 0.161 +38 20 69 17 2020 Oct 14 01:10-03:01 348, +34 0.158 +38 21 75 19 2020 Oct 15 01:03-02:56 347, +33 0.156 +38 22 82 20 2020 Oct 16 00:55-02:51 346, +33 0.154 +38 22 88 21 2020 Oct 17 00:48-02:47 346, +33 0.152 +38 23 95 22 2020 Oct 18 00:41-02:42 345, +32 0.150 +38 24 100 23 2020 Oct 19 00:34-02:38 345, +32 0.148 +38 25 110 24 2020 Oct 20 00:26-02:33 345, +32 0.146 +38 26 110 25 2020 Oct 21 00:19-02:29 344, +31 0.144 +37 27 130 26 2020 Oct 22 00:12-02:25 344, +31 0.143 +37 28 130 27 2020 Oct 23 00:05-02:20 343, +31 0.141 +37 29 140 29 2020 Oct 23 23:58-02:16 343, +30 0.139 +37 30 150 30 2020 Oct 24 23:52-02:12 342, +30 0.137 +37 31 160 31 2020 Oct 25 23:45-02:08 342, +29 0.136 +36 31 170 32 2020 Oct 26 23:39-02:04 342, +29 0.134 +36 32 180 34 2020 Oct 27 23:32-02:00 341, +28 0.132 +36 33 190 35 2020 Oct 28 23:26-01:56 341, +28 0.131 +35 34 200 37 2020 Oct 29 23:20-01:52 341, +27 0.129 +35 35 210 38 2020 Oct 30 23:14-01:48 341, +27 0.127 +35 36 230 40 2020 Oct 31 23:08-01:44 340, +26 0.126 +34 37 240 41 2020 Nov 01 23:03-01:40 340, +26 0.124 +34 38 250 43 2020 Nov 02 22:57-01:36 340, +25 0.123 +33 39 270 45 2020 Nov 03 22:52-01:32 340, +25 0.121 +33 39 280 47 2020 Nov 04 22:47-01:28 340, +24 0.120 +33 40 300 49 2020 Nov 05 22:42-01:24 340, +23 0.118 +32 41 310 51 2020 Nov 06 22:37-01:20 339, +23 0.117 +31 42 330 53 2020 Nov 07 22:32-01:17 339, +22 0.115 +31 43 350 55 2020 Nov 08 22:28-01:13 339, +21 0.114 +30 43 360 57 2020 Nov 09 22:23-01:09 339, +21 0.113 +30 44 380 60 2020 Nov 10 22:19-01:05 339, +20 0.111 +29 45 400 62 2020 Nov 11 22:15-01:01 339, +19 0.110 +28 44 410 65 2020 Nov 12 22:11-00:57 339, +19 0.108 +28 42 420 68 2020 Nov 13 22:08-00:53 339, +18 0.107 +27 44 450 71 2020 Nov 14 22:04-00:49 339, +17 0.106 +26 47 490 74 2020 Nov 15 22:01-00:45 339, +16 0.104 +26 47 510 77 2020 Nov 16 21:58-00:41 340, +16 0.103 +25 48 530 80 2020 Nov 17 21:56-00:37 340, +15 0.101 +24 48 560 84 2020 Nov 18 21:53-00:33 340, +14 0.100 +23 48 580 88 2020 Nov 19 21:51-00:29 340, +13 0.099 +23 48 610 92 2020 Nov 20 21:49-00:24 340, +12 0.097 +22 48 640 96 2020 Nov 21 21:47-00:20 340, +11 0.096 +21 48 670 100 2020 Nov 22 21:46-00:15 341, +11 0.095 +20 47 690 110 2020 Nov 23 21:45-00:10 341, +10 0.093 +19 47 720 110 2020 Nov 24 21:44-00:05 341, +9 0.092 +18 46 750 120 2020 Nov 25 21:43-00:00 341, +8 0.091 +17 45 770 120 2020 Nov 26 21:44-23:54 342, +7 0.089 +16 44 800 130 2020 Nov 27 21:44-23:49 342, +6 0.088 +15 42 810 130 2020 Nov 28 21:45-23:42 342, +5 0.087 +14 40 830 140 2020 Nov 29 21:47-23:35 343, +4 0.085 +13 38 820 150 2020 Nov 30 21:50-23:27 343, +3 0.084 +12 35 780 150 2020 Dec 01 21:55-23:18 344, +2 0.083 +10 30 710 140 2020 Dec 02 22:01-23:07 344, 0 0.081 +9 24 620 140 2020 Dec 03 22:14-22:50 344, -1 0.080 +8 13 430 120 Arecibo SNRs assume Ptx = 900 kW and gain = 10 K/Jy. Consequently, these numbers are optimistic by more than a factor of two. >> Observations at Arecibo will not be possible <<
Track Assignments
DOY BOA BOT EOT EOA 347 0150 0320 0510 0540 DSS14 AST RYUGU 347 0905 1035 1255 1325 DSS14 AST 2018 PK21 348 1100 1250 DSS14 Geminids Meteors 348 1100 1250 DSS13 Geminids Meteors 349 0140 0310 0455 0525 DSS14 AST RYUGU 349 0455 0800 DSS14 Geminids Meteors 349 0455 0800 DSS13 Geminids Meteors 349 1100 1400 DSS14 Geminids Meteors 349 1100 1400 DSS25 Geminids Meteors 351 0120 0250 0425 0455 DSS14 AST RYUGU 353 0000 0130 0415 0445 DSS14 AST RYUGU Goldstone tracks: UT UT PST Duration Round-trip DOY Date Target TX Window TX Window hh:mm time (sec) SNR/RTT Observer Notes 347 Dec 12 Ryugu DSS-14 0320-0510 1920-2110 Dec 11 1:50 70 12 MB Start early during precal? 347 Dec 12 2018 PK21 DSS-14 1035-1255 0235-0455 Dec 12 2:20 32 <1 MB Engineering tests 348 Dec 13 Geminids DSS-14 1100-1250 0300-0450 Dec 13 1:50 MB 348 Dec 13 Geminids DSS-13 1100-1250 0300-0450 Dec 13 1:50 MB 349 Dec 14 Ryugu DSS-14 0310-0455 1910-2055 Dec 13 1:45 68 12 LB 349 Dec 14 Geminids DSS-14 0455-0800 2055-0000 Dec 13 3:05 349 Dec 14 Geminids DSS-13 0455-0800 2055-0000 Dec 13 3:05 349 Dec 14 Geminids DSS-14 1100-1400 0300-0600 Dec 14 3:00 SN 349 Dec 14 Geminids DSS-25 1100-1400 0300-0600 Dec 14 3:00 SN 351 Dec 16 Ryugu DSS-14 0250-0425 1850-2025 Dec 15 1:35 67 13 SN Start early during precal? 353 Dec 18 Ryugu DSS-14 0130-0415 1730-2015 Dec 17 2:45 65 14 MB Start early during precal? Ryugu observations overlap dates scheduled for radar observations of the Geminids meteor stream, so the schedule for both targets appears above. Ryugu will be more than 20 degrees above the horizon at the start of precal on some days so we can begin to observe it as soon as we're ready, which could be as much as one hour early.
Expected Goldstone Rotational Phase coverage for Ryugu: Coverage uses BOT and EOT times; on some days observations started early and provided got more extensive coverage. 0 30 60 90 120 150 180 210 240 270 300 330 360 Dec 12 xxxxxxxxxxxxx Dec 14 xxxxxxxxxxxx Dec 16 xxxxxxxx xxxx Dec 18 xxxxxxxxxxxxxxxxxx
Arecibo tracks: UT UT PST Round-trip Date TX Window TX Window time (sec) ...Observations at Arecibo will not be possible...
Uncertainties
JPL/Horizons solution 195, # obs: 1836 (1986-2020) 2020 Dec 10 Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2020-Dec-10 00:00 * 347.36482 -8.93104 0.07270167646257 0.349 0.05 0.19 0.000209 2020-Dec-11 00:00 * 347.92970 -10.41619 0.07159835754412 0.368 0.06 0.21 0.000209 2020-Dec-12 00:00 * 348.51643 -11.94653 0.07053058048767 0.388 0.06 0.23 0.000208 2020-Dec-13 00:00 * 349.12590 -13.52254 0.06950100569790 0.408 0.07 0.25 0.000207 2020-Dec-14 00:00 *m 349.75902 -15.14451 0.06851230789468 0.430 0.07 0.27 0.000206 2020-Dec-15 00:00 *m 350.41675 -16.81249 0.06756720173828 0.453 0.08 0.29 0.000205 2020-Dec-16 00:00 *m 351.10004 -18.52623 0.06666847135566 0.476 0.09 0.32 0.000203 2020-Dec-17 00:00 *m 351.80994 -20.28520 0.06581899169220 0.501 0.10 0.35 0.000201 2020-Dec-18 00:00 *m 352.54753 -22.08844 0.06502173178450 0.526 0.11 0.38 0.000199 2020-Dec-19 00:00 *m 353.31404 -23.93458 0.06427973625451 0.551 0.11 0.42 0.000196 2020-Dec-20 00:00 *m 354.11083 -25.82173 0.06359608762873 0.577 0.12 0.45 0.000193 2020-Dec-21 00:00 *m 354.93947 -27.74746 0.06297385553408 0.604 0.13 0.49 0.000190 2020-Dec-22 00:00 *m 355.80174 -29.70875 0.06241603910939 0.630 0.14 0.52 0.000186 2020-Dec-23 00:00 *m 356.69969 -31.70198 0.06192550748807 0.656 0.15 0.56 0.000182 2020-Dec-24 00:00 *m 357.63563 -33.72293 0.06150494140261 0.682 0.16 0.60 0.000178 2020-Dec-25 00:00 *m 358.61225 -35.76680 0.06115677759049 0.707 0.17 0.63 0.000173 - - - - - - - - - - JPL/Horizons solution 150, # obs: 1341 (1986-2020) 2020 October 22 Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2020-Dec-10 00:00 * 347.36484 -8.93109 0.07270166990562 0.618 0.09 0.32 0.000324 2020-Dec-11 00:00 * 347.92972 -10.41624 0.07159835256809 0.649 0.09 0.34 0.000324 2020-Dec-12 00:00 * 348.51645 -11.94657 0.07053057715293 0.683 0.10 0.37 0.000323 2020-Dec-13 00:00 * 349.12591 -13.52259 0.06950100406309 0.717 0.11 0.40 0.000322 2020-Dec-14 00:00 *m 349.75904 -15.14456 0.06851230801620 0.754 0.12 0.44 0.000320 2020-Dec-15 00:00 *m 350.41676 -16.81253 0.06756720366958 0.791 0.13 0.48 0.000317 2020-Dec-16 00:00 *m 351.10006 -18.52628 0.06666847514661 0.831 0.15 0.53 0.000315 2020-Dec-17 00:00 *m 351.80996 -20.28525 0.06581899738829 0.871 0.16 0.58 0.000311 2020-Dec-18 00:00 *m 352.54755 -22.08849 0.06502173942604 0.913 0.17 0.63 0.000308 2020-Dec-19 00:00 *m 353.31406 -23.93463 0.06427974587581 0.955 0.19 0.69 0.000303 2020-Dec-20 00:00 *m 354.11085 -25.82178 0.06359609925724 0.998 0.21 0.75 0.000298 2020-Dec-21 00:00 *m 354.93949 -27.74751 0.06297386918944 1.042 0.22 0.81 0.000293 2020-Dec-22 00:00 *m 355.80176 -29.70880 0.06241605480270 1.086 0.24 0.87 0.000287 2020-Dec-23 00:00 *m 356.69971 -31.70203 0.06192552522109 1.129 0.26 0.93 0.000280 2020-Dec-24 00:00 *m 357.63566 -33.72298 0.06150496116712 1.172 0.27 0.99 0.000273 2020-Dec-25 00:00 *m 358.61227 -35.76685 0.06115679936778 1.213 0.29 1.05 0.000265
Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-brt S-O-T /r T-O-M/MN_Illu% 2020-Nov-01 00:00 340.39375 26.29349 0.12594323253851 16.762 n.a. 126.3906 /T 58.8/ 99.7960 2020-Nov-05 00:00 339.66291 23.96327 0.11987032994060 16.739 n.a. 122.5333 /T 98.0/ 83.4521 2020-Nov-09 00:00 339.27541 21.40628 0.11402834396827 16.721 n.a. 118.5834 /T 138.2/ 45.5284 2020-Nov-13 00:00 339.23350 18.61923 0.10835819599959 16.706 n.a. 114.5742 /T 137.4/ 7.4590 2020-Nov-17 00:00 339.53933 15.59318 0.10280543778057 16.694 n.a. 110.5331 /T 87.6/ 4.6639 2020-Nov-21 00:00 340.18426 12.30651 0.09731688630908 16.685 n.a. 106.4720 /T 38.8/ 38.0548 2020-Nov-25 00:00 341.14717 8.71244 0.09186820321207 16.677 n.a. 102.3809 /T 27.5/ 75.9488 2020-Nov-29 00:00 342.40732 4.73893 0.08648235178298 16.674 n.a. 98.2393 /T 67.3/ 98.1857 2020-Dec-03 00:00 343.95187 0.29503 0.08123008551877 16.678 n.a. 94.0297 /T 114.8/ 93.6156 2020-Dec-07 00:00 345.78166 -4.71870 0.07622732996111 16.695 n.a. 89.7542 /T 165.8/ 61.2929 2020-Dec-11 00:00 347.91785 -10.39233 0.07162501387481 16.729 n.a. 85.4577 /T 136.2/ 18.4194 2020-Dec-15 00:00 350.40456 -16.78476 0.06759071389801 16.783 n.a. 81.2488 /T 76.8/ 0.1504 2020-Dec-19 00:00 353.30120 -23.90297 0.06429923646101 16.857 n.a. 77.3055 /T 25.0/ 21.9735 2020-Dec-23 00:00 356.68571 -31.66697 0.06194014321664 16.947 n.a. 73.8746 /T 36.0/ 59.7476 2020-Dec-27 00:00 0.68416 -39.86404 0.06069495580641 17.042 n.a. 71.2552 /T 79.3/ 90.7513 2020-Dec-31 00:00 5.51012 -48.14208 0.06068496573912 17.124 n.a. 69.7195 /T 118.7/ 99.1908
Setups
Due the 7.6 h rotation period and diameter of 0.9 km, we are expecting a bandwidth of about 12 Hz. CW setup: --------------------------------------------------------------------------- TX polarization RCP RCV polarization LCP & RCP Frequency hops: no hopping Bandwidth: 5000 Hz TXoffset +500 Hz FFT 5000 Hz for 1 Hz resolution Ranging setups: --------------------------------------------------------------------------- 10-usec baud 10 usec code 127 PRP 1270 usec ncoh 1 bandwidth 787 Hz FFT 128 resolution 6.15 Hz TXoffset +100 Hz (echo in column 80) --------------------------------------------------------------------------- 11-usec baud 11 usec code 127 PRP 1397 usec ncoh 1 bandwidth 716 Hz FFT 128 resolution 5.6 Hz TXoffset +100 Hz (echo in column 82) ------------------------------------------------------------------------- 1-usec baud 1 usec code 511 ncoh 4 bandwidth 489.2 Hz FFT 128 resolution 3.8 Hz TXoffset +100 Hz (echo in column 91) ---------------------------------------------------------------------
Instructions
NOTE: Data should be moved to the appropriate subdirectories in aardvark:/export/data0/Ryugu/raw/
POINTING:
OSOD and predicts will be on aardvark: /export/data3/osod/ops/a162173/EPH.OUT.s197 /export/data3/osod/ops/a162173/PRDX.OUT.14f-14-14.s197 /export/data3/osod/ops/a162173/PRDX.OUT.14v-14-14.s197 /export/data3/osod/ops/a162173/PUNCH.OUT.14f-14-14.s197 /export/data3/osod/ops/a162173/PUNCH.OUT.14v-14-14.s197 POINTING MACRO TX Offsets Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD ...Not available yet... Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.197 TARGET IS A#0000 ET-UT(FIRST POINT) = 69.182398682 ET-UT1(FIRST POINT) = 69.357566315 TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER AZI DEC RA EL D-DOP D-RANGE ...Not available yet...
Ryugu GOLDSTONE MASTERLOG
============================================================================== Receive TX Setup code ncoh FFT runs start -stop OSOD offset Notes
Dr. Lance A. M. Benner | PHONE: (818) 354-7412 Mail Stop 183-601 | FAX: (818) 393-4445 Jet Propulsion Laboratory | email: lance.benner@jpl.nasa.gov California Institute of Technology | Plan: To live long and prosper Pasadena, CA 91109-8099 https://echo.jpl.nasa.gov/asteroids/Ryugu/ryugu.2020.goldstone.planning.html
Asteroid Radar Astronomy