2006 GY2 Planning
Background
2006 GY2 was discovered by LINEAR on April 9, 2006. It will make a very close approach
within 0.017 AU (only 6.6 lunar distances) on May 16. Its physical properties are unknown,
but its absolute magnitude of 18.6 suggests a diameter within a factor of two of 600 meters.
Using past experience as a guide, there is a 1/6 chance that it is a binary.
The PI of these observations is Dr. Michael Nolan at Arecibo Observatory.
Goldstone observations are scheduled on May 13 and 16, and Arecibo observations are
scheduled on May 15 and 16. The Goldstone SNRs will increase rapidly from the first to the
third track as the asteroid rapidly approaches Earth.
Due to the proximity of its orbit to Earth and its diameter, 2006 GY2 has been classified as a
"Potentially Hazardous Asteroid" by the Minor Planet Center.
Orbital and Physical Characteristics
orbit type Apollo
semimajor axis 1.853 AU
eccentricity 0.494
inclination 30.6°
perihelion distance 0.938 AU
aphelion distance 2.768 AU
absolute magnitude (H) 18.6
diameter 600 m +/- a factor of two (educated guesses)
rotation period unknown
pole direction unknown
lightcurve amplitude unknown
spectral class unknown
Last updated: 2006 May 13
Discovery
M.P.E.C. 2006-G37 Issued 2006 Apr. 10, 15:10 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.
Supported in part by the Brinson Foundation
Supported in part by the TABASGO Foundation
Prepared using the Tamkin Foundation Computer Network
MPC@CFA.HARVARD.EDU
URL http://cfa-www.harvard.edu/iau/mpc.html ISSN 1523-6714
2006 GY2
Observations:
K06G02Y* C2006 04 09.33747 16 10 34.87 +45 23 40.5 19.3 EG037704
K06G02Y C2006 04 09.34745 16 10 35.10 +45 23 47.9 19.3 EG037704
K06G02Y C2006 04 09.35765 16 10 35.29 +45 23 56.1 19.3 EG037704
K06G02Y C2006 04 09.36767 16 10 35.45 +45 24 03.6 19.0 EG037704
K06G02Y C2006 04 10.30868 16 11 00.96 +45 35 40.1 18.8 R EG037H36
K06G02Y C2006 04 10.31593 16 11 01.16 +45 35 44.9 18.8 R EG037H36
K06G02Y C2006 04 10.32317 16 11 01.22 +45 35 51.4 18.9 R EG037H36
K06G02Y C2006 04 10.33400 16 11 01.13 +45 36 00.8 19.4 R EG037850
K06G02Y C2006 04 10.34910 16 11 01.38 +45 36 12.0 19.6 R EG037850
K06G02Y C2006 04 10.43166 16 11 02.58 +45 37 12.7 19.3 R EG037850
Observer details:
704 Lincoln Laboratory ETS, New Mexico. Observers M. Bezpalko, L. Manguso,
D. Torres, R. Kracke, M. Blythe, H. Love, G. Spitz. Measurers J. Stuart,
J. Kommers. 1.0-m f/2.15 reflector + CCD.
850 Cordell-Lorenz Observatory, Sewanee. Observers D. T. Durig, B. T. Scott.
0.30-m f/2.5 Schmidt-Cassegrain + 765x510 CCD.
H36 Sandlot Observatory, Scranton. Observer G. Hug. 0.30-m
Schmidt-Cassegrain + CCD.
Orbital elements:
2006 GY2 PHA, Earth MOID = 0.0059 AU
Epoch 2006 Mar. 6.0 TT = JDT 2453800.5 MPC
M 321.42640 (2000.0) P Q
n 0.38351304 Peri. 216.05497 -0.04823908 +0.90740716
a 1.8762151 Node 55.03586 -0.75488968 +0.24057643
e 0.4987894 Incl. 30.62517 -0.65407535 -0.34457979
P 2.57 H 19.1 G 0.15 U 9
Residuals in seconds of arc
060409 704 0.3- 0.2+ 060410 H36 0.3- 0.5+ 060410 850 0.1+ 0.5-
060409 704 0.2+ 0.2- 060410 H36 0.5+ 0.4- 060410 850 0.1- 0.2+
060409 704 0.2+ 0.1+ 060410 H36 0.1- 0.5+
060409 704 0.1- 0.1- 060410 850 0.2- 0.3-
Ephemeris:
2006 GY2 a,e,i = 1.88, 0.50, 31 q = 0.9404
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2006 04 05 16 08.11 +44 29.6 0.458 1.256 113.6 46.9 19.7
2006 04 07 16 09.34 +44 54.6 0.436 1.242 113.6 47.6 19.6
2006 04 09 16 10.41 +45 19.4 0.415 1.228 113.6 48.4 19.5
2006 04 11 16 11.29 +45 44.2 0.394 1.214 113.5 49.2 19.3
2006 04 13 16 11.98 +46 08.8 0.372 1.200 113.5 50.0 19.2
2006 04 15 16 12.46 +46 33.4 0.351 1.187 113.4 50.9 19.1
2006 04 17 16 12.71 +46 58.0 0.329 1.174 113.3 51.8 18.9
2006 04 19 16 12.71 +47 22.8 0.308 1.161 113.2 52.7 18.8
2006 04 21 16 12.41 +47 47.8 0.286 1.148 113.0 53.7 18.6
2006 04 23 16 11.78 +48 13.3 0.265 1.135 112.9 54.7 18.5
2006 04 25 16 10.74 +48 39.4 0.243 1.122 112.7 55.8 18.3
2006 04 27 16 09.22 +49 06.7 0.221 1.110 112.5 56.9 18.1
2006 04 29 16 07.07 +49 35.6 0.200 1.098 112.2 58.1 17.9
2006 05 01 16 04.12 +50 07.0 0.178 1.086 111.9 59.4 17.7
2006 05 03 16 00.04 +50 42.3 0.156 1.075 111.4 60.8 17.4
2006 05 05 15 54.31 +51 23.5 0.134 1.064 110.9 62.3 17.1
2006 05 07 15 45.93 +52 14.2 0.112 1.053 110.2 64.1 16.7
2006 05 09 15 32.80 +53 20.3 0.0901 1.042 109.1 66.2 16.3
2006 05 11 15 09.88 +54 51.1 0.0684 1.032 107.4 69.0 15.8
2006 05 13 14 21.91 +56 50.1 0.0472 1.023 104.0 73.5 15.1
2006 05 15 12 14.41 +56 07.9 0.0278 1.014 94.9 83.5 14.3
2006 05 17 08 28.17 +21 54.2 0.0176 1.005 68.2 110.9 14.6
2006 05 19 06 35.43 -19 54.3 0.0292 0.996 58.0 120.6 16.3
2006 05 21 05 51.98 -32 40.6 0.0489 0.989 60.3 117.3 17.2
2006 05 23 05 30.53 -37 34.1 0.0702 0.981 62.0 114.4 17.7
2006 05 25 05 17.91 -40 00.1 0.0919 0.975 63.1 112.1 18.2
Timothy B. Spahr (C) Copyright 2006 MPC M.P.E.C. 2006-G37
SNR Calculation
Target Name: 2006 GY2
HMag: 18.6
Diameter: 0.6 km
Period: 4 h (a standard guess)
------------GOLDSTONE---------- -------------ARECIBO-----------
Max Max
Dat Run UTC Dat Run UTC
Date RA Decl Delta Runs SNR SNR Window Runs SNR SNR Window
2006 5 9 232 54 0.082 307 37 2 1:18-15:11 0 0 0 -
2006 5 10 230 55 0.071 353 66 4 0:54-15:00 0 0 0 -
2006 5 11 225 56 0.060 414 130 7 0:30-14:41 0 0 0 -
2006 5 12 219 57 0.050 497 270 14 23:53-38:23 0 0 0 -
2006 5 13 209 59 0.039 615 680 31 23:00-37:42 0 0 0 -
2006 5 14 191 59 0.030 700 2000 82 21:41-36:30 0 0 0 -
2006 5 15 161 53 0.022 700 6200 250 20:11-34:00 0 0 0 -
2006 5 16 130 31 0.017 700 13000 550 19:11-30:41 161 263000 23000 20:30-22:36
2006 5 17 110 2 0.019 619 8100 360 19:06-28:00 111 128000 14000 19:23-20:53
2006 5 18 99 -16 0.027 388 1900 110 19:23-26:00 0 0 0 -
2006 5 19 92 -26 0.036 245 480 34 19:48-24:30 0 0 0 -
2006 5 20 87 -31 0.046 160 150 13 20:18-23:18 0 0 0 -
2006 5 21 84 -34 0.057 107 56 6 21:18-21:41 0 0 0 -
2006 5 22 82 -37 0.067 70 24 3 - 0 0 0 -
Track Assignments
2006 GY2 tracks
UT UT PDT AST Duration Delta
DOY Date TX Window TX Window TX Window hh:mm (seconds)
--- ---- --------- --------- --------- ------- ---------
133 May 13 0700-1300 0000-0600 May 13 0300-1000 May 13 6:00 35
134-135 May 14-15 2305-0505 1605-2205 May 14 1905-0105 May 14-15 6:00 21 CANCELLED
136 May 16 0230-0600 1930-2300 May 15 2230-0200 May 15-16 3:30 17
Arecibo tracks
135 May 15 2102-2239 1402-1539 May 15 1702-1839 May 15 1:37 17
136 May 16 1916-2117 1216-1417 May 16 1516-1717 May 16 2:01 19
Interleaved Schedule
UTC DOY DOY DOY DOY
hhmm 133 134 135 136
0000 G
0100 G
0200 G G
0300 G G
0400 G G
0500 G G
0600 G
0700 G
0800 G
0900 G
1000 G
1100 G
1200 G
1300 G
1400
1500
1600
1700
1800
1900 A
2000 A
2100 A A
2200 A
2300 G A
Uncertainties
Solution 4, # obs: 24 (5 days)
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2006-May-13 00:00 * 208.79746 58.55700 .039174545570942 14129.9776 13412.25 47971.48 7.682956
2006-May-14 00:00 * 190.59088 58.70044 .029534711932430 25952.9061 12186.04 43585.72 6.863283
2006-May-15 00:00 * 161.06268 52.76133 .021406413246048 51578.3388 9050.62 32371.26 5.249576
2006-May-16 00:00 * 129.98643 31.10582 .017115903002189 84271.5207 1577.79 5643.26 1.791113
2006-May-17 00:00 * 109.80903 1.89306 .019411249924351 68508.1929 7216.78 25812.20 2.626199
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Solution 7, # obs: 39 (9 days)
2006-May-13 00:00 * 208.77551 58.57272 .039223842129536 3253.28914 5211.87 18641.26 2.119300
2006-May-14 00:00 * 190.53724 58.71639 .029567734035382 6030.94320 4732.06 16925.10 1.851264
2006-May-15 00:00 * 160.96542 52.75769 .021429188617278 12080.0801 3507.67 12545.86 1.410584
2006-May-16 00:00 * 129.89222 31.05892 .017143284205182 19841.6510 595.94 2131.48 0.570085
2006-May-17 00:00 * 109.74425 1.85005 .019458585542678 16181.7909 2819.21 10083.43 0.524880
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Horizons, 2006 April 24
Solution 10, # obs: 77 (15 days)
2006-May-13 00:00 208.93276 58.53626 .039337214914603 649.865165 1680.88 6011.97 0.515144
2006-May-14 00:00 190.85462 58.70253 .029679346136878 1220.19323 1527.15 5462.15 0.441890
2006-May-15 00:00 161.46940 52.88625 .021517642427173 2475.11131 1136.94 4066.50 0.337697
2006-May-16 00:00 130.33523 31.45146 .017156866790793 4142.34064 206.96 740.25 0.160847
2006-May-17 00:00 110.02639 2.19965 .019371432678295 3451.33602 898.11 3212.25 0.111076
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Horizons, 2006 May 01
Solution 16, # obs: 117 (21 days)
2006 May-13 00:00 * 209.05685 58.51572 .039470731080769 124.730386 684.24 2447.32 0.144549
2006-May-14 00:00 * 191.09942 58.70224 .029801260873623 239.212971 622.08 2224.97 0.119269
2006-May-15 00:00 * 161.85279 52.99941 .021612868511713 495.361099 464.93 1662.93 0.090593
2006-May-16 00:00 * 130.66943 31.77486 .017188622955065 850.093192 89.72 320.89 0.053790
2006-May-17 00:00 * 110.23676 2.49177 .019325032687602 727.750778 361.02 1291.25 0.042302
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Jon Giorgini, 2006 May 11
With new reported optical data, solution #25 was computed for 2006 GY2.
Based on 204 optical observations spanning 2006-Apr-9 to 2006-May-9,
files and nominal predicts have been updated.
Formal 3-sigma uncertainties are as follows:
Date__(UT)__HR:MN POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2006-May-12 00:00 4.28713429 355.94 1273.08 0.063599
2006-May-13 00:00 8.43262619 341.82 1222.59 0.050949
2006-May-14 00:00 18.0442320 310.80 1111.62 0.039028
2006-May-15 00:00 41.2000387 232.40 831.24 0.028682
2006-May-16 00:00 77.0763912 45.19 161.63 0.022177
2006-May-17 00:00 71.2223108 179.70 642.74 0.023686
Setups
Plans for the May 13 track
--------------------------
We will start with solution 25
On May 13 our objectives are get CW and ranging detections, update the ephemeris, and then
spend as much time with imaging as possible. The Doppler uncertainties are large so we will use
a wide sampling bandwidth:
CW setup
--------
TX polarization RCP
RCV polarization LCP
Frequencies: 2
Dwell: 10 seconds
Bandwidth: 20000 Hz
Sampling interval: 500 x 0.1 usec
VME FFT for PSD files: 8192 for 2.44-Hz resolution
After the initial CW detection, we'll update the ephemeris, do more CW with a narrow bandwidth to
verify that the new ephemeris is good, and then go to 10 and 11 usec ranging with the standard setups
below.
Possible ranging setups:
---------------------------------------------------------------------------
127 x 64 10-usec single sample
baud 10 usec
code 127
gates 127
FFT 64
CLT 2 (VME)
ncoh 1
bandwidth 787.4 Hz
resolution 12.30 Hz
TXOFF +100 Hz -> echo will be centered at +8.1 bins or in bin 32 + 8.1 = 40
---------------------------------------------------------------------------
127 x 64 11-usec single sample, 11.2-Hz resolution.
baud 11 usec
code 127
gates 127
PRP 1397
FFT 64
CLT 2 (VME)
ncoh 1
bandwidth 715.8 Hz
resolution 11.18 Hz
TXOFF +100 Hz --> echo will be centered at +8.9 bins or in bin 32 + 8.9 = 41
-------------------------------------------------------------------------
127 x 64 7-usec single sample
------------------------------
baud 7 usec
code 127
gates 127
PRP 889
FFT 64
CLT ??
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 4
ncoh 15
bandwidth 525 Hz
resolution 8.2 Hz
TXOFF +100 -> echo would be centered at +12.2 bins or in bin 32 + 12.2 = 44
-------------------------------------------------------------------------------
0.125-usec ranging (left over from the 1992 UY4 observations in August, 2005)
------------------
setup JX1XS001 revised
baud 0.125 usec
code 127
gates 127
FFT 64
ncoh 984
bandwidth 64.016384 Hz
resolution 1.000256 Hz
TXOFF We used 10 Hz, placing COM in cell 32+10=42
Henceforth use 15 Hz, to put COM in 32+15=47
incoh sums 4 looks=> 8 sec/record => expect records per run ~ RTT/8
PFS CLT gate 21
_____________________________________________________________________
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/2006GY2/raw/
2006 GY2 POINTING:
OSOD and predicts are at Goldstone on stealth:
/export/data2/osod/ops/2006gy2/PRDX.OUT.s25
/PUNCH.OUT.s25
/EPH.OUT.s25
and have been copied to:
/export/data0/rosema/2006GY2/support/
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2006 05 13 133 070000 204.7050 58.8322 A 36.5 25
2006 05 13 133 080000 204.0138 58.8569 A 36.0
2006 05 13 133 090000 203.3098 58.8756 A 35.6
2006 05 13 133 100000 202.5943 58.8884 A 0.0071 0.0001 35.2
2006 05 13 133 110000 201.8686 58.8958 A 34.8
2006 05 13 133 120000 201.1333 58.8985 A 34.4
2006 05 13 133 130000 200.3885 58.8971 A 34.0
2006 05 16 136 020000 128.4232 29.2698 A 17.1 23
2006 05 16 136 030000 127.3477 28.0016 A 0.0050 -0.0060 17.0
2006 05 16 136 040000 126.3007 26.7202 AB 17.0
2006 05 16 136 050000 125.2839 25.4291 B 0.0047 -0.0061 17.0
2006 05 16 136 060000 124.2985 24.1321 B 17.1
PRDX.OUT.s25
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2006 MAY 13 07:00 36.4520610410 971893.773 14.3057 58.8322 204.705 64.774
2006 MAY 13 07:10 36.3839734869 970871.661 16.9267 58.8368 204.591 64.081
2006 MAY 13 07:20 36.3159574386 969853.674 19.5482 58.8411 204.476 63.297
2006 MAY 13 07:30 36.2480125705 968840.850 22.1700 58.8454 204.361 62.431
2006 MAY 13 07:40 36.1801384850 967834.210 24.7923 58.8494 204.246 61.491
2006 MAY 13 07:50 36.1123347050 966834.759 27.4149 58.8532 204.130 60.486
2006 MAY 13 08:00 36.0446007004 965843.479 30.0379 58.8569 204.014 59.422
2006 MAY 13 08:10 35.9769358729 964861.329 32.6612 58.8605 203.897 58.308
2006 MAY 13 08:20 35.9093395334 963889.247 35.2849 58.8638 203.781 57.149
2006 MAY 13 08:30 35.8418109523 962928.140 37.9089 58.8670 203.663 55.952
2006 MAY 13 08:40 35.7743493211 961978.890 40.5333 58.8700 203.546 54.722
2006 MAY 13 08:50 35.7069537954 961042.347 43.1580 58.8729 203.428 53.463
2006 MAY 13 09:00 35.6396234393 960119.329 45.7830 58.8756 203.310 52.180
2006 MAY 13 09:10 35.5723572854 959210.618 48.4083 58.8781 203.191 50.878
2006 MAY 13 09:20 35.5051543046 958316.964 51.0340 58.8805 203.073 49.559
2006 MAY 13 09:30 35.4380134164 957439.076 53.6599 58.8827 202.953 48.227
2006 MAY 13 09:40 35.3709334922 956577.627 56.2862 58.8847 202.834 46.885
2006 MAY 13 09:50 35.3039133490 955733.248 58.9127 58.8866 202.714 45.535
2006 MAY 13 10:00 35.2369517780 954906.527 61.5395 58.8884 202.594 44.181
2006 MAY 13 10:10 35.1700475140 954098.011 64.1666 58.8900 202.474 42.824
2006 MAY 13 10:20 35.1031992795 953308.201 66.7940 58.8914 202.353 41.467
2006 MAY 13 10:30 35.0364057309 952537.555 69.4217 58.8927 202.233 40.111
2006 MAY 13 10:40 34.9696655187 951786.481 72.0496 58.8939 202.112 38.759
2006 MAY 13 10:50 34.9029772497 951055.343 74.6778 58.8949 201.990 37.412
2006 MAY 13 11:00 34.8363395239 950344.453 77.3063 58.8958 201.869 36.073
2006 MAY 13 11:10 34.7697509042 949654.078 79.9351 58.8966 201.747 34.742
2006 MAY 13 11:20 34.7032099616 948984.431 82.5641 58.8972 201.625 33.422
2006 MAY 13 11:30 34.6367152124 948335.678 85.1933 58.8977 201.502 32.113
2006 MAY 13 11:40 34.5702652127 947707.933 87.8229 58.8981 201.379 30.818
2006 MAY 13 11:50 34.5038584671 947101.259 90.4527 58.8983 201.256 29.538
2006 MAY 13 12:00 34.4374935104 946515.667 93.0827 58.8985 201.133 28.274
2006 MAY 13 12:10 34.3711688619 945951.119 95.7130 58.8985 201.010 27.028
2006 MAY 13 12:20 34.3048830456 945407.523 98.3436 58.8984 200.886 25.801
2006 MAY 13 12:30 34.2386346059 944884.737 100.9744 58.8983 200.762 24.595
2006 MAY 13 12:40 34.1724220826 944382.567 103.6056 58.8980 200.638 23.410
2006 MAY 13 12:50 34.1062440474 943900.768 106.2369 58.8976 200.513 22.249
2006 MAY 13 13:00 34.0400990743 943439.046 108.8686 58.8971 200.388 21.112
GOLDSTONE MASTERLOG
==============================================================================
RCV
file setup runs start -stop osod OFFSET TX Poln
------------------------------------------------------------------------------
==============================================================================
RADAR ASTROMETRY
2006 05 13 07:10:00 P 971389.7D0 5.0 8560.D6 -14 -14 Benner, L.A.M.
Correction of +518 Hz to soln 25 from several CW runs with
2.4 Hz res'n. Bandwidth is about 8 Hz.
2006 05 13 08:00:00 P 966358.2D0 2.0 8560.D6 -14 -14 Benner, L.A.M.
Correction of +2 Hz to soln 27 from 10 cw runs w/0.49 Hz res'n
2006 05 13 08:50:00 R 35.724788 20.0 8560.D6 -14 Benner, L.A.M.
Correction of -1901 usec to soln 27 from 10 and 11 usec.
2006 05 13 10:00:00 R 35.254532 1.0 8560.D6 -14 Benner, L.A.M.
Correction of -3 usec to soln 29 from 1 usec ranging.
Visible extent is only one range gate.
2006 05 13 11:50:00 R 34.521046 0.5 8560.D6 -14 Benner, L.A.M.
Correction of -3 usec to soln 29 from 1/8 usec imaging. Placed
COM at TE of the echo, which is about 8 gates deep.
==============================================================================
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
http://echo.jpl.nasa.gov/asteroids/2006GY2/html/2006GY2_planning.html
Asteroid Radar Astronomy