[X] My Assistant

[SteveM]

Here's one more JPL Horizons ephemeris for 2007 WD5's pass over the Spirit Landing Site. In this version the range and range rate are in km and km/sec rather than in AU. As the asteroid passes overhead at 24-30,000 km it will be about ninth magnitude. Does anyone know if such a faint object would be a feasible target for Spirit's cameras (even if the power and temperature conditions were acceptable)?

Steve M

CODE

Target body name: (2007 WD5) {source: JPL#13}
Center body name: Mars (499) {source: DE405}
Center-site name: Spirit Landing Site (MER) / Gusev
******************************************************************
Start time : A.D. 2008-Jan-30 11:00:00.0000 UT
Stop time : A.D. 2008-Jan-30 16:00:00.0000 UT
Step-size : 10 minutes
******************************************************************
Target pole/equ : No model available
Target radii : (unavailable)
Center geodetic : -175.48330,-14.566677,-.0066762 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: -175.48330,3288.23600,-844.4501 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : IAU_MARS {East-longitude -}
Center radii : 3396.2 x 3396.2 x 3376.2 km {Equator, meridian, pole}
Target primary : Sun {source: DE405}
Interfering body: PHOBOS (Req= 13.400) km {source: MAR063}
Deflecting body : Sun, MARS {source: DE405}
Deflecting GMs : 1.3271E+11, 4.2828E+04 km^3/s^2
Small perturbers: Ceres, Pallas, Vesta {source: SB405-CPV-2}
Small body GMs : 6.32E+01, 1.43E+01, 1.78E+01 km^3/s^2
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
RTS-only print : NO
EOP file : eop.080109.p080401
EOP coverage : DATA-BASED 1962-JAN-20 TO 2008-JAN-09. PREDICTS-> 2008-MAR-31
Units conversion: 1 AU= 149597870.691 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass n.a. , Daylight (NO )
Table cut-offs 2: Solar Elongation ( 0.0,180.0=NO )
*******************************************************************************
Initial FK5/J2000.0 heliocentric ecliptic osculating elements (AU, DAYS, DEG):
EPOCH= 2454453.5 ! 2007-Dec-19.00 (CT) Residual RMS= .19748
EC= .603018054551714 QR= 1.010175333097356 TP= 2454392.143492565
OM= 67.42386273883675 W= 312.82284512922 IN= 2.37739121318211
Asteroid physical parameters (KM, SEC, rotational period in hours):
GM= n.a. RAD= n.a. ROTPER= n.a.
H= 24.308 G= .150 B-V= n.a.
ALBEDO= n.a. STYP= n.a.
********************************************************************************
Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC Azi_(a-appr)_Elev APmag delta deldot L_Ap_SOL_Time
********************************************************************************

$$SOE
2008-Jan-30 11:00 17 35 28.31 -28 39 16.2 104.4087 -32.2166 n.a. 5.0892717819E+04 -11.2029689 02 15 53.6700
2008-Jan-30 11:10 17 14 18.72 -28 39 03.6 104.4425 -25.3692 n.a. 4.4311076783E+04 -10.6999279 02 25 37.7592
2008-Jan-30 11:20 16 46 05.05 -28 19 20.9 104.8366 -16.9852 n.a. 3.8108815355E+04 -9.9139691 02 35 21.8486
2008-Jan-30 11:30 16 07 58.95 -27 17 26.8 105.7380 -6.3778 n.a. 3.2509353860E+04 -8.6493924 02 45 05.9383
2008-Jan-30 11:40 r 15 17 15.33 -24 51 26.3 107.4310 7.2961 n.a. 2.7885074214E+04 -6.6071501 02 54 50.0281
2008-Jan-30 11:50 14 14 00.13 -20 06 55.7 110.5158 24.5101 10.50 2.4795608791E+04 -3.5079192 03 04 34.1182
2008-Jan-30 12:00 13 04 59.26 -12 53 50.7 116.4477 44.0536 9.54 2.3852394035E+04 0.4416623 03 14 18.2084
2008-Jan-30 12:10 12 01 23.59 -04 47 31.6 129.4788 62.2998 9.03 2.5301419991E+04 4.2764234 03 24 02.2990
2008-Jan-30 12:20 11 10 13.09 +02 11 28.1 162.4252 74.2606 8.86 2.8785660826E+04 7.1535750 03 33 46.3898
2008-Jan-30 12:30 t 10 31 43.87 +07 21 51.7 212.3312 74.6315 8.89 3.3679846689E+04 9.0159765 03 43 30.4808
2008-Jan-30 12:40 10 03 13.21 +11 00 26.9 237.6421 68.3862 9.01 3.9463030651E+04 10.1716770 03 53 14.5722
2008-Jan-30 12:50 09 41 51.82 +13 34 49.0 247.9167 61.6993 9.17 4.5799900008E+04 10.8990291 04 02 58.6638
2008-Jan-30 13:00 09 25 32.12 +15 26 24.7 252.8925 55.7130 9.34 5.2490600110E+04 11.3729441 04 12 42.7557
2008-Jan-30 13:10 09 12 46.27 +16 49 25.3 255.6343 50.4328 9.51 5.9416041015E+04 11.6938850 04 22 26.8479
2008-Jan-30 13:20 x 09 02 34.97 +17 52 54.5 257.2555 45.7183 9.68 6.6503237103E+04 11.9192712 04 32 10.9404
2008-Jan-30 13:30 x 08 54 17.82 +18 42 41.7 258.2409 41.4394 9.84 7.3705812518E+04 12.0827296 04 41 55.0332
2008-Jan-30 13:40 x 08 47 26.83 +19 22 36.4 258.8322 37.4958 9.99 8.0993208718E+04 12.2046180 04 51 39.1263
2008-Jan-30 13:50 x 08 41 42.20 +19 55 13.0 259.1619 33.8128 10.13 8.8344596219E+04 12.2976915 05 01 23.2198
2008-Jan-30 14:00 x 08 36 49.59 +20 22 18.5 259.3086 30.3356 10.26 9.5745334523E+04 12.3702049 05 11 07.3136
2008-Jan-30 14:10 x 08 32 38.44 +20 45 08.4 259.3213 27.0231 10.39 1.0318484544E+05 12.4276615 05 20 51.4077
2008-Jan-30 14:20 x 08 29 00.83 +21 04 37.6 259.2318 23.8444 10.51 1.1065529363E+05 12.4738296 05 30 35.5021
2008-Jan-30 14:30 x 08 25 50.68 +21 21 26.6 259.0616 20.7759 10.62 1.1815074368E+05 12.5113523 05 40 19.5969
2008-Jan-30 14:40 x 08 23 03.30 +21 36 05.9 258.8257 17.7992 10.73 1.2566660660E+05 12.5421234 05 50 03.6921
2008-Jan-30 14:50 x 08 20 34.98 +21 48 58.9 258.5342 14.9001 10.84 1.3319926719E+05 12.5675268 05 59 47.7875
2008-Jan-30 15:00 x 08 18 22.78 +22 00 23.7 258.1945 12.0673 10.93 1.4074582793E+05 12.5885914 06 09 31.8833
2008-Jan-30 15:10 *x 08 16 24.32 +22 10 34.6 257.8117 9.2917 11.03 1.4830392897E+05 12.6060945 06 19 15.9795
2008-Jan-30 15:20 *x 08 14 37.67 +22 19 42.9 257.3893 6.5661 11.12 1.5587161954E+05 12.6206319 06 29 00.0760
2008-Jan-30 15:30 *x 08 13 01.22 +22 27 57.9 256.9295 3.8846 11.21 1.6344726457E+05 12.6326666 06 38 44.1728
2008-Jan-30 15:40 *x 08 11 33.67 +22 35 27.1 256.4337 1.2424 11.29 1.7102947578E+05 12.6425630 06 48 28.2700
2008-Jan-30 15:50 *s 08 10 13.91 +22 42 16.5 255.9024 -1.3643 11.37 1.7861706012E+05 12.6506111 06 58 12.3676
2008-Jan-30 16:00 *x 08 09 01.00 +22 48 31.4 255.3354 -3.9386 11.45 1.8620898100E+05 12.6570443 07 07 56.4654
$$EOE

This post has been edited by SteveM: Jan 11 2008, 03:32 PM

[djellison]

Does anyone know if such a faint object would be a feasible target for Spirit's cameras (even if the power and temperature conditions were acceptable)?

Moving object, of 10th Mag? I'd say no.

http://pancam.astro.cornell.edu/pancam_ins...projects_2.html

Spirit managed 6th Mag when looking at Orion a few years ago.

Doug

[ustrax]

How come did I miss that Sol 682 Early Morning Moons animation?!

That's one of my favourite Mars scenarios EVER!

[SteveM]

Moving object, of 10th Mag? I'd say no.

Doug,

Thanks for the link to the Cornell night time images. Even though the asteroid will get as bright as about 8.86 mag (+/- ?), I'd have to agree it would be hard to extract such a faint streak out of the noisy background.

Steve M

[ugordan]

... Sol 682 Early Morning Moons ...

Wasn't that taken after dusk, Deimos is slowly descending while retrograde Phobos rises in the west?

[Guest_PhilCo126_*]

Well, now NASA has put the odds 1 to 10000, some webpages start to mention asteroid TU24, which will pass "close" to Earth on 29th January 2008. However it will NOT Earth

http://www.badastronomy.com/bablog/2008/01...rth-january-29/

http://neo.jpl.nasa.gov/ca/

[slinted]

I was just curious if anyone could rule out this body entirely.

I think the moons are like Mars itself at this point, not a statistical 0, but rather just an extremely small chance. Closest Phobos approach to the nominal path is even further than Mars itself, about 34,499km. The closest the nominal will get to Deimos is 20,344 km (from JPL Horizons).

And, just back-of-napkin'ing, Mars presents a 280,000 times larger 'target' to hit than Deimos (90,000 for Phobos)...so...not likely

[tedstryk]

For stars, which trail much slower than a moving asteroid would, Spirit can see to 7th magnitude, so it wouldn't have a chance at a 9th magnitude object. If approach is closer, it would of course be possible. However, I am just looking at camera capability here, not power. If they had really precise ephemeris so that it could be observed in a session lasting just a few minutes and the flyby was only a few hundred kilometers, then I would hope that they would start really conserving power to charge that batteries for a session. However, given that in a best likely case (4,000 km) and given the margin of error, leading to a very limited return, plus the risk considering Spirit's limited power, unless predictions radically change and improve, it would not be worth it.

[Guest_PhilCo126_*]

Hopefully we'll be able to spot the 29th January asteroid
http://neo.jpl.nasa.gov/?msource=01208&...mp;auid=3329949

[tedstryk]

Hubble will be covering the 2007 WD5/Mars close approach. From the schedule:


11497 A6C Noll Observations of Mars and 2007 WD5
2008.030 10:54:00 11:05:00 1149705 Noll 05-001 MARS WFPC2 IMAGE PC1-FIX F410M 1.20 05 01 02
2008.030 10:54:00 11:05:00 1149705 Noll 05-002 MARS WFPC2 IMAGE PC1-FIX F502N 1.80 05 01 03
2008.030 10:54:00 11:05:00 1149705 Noll 05-003 MARS WFPC2 IMAGE PC1 F673N 0.40 05 01 04

By the fact that they are only using three filters (approximately RGB) and Kieth Noll who sets up Hubble Heritage observations, this is likely simply being done for the coolness factor.

[climber]

Hopefully we'll be able to spot the 29th January asteroid
http://neo.jpl.nasa.gov/?msource=01208&...mp;auid=3329949

Alert !
That's not a fly by ! The Solar System is under attack !

[rogelio]

It's "official", it missed Mars by 6.5 radii, see space.com:

http://www.space.com/scienceastronomy/080130-mars-miss.html

...right next to an article entitled "NASA Spots Mysterious 'Spider' on Mercury...

[ugordan]

It's "official", it missed Mars by 6.5 radii, see space.com:

"Space Rock Misses Mars, Barely"

Barely? 6.5 planet radii is hardly "barely"...

[helvick]

I suppose whether it is "barely" or not depends on your perspective - that's about 22,000km or put it another way it's about as far as a geostationary satellite for us earthlings. I'd say that an asteroid coming that close to us would get called a very near miss even.

[nprev]

Here's a very near miss...(lot smaller rock, though).