Closest asteroid in recorded history

[glenc]

"The asteroid, referred to as 2012 DA14, has a diameter of approximately 45m and an estimated mass of 130,000 tonnes.
It was discovered at the start of 2012 and is set to travel between the Earth and our geostationary communication satellites on 15 February 2013.
At a distance of just 22,500km this will be the closest asteroid ‘fly by’ in recorded history."
http://www.cosmosmagazine.com/news/6114/closest-asteroid-recorded-history-pass-earth

On this date, the asteroid will travel rapidly from the southern evening sky into the northern morning sky with its closest Earth approach occurring about 19:26 UTC when it will achieve a magnitude of less than seven..
http://neo.jpl.nasa.gov/news/news174.html

[pmrid]

That will have a few credulous souls digging their Mayan Calendars out of the wheelie bin and rechecking the dates!!

Peter

[glenc]

You can calculate the local RA and Dec for DA14 here
http://ssd.jpl.nasa.gov/horizons.cgi#top

For Casino NSW the position and mag at one hour intervals are:
Date (UT) RA dec mag
2013-Feb-15 17:00 (4am DST) RA 10 25 52.64 dec -76 18 59.7 mag 10.67 in Cha
2013-Feb-15 18:00 (5am DST) RA 10 54 01.76 dec -59 12 07.1 mag 9.27 (near eta Car start of astro twilight Feb 16)
2013-Feb-15 19:00 (6am DST) RA 11 09 06.30 dec -22 15 33.6 mag 7.56 in Crt

[Scorpius51]

Thanks for the information and links, Glen. Very interesting stuff!



Hmm .. I guess they need to explain why we are still here Peter, and not reduced to star stuff :rolleyes:.

[jjjnettie]

Who's going to try to image it??
I think a time lapse could be in order. :)
Thanks for the head up, or should that be heads ducking. lol

[glenc]

jjj :)

Perth will see more, here are the numbers:

Date/time (UT), RA dec m=mag const
2013-Feb-15 13:00, 00 52 10.45 -85 18 20.7 m13.35 Oct (moon is up)
2013-Feb-15 14:00, 01 28 17.38 -87 14 52.6 m12.92 Oct
2013-Feb-15 15:00, 07 11 46.76 -88 46 06.7 m12.38 Oct
2013-Feb-15 16:00, 10 50 17.81 -84 46 58.1 m11.67 Oct
2013-Feb-15 17:00, 11 18 14.33 -76 46 03.3 m10.71 Cha
2013-Feb-15 18:00, 11 27 38.95 -60 21 15.1 m9.31 Cen
2013-Feb-15 19:00, 11 32 31.33 -23 06 30.0 m7.53 Crt
2013-Feb-15 20:00, 11 35 33.58 +26 59 16.3 m7.40 Leo
2013-Feb-15 21:00, 11 37 57.96 +53 43 03.9 m8.84 UMa (nautical twilight)

It goes from dec -88.8 to dec +53.7 in just 6 hours!

[MortonH]

What are the odds it takes out a satellite or two? :P

[Scorpius51]

... and if it does, will that be enough to perturb it's trajectory and make things more interesting? Probably nothing more than like swatting flies - it won't feel a thing! :question:

[astroron]

On the 15th at 23:00 AEST, 13:00 UT it will be only 4.5 degs from Sigma Octans, and the moon sets at 21:28 Brisbane time, so no moon to make things difficult :D
If you can spot it,you should be able to track it for the rest of the night, as it is moving fast against the background stars.
Cheers:thumbsup:

[gary]

151.205000,-33.861527,0.0751113 {E-lon(deg),Lat(deg),Alt(km)}


Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC Azi_(a-appr)_Elev APmag Illu% Cnst
*********************************** *********************************** **************

2013-Feb-15 12:00 00 44 29.88 -82 50 26.5 188.1776 31.6310 13.76 34.736 Oct
2013-Feb-15 13:00 01 03 07.96 -84 11 55.0 186.1517 31.1171 13.39 35.844 Oct
2013-Feb-15 14:00 01 55 36.92 -85 57 12.2 184.2508 31.8335 12.94 37.470 Oct
2013-Feb-15 15:00 05 16 22.91 -87 21 50.2 183.1775 34.0851 12.38 39.958 Oct
2013-Feb-15 16:00 09 21 22.25 -84 20 13.3 184.2858 38.2683 11.65 43.998 Oct
2013-Feb-15 17:00 10 30 01.66 -76 02 30.0 191.0498 44.8470 10.65 51.162 Cha
2013-Feb-15 18:00 10 56 35.42 -58 44 08.2 215.2169 52.3851 9.25 65.249 Car



Times are UTC. Sydney is UTC + 11 hours.
So, for example, 2013-Feb-15 12:00 UTC corresponds to 2013-Feb-15 23:00 AEDT,
that is 11pm in Sydney on the night of the 15th of Feb.

R.A._(ICRF/J2000.0)_DEC =
J2000.0 astrometric right ascension and declination of target center.

Azi_(a-appr)_Elev =
Airless apparent azimuth and elevation of target center. Corrected for
light-time, the gravitational deflection of light, stellar aberration,
precession and nutation. Azimuth measured North(0) -> East(90) -> South(180) ->
West(270) -> North (360). Elevation is with respect to plane perpendicular
to local zenith direction. TOPOCENTRIC ONLY. Units: DEGREES

APmag =
Asteroid's approximate apparent visual magnitude by following definition:
APmag = H + 5*log10(delta) + 5*log10(r) - 2.5*log10((1-G)*phi1 + G*phi2).
In principle, accurate to ~ +/- 0.1 magnitude. For solar phase angles > 90 deg,
the error could exceed 1 magnitude. No values are output for phase angles
greater than 120 degrees, since the extrapolation error could be large and
unknown. Units: NONE

Illu% =
Fraction of target circular disk illuminated by Sun (phase), as seen by
observer. Units: PERCENT

Cnst =
Constellation ID; the 3-letter abbreviation for the name of the
constellation containing the target center's astrometric position,
as defined by IAU (1930) boundary delineation.

[gary]

It is important for observers to note that since this object is passing so close to
Earth, the effects of parallax become significant, so you should compute an
ephemeris based on your observing city or town.
http://ssd.jpl.nasa.gov/horizons.cgi#top

For example, at 17:00 UTC, there is a 22 arc minute (over one third of a degree)
difference in apparent RA/Dec from Glen's location in Casino, NSW compared to
an observer in Sydney, even though the distance between Casino and Sydney is
only 588km.

[AstroJunk]

Yup, this will be a great on to watch and is travelling at 2283.35" per min (if my calculations are close to correct, that's about 2/3rd of a degree every 60 seconds.

From a dark sky site it will be possible to watch this with binos! Incredible.

I've recorded a few of these objects but none near as this. As has been said already, parallax is critical so plot out the path locally, find out when it passes an obvious star, then wait in ambush for it to enter the field of view...

[astroron]

Could anyone convert this Ephemeris into the language that "The Sky 6"
Can understand please.
I have tried all sorts of combinations to no avail :shrug:

JPL/HORIZONS (2012 DA14) 2013-Jan-07 02:05:03 Rec #:732120 (+COV) Soln.date: 2012-May-13_02:50:12 # obs: 188 (79 days) FK5/J2000.0 helio. ecliptic osc. elements (AU, DAYS, DEG, period=Julian yrs): EPOCH= 2456007.5 ! 2012-Mar-21.00 (CT) Residual RMS= .28422 EC= .1082356434519823 QR= .8933003245207058 TP= 2455895.355491354 OM= 147.2896474597286 W= 271.0806938513611 IN= 10.33969989795044 A= 1.001722392200821 MA= 110.2455360245707 ADIST= 1.110144459880936 PER= 1.0026 N= .9830667360000001 ANGMOM= .017115762 DAN= .98797 DDN= .9920099999999999 L= 58.3881762 B= -10.3378405 TP= 2011-Nov-29.8554914 Physical parameters (KM, SEC, rotational period in hours): GM= n.a. RAD= n.a. ROTPER= n.a. H= 24.377 G= .150 B-V= n.a. ALBEDO= n.a. STYP= n.a. ASTEROID comments: 1: soln ref.= JPL#35, OCC=4

Your help would be greatly appreciated.
Cheers:thumbsup:

[gary]

Good Morning Ron,

2012 DA14 |2012 09 30.000|0.108123 |1.001831| 10.3355|147.2622 |271.0757 | 2000|300.0043 |24.4 | 0.15| 0.00

Best Regards

Gary

[mithrandir]

Gary's way works too.

Ron, which parameters did you feed Horizons? If I use:

Current Settings
Ephemeris Type [change] : ELEMENTS
Target Body [change] : Asteroid (2012 DA14)
Center [change] : Sun (body center) [500@10]
Time Span [change] : discrete time(s)=2013-02-15 18:00
Table Settings [change] : defaults
Display/Output [change] : plain textI get something like what you pasted. The easiest part to use is the bit below. The "Symbol meaning" bit identifies what value goes in each box. You can paste them as they appear here and TheSky can handle the scientific notation. The only tricks are:


TheSky6 calls "Argument of Perifocus" in the Minor Planets "Add" panel "Argument of Perihelion".



The day in "Element epoch" is the day as decoded from MJD with the decimal part added - so in this case 15.25.

and I don't seem to be able to stop the editor wrapping this block without butchering it. It sort of looks like this:

$$SOE
2456339.250000000 = A.D. 2013-Feb-15 18:00:00.0000 (CT)
EC= 1.119223267411774E-01 QR= 8.793252519475666E-01 IN= 1.277276690753689E+01
OM= 1.471236673414090E+02 W = 2.645957382478340E+02 Tp= 2456256.793500953820
N = 1.000359691344981E+00 MA= 8.248615793535961E+01 TA= 9.532953427349806E+01
A = 9.901445317512164E-01 AD= 1.100963811554866E+00 PR= 3.598705576750907E+02
$$EOE
Coordinate system description: Ecliptic and Mean Equinox of Reference Epoch Reference epoch: J2000.0
xy-plane: plane of the Earth's orbit at the reference epoch
x-axis : out along ascending node of instantaneous plane of the Earth's
orbit and the Earth's mean equator at the reference epoch
z-axis : perpendicular to the xy-plane in the directional (+ or -) sense
of Earth's north pole at the reference epoch.

Symbol meaning [1 AU=149597870.691 km, 1 day=86400.0 s]:
JDCT Epoch Julian Date, Coordinate Time
EC Eccentricity, e
QR Periapsis distance, q (AU)
IN Inclination w.r.t xy-plane, i (degrees)
OM Longitude of Ascending Node, OMEGA, (degrees)
W Argument of Perifocus, w (degrees)
Tp Time of periapsis (Julian day number)
N Mean motion, n (degrees/day)
MA Mean anomaly, M (degrees)
TA True anomaly, nu (degrees)
A Semi-major axis, a (AU)
AD Apoapsis distance (AU)
PR Sidereal orbit period (day)

[AstroJunk]

But sky 6 or any other planetarium program won't account for the parallax and therefore will most likely be displayed incorrectly.

http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=2012%20DA14

Follow this link, change your location and select a timespan for the observation - you will get a very accurate set of coordinates to plot manually (or just follow in may case)

[astroron]

Thanks Gary, I had that, but the sky would not except it, so I tried importing it from the web,and it excepted it.
Cheers:thumbsup:
PS I hope today is not hot for you :)

[clueless]

too confusing for me....I'll try the coordinate thing and even though I can't really find the SCP, I can get pretty close.......
I'm on the sapphire coast near Merimbula.....2548.......
Andrew

[mithrandir]

All the user info is stored in cookies, so your link won't help others. Set it to something like:


Current Settings
Ephemeris Type [change] : OBSERVER
Target Body [change] : Asteroid (2012 DA14)
Observer Location [change] : user defined ( your location goes here )
Time Span [change] : Start=2013-02-15 18:00, Stop=2013-02-15 21:00, Step=5 m
Table Settings [change] : QUANTITIES=1,4,9,20,23,24,29,34
Display/Output [change] : plain text
and don't forget to put 399 in the bottom box to signify it is on earth.

[04Stefan07]

What about Melbourne? I don't fully understand all these numbers the generator is pumping out.

Does anyone know a good website that has detailed descriptions of what each column means and how to use it. I would like to learn how to read these complex tables.

[Varangian]

Okay, I'll ask the question in order to answer all the questions I get about it from all the laypeople I tell. Is there any chance this thing can hit us? 20,000 km is blooming close. Regards, John.

[clueless]

Is this asteroid the same asteroid that is passing us on Thursday..

"PLANET Earth will get a close look at a wandering demon when asteroid Apophis passes within a few million kilometres on Thursday." ????

http://www.dailytelegraph.com.au/news/world/asteroid-apophis-which-may-hit-earth-in-2036-will-pass-close-by-this-week/story-fnddckzi-1226549305351

[pluto]

This thread was about "2012 DA14" which is different from "99942 Apophis"

[gary]

Hi John,

Imagine for a moment that in the future, conflicting news reports came out about
whether a new object was going to hit Earth or not. Suddenly, a whole lot of "experts"
with seemingly credible credentials would come out of the woodwork, some
unequivocally stating that it would hit and others just as forcefully arguing it would
not.

Who would you believe?

In such a hypothetical scenario, go here to the IAU Minor Planet Center at Harvard.
http://www.minorplanetcenter.org/iau/mpc.html

If those people say it will miss, then it will miss. If they say it will hit, then
it will be time to put the head between the legs. :lol:

This time with regards minor planet 2012 DA14, they have computed it will miss. :thumbsup:

[clueless]

Thanks Pluto, I thought so. I started a different threat for 99942 Apophis and someone told me to see this thread...which has nothing to do with 99942 Apophis :)

[mithrandir]

If by that you mean:

Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC Azi_(a-appr)_Elev APmag delta deldot S-O-T /r S-T-O Cnst L_Ap_SOL_Time
2013-Feb-15 18:00 10 56 40.71 -58 45 54.8 214.9957 52.3767 9.25 0.00029774617094 -4.9792007 107.7070 /L 72.2754 Car 03 49 52.4574

the explanations are all further down the page.

You are probably only interested in RA/Dec and/or Az/Elev and either the time in UTC or local apparent solar time.

[clueless]

LOL mate, we've got just over a month to learn :D

[gary]

Hi Stefan,

Here you go.

Hopefully the following is self evident.

Melbourne is +11 hours ahead of UTC.

Melbourne
144.975800,-37.831594,0.0529483 {E-lon(deg),Lat(deg),Alt(km)}


*********************************** *********************************** **************
Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC Azi_(a-appr)_Elev APmag Illu% Cnst
*********************************** *********************************** **************
2013-Feb-15 12:00 00 45 52.92 -83 01 11.1 188.6560 36.3905 13.75 34.869 Oct
2013-Feb-15 13:00 01 03 25.36 -84 24 46.1 186.5521 35.7229 13.38 35.968 Oct
2013-Feb-15 14:00 01 55 34.16 -86 12 36.4 184.4216 36.2909 12.93 37.576 Oct
2013-Feb-15 15:00 05 34 16.10 -87 36 49.0 182.9299 38.4645 12.37 40.031 Oct
2013-Feb-15 16:00 09 37 51.84 -84 21 42.0 183.3906 42.7738 11.64 44.018 Oct
2013-Feb-15 17:00 10 39 05.09 -76 01 00.4 189.4299 50.0034 10.64 51.107 Cha
2013-Feb-15 18:00 11 02 32.96 -58 39 55.0 215.7319 59.2798 9.23 65.127 Car


For example, consider the first row.
2013-Feb-15 12:00 corresponds to 23:00 on the night of 15th Feb in Melbourne.
RA is 00:45:52.92 and Dec is -83:01:11.1, which corresponds to an azimuth of 188.6 degrees (i.e in the south) and a elevation of 36 degrees
above the horizon. At that time it will be 34% illuminated with an apparent magnitude of 13.75, so pretty dim.
At that instant, it will be in Octans.

[gary]

Hi Andrew,

Here is the ephemeris for Merimbula, NSW.
Center geodetic : 149.901110,-33.898044,0.0486492 {E-lon(deg),Lat(deg),Alt(km)}


*********************************** *********************************** **************
Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC Azi_(a-appr)_Elev APmag Illu% Cnst
*********************************** *********************************** **************
2013-Feb-15 12:00 00 44 11.88 -82 52 40.8 188.2002 31.8250 13.76 34.754 Oct
2013-Feb-15 13:00 01 02 24.24 -84 14 20.0 186.1776 31.2729 13.39 35.855 Oct
2013-Feb-15 14:00 01 54 17.73 -86 00 00.0 184.2464 31.9531 12.94 37.472 Oct
2013-Feb-15 15:00 05 17 15.76 -87 25 34.1 183.0970 34.1839 12.38 39.948 Oct
2013-Feb-15 16:00 09 24 02.58 -84 22 53.9 184.0603 38.3887 11.65 43.968 Oct
2013-Feb-15 17:00 10 31 31.57 -76 05 48.0 190.5737 45.1026 10.66 51.103 Cha

[clueless]

Thanks Garry I'll work it out now

[Varangian]

Yes thank you for the link Gary, very informative and one to bookmark. Regards, John.

[glenc]

The asteroid 2012 DA14 will be between the star cluster NGC 3532 and the nebula NGC 3372 at 5am DST on 16 Feb 2013. The attached SkyMapPro map shows the Southern Cross and these two objects. You will see the asteroid moving slowly towards the north (top right) if you use binoculars.

[mr bruess]

were gonna live!
The asteroid is not going to hit the earth!

[Baddad]

Does this become catagorised as another apocalypse?
If so, then I have survived 7 world ending apocalpses.:lol::lol::P

Cheers

[mbyrr]

So does this mean I will be able to see it with my 8" dob? (assuming I can find it)
I'm in Melb.

[glenc]

Yes Anthony. You can calulate its position here using your latitude and longitude (37.5S, 145 E). Add 11 hours to get DST.
http://ssd.jpl.nasa.gov/horizons.cgi#top

[okiscopey]

Here's a speeded-up view of 2012 DA14's varaible but rapid progress through the constellations in Sky Safari Plus.

Only my second YouTube video, so quality not the best!

http://www.youtube.com/watch?v=hUEfOLDcWYc&feature=youtu.be

[mbyrr]

Thanks Glen, will check that out!

[clueless]

Thanks Glen...

[clueless]

Good job mate...
Andrew

[04Stefan07]

Thanks for that Gary!

Nice video Mike!

[Matt Starwave]

Also ESA reports asteroid Apophis also going past, is 55metres larger than NASA recorded --now 325 metres--get that thing out of our solar system for good. Next time round get rid of it.

[04Stefan07]

I can't seem to find the asteroid in SkySafari

[okiscopey]

In the desktop version, go to 'Solar System' and hit 'Update Minor Body Orbit Data'. In the iOS version, the Update button is in 'Settings' / 'Solar System'

[Eggmoon]

Closest ever asteroid??? Really?? Maybe you should ask the dinsours how much that big one missed by... ;)

Just teasing....

[mithrandir]

IIRC whether you can update minors on demand depends on what version of SS you have. It definitely works in SSPro and both 2012 DA14 and 99942 Apophis are there.

[04Stefan07]

What about Plus on Android?

[glenc]

Mike your video seems to show DA14 going through the pointers.
Is that correct?

"Closest ever asteroid??? Really?? Maybe you should ask the dinsours how much that big one missed by... ;)"
They were too stunned to record it.

[widow18]

Closest ever asteroid I remember is one that passed through the upper atmosphere and kept going, sometime in the 60's I think. There is video (super 8 maybe) of it on guess what. Possible search is fireball.
Regards
Peter

[okiscopey]

It's only correct if Sky Safari's minor body data are accurate! Maybe someone can check in another planetarium program. Anyway, it's a bit academic ... SS shows the fly-through occuring in daylight around 07:15 AEDT.

[glenc]

The attached file gives RA dec mag and const for Sydney.
Refr http://ssd.jpl.nasa.gov/horizons.cgi#results

[Danack]

I've been looking for that and just found it (or one very similar):

http://youtu.be/vBu-yUzWXqg?t=30s

Apparently it was between only 3 metres and 14 metres in diameter which is surprisingly little to me, given it's resistance to disintegrating.
Great Daylight Fireball 1972 (http://en.wikipedia.org/wiki/Great_Daylight_1972_Fireball)

[glenc]

I like the way science corrects itself. Thanks Dan.

[Shark Bait]

I have plugged NASA's JPL data into Starry Night Enthusiast V6.3 in order to work out where to view Asteroid 2012 DA14. It is the first time that I have used this method and it took a while to learn what the various figures mean. I hope the information shown below is correct.

Screen Image Dates and Timings (EST):

1. 14th Feb 2000 hrs
2. 14th Feb 2100 hrs
3. 14th Feb 2200 hrs
4. 14th Feb 2300 hrs
5. 15th Feb 0001 hrs
6. 15th Feb 0100 hrs
7. 15th Feb 0200 hrs
8. 15th Feb 0300 hrs

EDIT: DISREGARD THIS POST.....THE CO-ORDS PUT OUT BY JPL DO NOT MATCH WHAT I HAVE EXTRACTED FROM MY SN DATA INPUT. :bashcomp:

[Shark Bait]

Screen Image Dates and Timings (EST):

1. 15th Feb 0400 hrs
2. 15th Feb 0500 hrs
3. 15th Feb 2000 hrs
4. 15th Feb 2100 hrs
5. 15th Feb 2200 hrs
6. 15th Feb 2300 hrs
7. 16th Feb 0001 hrs
8. 16th Feb 0100 hrs

EDIT: DISREGARD THIS POST.....THE CO-ORDS PUT OUT BY JPL DO NOT MATCH WHAT I HAVE EXTRACTED FROM MY SN DATA INPUT. :bashcomp:

[Shark Bait]

Screen Image Dates and Timings (EST):

1. 16th Feb 0200 hrs
2. 16th Feb 0300 hrs
3. 16th Feb 0400 hrs
4. 16th Feb 0500 hrs

This will be the last that we will see of Asteroid 2012 DA14 as it becomes an object for the Northern Hemisphere.

EDIT: DISREGARD THIS POST.....THE CO-ORDS PUT OUT BY JPL DO NOT MATCH WHAT I HAVE EXTRACTED FROM MY SN DATA INPUT. :bashcomp:

[AstroJunk]

This is where I will be looking on the 15th at 8pm (weather permitting). I reckon JPL have a much better chance of knowing its position relative to Brisbane that any commercial planetarium program.

At mag 14.5, it should just becoming possible to see in the video camera.

Make sure you look in the right direction from your site :P

[Shark Bait]

Thanks AstroJunk. I have gone old school and plotted the JPL co-ordinates onto a star chart. It is covering a lot of sky and will be fun to track.

I was attempting to input NASA's JPL data into Starry Night as they have not provided an update which includes 2012 DA14. The information that was extracted from this data is way off the JPL coordinates given for our location. I was being very careful, but I have messed up the data entry somehow.

Even though my attempt at adding a new object into SN failed, I now know a little more about the process than I did before.

[AstroJunk]

No, don't beat yourself up Stu - you did it just fine. The issue is that the planetarium software doesn't take the fact that the object is so close into account. If it were a normal asteroid orbiting beyond Mars the plot would have been spot on.

The first time I went on the hunt for a NEO I did exactly the same and found myself searching for the rock over a degree in the wrong direction and saw nothing of course.

The next night I had licked my wounds and found it in a few mins!

Its a real thrill to find these objects and I plan to track this one over a few hours to see if It is a variable or not. If it is irregular in shape and is tumbling, it should vary in brightness over a few minutes and that will give an indication of the nature of the asteroid as only solid rocks can spin quickly. And of course it makes a difference to know if a single rock or a hail storm of smaller rocks is going to hit you :scared3:

[okiscopey]

Sounds familiar! I updated the minor body data in SkySafari Plus v1.5 (OS X) and did a YouTube video of this asteroid's progress across the sky. Subsequently found the SSPlus positions 'fictional' compared with the JPL data, presumably due to the 'closeness' factor.

Upgraded to SSPlus v1.7, updated the data and ... lo and behold! ... 2012 DA14 doesn't appear at all in the search list of the new version!

SSPlus is a great program, and the folks at Southern Stars have said they'll fix this known bug very soon, but the moral seems to be: when the going gets tough, plot the JPL data on a paper star chart!

[The_bluester]

A bit of a thread dig but better to put it here than start another.

When this asteroid passes by, understanding that both its orbit and ours will change, but ours by such a tiny amount to probably be not measurable (would pinhead to bowling ball as a comparison be overstating the asteroids mass?) what will be the effect on the asteroids orbit of passing so close to an object the mass of earth?

[AstroJunk]

My guess is that an atom to a bowling ball would be a better analogy. The asteroid will indeed be perturbed by the Earth, but not measurably the other way around. Orbital measurements are being taken regualrly and the orbit refined. This process will continue for some time and the results published by the NEO office.

[The_bluester]

It will be interesting to see what the end result is, a great example of gravity in action. It is probably too much to hope for but it would be nice to see an animation sometime in the future of what the change in the asteroids orbit was.

The last animation of that type that actually sticks in my mind is the one of the voyager paths through the solar system.

[glenc]

"Expect a small asteroid to make big news on February 15, 2013. The gymnasium-sized rock 2012 DA14, 40 or 50 meters (130 to 160 feet) across, will make the closest Earth flyby of a natural object ever predicted well in advance. It will pass within 28,500 km (18,000 miles) of Earth’s surface around 19:25 Universal Time February 15th, reaching 8th magnitude as it whizzes north across the stars at a rate of 0.8° per minute." Feb 16 here.
http://www.skyandtelescope.com/observing/highlights/Asteroid-DA14-to-Zip-Past-Earth-189052161.html

[glenc]

Attached is the MSLP map for 5am EDST (18 UT) on Saturday 16 Feb.
Perth will see DA 14 for longer than the other capitals.
Is anyone in Perth planning to image the event?

[glenc]

The asteroid's position varies a lot depending on your location.
The attached file is for Brisbane and Perth.

SOLAR PRESENCE (OBSERVING SITE)
Time tag is followed by a blank, then a solar-presence symbol:
'*' Daylight (refracted solar upper-limb on or above apparent horizon)
'C' Civil twilight/dawn
'N' Nautical twilight/dawn
'A' Astronomical twilight/dawn
' ' Night OR geocentric ephemeris

LUNAR PRESENCE WITH TARGET RISE/TRANSIT/SET MARKER (OBSERVING SITE)
The solar-presence symbol is immediately followed by another marker symbol:
'm' Refracted upper-limb of Moon on or above apparent horizon
' ' Refracted upper-limb of Moon below apparent horizon OR geocentric
'r' Rise (target body on or above cut-off RTS elevation)
't' Transit (target body at or past local maximum RTS elevation)
's' Set (target body on or below cut-off RTS elevation)

[bloodhound31]

So what will this look like through binoculars or a telescope? Will it be visible? What about photographing it? Will it be just like photographing a comet or is it moving a lot faster? (Comparatively)?

Baz.

[glenc]

Its magnitude varies rapidly and it also moves rapidly, much faster than a comet.
You will be able to see it in binoculars for a while. It will be like a faint moving star.

[Suzy]

Glen, if it's magnitude is changing so quickly, what do you think the best time to observe it in binoculars would be for Brisbane (I have 10x60's)?
I was looking forward to seeing it come within 3 degrees of Comet Lemon & making a nice triangle with 47Tuc at 1.20am Brisbane time on the 16th. I need to see this! :prey2:

I came across what looks like to be a gem of a site for tracking this comet (thanks Teale!).

http://nightskyonline.info/?p=5758

You don't need to log in to access it btw.

[mithrandir]

Baz, it will move from Octans to the northern horizon and then vanish in the dawn over a couple of hours. JPL Horizons, MPC ephemeris service, Heavens-above and probably others will generate an ephemeris customised for your location.

http://ssd.jpl.nasa.gov/horizons.cgi
Ephemeris Type : OBSERVER
Target Body : Asteroid (2012 DA14)
Observer Location : user defined ( your location and altitude)
Time Span : Start=2013-02-15 10:00, Stop=2013-02-16 02:00, Step=10 m
Table Settings : defaults
Display/Output : default (formatted HTML)those all have a "change" link. I added the "skip daylight" and "show constellations" options to Table Settings.

[inline_online]

Lots of good advice from many people here.
For what its worth, here is the process I am using to find and track 2012 DA14.

Head over to Google Maps and centre your observing location. Right-click and click on 'Whats Here'. This will give your exact latitude and longitude to a sufficient degree (no pun intended:lol:) of accuracy.

Next, head over to http://ssd.jpl.nasa.gov/horizons.cgi?s_loc=1#top and you can enter the lat and long parameters for your site. I had the site give me coordinates for DA14 in 10min intervals and spent about 2hrs last night plotting the path on the Great Atlas of the Sky.

I've also made a record of all mag 7 or brighter stars that it'll pass with a distance of 20' or less and the exact times of passing. I'll skip along to these stars until I have the asteroid in sight.

I will not have the advantage of a dark site but am hoping to find it in both a 5" refractor and a 12" dob from my city site!

Good luck everybody.

[seanliddelow]

Hi Dan,

I've been having trouble finding the Body ID for 2012 DA14:question:

Sean

[chrisp9au]

I would love for somebody to tell me whether I'm on the right track here?

1. Plugged my location into http://ssd.jpl.nasa.gov/horizons.cgi (Pic 1)
2. From the generated ephemeris, selected the time period of closest approach (Pic 2)
3. Plotted the RA and DEC for times before dawn twilight (Pic 3)

So, on Saturday morning around 4:40am, I should be looking in the right direction?

Cheers :thumbsup:

Chris

[mithrandir]

Sean, you have to spell it exactly "2012 DA14" - spaces and case matter. Or you can use K12D14A - the compact version of the name.

[seanliddelow]

Ok thanks :)

[mithrandir]

Chris, you don't really need data before about 2012-02-15 10:00 UTC. Up until then just about any planetarium program will get close. It will be in Octans.

I'd suggest you start earlier. If you go much later than 05:00 (18:00 UTC) you'll be competing with morning twilight.

You can set flags in the "Table Settings" to show constellation ids and not display values after sunrise.

[chrisp9au]

Thanks Andrew, that's why I extracted just the relevant data.
If I go much earlier I'm going to be struggling with the lower magnitudes.
My dob is out of action at the moment so I'll be using my C6.
But I take heart from the fact that you didn't say I'd be looking in the wrong direction! :)

Thanks again :thumbsup:

Chris

[mithrandir]

It might be academic Chris. If the weather doesn't improve no-one will see it.

[Suzy]

Thanks Glen for the Brisbane info- I hadn't seen you post it when I posted so all my questions are answered there. :thumbsup:

[AstroJunk]

Well, rather incredibly, I've been called by NASA today to confirm arrangements for me to be one of the broadcasters of the fly-by live from my observatory. Looks like I may get a dedicated NASA channel and some airtime on NASA TV if the clouds stay off.

Could be an interesting night :scared:

[pdthomas23]

Here are some plots I made a couple of weeks ago when mentioning the pass at the ASV January meeting.
The Orbital Elements Change plots show how the Keplerian elements change from 1200 UT on 2013/02/15 to 0000 UT on 2013/02/16. I didn't include the orbital inclination in the plots as it didn't fit into either the group around 1.0 or the group in the 100s. Inclination changes from about 10 degrees to about 14 degrees from memory. But these changes in elements explain why most planetarium software has problems. You really need an integrator like Solex or similar.

By the way, the following link explains how to plot the position using Cartes du Ciel (Skycharts) by importing a file of positions calculated by JPL HORIZONS or the MPC Ephemeris Services as a catalogue of "objects".
http://www.ap-i.net/skychart/en/documentation/display_of_neos

My other plot shows the effect on the trajectory by plotting the motion in two planes (X-Y is the instantaneous plane of Earth's orbit in this case, with X being a Sun vector and Y perpendicular). The JPL NEO site shows much nicer plots and I've seen a few YouTube videos that show the fly-by from the asteroid's perspective.

Now I need a weather expert to tell me where I should be heading for Friday night/Saturday morning.

Peter Thomas
Oakleigh

[glenc]

Notice in the table for Perth and Brisbane (post 66) that At means
'A' Astronomical twilight/dawn
't' Transit (target body at or past local maximum RTS elevation)

[mithrandir]

Sky Safari users see the thread in Mobile Astronomy Apps (http://www.iceinspace.com.au/forum/showpost.php?p=945946&postcount=1)
.
I've just tried simulating 2012 DA14 in SSPro and it really works.

[glenc]

I hope someone in WA images this event on Saturday morning.
It looks like it will be cloudy in the eastern states.
See post 66 for the RA & dec of DA14 for Perth.

[inline_online]

Woo hoo :rofl:
The day has dawned bright and clear and not a cloud in sight. Expected max of 35 degrees today.
The 12" dob and 5" Tak will be set up tonight after dinner and then the long wait will begin.
Both my boys (7 & 8) have asked me to wake them up to see it; my wife said no way (for both them and her!!). I reckon i'll sneak into their room at about 0200hrs and see if they are keen (shhh boys, don't tell mummy:lol:).
I've only seen one asteroid before and that was Vesta about 14 years or so ago. This once-in-a-lifetime event should be a lot more exciting.

Good luck everybody.
Dan:thumbsup:

[bloodhound31]

What time for Canberra?

[rousey346]

ill be trying to image it,..... it just comes down to light pollution in my area, which is really bad.
My partner is sick and cant travel out bush (which i normally do)

link to my setup is here already set up lol

http://www.iceinspace.com.au/forum/showthread.php?t=103382