From planetaryscience at yahoo.com Wed Aug 26 04:47:47 2020 From: planetaryscience at yahoo.com (Sam Deen) Date: Wed, 26 Aug 2020 08:47:47 +0000 (UTC) Subject: [neo_followup] C1979M1 earth-orbiting object (maybe artificial) decent chance of Earth impact on September 1. FOLLOWUP NEEDED ASAP!!!!!! References: <377504091.7779355.1598431667243.ref@mail.yahoo.com> Message-ID: <377504091.7779355.1598431667243@mail.yahoo.com> Hi all, Forgive this being a bit hasty, and possibly poorly researched depending on the outcome of the coming hours/days. I'm not sure what to make of it but can not overemphasize the importance of followup C1979M1, discovered by catalina (703) 3 hours ago as of writing, is currently on a geocentric orbit of Earth that looks like this at the present epoch: Perigee 2020 Aug 25.334348 +/- 0.00271 TT = 8:01:27 (JD 2459086.834348) Epoch 2020 Aug 26.0 TT = JDT 2459087.5 Find_Orb M 104.26387312 +/- 0.49 (J2000 equator) n 156.63422190 +/- 0.117 Peri. 205.69821 +/- 0.06 a 73566.3264 +/- 36.6 Node 306.95991 +/- 0.009 e 0.9117157 +/- 0.000112 Incl. 55.14735 +/- 0.0056 P3309.56m/2.298d H 29.8 G 0.15 U 11.3 q 6494.74942 +/- 5.6 Q 140637.903 +/- 77.2 >From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 I'm not an expert on satellite orbits, but as far as I'm aware there's no known artificial satellites with an orbit like this. Again, take that with a grain of salt as my knowledge isn't complete, but what I can say more confidently is that if it is known, what isn't known is that, assuming it has a fairly low AMR, it will almost certainly be impacting Earth on September 1st (upcoming artsat reentries don't list any objects on an orbit even remotely similar to this one any time soon): Perigee 2020 Sep 1.229800 +/- 0.00772 TT = 5:30:54 (JD 2459093.729800) Epoch 2020 Sep 1.0 TT = JDT 2459093.5 Find_Orb M 323.99451483 +/- 1.1 (J2000 equator) n 156.68156709 +/- 0.117 Peri. 205.92251 +/- 0.06 a 73551.5058 +/- 36.6 Node 306.55647 +/- 0.011 e 0.9136219 +/- 0.000111 Incl. 54.78299 +/- 0.006 P3308.56m/2.298d H 29.8 G 0.15 U 11.3 q 6353.23441 +/- 5.6 Q 140749.777 +/- 77.3 >From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 IMPACT at 1 Sep 2020 5:28:32.46 lat -15.45909 lon E74.93635 As you can see with the long and lat of the impact, it will probably be over the middle of the Indian ocean and (sadly for any hope of fireworks) far away from land. Of course, all of this is made assuming that it's an asteroid and not an unidentified artsat. It being one probably won't change the September 1st impact considering the object hasn't displayed any trash-baggy behavior in its 3 hour observation arc so far- but it would be extremely important nonetheless scientifically at least to confirm if this thing is a rock or not. ~Sam From planetaryscience at yahoo.com Wed Aug 26 05:09:23 2020 From: planetaryscience at yahoo.com (Sam Deen) Date: Wed, 26 Aug 2020 09:09:23 +0000 (UTC) Subject: [neo_followup] {MPML} C1979M1 earth-orbiting object (maybe artificial) decent chance of Earth impact on September 1. FOLLOWUP NEEDED ASAP!!!!!! In-Reply-To: <162EC52261A0E5C7.27554@groups.io> References: <377504091.7779355.1598431667243.ref@mail.yahoo.com> <162EC52261A0E5C7.27554@groups.io> Message-ID: <1432631663.7764816.1598432963620@mail.yahoo.com> Hi all, Quick update The orbit of this object has an orbit very suspiciously similar to that of INTEGRAL: Orbital elements: WJ2B5AC = INTEGRAL = 2002-048A = NORAD 27540 Perigee 2015 Aug 1.827363 +/- 0.000663 TT = 19:51:24 (JD 2457236.327363) Epoch 2015 Aug 1.0 TT; AMR 0.062553 +/- 0.0213 m?/kg Find_Orb M 248.04907 +/- 0.08 (J2000 equatorial) n 135.31051136 +/- 0.000348 Peri. 258.63494 +/- 0.018 a 81105.2839 +/- 0.139 Node 219.10574 +/- 0.012 e 0.8104486 +/- 0.000103 Incl. 53.15620 +/- 0.0018 P 2.66d H 28.4 G 0.15 U 7.4 q 15373.6177 +/- 8.34 Q 146836.950 +/- 8.45 34 of 75 observations 2015 June 21-Nov. 20; mean residual 62".177 C1979M1: Perigee 2020 Aug 25.334348 +/- 0.00271 TT = 8:01:27 (JD 2459086.834348) Epoch 2020 Aug 26.0 TT = JDT 2459087.5 Find_Orb M 104.26387307 +/- 0.49 (J2000 equator) n 156.63422189 +/- 0.117 Peri. 205.69821 +/- 0.06 a 73566.3264 +/- 36.6 Node 306.95991 +/- 0.009 e 0.9117157 +/- 0.000112 Incl. 55.14735 +/- 0.0056 P3309.56m/2.298d H 29.8 G 0.15 U 11.3 q 6494.74942 +/- 5.6 Q 140637.903 +/- 77.2 >From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 However, the biggest problem with this is that INTEGRAL is an active and continually operating spacecraft, and there's no recorded (officially or unofficially) "debris" from it, orbiting or not orbiting. Not to mention that I feel like debris almost as large as the spacecraft itself (H = 28.4 vs 29.8) would definitely have been catalogued in some shape or another. So if it is related to INTEGRAL, it's quite the strange object. ~Sam On Wednesday, August 26, 2020, 01:47:51 AM MST, Sam Deen via groups.io wrote: Hi all, Forgive this being a bit hasty, and possibly poorly researched depending on the outcome of the coming hours/days. I'm not sure what to make of it but can not overemphasize the importance of followup C1979M1, discovered by catalina (703) 3 hours ago as of writing, is currently on a geocentric orbit of Earth that looks like this at the present epoch: ? Perigee 2020 Aug 25.334348 +/- 0.00271 TT =? 8:01:27 (JD 2459086.834348) Epoch 2020 Aug 26.0 TT = JDT 2459087.5? ? ? ? ? ? ? ? ? ? ? ? Find_Orb M 104.26387312 +/- 0.49? ? ? ? ? ? (J2000 equator) n 156.63422190 +/- 0.117? ? ? ? ? ? Peri.? 205.69821 +/- 0.06 a 73566.3264 +/- 36.6? ? ? ? ? ? ? Node? 306.95991 +/- 0.009 e? 0.9117157 +/- 0.000112? ? ? ? ? Incl.? 55.14735 +/- 0.0056 P3309.56m/2.298d? ? ? ? ? H 29.8? G? 0.15? U 11.3? q 6494.74942 +/- 5.6? ? Q 140637.903 +/- 77.2 >From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 I'm not an expert on satellite orbits, but as far as I'm aware there's no known artificial satellites with an orbit like this. Again, take that with a grain of salt as my knowledge isn't complete, but what I can say more confidently is that if it is known, what isn't known is that, assuming it has a fairly low AMR, it will almost certainly be impacting Earth on September 1st (upcoming artsat reentries don't list any objects on an orbit even remotely similar to this one any time soon): ? Perigee 2020 Sep 1.229800 +/- 0.00772 TT =? 5:30:54 (JD 2459093.729800) Epoch 2020 Sep? 1.0 TT = JDT 2459093.5? ? ? ? ? ? ? ? ? ? ? ? Find_Orb M 323.99451483 +/- 1.1? ? ? ? ? ? ? (J2000 equator) n 156.68156709 +/- 0.117? ? ? ? ? ? Peri.? 205.92251 +/- 0.06 a 73551.5058 +/- 36.6? ? ? ? ? ? ? Node? 306.55647 +/- 0.011 e? 0.9136219 +/- 0.000111? ? ? ? ? Incl.? 54.78299 +/- 0.006 P3308.56m/2.298d? ? ? ? ? H 29.8? G? 0.15? U 11.3? q 6353.23441 +/- 5.6? ? Q 140749.777 +/- 77.3 >From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 IMPACT at? 1 Sep 2020? 5:28:32.46 lat -15.45909 lon E74.93635 As you can see with the long and lat of the impact, it will probably be over the middle of the Indian ocean and (sadly for any hope of fireworks) far away from land. Of course, all of this is made assuming that it's an asteroid and not an unidentified artsat. It being one probably won't change the September 1st impact considering the object hasn't displayed any trash-baggy behavior in its 3 hour observation arc so far- but it would be extremely important nonetheless scientifically at least to confirm if this thing is a rock or not. ~Sam -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#35757): https://groups.io/g/mpml/message/35757 Mute This Topic: https://groups.io/mt/76424462/2027585 -=-=- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Posts to this list or information found within may be freely used, with the stipulation that MPML and the originating author are cited as the source of the information. -=-=- Group Owner: mpml+owner at groups.io Unsubscribe: https://groups.io/g/mpml/unsub [planetaryscience at yahoo.com] -=-=-=-=-=-=-=-=-=-=-=- -------------- next part -------------- An HTML attachment was scrubbed... URL: From planet4589 at gmail.com Wed Aug 26 10:10:56 2020 From: planet4589 at gmail.com (Jonathan McDowell) Date: Wed, 26 Aug 2020 10:10:56 -0400 Subject: [neo_followup] {MPML} C1979M1 earth-orbiting object (maybe artificial) decent chance of Earth impact on September 1. FOLLOWUP NEEDED ASAP!!!!!! In-Reply-To: <377504091.7779355.1598431667243@mail.yahoo.com> References: <377504091.7779355.1598431667243.ref@mail.yahoo.com> <377504091.7779355.1598431667243@mail.yahoo.com> Message-ID: I don't have a specific candidate in my catalog, but I'd be surprised if this is not an artsat. Likely one of the lost objects previously in a higher apogee orbit, that had closer to lunar apogee before making a previous perigee pass? It'll experience a lot of drag at each perigee pass with that low perigee so I guess it's hard to propagate it back more than a few days to figure out what its origin might be, I can imagine if a piece came off 2011-037's Fregat rocket stage it might get perturbed into an orbit like this. - Jonathan On Wed, 26 Aug 2020 at 04:47, Sam Deen via groups.io wrote: > Hi all, > > Forgive this being a bit hasty, and possibly poorly researched depending > on the outcome of the coming hours/days. I'm not sure what to make of it > but can not overemphasize the importance of followup > > C1979M1, discovered by catalina (703) 3 hours ago as of writing, is > currently on a geocentric orbit of Earth that looks like this at the > present epoch: > > Perigee 2020 Aug 25.334348 +/- 0.00271 TT = 8:01:27 (JD 2459086.834348) > Epoch 2020 Aug 26.0 TT = JDT 2459087.5 Find_Orb > M 104.26387312 +/- 0.49 (J2000 equator) > n 156.63422190 +/- 0.117 Peri. 205.69821 +/- 0.06 > a 73566.3264 +/- 36.6 Node 306.95991 +/- 0.009 > e 0.9117157 +/- 0.000112 Incl. 55.14735 +/- 0.0056 > P3309.56m/2.298d H 29.8 G 0.15 U 11.3 > q 6494.74942 +/- 5.6 Q 140637.903 +/- 77.2 > From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 > > I'm not an expert on satellite orbits, but as far as I'm aware there's no > known artificial satellites with an orbit like this. Again, take that with > a grain of salt as my knowledge isn't complete, but what I can say more > confidently is that if it is known, what isn't known is that, assuming it > has a fairly low AMR, it will almost certainly be impacting Earth on > September 1st (upcoming artsat reentries don't list any objects on an orbit > even remotely similar to this one any time soon): > > Perigee 2020 Sep 1.229800 +/- 0.00772 TT = 5:30:54 (JD 2459093.729800) > Epoch 2020 Sep 1.0 TT = JDT 2459093.5 Find_Orb > M 323.99451483 +/- 1.1 (J2000 equator) > n 156.68156709 +/- 0.117 Peri. 205.92251 +/- 0.06 > a 73551.5058 +/- 36.6 Node 306.55647 +/- 0.011 > e 0.9136219 +/- 0.000111 Incl. 54.78299 +/- 0.006 > P3308.56m/2.298d H 29.8 G 0.15 U 11.3 > q 6353.23441 +/- 5.6 Q 140749.777 +/- 77.3 > From 13 observations 2020 Aug. 26 (2.6 hr); mean residual 0".28 > IMPACT at 1 Sep 2020 5:28:32.46 lat -15.45909 lon E74.93635 > > As you can see with the long and lat of the impact, it will probably be > over the middle of the Indian ocean and (sadly for any hope of fireworks) > far away from land. > > Of course, all of this is made assuming that it's an asteroid and not an > unidentified artsat. It being one probably won't change the September 1st > impact considering the object hasn't displayed any trash-baggy behavior in > its 3 hour observation arc so far- but it would be extremely important > nonetheless scientifically at least to confirm if this thing is a rock or > not. > > ~Sam > > -=-=-=-=-=-=-=-=-=-=-=- > Groups.io Links: You receive all messages sent to this group. > > View/Reply Online (#35757): https://groups.io/g/mpml/message/35757 > Mute This Topic: https://groups.io/mt/76424462/2702684 > -=-=- > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Posts to this list or information found within may be freely used, with > the stipulation that MPML and the originating author are cited as the > source of the information. > -=-=- > Group Owner: mpml+owner at groups.io > Unsubscribe: https://groups.io/g/mpml/unsub [planet4589 at gmail.com] > -=-=-=-=-=-=-=-=-=-=-=- > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From pluto at projectpluto.com Wed Aug 26 16:50:18 2020 From: pluto at projectpluto.com (Bill Gray) Date: Wed, 26 Aug 2020 16:50:18 -0400 Subject: [neo_followup] C1971M1 = 1964-054A = OGO-1 Message-ID: <532c3cab-6a12-ea70-4a55-3f52b189cbba@projectpluto.com> Hello all, (Just got back from a couple of days of camping with my wife, outside the range of Internet availability.) This is definitely 1964-054A. I should have posted something about it; we've known for a few years now that it would re-enter the earth's atmosphere sometime around 2020 Aug 31 : https://www.projectpluto.com/pluto/mpecs/64054a.htm Note that the prediction was made in early 2018, based on observations from 2016 to 2020. I do have further observations, mostly from Goran Gasparovic, for as late as August 18. Based on those, it was still difficult to tell when it would re-enter; there were a few "skimming" passes causing the apogee to drop, but there was a lot of uncertainty as to how much. The problem is that Find_Orb computes an area/mass ratio for the object based on how much it's pushed around by sunlight. This dodges around effects caused by the object shape and thermal properties (a really shiny object that did a good job of reflecting most sunlight back where it came from would appear "lighter" than a similar object that absorbed most of the sunlight, then re-radiated it in all directions.) The object then dips into the earth's atmosphere, and then I start modelling drag effects as if it's a sphere with that AMR, and using a "standard atmosphere model". The overall effect is about right, and you see the object lose speed and spiral in after a couple of orbits, but the specifics are not very specific. We've had a couple of other objects do the same thing (such as 1977-093 a year or two ago, mentioned at the above URL), and there are a few others expected to re-enter in the next year or two. If you look at the plot of the perigee height of 1964-054A since launch in 1964 to the present... https://www.projectpluto.com/pluto/mpecs/64054a.pdf ...you'll see that the perigee (red line) came really close to scraping the upper atmosphere in late 1980, and had various rises and falls over the subsequent decades. This most recent "peri-perigee" was just a little too low. I'll post the rest of the data for this object at the above URL and further comments once I catch up on various things that erupted during my vacation. -- Bill From pluto at projectpluto.com Wed Aug 26 21:35:59 2020 From: pluto at projectpluto.com (Bill Gray) Date: Wed, 26 Aug 2020 21:35:59 -0400 Subject: [neo_followup] {MPML} C1979M1 earth-orbiting object (maybe artificial) decent chance of Earth impact on September 1. FOLLOWUP NEEDED ASAP!!!!!! In-Reply-To: References: <377504091.7779355.1598431667243@mail.yahoo.com> <2856.1598450397420323789@groups.io> <1329278032.8033977.1598465719653@mail.yahoo.com> Message-ID: Hi folks, Okay, I've had a little more opportunity to dig into this, plus some additional data from David Briggs at (J69). Here's everything I've got : https://projectpluto.com/temp/64054a.htm This is just using some data from earlier in August, plus the recent C1979M1 observations. The ephemerides show the currently predicted ground path... which involves a close perigee in about fourteen hours (at 15:06 UTC on the 27th), slowing it down a bit, then a re-entry around 21:00, probably around French Polynesia. Quite a bit depends on how much the spacecraft slows down after the upcoming perigee, and there's considerable guessing involved in that. The above orbit is based on assuming the AMR for solar radiation pressure is the same as that for atmospheric drag, which is pretty stupid, but probably close enough for the current situation. More data tomorrow, after perigee, ought to show just how much the object got slowed down. To compute ephemerides for this object, you'll need the "current" Find_Orb (for Windows users, the version described at https://www.projectpluto.com/find_con.htm The older, GUI version and the on-line Find_Orb don't support the trickery I'm about to describe.) Cut-and-paste this e-mail into Find_Orb, including the data shown below. Easiest way is to select all, copy, run Find_Orb, and click on "Copy astrometry from clipboard". You'll get a pretty good orbit, except one that doesn't know anything about atmospheric drag. We don't have enough data here to determine an AMR, so you have to help Find_Orb along. Hit the '*' key to turn on solar radiation pressure. (If the Find_Orb window is wide enough, you may have an 'SRP' option at the top and can click on that instead.) Now right-click on the orbital elements, then on "Constraints=(none)". Enter 'A=.03'. Do a full step or two (hitting the 'f' key will do that). In truth, that value may be off by quite a bit. But even if it is, I think it'll be close enough to put you within a few arcminutes of the object (I tried a range of AMRs, and that's about the spread I get.) You should now be able to generate customized ephemerides for your location. Once we have some post-perigee data, we should be able to fit it without constraining the AMR, and will have a _much_ better idea as to the re-entry path. -- Bill COM = 1964-054A C1979M1* C2020 08 26.22870 21 19 52.55 +16 27 32.5 ~8Q6M 15.7 GVNEOCP703 C1979M1 C2020 08 26.24365 21 19 41.29 +16 42 30.8 ~8Q6M 15.7 GVNEOCP703 C1979M1 C2020 08 26.29283 21 19 02.64 +17 28 19.3 ~8Q7M 15.5 GVNEOCPI52 C1979M1 C2020 08 26.29299 21 19 02.53 +17 28 27.7 ~8Q7M 15.7 GVNEOCPI52 C1979M1 C2020 08 26.29314 21 19 02.42 +17 28 35.8 ~8Q7M 15.6 GVNEOCPI52 C1979M1 C2020 08 26.29329 21 19 02.31 +17 28 44.0 ~8Q7M 15.4 GVNEOCPI52 C1979M1 C2020 08 26.32367821 20 57.83 +17 12 40.7 ~8Q8M 15.6 GVNEOCPU55 C1979M1 C2020 08 26.32554421 20 57.92 +17 14 19.6 ~8Q8M 15.5 GVNEOCPU55 C1979M1 C2020 08 26.32766221 20 58.01 +17 16 11.3 ~8Q8M 15.6 GVNEOCPU55 C1979M1 C2020 08 26.33511 21 18 36.03 +18 03 41.5 ~8Q8M 15.4 GVNEOCPI52 C1979M1 C2020 08 26.33526 21 18 35.95 +18 03 48.8 ~8Q8M 15.3 GVNEOCPI52 C1979M1 C2020 08 26.33541 21 18 35.88 +18 03 56.2 ~8Q8M 15.6 GVNEOCPI52 C1979M1 C2020 08 26.33557 21 18 35.81 +18 04 03.5 ~8Q8M 15.8 GVNEOCPI52 C1979M1 C2020 08 26.39013 21 18 28.43 +18 44 27.3 ~8Q9b 15.7 GVNEOCPI52 C1979M1 C2020 08 26.39028 21 18 28.45 +18 44 34.2 ~8Q9b 15.7 GVNEOCPI52 C1979M1 C2020 08 26.39044 21 18 28.50 +18 44 40.2 ~8Q9b 15.5 GVNEOCPI52 C1979M1 C2020 08 26.39059 21 18 28.53 +18 44 46.6 ~8Q9b 15.8 GVNEOCPI52 C1979M1 C2020 08 26.40323 21 19 26.00 +18 33 47.0 ~8QA7 15.7 rNEOCP718 C1979M1 C2020 08 26.40415 21 19 26.56 +18 34 25.3 ~8QA7 15.8 rNEOCP718 C1979M1 C2020 08 26.40506 21 19 27.14 +18 35 03.0 ~8QA7 15.7 rNEOCP718 C1979M1 C2020 08 26.40597 21 19 27.76 +18 35 41.9 ~8QA7 15.8 rNEOCP718 C1979M1 C2020 08 26.40688 21 19 28.34 +18 36 19.4 ~8QA7 15.8 rNEOCP718 C1979M1 C2020 08 26.41689 21 18 40.80 +19 02 24.1 ~8QA7 16.2 GVNEOCPI52 C1979M1 C2020 08 26.41700 21 18 40.87 +19 02 28.7 ~8QA7 15.5 GVNEOCPI52 C1979M1 C2020 08 26.41711 21 18 40.95 +19 02 33.1 ~8QA7 15.9 GVNEOCPI52 C1979M1 C2020 08 26.41739 21 18 41.13 +19 02 43.8 ~8QA7 15.4 GVNEOCPI52 COD J69 CON David Briggs [davidbriggs124 at googlemail.com] OBS D. Briggs MEA D. Briggs TEL 0.41-m f/4.5 Newtonian reflector + CCD ACK MPCReport file updated 2020.08.26 22:32:56 AC2 davidbriggs124 at googlemail.com NET Gaia DR2 1964-054A KC2020 08 26.92697721 55 22.19 +26 08 09.1 15.8 G J69 1964-054A KC2020 08 26.92801421 55 23.25 +26 09 18.4 15.9 G J69 1964-054A KC2020 08 26.92905221 55 24.32 +26 10 27.8 15.8 G J69 1964-054A KC2020 08 26.93009121 55 25.41 +26 11 37.0 16.0 G J69 1964-054A KC2020 08 26.93112721 55 26.45 +26 12 46.2 16.0 G J69 1964-054A KC2020 08 26.93216421 55 27.52 +26 13 55.2 15.9 G J69 ----- end ----- From pluto at projectpluto.com Thu Aug 27 11:30:30 2020 From: pluto at projectpluto.com (Bill Gray) Date: Thu, 27 Aug 2020 11:30:30 -0400 Subject: [neo_followup] Improved 1964-054A = OGO-1 data, ephems Message-ID: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> Hello all, I found quite a bit of additional data for this object in my inbox this morning (thank you!). At present, I've got 46 observations from the current orbit : https://www.projectpluto.com/temp/ogo1.txt A correction to my previous e-mail : you can just download the above file and feed it into Find_Orb, either "current" Windows or Linux, or on-line, or the old Windows GUI version, and compute ephemerides for your location that should be good to within a few arcminutes. That's about the level of effect I expect the upcoming perigee (occurring as I write) to have. You can still turn on solar radiation pressure (by hitting the '*' key) and constrain the area/mass ratio to be A=0.03, and get suitably adjusted results. But unless you have a small field of view, the non-SRP version should at least let you find the object. The good news is that, if the nominal AMR makes a five arcminute difference (300") and the object is measured to an arcsecond, it means the effects of atmospheric drag during that pass will be measured to about one part in 300. Which is pretty good. And we'll probably get enough data to _really_ nail down the re-entry time and location. (Currently looks to be at about 21:00 UTC on the 29th over French Polynesia, but a little more or less drag could make that prediction look stupid.) This may be a useful exercise to prepare for something like the 1972 fireball that zipped through the atmosphere, lost lots of speed, and probably was left in Earth orbit and crashed at the next perigee. -- Bill From albireo3000 at gmail.com Thu Aug 27 12:52:24 2020 From: albireo3000 at gmail.com (=?UTF-8?Q?Francisco_Oca=C3=B1a_Gonz=C3=A1lez?=) Date: Thu, 27 Aug 2020 18:52:24 +0200 Subject: [neo_followup] Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> Message-ID: Hello Bill, regarding the 1972 fireball, it seems the meteoroid is still out there: https://ui.adsabs.harvard.edu/abs/1994A%26A...283..287C/abstract. Indeed most of them do not lose enough energy to get into a geocentric orbit. Even more, some geometry encounters are lucky enough to put them in a larger orbit (e.g., this recent fireball https://iopscience.iop.org/article/10.3847/1538-3881/ab8002/pdf btw, nice paper, including review of grazing fireballs). And following the topic, another relevant papers on how these grazing fireballs end up in JFC orbits: https://arxiv.org/pdf/2008.08848.pdf Regards, Paco El jue., 27 ago. 2020 a las 17:30, Bill Gray () escribi?: > > Hello all, > > I found quite a bit of additional data for this object in > my inbox this morning (thank you!). At present, I've got > 46 observations from the current orbit : > > https://www.projectpluto.com/temp/ogo1.txt > > A correction to my previous e-mail : you can just download > the above file and feed it into Find_Orb, either "current" > Windows or Linux, or on-line, or the old Windows GUI version, > and compute ephemerides for your location that should be good > to within a few arcminutes. That's about the level of effect > I expect the upcoming perigee (occurring as I write) to have. > > You can still turn on solar radiation pressure (by hitting > the '*' key) and constrain the area/mass ratio to be A=0.03, > and get suitably adjusted results. But unless you have a > small field of view, the non-SRP version should at least let > you find the object. > > The good news is that, if the nominal AMR makes a five > arcminute difference (300") and the object is measured to an > arcsecond, it means the effects of atmospheric drag during > that pass will be measured to about one part in 300. Which > is pretty good. And we'll probably get enough data to > _really_ nail down the re-entry time and location. > (Currently looks to be at about 21:00 UTC on the 29th over > French Polynesia, but a little more or less drag could > make that prediction look stupid.) > > This may be a useful exercise to prepare for something > like the 1972 fireball that zipped through the atmosphere, > lost lots of speed, and probably was left in Earth orbit > and crashed at the next perigee. > > -- Bill > > -- > neo_followup mailing list > neo_followup at projectpluto.com > http://projectpluto.com/mailman/listinfo/neo_followup_projectpluto.com From pluto at projectpluto.com Thu Aug 27 17:23:08 2020 From: pluto at projectpluto.com (Bill Gray) Date: Thu, 27 Aug 2020 17:23:08 -0400 Subject: [neo_followup] Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> Message-ID: <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Just got my first post-perigee data. The object was a few arcminutes off prediction (8' north, 6' east), corresponding to an AMR of 0.046. So modify my earlier message : if you turn on SRP and constrain A=0.046, you'll nail the object within an arcsecond or two. More later... -- Bill On 8/27/20 11:30 AM, Bill Gray wrote: > Hello all, > > ?? I found quite a bit of additional data for this object in > my inbox this morning (thank you!).? At present,? I've got > 46 observations from the current orbit : > > https://www.projectpluto.com/temp/ogo1.txt > > ?? A correction to my previous e-mail : you can just download > the above file and feed it into Find_Orb,? either "current" > Windows or Linux,? or on-line,? or the old Windows GUI version, > and compute ephemerides for your location that should be good > to within a few arcminutes.? That's about the level of effect > I expect the upcoming perigee (occurring as I write) to have. > > ?? You can still turn on solar radiation pressure (by hitting > the '*' key) and constrain the area/mass ratio to be A=0.03, > and get suitably adjusted results.? But unless you have a > small field of view,? the non-SRP version should at least let > you find the object. > > ?? The good news is that,? if the nominal AMR makes a five > arcminute difference (300") and the object is measured to an > arcsecond,? it means the effects of atmospheric drag during > that pass will be measured to about one part in 300.? Which > is pretty good.? And we'll probably get enough data to > _really_ nail down the re-entry time and location. > (Currently looks to be at about 21:00 UTC on the 29th over > French Polynesia,? but a little more or less drag could > make that prediction look stupid.) > > ?? This may be a useful exercise to prepare for something > like the 1972 fireball that zipped through the atmosphere, > lost lots of speed,? and probably was left in Earth orbit > and crashed at the next perigee. > > -- Bill From pluto at projectpluto.com Fri Aug 28 00:13:21 2020 From: pluto at projectpluto.com (Bill Gray) Date: Fri, 28 Aug 2020 00:13:21 -0400 Subject: [neo_followup] Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Message-ID: We now have post-perigee data from (Z84) Calar Alto and (K19) PASTIS. With that, I'm getting... https://projectpluto.com/temp/64054a.htm ...with the ephemerides showing the ground path, right up to the predicted re-entry at 20:45 on August 29, at the south end of French Polynesia. So I'm quite confident we'll be able to track it all the way in to re-entry. -- Bill From 4099wiggins at gmail.com Fri Aug 28 01:00:08 2020 From: 4099wiggins at gmail.com (Patrick Wiggins) Date: Thu, 27 Aug 2020 23:00:08 -0600 Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Message-ID: Apologies for the newbie question but how are y?all figuring out where to look? I?m at 718 and would like to try. I did so yesterday but that?s because it was on NEOCP. Not there tonight. Thanks, patrick > On 27 Aug 2020, at 22:13, Bill J. Gray wrote: > > We now have post-perigee data from (Z84) Calar Alto and (K19) PASTIS. > With that, I'm getting... > > https://projectpluto.com/temp/64054a.htm > > ...with the ephemerides showing the ground path, right up to the > predicted re-entry at 20:45 on August 29, at the south end of > French Polynesia. So I'm quite confident we'll be able to track > it all the way in to re-entry. > > -- Bill > > -=-=-=-=-=-=-=-=-=-=-=- > Groups.io Links: You receive all messages sent to this group. > > View/Reply Online (#35788): https://groups.io/g/mpml/message/35788 > Mute This Topic: https://groups.io/mt/76453944/2702017 > -=-=- > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Posts to this list or information found within may be freely used, with the stipulation that MPML and the originating author are cited as the source of the information. > -=-=- > Group Owner: mpml+owner at groups.io > Unsubscribe: https://groups.io/g/mpml/unsub [4099wiggins at gmail.com] > -=-=-=-=-=-=-=-=-=-=-=- > From 4099wiggins at gmail.com Fri Aug 28 02:29:18 2020 From: 4099wiggins at gmail.com (Patrick Wiggins) Date: Fri, 28 Aug 2020 00:29:18 -0600 Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <162F55DF958ACB0F.13088@groups.io> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> <162F55DF958ACB0F.13088@groups.io> Message-ID: <8FC5C2AD-0515-4556-885A-095D2CA53BE4@gmail.com> Many thanks to Masayuki Suzuki, He sent me data he calculated using Find Orb and I was able to spot it right away. patrick 718 > On 27 Aug 2020, at 23:00, Wiggins Patrick via groups.io <4099wiggins=gmail.com at groups.io> wrote: > > Apologies for the newbie question but how are y?all figuring out where to look? > > I?m at 718 and would like to try. I did so yesterday but that?s because it was on NEOCP. Not there tonight. > > Thanks, > > patrick From 4099wiggins at gmail.com Fri Aug 28 03:30:14 2020 From: 4099wiggins at gmail.com (Patrick Wiggins) Date: Fri, 28 Aug 2020 01:30:14 -0600 Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Message-ID: Hi Bill (et al.), I was originally only going to get a few images but it?s so bright I decided to keep imaging until it left the field (I?ll put them in an animation and post to my Facebook page later). Appended below is what I got (and, again, thanks to Masayuki Suzuki for his help). patrick 718 > On 27 Aug 2020, at 22:13, Bill J. Gray wrote: > > We now have post-perigee data from (Z84) Calar Alto and (K19) PASTIS. > With that, I'm getting... > > https://projectpluto.com/temp/64054a.htm > > ...with the ephemerides showing the ground path, right up to the > predicted re-entry at 20:45 on August 29, at the south end of > French Polynesia. So I'm quite confident we'll be able to track > it all the way in to re-entry. > > ? C1979M1 C2020 08 28.26725 21 04 12.34 +11 44 50.6 15.1 718 C1979M1 C2020 08 28.26780 21 04 12.30 +11 45 32.6 15.5 718 C1979M1 C2020 08 28.26808 21 04 12.30 +11 45 52.8 15.0 718 C1979M1 C2020 08 28.26835 21 04 12.25 +11 46 13.0 15.4 718 C1979M1 C2020 08 28.26862 21 04 12.26 +11 46 34.0 15.5 718 C1979M1 C2020 08 28.26917 21 04 12.18 +11 47 14.6 15.2 718 C1979M1 C2020 08 28.26972 21 04 12.10 +11 47 55.5 15.0 718 C1979M1 C2020 08 28.26999 21 04 12.12 +11 48 16.4 15.1 718 C1979M1 C2020 08 28.27054 21 04 12.07 +11 48 57.5 15.2 718 C1979M1 C2020 08 28.27082 21 04 12.05 +11 49 17.2 15.2 718 C1979M1 C2020 08 28.27109 21 04 11.99 +11 49 37.4 15.8 718 C1979M1 C2020 08 28.27136 21 04 12.01 +11 49 58.2 15.3 718 C1979M1 C2020 08 28.27191 21 04 11.92 +11 50 38.8 15.4 718 C1979M1 C2020 08 28.27219 21 04 11.93 +11 51 00.2 15.5 718 C1979M1 C2020 08 28.27247 21 04 11.91 +11 51 20.2 15.0 718 C1979M1 C2020 08 28.27275 21 04 11.84 +11 51 39.8 15.7 718 C1979M1 C2020 08 28.27329 21 04 11.84 +11 52 21.5 15.0 718 C1979M1 C2020 08 28.27385 21 04 11.79 +11 53 01.9 15.8 718 C1979M1 C2020 08 28.27412 21 04 11.79 +11 53 21.8 15.0 718 C1979M1 C2020 08 28.27467 21 04 11.74 +11 54 02.0 15.8 718 C1979M1 C2020 08 28.27521 21 04 11.70 +11 54 42.2 15.1 718 C1979M1 C2020 08 28.27549 21 04 11.69 +11 55 02.4 15.8 718 C1979M1 C2020 08 28.27604 21 04 11.65 +11 55 42.8 15.1 718 C1979M1 C2020 08 28.27631 21 04 11.63 +11 56 02.6 15.4 718 C1979M1 C2020 08 28.27658 21 04 11.64 +11 56 23.4 15.6 718 C1979M1 C2020 08 28.27713 21 04 11.57 +11 57 03.0 15.3 718 C1979M1 C2020 08 28.27741 21 04 11.60 +11 57 23.7 15.8 718 C1979M1 C2020 08 28.27768 21 04 11.56 +11 57 43.7 14.9 718 C1979M1 C2020 08 28.27795 21 04 11.51 +11 58 03.3 15.2 718 C1979M1 C2020 08 28.27823 21 04 11.53 +11 58 24.3 15.9 718 C1979M1 C2020 08 28.27850 21 04 11.51 +11 58 43.6 15.2 718 > Bill From planetaryscience at yahoo.com Fri Aug 28 06:19:18 2020 From: planetaryscience at yahoo.com (Sam Deen) Date: Fri, 28 Aug 2020 10:19:18 +0000 (UTC) Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Message-ID: <1048874906.294929.1598609958531@mail.yahoo.com> More observations, again on the NEOCP: ZTF0ENg* C2020 08 28.27829921 04 54.29 +12 20 28.0 16.03gUNEOCPI41 ZTF0ENg C2020 08 28.27864621 04 54.11 +12 20 52.4 16.03gUNEOCPI41 ZTF0ENg C2020 08 28.27876221 04 53.96 +12 21 03.3 16.19gUNEOCPI41 ZTF0ENg C2020 08 28.27910921 04 53.78 +12 21 28.4 16.19gUNEOCPI41 ZTF0ENg C2020 08 28.27923621 04 53.88 +12 21 36.5 16.15gUNEOCPI41 ZTF0ENg C2020 08 28.27958321 04 53.66 +12 22 01.5 16.15gUNEOCPI41 ZTF0ENg C2020 08 28.33038 21 03 31.89 +13 21 13.1 15.8 GVNEOCPI52 ZTF0ENg C2020 08 28.33051 21 03 31.89 +13 21 21.3 15.1 GVNEOCPI52 ZTF0ENg C2020 08 28.33065 21 03 31.89 +13 21 29.6 15.1 GVNEOCPI52 ZTF0ENg C2020 08 28.33078 21 03 31.89 +13 21 37.9 15.8 GVNEOCPI52 ZTF0ENg AC2020 08 28.36763 21 03 02.82 +13 55 04.4 14.7 GVNEOCPH06 ZTF0ENg AC2020 08 28.36976 21 03 04.68 +13 57 04.5 14.9 GVNEOCPH06 You'd think they'd have learned after two accidental finds just two days ago, wouldn't you? ~Sam On Friday, August 28, 2020, 12:31:43 AM MST, Patrick Wiggins <4099wiggins at gmail.com> wrote: Hi Bill (et al.), I was originally only going to get a few images but it?s so bright I decided to keep imaging until it left the field (I?ll put them in an animation and post to my Facebook page later). Appended below is what I got (and, again, thanks to Masayuki Suzuki for his help). patrick 718 > On 27 Aug 2020, at 22:13, Bill J. Gray wrote: > >? We now have post-perigee data from (Z84) Calar Alto and (K19) PASTIS. > With that,? I'm getting... > > https://projectpluto.com/temp/64054a.htm > >? ...with the ephemerides showing the ground path,? right up to the > predicted re-entry at 20:45 on August 29,? at the south end of > French Polynesia.? So I'm quite confident we'll be able to track > it all the way in to re-entry. > > ? ? ? C1979M1? C2020 08 28.26725 21 04 12.34 +11 44 50.6? ? ? ? ? 15.1? ? ? ? 718 ? ? C1979M1? C2020 08 28.26780 21 04 12.30 +11 45 32.6? ? ? ? ? 15.5? ? ? ? 718 ? ? C1979M1? C2020 08 28.26808 21 04 12.30 +11 45 52.8? ? ? ? ? 15.0? ? ? ? 718 ? ? C1979M1? C2020 08 28.26835 21 04 12.25 +11 46 13.0? ? ? ? ? 15.4? ? ? ? 718 ? ? C1979M1? C2020 08 28.26862 21 04 12.26 +11 46 34.0? ? ? ? ? 15.5? ? ? ? 718 ? ? C1979M1? C2020 08 28.26917 21 04 12.18 +11 47 14.6? ? ? ? ? 15.2? ? ? ? 718 ? ? C1979M1? C2020 08 28.26972 21 04 12.10 +11 47 55.5? ? ? ? ? 15.0? ? ? ? 718 ? ? C1979M1? C2020 08 28.26999 21 04 12.12 +11 48 16.4? ? ? ? ? 15.1? ? ? ? 718 ? ? C1979M1? C2020 08 28.27054 21 04 12.07 +11 48 57.5? ? ? ? ? 15.2? ? ? ? 718 ? ? C1979M1? C2020 08 28.27082 21 04 12.05 +11 49 17.2? ? ? ? ? 15.2? ? ? ? 718 ? ? C1979M1? C2020 08 28.27109 21 04 11.99 +11 49 37.4? ? ? ? ? 15.8? ? ? ? 718 ? ? C1979M1? C2020 08 28.27136 21 04 12.01 +11 49 58.2? ? ? ? ? 15.3? ? ? ? 718 ? ? C1979M1? C2020 08 28.27191 21 04 11.92 +11 50 38.8? ? ? ? ? 15.4? ? ? ? 718 ? ? C1979M1? C2020 08 28.27219 21 04 11.93 +11 51 00.2? ? ? ? ? 15.5? ? ? ? 718 ? ? C1979M1? C2020 08 28.27247 21 04 11.91 +11 51 20.2? ? ? ? ? 15.0? ? ? ? 718 ? ? C1979M1? C2020 08 28.27275 21 04 11.84 +11 51 39.8? ? ? ? ? 15.7? ? ? ? 718 ? ? C1979M1? C2020 08 28.27329 21 04 11.84 +11 52 21.5? ? ? ? ? 15.0? ? ? ? 718 ? ? C1979M1? C2020 08 28.27385 21 04 11.79 +11 53 01.9? ? ? ? ? 15.8? ? ? ? 718 ? ? C1979M1? C2020 08 28.27412 21 04 11.79 +11 53 21.8? ? ? ? ? 15.0? ? ? ? 718 ? ? C1979M1? C2020 08 28.27467 21 04 11.74 +11 54 02.0? ? ? ? ? 15.8? ? ? ? 718 ? ? C1979M1? C2020 08 28.27521 21 04 11.70 +11 54 42.2? ? ? ? ? 15.1? ? ? ? 718 ? ? C1979M1? C2020 08 28.27549 21 04 11.69 +11 55 02.4? ? ? ? ? 15.8? ? ? ? 718 ? ? C1979M1? C2020 08 28.27604 21 04 11.65 +11 55 42.8? ? ? ? ? 15.1? ? ? ? 718 ? ? C1979M1? C2020 08 28.27631 21 04 11.63 +11 56 02.6? ? ? ? ? 15.4? ? ? ? 718 ? ? C1979M1? C2020 08 28.27658 21 04 11.64 +11 56 23.4? ? ? ? ? 15.6? ? ? ? 718 ? ? C1979M1? C2020 08 28.27713 21 04 11.57 +11 57 03.0? ? ? ? ? 15.3? ? ? ? 718 ? ? C1979M1? C2020 08 28.27741 21 04 11.60 +11 57 23.7? ? ? ? ? 15.8? ? ? ? 718 ? ? C1979M1? C2020 08 28.27768 21 04 11.56 +11 57 43.7? ? ? ? ? 14.9? ? ? ? 718 ? ? C1979M1? C2020 08 28.27795 21 04 11.51 +11 58 03.3? ? ? ? ? 15.2? ? ? ? 718 ? ? C1979M1? C2020 08 28.27823 21 04 11.53 +11 58 24.3? ? ? ? ? 15.9? ? ? ? 718 ? ? C1979M1? C2020 08 28.27850 21 04 11.51 +11 58 43.6? ? ? ? ? 15.2? ? ? ? 718 > Bill -- neo_followup mailing list neo_followup at projectpluto.com http://projectpluto.com/mailman/listinfo/neo_followup_projectpluto.com -------------- next part -------------- An HTML attachment was scrubbed... URL: From magnus.ringman at gmail.com Fri Aug 28 06:41:38 2020 From: magnus.ringman at gmail.com (Magnus Ringman) Date: Fri, 28 Aug 2020 12:41:38 +0200 Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Message-ID: Gosh, looks like it might turn into quite a sight. It's going to pass straight over Pape'ete in the interval that it's entering the atmosphere proper. Late morning, 10:43 Tahiti time if I'm doing it right. Accuweather says Pape'ete's weather tomorrow is going to be "mostly sunny". (And satellite-y, as it were?) Ground track image . This is from Bill's ground track as of the below message, and presumably does not include improvements from Masayuki's and Patrick's more recent observations. On Fri, Aug 28, 2020 at 6:13 AM Bill J. Gray wrote: > >> We now have post-perigee data from (Z84) Calar Alto and (K19) PASTIS. >> With that, I'm getting... >> >> https://projectpluto.com/temp/64054a.htm >> >> ...with the ephemerides showing the ground path, right up to the >> predicted re-entry at 20:45 on August 29, at the south end of >> French Polynesia. So I'm quite confident we'll be able to track >> it all the way in to re-entry. >> >> -- Bill >> >> -=-=-=-=-=-=-=-=-=-=-=- >> Groups.io Links: You receive all messages sent to this group. >> >> View/Reply Online (#35788): https://groups.io/g/mpml/message/35788 >> Mute This Topic: https://groups.io/mt/76453944/2194426 >> -=-=- >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> Posts to this list or information found within may be freely used, with >> the stipulation that MPML and the originating author are cited as the >> source of the information. >> -=-=- >> Group Owner: mpml+owner at groups.io >> Unsubscribe: https://groups.io/g/mpml/unsub [magnus.ringman at gmail.com] >> -=-=-=-=-=-=-=-=-=-=-=- >> >> -------------- next part -------------- An HTML attachment was scrubbed... URL: From pluto at projectpluto.com Fri Aug 28 15:23:51 2020 From: pluto at projectpluto.com (Bill Gray) Date: Fri, 28 Aug 2020 15:23:51 -0400 Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <1048874906.294929.1598609958531@mail.yahoo.com> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> <1048874906.294929.1598609958531@mail.yahoo.com> Message-ID: <3738d3ad-ef2f-b4e9-9b42-86f569ad1217@projectpluto.com> Hi Sam, all, On 8/28/20 6:19 AM, Sam Deen via groups.io wrote: > > You'd think they'd have learned after two accidental finds just two days ago, wouldn't you? Well... that's mostly on me, I'm afraid. For the first "find" of OGO-1, I have a decent excuse. We've had pretty good TLEs and lots of data for this object for the last five years. Generally speaking, we've known where it was. But during late August, it had just enough drag to make it difficult to predict. I'd have told you that we just had rough guesses as to where it might be. For all I knew, it might have already re-entered. The data were actually quite good -- thank you, Goran Ga?parovi?! -- but I wasn't too sure how well the theoretical modelling of grazing atmospheric passes would match reality. As it turned out, I was overly pessimistic. The first "find" was within about two degrees of prediction. But that wouldn't really have been close enough to be considered a match, and the object would have ended up on NEOCP anyway. For the second "find" (ZTF0ENg), I don't have such a good alibi. If I'd posted TLEs from before the recent perigee at 27.63 August, with "guessed" AMR=0.03, the object would have been within 7' of prediction. If I'd been quick about posting TLEs after that, we'd be good to arcseconds. So yes, that one did slip by. The TLEs used for this identification are posted to my GitHub site, https://github.com/Bill-Gray/tles with the TLEs for this particular object updated a couple of minutes ago. MPC will pull those changes in a few hours; after that, the object ought to be safe from NEOCP posting. I should note that the tracking of such objects is indeed somewhat "casual". I get observations mostly from amateurs. It's been a hobby for me. Given all that, we've been doing reasonably well. -- Bill From planet4589 at gmail.com Fri Aug 28 15:35:23 2020 From: planet4589 at gmail.com (Jonathan McDowell) Date: Fri, 28 Aug 2020 15:35:23 -0400 Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <3738d3ad-ef2f-b4e9-9b42-86f569ad1217@projectpluto.com> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> <1048874906.294929.1598609958531@mail.yahoo.com> <3738d3ad-ef2f-b4e9-9b42-86f569ad1217@projectpluto.com> Message-ID: Yes, I'd like to reiterate that the community owes a big debt to Bill. The observer community are not in a position to complain when things aren't perfect. (At least not to Bill... it is of course ridiculous that there is no serious funded and long-term-planned effort to do this work.) - Jonathan On Fri, 28 Aug 2020 at 15:24, Bill J. Gray wrote: > Hi Sam, all, > > On 8/28/20 6:19 AM, Sam Deen via groups.io wrote: > > > > You'd think they'd have learned after two accidental finds just two days > ago, wouldn't you? > > Well... that's mostly on me, I'm afraid. > > For the first "find" of OGO-1, I have a decent excuse. We've > had pretty good TLEs and lots of data for this object for the last > five years. Generally speaking, we've known where it was. But > during late August, it had just enough drag to make it difficult > to predict. I'd have told you that we just had rough guesses as > to where it might be. For all I knew, it might have already > re-entered. The data were actually quite good -- thank you, > Goran Ga?parovi?! -- but I wasn't too sure how well the theoretical > modelling of grazing atmospheric passes would match reality. > > As it turned out, I was overly pessimistic. The first > "find" was within about two degrees of prediction. But > that wouldn't really have been close enough to be considered > a match, and the object would have ended up on NEOCP anyway. > > For the second "find" (ZTF0ENg), I don't have such a good > alibi. If I'd posted TLEs from before the recent perigee > at 27.63 August, with "guessed" AMR=0.03, the object would > have been within 7' of prediction. If I'd been quick about > posting TLEs after that, we'd be good to arcseconds. So > yes, that one did slip by. > > The TLEs used for this identification are posted to my > GitHub site, > > https://github.com/Bill-Gray/tles > > with the TLEs for this particular object updated a couple > of minutes ago. MPC will pull those changes in a few hours; > after that, the object ought to be safe from NEOCP posting. > > I should note that the tracking of such objects is indeed > somewhat "casual". I get observations mostly from amateurs. > It's been a hobby for me. Given all that, we've been doing > reasonably well. > > -- Bill > > -=-=-=-=-=-=-=-=-=-=-=- > Groups.io Links: You receive all messages sent to this group. > > View/Reply Online (#35796): https://groups.io/g/mpml/message/35796 > Mute This Topic: https://groups.io/mt/76470696/2702684 > -=-=- > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Posts to this list or information found within may be freely used, with > the stipulation that MPML and the originating author are cited as the > source of the information. > -=-=- > Group Owner: mpml+owner at groups.io > Unsubscribe: https://groups.io/g/mpml/unsub [planet4589 at gmail.com] > -=-=-=-=-=-=-=-=-=-=-=- > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From planetaryscience at yahoo.com Fri Aug 28 16:35:34 2020 From: planetaryscience at yahoo.com (Sam Deen) Date: Fri, 28 Aug 2020 20:35:34 +0000 (UTC) Subject: [neo_followup] {MPML} Improved 1964-054A = OGO-1 data, ephems In-Reply-To: <3738d3ad-ef2f-b4e9-9b42-86f569ad1217@projectpluto.com> References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> <1048874906.294929.1598609958531@mail.yahoo.com> <3738d3ad-ef2f-b4e9-9b42-86f569ad1217@projectpluto.com> Message-ID: <438560888.33207.1598646934804@mail.yahoo.com> Hi Bill, Wow! I knew you were huge contributor to modern asteroid observation, but I didn't know you'd been helping out this much with artsats! Huge kudos to you for taking up the TLE-tracking task. My apologies for being a bit flippant, I had no idea one guy was coordinating it to such a degree... ~Sam On Friday, August 28, 2020, 12:24:01 PM MST, Bill J. Gray wrote: Hi Sam, all, On 8/28/20 6:19 AM, Sam Deen via groups.io wrote: > > You'd think they'd have learned after two accidental finds just two days ago, wouldn't you? ? ? Well... that's mostly on me,? I'm afraid. ? ? For the first "find" of OGO-1,? I have a decent excuse.? We've had pretty good TLEs and lots of data for this object for the last five years.? Generally speaking,? we've known where it was.? But during late August,? it had just enough drag to make it difficult to predict.? I'd have told you that we just had rough guesses as to where it might be.? For all I knew,? it might have already re-entered.? The data were actually quite good -- thank you, Goran Ga?parovi?! -- but I wasn't too sure how well the theoretical modelling of grazing atmospheric passes would match reality. ? ? As it turned out,? I was overly pessimistic.? The first "find" was within about two degrees of prediction.? But that wouldn't really have been close enough to be considered a match,? and the object would have ended up on NEOCP anyway. ? ? For the second "find" (ZTF0ENg),? I don't have such a good alibi.? If I'd posted TLEs from before the recent perigee at 27.63 August,? with "guessed" AMR=0.03,? the object would have been within 7' of prediction.? If I'd been quick about posting TLEs after that,? we'd be good to arcseconds.? So yes,? that one did slip by. ? ? The TLEs used for this identification are posted to my GitHub site, https://github.com/Bill-Gray/tles ? ? with the TLEs for this particular object updated a couple of minutes ago.? MPC will pull those changes in a few hours; after that,? the object ought to be safe from NEOCP posting. ? ? I should note that the tracking of such objects is indeed somewhat "casual".? I get observations mostly from amateurs. It's been a hobby for me.? Given all that,? we've been doing reasonably well. -- Bill -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#35796): https://groups.io/g/mpml/message/35796 Mute This Topic: https://groups.io/mt/76470696/2027585 -=-=- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Posts to this list or information found within may be freely used, with the stipulation that MPML and the originating author are cited as the source of the information. -=-=- Group Owner: mpml+owner at groups.io Unsubscribe: https://groups.io/g/mpml/unsub [planetaryscience at yahoo.com] -=-=-=-=-=-=-=-=-=-=-=- -------------- next part -------------- An HTML attachment was scrubbed... URL: From 4099wiggins at gmail.com Sat Aug 29 06:12:32 2020 From: 4099wiggins at gmail.com (Patrick Wiggins) Date: Sat, 29 Aug 2020 04:12:32 -0600 Subject: [neo_followup] 1964-054A Ephemerides In-Reply-To: References: <506d47bc-6bd4-2bae-af2a-b29643a08877@projectpluto.com> <2155e7ae-adc7-2ae1-505f-4fcae10a5098@projectpluto.com> Message-ID: <3AC753D5-CC30-48F2-A9A0-A8CBCFD3731E@gmail.com> One more set of data before it makes its final plunge. Interesting to see how quickly its brightness changes. It must really be tumbling. And thanks again to Masayuki for showing me where to look. patrick 718 C1979M1 C2020 08 29.32794 22 00 31.67 +29 32 25.4 15.6 718 C1979M1 C2020 08 29.32839 22 00 31.97 +29 32 56.3 15.3 718 C1979M1 C2020 08 29.32883 22 00 32.31 +29 33 27.0 15.2 718 C1979M1 C2020 08 29.32928 22 00 32.65 +29 33 58.9 15.2 718 C1979M1 C2020 08 29.32973 22 00 32.92 +29 34 29.7 15.2 718 C1979M1 C2020 08 29.33017 22 00 33.26 +29 35 00.8 15.3 718 C1979M1 C2020 08 29.33062 22 00 33.58 +29 35 31.4 15.6 718 C1979M1 C2020 08 29.33107 22 00 33.96 +29 36 02.7 15.9 718 C1979M1 C2020 08 29.33151 22 00 34.26 +29 36 34.3 15.4 718 C1979M1 C2020 08 29.33196 22 00 34.59 +29 37 05.2 15.2 718 C1979M1 C2020 08 29.33241 22 00 34.91 +29 37 36.4 15.3 718 C1979M1 C2020 08 29.33286 22 00 35.23 +29 38 07.2 15.2 718 C1979M1 C2020 08 29.33330 22 00 35.57 +29 38 38.1 15.2 718 C1979M1 C2020 08 29.33375 22 00 35.95 +29 39 09.0 15.4 718 C1979M1 C2020 08 29.33420 22 00 36.26 +29 39 40.2 15.8 718 C1979M1 C2020 08 29.33464 22 00 36.61 +29 40 11.0 15.9 718 C1979M1 C2020 08 29.33509 22 00 36.96 +29 40 42.0 15.3 718 C1979M1 C2020 08 29.33554 22 00 37.31 +29 41 13.2 15.3 718 C1979M1 C2020 08 29.33598 22 00 37.69 +29 41 43.9 15.4 718 C1979M1 C2020 08 29.33643 22 00 38.04 +29 42 15.2 15.1 718 C1979M1 C2020 08 29.33688 22 00 38.35 +29 42 45.7 15.2 718 C1979M1 C2020 08 29.33733 22 00 38.69 +29 43 16.8 15.7 718 C1979M1 C2020 08 29.33778 22 00 39.10 +29 43 48.3 15.8 718 C1979M1 C2020 08 29.33822 22 00 39.43 +29 44 20.0 15.1 718 C1979M1 C2020 08 29.33867 22 00 39.87 +29 44 49.2 15.1 718 C1979M1 C2020 08 29.33912 22 00 40.15 +29 45 20.7 15.3 718 C1979M1 C2020 08 29.33956 22 00 40.53 +29 45 51.5 15.2 718 C1979M1 C2020 08 29.34001 22 00 40.88 +29 46 22.1 15.2 718 From pluto at projectpluto.com Sat Aug 29 20:42:47 2020 From: pluto at projectpluto.com (Bill Gray) Date: Sat, 29 Aug 2020 20:42:47 -0400 Subject: [neo_followup] OGO-1 re-entry over Tahiti Message-ID: <0d82d222-dd87-f16a-9140-a07e059ba8c1@projectpluto.com> Hello all, Only video I've seen thus far of the re-entry : https://www.facebook.com/pyfspotters/ (no Facebook account required). -- Bill