<div>                Hi Bill,<br><br>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...<br><br>~Sam            </div>            <div class="yahoo_quoted" style="margin:10px 0px 0px 0.8ex;border-left:1px solid #ccc;padding-left:1ex;">                        <div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">                                <div>                    On Friday, August 28, 2020, 12:24:01 PM MST, Bill J. Gray <pluto@projectpluto.com> wrote:                </div>                <div><br></div>                <div><br></div>                <div><div dir="ltr">Hi Sam, all,<br clear="none"><br clear="none">On 8/28/20 6:19 AM, Sam Deen via groups.io wrote:<br clear="none">> <br clear="none">> You'd think they'd have learned after two accidental finds just two days ago, wouldn't you?<br clear="none"><br clear="none">    Well... that's mostly on me,  I'm afraid.<br clear="none"><br clear="none">    For the first "find" of OGO-1,  I have a decent excuse.  We've<br clear="none">had pretty good TLEs and lots of data for this object for the last<br clear="none">five years.  Generally speaking,  we've known where it was.  But<br clear="none">during late August,  it had just enough drag to make it difficult<br clear="none">to predict.  I'd have told you that we just had rough guesses as<br clear="none">to where it might be.  For all I knew,  it might have already<br clear="none">re-entered.  The data were actually quite good -- thank you,<br clear="none">Goran Gašparović! -- but I wasn't too sure how well the theoretical<br clear="none">modelling of grazing atmospheric passes would match reality.<br clear="none"><br clear="none">    As it turned out,  I was overly pessimistic.  The first<br clear="none">"find" was within about two degrees of prediction.  But<br clear="none">that wouldn't really have been close enough to be considered<br clear="none">a match,  and the object would have ended up on NEOCP anyway.<br clear="none"><br clear="none">    For the second "find" (ZTF0ENg),  I don't have such a good<br clear="none">alibi.  If I'd posted TLEs from before the recent perigee<br clear="none">at 27.63 August,  with "guessed" AMR=0.03,  the object would<br clear="none">have been within 7' of prediction.  If I'd been quick about<br clear="none">posting TLEs after that,  we'd be good to arcseconds.  So<br clear="none">yes,  that one did slip by.<br clear="none"><br clear="none">    The TLEs used for this identification are posted to my<br clear="none">GitHub site,<br clear="none"><br clear="none"><a shape="rect" href="https://github.com/Bill-Gray/tles" target="_blank">https://github.com/Bill-Gray/tles</a><br clear="none"><br clear="none">    with the TLEs for this particular object updated a couple<br clear="none">of minutes ago.  MPC will pull those changes in a few hours;<br clear="none">after that,  the object ought to be safe from NEOCP posting.<br clear="none"><br clear="none">    I should note that the tracking of such objects is indeed<br clear="none">somewhat "casual".  I get observations mostly from amateurs.<br clear="none">It's been a hobby for me.  Given all that,  we've been doing<br clear="none">reasonably well.<div class="yqt8721175409" id="yqtfd78905"><br clear="none"><br clear="none">-- Bill</div><br clear="none"><br clear="none">-=-=-=-=-=-=-=-=-=-=-=-<br clear="none">Groups.io Links: You receive all messages sent to this group.<br clear="none"><br clear="none">View/Reply Online (#35796): <a shape="rect" href="https://groups.io/g/mpml/message/35796" target="_blank">https://groups.io/g/mpml/message/35796</a><br clear="none">Mute This Topic: <a shape="rect" href="https://groups.io/mt/76470696/2027585" target="_blank">https://groups.io/mt/76470696/2027585</a><br clear="none">-=-=-<br clear="none">~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br clear="none"><br clear="none">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.<br clear="none">-=-=-<br clear="none">Group Owner: mpml+<a shape="rect" ymailto="mailto:owner@groups.io" href="mailto:owner@groups.io">owner@groups.io</a><br clear="none">Unsubscribe: <a shape="rect" href="https://groups.io/g/mpml/unsub " target="_blank">https://groups.io/g/mpml/unsub </a> [<a shape="rect" ymailto="mailto:planetaryscience@yahoo.com" href="mailto:planetaryscience@yahoo.com">planetaryscience@yahoo.com</a><div class="yqt8721175409" id="yqtfd74200">]<br clear="none">-=-=-=-=-=-=-=-=-=-=-=-<br clear="none"><br clear="none"></div></div></div>            </div>                </div>