1. nickrulercreator

    nickrulercreator New Member

    Ah, I see my mistake. Thank's for this, this is extremely informative
     
  2. Mick West

    Mick West Administrator Staff Member

    The phase diagram for water shows if it wants to be a solid, liquid, or gas for any combination of temperature and pressure. Water starts at one point (say 37°C, 1 bar) for body temperature water at one atmosphere pressure (when it's liquid). Then it goes to essentially zero pressure, and a very low equilibrium temperature (when it's solid)

    To get from from one point to another it has to follow a line. You can see it either goes from liquid to solid, or liquid to vapor to solid, depending on what decreases most rapidly, temperature or pressure.
    Metabunk 2018-02-12 20-05-32.
     
  3. Astro

    Astro Member

    Hey sweet, that's me! I actually over-killed it by going with the 0.7 meter, but I wanted to maximize my chances of detecting it. Yesterday I shot it again with a 0.5 meter scope at the same site when it was over 5 LD away from earth according to the orbit calculations, which included my data from the video as well as observations from other observatories.
    https://projectpluto.com/temp/spacex.htm#eph
    It's at about magnitude 19 right now, which is still within the reach of larger amateur telescopes like this. Unfortunately today it's cloudy at Siding Spring, but here's a short two image gif from yesterday:
    http://h.dropcanvas.com/la9rq/tesla21318.gif
    Get your last shots in now while the getting's good. It won't be coming this close to earth anytime in at least the next 40 years (as far as JPL has projected out so far).

    *Edit to add, there are some important bits of evidence in the orbital elements that validate its identity as the SpaceX second stage, regardless of all the hoax claims. The perigee date and time indicates it was closest to earth at about 9:35 pm eastern time on the 6th of February (2:35 AM on February 7th by universal time which is close to terrestrial time or TT), about 6 hours after the Tesla was launched, right when the final burn to eject it from earth orbit was supposed to be occurring.

    Secondly, the geocentric inclination is about 28 degrees, which just happens to be the latitude of Florida where it launched from. That's not a coincidence though; they launched it from Florida with a heading of about 90 degrees due east, so it should have had an inclination roughly equal to the latitude of the launch site. There may have been a very slight off-plane component in one or more of the burns so it's not exactly centered on LC-39A, but it's significantly less than a degree from that site.

    Lastly, the perigee distance is less than 1000 km from the surface, which would be extraordinarily unusual for a natural object. Combined with the other factors it's clear this was an artificial object launched from earth, and its inclination and departure time perfectly match the SpaceX Falcon Heavy launch.
     
    Last edited: Feb 14, 2018 at 9:22 AM
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  4. Astro

    Astro Member

    One more update, I tracked it again today. It's faint but it's still detectable to the 0.7 meter scope at Siding Spring.
    http://h.dropcanvas.com/9plen/tesla21618.gif
    With this I hope to have enough of my own data to nail down the orbit precisely enough to get very close to the official orbit published by NASA. I plan to use that to trace it back to its departure burn precisely enough to match it up with an Orbiter simulation of the launch and departure and show in a webcast that it's a perfect match for the position and timing of the Second Stage/Tesla. I've been getting a ton of negative comments on youtube from people who don't seem to understand that it's possible to identify it because "it's just a dot." While I can't necessarily expect most people to understand orbital mechanics, I hope to do a webcast this weekend educating them on the fact that it's a perfect match for the trajectory of the second stage and matches the position of the second stage burn witnessed by multiple people as it departed earth orbit around 9:30 eastern time on the day of the launch.
     
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