[2018-02-07] NEW DATA CAME THROUGH - CHECK THIS UPDATE INSTEAD
In this page, I will post my best estimate of Starman’s whereabouts. I will update the page as I gain access to additional and more accurate information.
Space is big. It is also full of forces, big and small, acting over extended periods. Without access to the precise orbital estimates calculated by SpaceX, my results are bound to be extremely innacurate. How innacurate? Well, consider them useless for any purpose, except, perhaps, for entertainment.
You will notice that my calculations carry many decimals digits. This is intentional, and meant to make it easier for others to compare their calculations against mine. It should not be made to imply that my results carry that many significant figures.
In the following calculations, I take the Astronomical Unit as
the gravitational parameter of the Sun as provided in DE430, JPL’s latest Planetary Ephemerides,
and the known orbital parameters as provided in Elon Musk’s tweet (the tweet’s image is shown below)
When is Starman coming back?
From the information available as of this writing, we can readily approximate Starman’s heliocentric eccentricity
or \(268528177.9065\) km, and heliocentric orbital period,
equivalent to \(878.40562107150913\) days, or \(2.4049435210718935\) years (I take a year as \(365.25\) days).
Elon’s tweet was sent on February 06th, 2018 at 07:46:00 PM (PST). Adding the orbital period, we determine that Starman would reach periapsis on July 4th, 2020 at 05:30:05 AM (PST).
Before you prepare to celebrate Starman’s arrival, keep in mind that (1) the calculations are innacurate, (2) periapsis means the orbital point closest to the Sun, as opposed to Earth encounter. In fact, even if the calculations were perfect, Earth would not be at the orbital location of Starman’s periapsis on that date.
Can Starman Hit Us?
I have very limited data to perform reliable calculations, but my money is on Starman staying safely away from us for the foreseable future (as in, you’ll be a fossil before he returns, if he ever does. And even if he does, his Trusty Tesla Roadster does not care for fossils, so he’ll most likely ignore you). If you are still uneasy, consider that you can save a bundle by switching to Geico.