# When was the last time that Starman/Roadster was seen?

Starman/Roadster (2018-017A, 43205) is a Falcon 9 2nd stage with a red sports car attached, in a heliocentric orbit in deep space.

It was tracked by telescopes for several weeks at least after launch and boost from LEO to it's orbit around the Sun.

You can see one of those telescope images of Roadster in deep space in the question Where might astrometric observations of the Roadster spacecraft be catalogued?.

Question: When was the last time that Roadster was seen, before it became to dim to observe?

Don't forget to include a verifiable source for the date!

@uhoh's answers are correct in that we at LCO were the last to observe the Tesla Roadster. For some reason, a Distant Artificial Satellites Observation (DASO) circular was not issued in the March 2018 lunation with our data from MPC site code K93 or with the data from the ESA Optical Ground Station in Tenerife (J04) but the data at Bill Gray's Project Pluto site (pseudo MPEC link) are correct as he was CC'd on the reported observations. I have contacted the MPC and the "missing" data will get published in a DASO the next time there are enough observations of other things to issue one.

The observations are in the old standard MPC1992 observation format so the (decimal) date of the middle of the stack of CCD images (hence the KC) is columns 16-32 which translates to 2018-03-19 03:22:33 UTC. JPL computes orbits based on the data reported to the Minor Planet Center so the fact there isn't a Solution #11 means that no new data and observations of the Tesla Roadster have been reported. It was at the limits of what we could do with our 1-meter telescopes at the time and it's doubtful anyone would have pointed bigger glass at what was in the end, a publicity stunt.

The telescope with the MPC site code K93 is the southern-most of the three 1-m telescopes LCO installed at the SAAO in early 2013; they are shown in this captured Google Street View from Jan 2017 (K93/Dome C is the central telescope in that view) but not in the earlier one above (since that was before our telescopes showed up). As commented above, in this image from the south end of the plateau looking North to the SALT telescope (center of the picture) the LCO 1m telescopes are the white domes at the front, left of center. We've added telescopes and a spectrograph (in a shipping container) since that picture and the Street View images were taken.

• Wow thanks for the thorough and informative answer, and welcome (again) to space! We can say that one of these three is it? i.stack.imgur.com/CnV3I.png I grabbed a screen shot since google could change things over time.
– uhoh
Oct 29 '18 at 17:52
• Thanks also for digging in to the data and figuring out the source of the discrepancy. While it was a publicity stunt, now that the F9 first stage is in this orbit I think there may be at least some useful information coming from the continued, and hopefully in a year or two, continuing observations. Maybe not planetary science, but there could be something interesting to people who worry about the dynamics of artificial bodies over long periods of time.
– uhoh
Oct 29 '18 at 17:57
• In principle since we know exactly what size it is and what it's made out of, it could be a calibrator for models of solar radiation pressure/Yarkovsky drift or YORP spin-up/down although I don't know of anyone planning to do it. Depends on whether the upper stage is still attached and whether any venting occurred. Oct 29 '18 at 18:04
• @uhoh Dome C (K93) is the Southmost dome furthest from the road and the central one in the image you have (Longitude 020 48 36.39 E, Latitude 32 22 50.38 S) Oct 30 '18 at 16:56
• Thank you for tracking that last detail down! Apparently yours is now the accepted answer ;-) Would you like to just include that here as well? You've already got the time listed here, so it's complete.
– uhoh
Oct 30 '18 at 17:37

The latest measurements used by JPL Horizons to calculate its trajectory were reported on 3/27 as follows:

2018-Mar-27: Two reporting sites (J94 & K93) extend data arc one month.

That is the last update that is included on the site, and thus seems likely to be the last update.

Looking at the two mentioned observatories, neither of them has a public log of when they actually recorded the observation, but from the context, specifically "extend data arc one month", I believe it was within a few days of March 27.

• Last sentence: "Don't forget to include a verifiable source for the date!" Where/how can we the block quote? Where is it quoted from?
– uhoh
Aug 7 '18 at 0:04
• First sentence "used by Horizons". I added a link and JPL, but... Aug 7 '18 at 0:05
• The notation was made on 27-Mar-2018 because that is the date that solution #10 was generated. There's no reason to assume that those to measurements were made on the same day. So there's no way to know if this answer is right or wrong. Thus the last sentence: "Don't forget to include a verifiable source for the date!"
– uhoh
Aug 7 '18 at 0:11
• The statement indicates extending the data arc one month. The date might be off a day or two, but isn't likely off by much more then that. Aug 7 '18 at 0:21
• i.stack.imgur.com/JWIbn.png
– uhoh
Aug 7 '18 at 4:54

Using the information from this answer the last actual documented sighting of Roadster (2018-017A) that I can find is given in DASO circular 0567 on 2018/02/22.35017

Last observation that I can find documented is 22-Feb-2018.

While the other answer shows displays the date of an orbit solution, and in comments tries to link that to an estimated observation date, without any explanation of that, nor why it should be considered the last time Roadster was seen, at least my answer is sourced, which was stipulated in the original question for precisely this reason.

However, there is an explicit statement in Solution #10 of JPL's Horizons ephemeris for Roadster:

TRAJECTORY:
This trajectory is based on JPL solution #10, a fit to 364 ground-based
optical astrometric measurements spanning 2018 Feb 8.2 to March 19.1


Last observation that I can find mentioned but haven't found any documentation of is 19-Mar-2018.

So there should be a documented sighting around 2AM 19-Mar-2018 UTC reported somewhere! That doesn't mean it's the last, any observation after 27-Mar-2018 would not be documented in Solution #10, so this is not a good source for the answer. The dimming rate is slow enough that further observations are possible, just less likely.

Screen shots (click for full size):

The last documented observation of Roadster was made in Elon Musk's country of origin South Africa by "Observers T. Lister, J. Chatelain, S. Greenstreet, E. Gomez." and it's position was determined by "Measurer T. Lister." using a "1.0-m f/8 Ritchey-Chrétien + CCD." which is one of the Las Cumbres Observatory's telescopes located at the South African Astronomical Observatory at Sutherland (SAOO/Sutherland).

(K93) Sutherland-LCOGT C (S32.380670 E20.810110) South Africa. Observers T. Lister, J. Chatelain, S. Greenstreet, E. Gomez. Measurer T. Lister. 1.0-m f/8 Ritchey-Chrétien + CCD.

The observations used to produce Solution #10 for Roadster, which is the solution used to generate the ephemeris for Roadster in Horizons can be currently found in

The last line is

2018-017A KC2018 03 19.14066614 21 58.09 -24 51 55.9 21.7 GU K93

which is about 2018-Mar-19 03:23 UTif I understand correctly.

Thanks to Senior Analyst Jon Giorgini of NASA/JPL's Solar System Dynamics Group for assistance tracking this down!

• AFAIK we were the last people to track (and report) positions for the Tesla Roadster (2018-017A) and these did indeed come from the 1-m telescopes at South Africa. Your location for the LCO(GT) telescopes is correct but the image in the middle is not; the capture date is three years before we installed telescopes. In this image the LCO 1m telescopes are the white domes at the front, left of center. Oct 29 '18 at 16:15
• @astrosnapper Wow thank you very much for the correction! If you feel so inlined, you are welcome to just go right ahead and edit my answer, or better yet post a supplemental answer with this and any other information about "the last sighting of Roadster". Welcome to Space!
– uhoh
Oct 29 '18 at 16:23