Posts

1,000 Teslas, 200 years

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In my previous post, I simulated my best available information on the SpaceX Tesla roadster. In this post, I investigate a range of possible futures for the Tesla. I started with JPL's HORIZONS ephemeris . It turns out that it can evaluate probabilistic orbits; here are its predictions for close planetary encounters by the Tesla given the current uncertainties in its position:           Date (TDB)      Body   CA Dist  MinDist  MaxDist   Vrel  TCA3Sg  Nsigs  P_i/p   ----------------------  -----  -------  -------  -------  ------ ------ ------ -------   A.D. 2020 Oct 07.26668  Mars   .049589  .047961  .052381   8.153  92.21 1.57E5 .000000   A.D. 2035 Apr 22.36925  Mars   .014376  .003802  .055862   8.199 601.42 10658. .000000   A.D. 2047 Jan 11.95105  Earth  .031798...

Initial Evaluation of SpaceX / Tesla Orbital Stability

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Executive summary: its orbit is not very stable. Photo courtesy of SpaceX On February 6, 2018, SpaceX performed its test launch of its new Falcon Heavy rocket. It was a very successful launch. As most people know, the payload was Elon Musk's 2008 Tesla Roadster . After orbiting the Earth for a few hours, the upper stage lit up again and sent the Tesla on a Solar orbit: Musk has famously tweeted that the Tesla will be orbiting for "a billion years." This is extremely unlikely. In fact, it will likely crash into the Sun, or a planet (most likely Earth but perhaps Venus), or be ejected from the Solar System. To try to characterize this, I went to NASA's JPL Horizons web page to get current Cartesian elements for the Tesla (these are vectors of position and velocity). These are the elements as of today, February 10, 2018: 2458159.500000000 = A.D. 2018-Feb-10 00:00:00.0000 TDB  X =-7.690802173107607E-01 Y = 6.236475652855626E-01 Z =-1.393643118679943E-03 ...

Total Lunar Eclipse - Jan 31, 2018

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This morning was a Total Lunar Eclipse. Despite the moon setting during totality, I decided to take a sequence. Here is a collage of photos taken roughly every 10 minutes (I say roughly, since I was dodging clouds the whole time). Taken from the sidewalk in front of our house:  Here is an animated GIF of the sequence: And here is a parting shot of the moon in eclipse setting over Arthur's Rock and The Big A:

Ecuador and Galápagos, 20 Sep - 4 Oct 2017

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This is the story of an epic adventure. These two photos are iconic of our experience: Orca off Isabela Same orca, different perspective This trip was nearly two years in the making. Jill's mom, Marie, started talking about a trip to Ecuador that a mutual friend of ours had made. I mentioned that I had always wanted to see the Galápagos Islands, and it turned out that she has, too. So we embarked on a grand plan. I started by researching various Galápagos tour groups; I found this website describing  Galápagos  trips in 2009 and 2013 particularly helpful. We chose Ecoventura for our tour group; they came highly recommended, have been in operation for a long time, and have a strong commitment to sustainability . I also highly recommend them; they were very helpful preparing for the trip, and the service provided by the crew and guides was top-notch. For a ship, we chose the MV Origin , partly because of its very large windows (hoping that would reduce chances ...

San Cristóbal, Guayaquil, and home, 1-4 Oct 2017

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Still recovering from our bout of gastro, Jill, Marie and I waved goodbye to our fellow passengers as we rested up for a couple more hours: Sofia, crewmember, Leysa, Sarah, John, Mariangela, Pedro, Barb, Cedric, Suzanne, Pete, Panga pilot, Francois When it was time to go, we met everybody at a little cafe in Puerto Baquerizo Moreno. A yellow warbler pretended to be our barista: Yellow Warbler We walked to the bus; on the way, we saw a very large lizard - I think it is what a Lava Lizard looks like if it gets enough to eat: Lava Lizard? At the airport, I took my last wildlife photo on the Galápagos (this trip, anyway): Grasshopper Here are Jill and Marie preparing to board the airplane: Jill and Marie The flight was uneventful; it was cloudy, so I mostly watched the flight map: Flight map We got a taxi to our hotel (back at Parque Historico) and Jill and I did a little more exploring while Marie rested. We saw more hummingbirds: Short-taile...

Santa Cruz (south), 30 Sep 2017

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This day was fun, but was marred by Jill coming down with a gastrointestinal bug (and then later Marie and I both ended up with it). If we had to pick a day to have this happen, this was a good day (no airplanes involved, mostly wildlife that we had seen). Marie and I were not yet experiencing symptoms, so we went on the bus to the highlands. There we saw a variety of Giant Galápagos Tortoises. The first were on the road to our destination: Galápagos Traffic Jam Tortoises on the road Galápagos Tortoise We of course all got out of the bus to look: Sarah, John, Suzanne, Fabricio, Pete, Cedric, Francois, Barb Tortoise stuck in barbed wire John, Francois, Cedric, Fabricio, Sarah, Pete, Marie, Barb, tortoise It was a good thing that we did, because one of the tortoises got its shell snagged by a barbed-wire fence. Our guide Fabricio pulled the strand up so the tortoise could get through. At our destination, we donned boots and wandered ...