
Capturing Starman from 1M miles away - wglb
http://www.deepskycolors.com/archivo/2018/02/13/capturing-Starman-from-1-million-miles.html
======
WD-42
We were able to observe it last week from Chile. Animated gif:
[https://twitter.com/ribarides/status/962045432875503621](https://twitter.com/ribarides/status/962045432875503621)

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Fwirt
For those interested in astrophotography, when asked how to get into the
hobby, most astrophotographers will tell you, "don't".

The setup that he's got in the picture is very conservatively $10,000 worth of
equipment. Not to mention the time spent in setup, planning, extensive
postprocessing, etc. Personally, with a day job and living in a city (light
pollution), I find it difficult to get time for visual astronomy, and
astrophotography takes a lot more time and dedication. All that for something
that the big scopes are going to do a lot better.

Not trying to dissuade anyone who's passionate about it. If you're up for the
fun and challenge of it, you'll get some nice results for the rest of us to
enjoy. :)

~~~
otterpro
$10k is too much of a barrier for a hobby? I know amateur musicians who spend
more on guitars than that.

Other examples: * Photographers and youtubers with a Canon 5D Mark3 DSLR with
decent set of lens will cost thousands, and I wish I could afford a Red
cameras that cost $10k-$50k, not including lens.

* I had few car enthusiast friends who spent thousands, more than what they paid on their cars, so they could drag race or so they could race on SCCA tracks.

* My die-hard NFL fan friend, who spends $20k on the season ticket, jerseys, merchandises, and collectibles EVERY year

* my frends who is an audio enthusiast, dropping $50k on home speakers and amps. He's not that wealthy, but that's his priority, I guess.

* My animator friend who spends $10k+ on his PC render farm.

Of course, I don't think you need to spend that much money to enjoy
astrophotography. But it takes a little bit of effort and time, which is the
fun part in a hobby. In high school (in pre-internet days), I built a
Dobsonian telescope from scratch for my science project, except for the
mirror, since I didn't have the skill to grind my own mirror. I still remember
pestering my mom to drive me around the town, looking for a 7 foot long Sono
tube, which looks like a giant cardboard toilet paper roll. We went to every
single Home Depot/hardware stores/construction supply stores within 30 mile
radius of my home, and eventually found one after months of searching.

~~~
brann0
Dude your friends are rich. Period.

~~~
flashman
If you put $20 into your hobby weekly on average, you'll have invested $10k in
a decade. Sounds obvious but I know people who put that much into _coffee_.

~~~
toomanybeersies
It doesn't look like GPs friends have been spending $20 per week on their
hobbies. You don't build a render farm over 10 years.

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obiefernandez
Parallax error prevented him from finding it at first! Didn't know this was a
thing in astronomy.

> "Since the Roadster is still fairly close to us, parallax is significant,
> meaning, different locations on Earth will see Starman at slightly different
> coordinates," Andreo said. "I quickly recalculate, get the new coordinates,
> go to my images, and thanks to the wide field captured by my telescopes...
> boom! There it was! Impossible to miss! It had been right there all along; I
> just never noticed!"

~~~
jjaredsimpson
Not accounting for position on the surface of the earth could introduce as
much as 0.45 degrees of error in the apparent position for an object 500000
miles away. This is same as the apparent diameter of the moon for a reference.

~~~
schiffern
Cool.

By symmetry, right now from Starman's perspective the Earth appears as large
as [we see] the Moon.

~~~
jjaredsimpson
Twice as large. The angle was subtending the radius of the Earth not the
diameter.

~~~
schiffern
It all depends on whether the software defaults to some observing location on
the Earth's surface (eg the Royal Observatory), or to the center of the Earth.
I was making a conservative assumption that it could do either one (having
seen both behaviors in different astronomical software), but your argument is
only correct if it's the latter.

~~~
jjaredsimpson
It does default to center of Earth. However even if the default wasn't center
of the Earth, that couldn't alter the apparent size of the Earth from the
perspective of the Roadster. It would've altered the parallax.

~~~
schiffern
>It does default to center of Earth.

Thank you! This is the first I've heard either way.

I do hope you can overcome the curse of knowledge[1] to see how the original
post was ambiguous without that information. I simply had to _know_
a-posteriori that the software worked like that (I didn't, the manual[2]
offered no clues, and I hadn't yet re-done the calculation).

>However even if the default wasn't center of the Earth, that couldn't alter
the apparent size of the Earth from the perspective of the Roadster.

I know the software doesn't rearrange the sky, but my hope is that you can
understand how I arrived at that particular off-by-a-factor-of-two error[3]
(oddly, by assuming _less_ than I should have).

[1]
[https://en.wikipedia.org/wiki/Curse_of_knowledge](https://en.wikipedia.org/wiki/Curse_of_knowledge)

[2]
[http://www.ruf.rice.edu/~ruco/manuals/TheSky6Manual.pdf](http://www.ruf.rice.edu/~ruco/manuals/TheSky6Manual.pdf)

[3]
[https://news.ycombinator.com/item?id=16384844](https://news.ycombinator.com/item?id=16384844)

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cyberferret
Given its elliptical orbit, when is the next time the vehicle will be close
enough to earth so that it can be observed with hobby telescopes etc.? I can
imagine in the years/decades to come, this will become as significant as
seeing Halley's comet returning etc.? It will also be interesting to see how
the car holds up to the rigours of space (effect of sunlight and the extreme
cold on the paintwork, rubber tyres etc.)

~~~
svantana
Halley's comet is ~11 km in diameter, which makes it visible to the naked eye
when it's close enough. Potentially astronomers will be able to spot this car
at some point in the future, but I doubt that will give the same wow factor to
the average joe.

~~~
zaroth
Elon’s just gonna have to go bigger next time.

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mixedmath
I looked through this site, and I wanted to note (so that others don't make
the same quick mistake that I made) that his online gallery is visible after
clicking on "Buy Prints" (and not by clicking on "The Gallery", which is about
his physical gallery). His photos are very impressive.

------
tonyedgecombe
_I headed to a semi-dark site not far from home (I live in Sunnyvale,
California) for which I have a night permit - Montebello OSP._

You need a permit to take pictures of the sky?

~~~
M_Bakhtiari
Land of the free.

~~~
isostatic
Free to observe the night sky without someone else trampling on that freedom

~~~
M_Bakhtiari
As long as you have a night sky observation permit.

The United States has serious problems with bean counter overreach:
[https://www.washingtonpost.com/news/morning-
mix/wp/2017/12/0...](https://www.washingtonpost.com/news/morning-
mix/wp/2017/12/08/criticizing-red-light-cameras-is-not-a-punishable-offense-
oregon-concedes/?utm_term=.28a5dee72b95)

Meanwhile the conservative politicians keep talking incessantly about
deregulation, but it seems like it only applies to specific regulations that
are inconvenient to friends of their, instead of actually attacking the deep
cultural problem American society has with bureaucratic overreach. For
goodness sake, a lot of actual dictatorships will meddle less in your personal
business than the United States.

~~~
haZard_OS
Would you mind naming 2 of those dictatorships and perhaps explain what metric
you used to arrive at your conclusion?

------
sxcurry
Rogelio is very well known in the Astrophotography community - he's one of the
best.

------
wiradikusuma
Sorry for the stupid question (I wasn't following this event): so it's a
_real_ car? inside an aircraft (which i imagine the inside is like military
cargo ship as seen in movies)?

~~~
mapt
The first few launches of a new vehicle are risky. Even some of the most
mature launch platforms still fail 2-10% of the time after hundreds of
launches, but a new platform needs a period to discover all the failure modes
that they didn't hypothesize. Usually for the very first proving launch,
commercial customers don't want to send anything, and insurers refuse to touch
them.

So launch providers typically send a block of concrete, or something similar,
and call it a 'Mass Simulator', to prove that the launch vehicle can function
with a load that heavy.

Elon Musk literally thought 'Hey, the Tesla Roadster I've been driving would
be a cool thing to send into space as a mass simulator.' And so he did. With a
mannequin inside a production Tesla spacesuit. Blaring David Bowie the whole
way. Aiming roughly at Mars and burning until the propellant runs out.

Starman will be in heliocentric orbit indefinitely.

~~~
swyx
ok and more stupid questions please:

\- the proving launch mass is only the mass of a Tesla? i mean thats great but
i would have expected a much bigger mass for a fully functional satellite. but
then again I dont know anything about satellites. how big are those? its
definitely not space shuttle big. is the Falcon Heavy able to carry something
as big as the space shuttle?

\- i thought starman was orbiting mars. how does orbital decay look for
something small like starman since it really can just get pulled in or out by
basically any nearby planet?

~~~
pas
> i mean thats great but i would have expected a much bigger mass for a fully
> functional satellite.

Iridium sats are 700kg each, GEOsats are also less than that.

The upcoming James Webb Space Telescope's launch/payload mass is 6 200 kg.

The Falcon Heavy can push 1 400 000 kg, and 16 800 kg of that can be payload.
To Mars.

~~~
JshWright
Geostationary satellites are way more than 700kg. Most are >5,000kg.

~~~
adventured
5,000 kg is the higher end. They are typically way more than 700 kg as you
note.

[https://en.wikipedia.org/wiki/List_of_satellites_in_geosynch...](https://en.wikipedia.org/wiki/List_of_satellites_in_geosynchronous_orbit)

Echostar 1: 3,287 kg

Americom 7: 1,983 kg

Yamal 300k: 1,870 kg

Ciel-2: 5,561 kg

Horizons-1: 4,060 kg

EchoStar X: 4,333 kg

Amos 2: 1,370 kg

NSS-7: 4,692 kg

Star One B4: 2,495 kg

~~~
JshWright
Yeah, 5,000 was a typo (meant 4,000, but even that it is a little high, I
suppose)

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cglace
If I were to intercept the vehicle in space and bring it back to Earth. Who is
the owner? Did Elon abondon the vehicle by sending it to space?

~~~
craftyguy
I'd guess that technically Elon still owns it. The same could be said for
anything fired off into space (e.g. satellites in orbit, landers, etc), that
the ownership is maintained until it (or the owner) is destroyed, or the owner
says "this isn't mine anymore".

You ask an important question, and if it has no clear internationally agreed
upon answer then it'll probably need one as nations and companies fire stuff
off into space.

~~~
fnord77
marine salvage rules might apply...

which means the ownership is not maintained.

~~~
craftyguy
How though? Don't marine salvage rules depend on the original owner no longer
being in control of the object (i.e. it's in 'peril')? If that's not the case,
then it seems like anyone with the resources could go pick up the Curosity
rover, or snatch up the Hubble.

~~~
fnord77
hubble is being controlled - by its gyros. Curiosity is still under its own
power.

there might be special rules for things that aren't specifically craft - like
observation equipment.

------
mirimir
Sending a Roadster past Mars is very cool. But I wonder how the interior trim
will stand up to prolonged vacuum, solar heating, etc. Probably not so well,
right?

------
eevilspock
Seems such a waste. Launches are expensive. There isn't something useful to
put into heliocentric orbit for which the higher risk of a new rocket is worth
the tradeoff for a free launch?

~~~
throwaway5752
I upvoted you because it's a good point, but consider it was the first launch
ever of this rocket so presumably people were reluctant to put important and
expensive payloads on it.

~~~
ars
Why not just a huge tub of water? And just leave it space in case someone
needs it.

Float it near the ISS as extra shielding from Solar Flares maybe.

~~~
throwaway5752
Wouldn't that be heavier by volume, have less mechanical resiliency by volume
(no internal rigidity), and have more complicated physics (free flowing,
capable of convection/rotation)? Maybe a big block of water ice... but
honesty, seems to to have pretty limited utility. If long distance space
exploration relies on lifting water vs harvesting it, then it's kind of a
nonstarter?

------
VMG
resource is much better than the submission that went to space.com

~~~
dang
That was
[https://news.ycombinator.com/item?id=16382594](https://news.ycombinator.com/item?id=16382594),
and we've moved most comments from that thread hither.

------
Fwirt
Since this is a better source than the space.com article, I'll repeat this
here:

For those interested in astrophotography, when asked how to get into the
hobby, most astrophotographers will tell you, "don't".

The setup that he's got in the picture is _very_ conservatively $10,000 worth
of equipment. Not to mention the time spent in setup, planning, extensive
postprocessing, etc. Personally, with a day job and living in a city (light
pollution), I find it difficult enough to get time for visual astronomy, and
astrophotography takes a lot more time and dedication. All that for something
that the big scopes are going to do a lot better.

Not trying to dissuade anyone who's passionate about it. If you're up for the
fun and challenge of it, you'll get some nice results for the rest of us to
enjoy. :)

~~~
dang
> I'll repeat this here

Please don't do that. It makes merging threads a real pain because then we
have to worry about duplicate comments and who replied to which. For example,
I've moved the replies to this one to the other one.

Also, HN is not a place for copy-pasting. On a site dedicated to intellectual
curiosity, repetition is the enemy.

------
makmanalp
Perhaps "Capturing Starman from 1 million miles away" is a better title?

~~~
dang
Yes. Fixed now.

------
nategri
First read "Capturing Stallman from 1M miles away" and had a good laugh

