Photo captures space station crossing the moon | Hacker News Reader

Photo captures space station crossing the moon

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209 pointsmonkeydust61 comments

Thierry Legault does some of the best solar system astrophotography I'm aware of (or at least the stuff I'm most interested in). Many amazing images of ISS and other spacecraft, images of the surface of the sun, lunar images, lunar occultation of other planets, etc etc. This is just another example of his excellent work.

More examples here: http://www.astrophoto.fr/

Edit: That said there are some amazing amateur astrophotographers quietly going about their art. https://astrobin.com is their Flickr.

Thanks for mentioning the site. I just checked his HR Moon. Incredible.

Thank you for pointing this out. After reading the opening line of "Thierry Legault pointed his camera up at the night sky..." I thought to myself "Man, that must be some camera." Turns out he very much does this professionally and a telescope is also involved.

Some details on his equipment here: http://www.astrophoto.fr/info.html. For reference, the first tube and mount he lists:

Celestron C14 Edge HD - The telescope 'tube' alone (aka OTA) ~$8k USD

Takahashi EM400 - Equatorial mount, ~$9kUSD

This doesn't include any additional optics, filters, cameras, etc.

Solar imaging is technically challenging and gets ridiculously expensive very quickly because of the contrast benefits of extremely narrowband filtering. He references using a Takahashi FSQ-106 (~$7k), Coronado double stack (also ~$7k) and a .5 angstrom Daystar filter (~$4k).

Massive massive investment in equipment. Hard to say if he has everything he lists but easily $100k total, probably closer to $200k. I would hazard that if you tried to start today, you couldn't find any of the above in stock. You're going to be scrounging the used market (which is fortunately quite active) and/or waiting 2-3 years for order fulfillment. I started into this hobby last fall and it is quite frustrating just getting your hands on what you want.

Alternatively, you could use a $2000 - $4000 (used price) C14 telescope on a $4000 AP900 (used price) mount, with a $1000 planetary camera. Still a chunk of change.

The only thing you can't buy used is the apparently killer atmospheric conditions he enjoys wherever he shoots.

Totally agree. I've got the CPC1100 version of the C11 sitting behind me that I bought minus the tripod through an Amazon pallet liquidation. Had to buy the tripod for a total outlay of ~$2k for basically a new scope.

I can easily get Tycho in that same field of view, but the contrast is going to suck and relative clarity be pretty laughable. The fun part is there's a lot to learn, the sucky part is there's a lot to learn :)

The photo is amazing. This one from the same author, with a Solar crossing and the Shuttle Atlantis getting close to the ISS, is stunning...

http://www.astrophoto.fr/iss_atlantis_2010.jpg

"ISS distance to observer: 391 km. Speed in orbit: 7.4km/s (26500 km/h or 16500 mph)."

In a similar vein, a high-res ISS image by Alessandro Bianconi showing a damaged radiator:

https://www.astrobin.com/375799/?nc=all

(Taken with a 14" telescope. Good "astronomical seeing" conditions and necessary post-processing notwithstanding, the smallest resolvable details depend linearly on telescope's aperture (i.e., the primary optical element's diameter).)

EDIT: I also like this animation a lot, ISS crossing the sky (9.25" telescope):

https://astropolis.pl/topic/79691-przelot-iss-z-ogniskowej-2...

I read the title and was surprised to find the article isn't about AJamesMcCarthy - he has an amazing ISS-moon transit picture from a few months back.

Turns out he (of course) saw this one, and thinks it's better than his own: https://twitter.com/AJamesMcCarthy/status/149619122880292454...

Huge fan of him as well. Extremely creative, eg. this exaggerated height image of the moon - https://www.instagram.com/p/CVvktGkP8sL/

Link to the original tweet by the photographer:

https://twitter.com/ThierryLegault/status/149514029055385600...

(alternatively https://nitter.net/thierrylegault/status/1495140290553856001)

If anyone would like to buy the print: https://www.galleryastro.fr/-/galleries/auteurs/thierry-lega...

Just ordered one for my kids!

If anyone wants a regular dose of astrophotography see Astronomy Picture of the Day:

* https://apod.nasa.gov/apod/astropix.html

An RSS feed is available.

Jaw-dropping is an understatement -- that's a stunning composition. How did he convince the moon and space station to perfectly pose together and the sun to light them so sharply like that?

I've never seen a photo that reveals the roughness of the moon in profile like the high contrast craters and mountains along the edge.

> How did he convince the moon and space station to perfectly pose together

The negotiations were tense, but in the end, the Space Station agreed to stop calling the Moon "crater face," and the Moon agreed to stop talking about Flat Earth Theory.

That is indeed a stunning photo. Especially considering that the ISS orbits at around 400km and the moon at ~380,000km. It looks like it would be in a dangerously low orbit around the moon.

Yeah, it all looks kinda Little Prince-esque.

The "Tiny Planet" / "Little Planet" effect!

https://wiki.panotools.org/Unusual_remappings

>Little planet

>Fisheye little planet remapping result © Erik Krause

>Stereographic little planet remapping result © Erik Krause This is a remapping already used by Helmut Dersch as a thumbnail for his virtual Marburg tour on [2], where he remapped an equirectangular full spherical panorama to a 360 degree fisheye image with the nadir in the center and the zenith at the circle border. This is the same projection as used in the first example.

>Nowadays most GUI front-ends feature stereographic and fisheye output projection directly. Stereographic is far better for Little Planets since the outer regions are less compressed and hence keep their natural proportions. The stereographic example here has a smaller Field of View (250°) although the apparent size of the planet is approximately the same like the fisheye one.

>Some Panorama Viewers like f.e. KRPano or DevalVR also feature stereographic projection or even "Little Planet" directly.

How to create high resolution (hi-res) "Tiny Planet" images with your drone and DJI Go 4

https://www.youtube.com/watch?v=tATZmiKKaMw

Dyson Sphere Project seems to distort and exaggerate the field of view to produce that same effect. Or maybe it's just that its planets are actually tiny! But you feel quite gigantic walking around them.

GIANT ROBOT; SMALL PLANET | #1 | Dyson Sphere Program | Lets Play/Guide/Walkthrough:

https://www.youtube.com/watch?v=9tTU97bAMM4&t=2m28s

Another interesting perspective:

What If The Moon Were As Close As The ISS? (VIDEO)

https://www.huffpost.com/entry/moon-as-close-as-iss-video_n_...

The nice green field, blue sky, and fluffy clouds in the video would probably be a smoking bubbling magma hell-scape thanks to the intense tidal forces, though.

>> "I did it, so it can be done," Legault replied. "Anyway, will a million dollar racket will (sic) make you defeat Federer or Nadal?"

My wife is a not-bad-for-an-amateur photographer of family events etc and any time she takes a good photo people ask "What camera did you use?"

I wonder if people used to go up to Shakespeare and say "Great play. What quill did you use?" Not that I'm comparing my wife to Shakespeare, but I could thrash around with an expensive DSLR for ages and not get a photo as good as a pro with an iphone 7. It's not the camera that makes a good photo.

I had the reverse experience... I borrowed a friends super fancy camera, and used it on all the 'auto' modes, and it gave amazing results, despite me having no real photography skill.

The camera will make the picture bright, in focus etc but it won't help you with composition and capturing the right moment.

Oh but it does... The 'burst' ability lets me take 50 photos in a few seconds and choose the best. And the high res sensor lets me crop afterwards to get much improved composition. No skill required.

And knowing how to crop the shot for the best composition?

I would like to know the camera too, because he takes the shot at 1/6000. What kind of camera lets in enough light at that shutter speed in the night sky to get that kind of photo at an apparently-low ISO (not a lot of grain apparent in the photo)?

The moon is bright. It's directly lit by the sun.

Probably using a ZWO ASI camera. He has used the 183 pro in the past I know.

Moon is bright, and the telescope has a much larger aperture than your typical camera lens.

No grain; he's using a digital sensor, not silver nitrate emulsion.

In terms of technical difficulty and required equipment, there is a significant difference between "family events" and astrophotography.

Well yes, but you could give me his cameras and I would still fuck it up.

Nice thing about the moon and ISS is that there are lots of opportunities to photograph them. To get an actual transit like that you may have to travel some distance or wait a long time: https://transit-finder.com/

Obligatory "here is the moon photo I took two days ago": https://litter.catbox.moe/5zj2s5.jpg

Anyone know what are the chances of this happening again in the future? Except the "take the photo" part. I'm talking about: - it's night - clear sky - right geo coordinates - ISS passing between the moon and said right geo coordinates

Just thinking of these and then add on top that you have 0.5s to take the photo. This was truly a "right moment, right place, right person" kind of thing.

There is a lot of occasions for observations if you are into it.

This photo is not a happy accident, though. It took careful preparation.

Let's see... it looks that at a distance of 400km we can see features of size roughly 1m (or even better). This points to resolution of 0.01 arcsecond which is fenomenal for an amateur setup.

That's not quite right. 1 meter at 400 km distance is ~0.51 arcseconds, which is on the edge of doable with good seeing. 0.01 arcseconds would never be possible within the atmosphere.

The most depressing statistic here (for me anyway) is that to directly image the nearest exoplanet at 1km per pixel we're going to need a telescope with ~.000000005 arcseconds of resolution.

Someone check my math but that would be like imaging the ISS at the nanometer scale from the surface of the earth.

Now compute what kind of virtual aperture size it takes to get this resolution without being diffraction limited.

Edit: I did it, about 25000km (for light with a wavelength of 500nm), or twice the radius of the earth. That actually suggests it could be doable with a constellation of telescopes in high orbit.

Or a gigantic obstruction: https://www.nasa.gov/content/the-aragoscope-ultra-high-resol...

Sadly the occulder has to be smooth at sub wavelength scales, or solar system bodies could be used.

I couldn't find a quick summary to this question. But what size aragascope do you need to achieve the equivalent of an x meter aperture?

My gut says probably the same size, but the claims suggest the aragascope can actually be smaller. My gut can also imagine it depends on the distance between the aragascope and the telescope.

The synopsis on the site suggests the same size as the disk. But I guess it doesn't say it scales the same as with mirror size.

> can be used to achieve the diffraction limit based on the size of the low cost disk, rather than the high cost telescope mirror

> the claims suggest the aragascope can actually be smaller.

This may be because of the shape of the PSF is different from the normal airy disk one.

Here is a random google result showing the spot of arago, https://www.lighttrans.com/use-cases/application/observation... -- which looks to me like it would have poor contrast but good resolution. Though I'm out of my depth so it could be nonsense. :P

Edit: Ah, yeah the graph at figure 9 in the report linked on the linked page shows something like that.

Believe or not, that project is already underway and will use our Sun as a gravitational lens.

https://en.wikipedia.org/wiki/Solar_gravitational_lens

I predict in couple decades we will learn to build swarms of drone craft that we will send to the right location and they will be able to image nearby planets (one per swarm...) with at least ~10-40km per pixel if not better.

“Underway “ is a little strong. Putting something at 500 AU is still not really feasible within a reasonable timeframe.

But I think there are exciting things to come up in the next decades for sure.

1km would be fantastic but I think 1000km would already give us a ton of information.

I heard about this fascinating idea of using the gravitational lensing of our own sun to image the surface of exoplanets: https://www.youtube.com/watch?v=NQFqDKRAROI

It wouldn't look like any telescope you might have ever seen. Once we have a candidate exoplanet we want to take a picture of we would launch a flock of free-flying solar-sail propelled satellites in such an orbit that they get yeeted away from the sun on a trajectory opposite of the target exoplanet. They would travel to the "focal plane" of the sun's gravitational lens where the exoplanet's light is smeared to a ring around the sun which they collaboratively capture. Probably one such a pass wouldn't be enough, so we would need to send such flocks multiple times, like waves following on each other.

What I love about the plan is that it is both super scifi, yet we already have all the components to make it happen if we want to.

A few months ago the ISS passed through my city during sunset, while me and my family were hanging out outside. It was an amazing experience. I saw it first, it was reflecting the sun so it looked like a shooting star but it was too slow for a shooting star and too fast for a plane. It was too bright for it to be satellite? So I googled ISS position and it matched! We were able too see it for a while.

This will help you find ISS and other transits https://transit-finder.com/

> Anyone know what are the chances of this happening again in the future?

After ~2031, when the ISS is scheduled to be crashed into the ocean, the chances will tend to zero.

Why are they scrapping it? Isn't it useful?

From my reading it will no longer be safe to use it, basically the warranty of the materials expires, it will be risky to continue using it.

Ah hmm, that's interesting, thank you.

There are quite a few calculators that give you exact transit times for a location. You need a precise clock on your phone and then you can start shooting bursts half a second before transit until your buffer is full. It’s very anxiety inducing because you can’t see anything but so far it has worked out every time. I only have a 400mm lens so the quality is not that great but you can see the solar panels and the outline of the station.

I have also done it in front of the moon but that’s way harder because you have less light and get slower shutter speeds resulting in motion blur.

It’s actually quite common. I have a photo of a transit of the Moon taken from my backyard, and another from a couple of miles down the road. I also took one ISS transit of the Sun in my parent’s backyard the day before Atlantis undocked on the last ever Shuttle flight. So I really haven’t had to go out of my way to capture them.

Those photos were within a couple of years of each other, obviously some time ago now.

It's cool. But much clickbait with the title?

No, the title is not a clickbait. This is best photo of ISS transiting Moon I have seen, by a large margin.

Indeed. There are also pretty stunning transits of the Sun (with Canadarm and Crew Dragon resolved) on the photographer's website [1]. But Moon transits are likely much more challenging since it is much fainter as a background than the Sun.

1. http://www.astrophoto.fr/iss_transits_june2020.html

I would guess the Moon is actually much brighter once you filter the Sun to safe levels.

OP here - think I followed guidelines here.

"Otherwise please use the original title, unless it is misleading or linkbait; don't editorialize."

What definition of clickbait are you using here? In my head, clickbait is still "You won't BELIEVE this ONE CLEVER TRICK! Astrophotographers HATE him!", or something like that. I'm guessing you don't like the emotional wording in "jaw-dropping"?

https://xkcd.com/2463/

How long until we can photograph the moon landings from Earth?

Reminds me a little of this beauty (keep watching until the end) https://www.youtube.com/watch?v=WjNssEVlB6M

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