What does the night sky look like on Mars? | Hacker News Reader

What does the night sky look like on Mars?

skyatnightmagazine.com

175 pointsohjeez82 comments

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> Night-time temperatures can drop to -900C

wait, what?

I believe that's supposed to be -90C. Clearly a typo.

You'd expect better from Sky At Night.

(Wikipedia says -143 °C, -225 °F)

The attack on spacex at the start - the one company that’s actually likely to put sky at night readers on Mars - took me out of it before the 900C hilarity.

The star link complaint seems kind of like how people must have been when telegram/power lines went up.

Yeah, early above-ground telephone wiring was a horrible mess. This is one of those intermediate steps where the satellites are are awful. Even as they're implemented there should be a plan to get rid of them. If you search from pictures of overhead wires you can see what it was like for a while. https://uh.edu/engines/nycandwires.jpg

Astronomers, amateur or otherwise, have been complaining about "light pollution" forever. Traditionally, it's about night-time lighting on Earth that isn't shielded from transmitting light upwards.

It startled me to find (in a long ago HN thread) that people, presumably nerdy types, are not generally sympathetic to the complaints. I somehow assumed that universal lukewarm quasi-environmental feelings would mean people would go "yeah, lighting the night sky is inefficient and dumb, and astronomy makes pretty pictures" but apparently "fuck astronomers" is a popular opinion.

The kinds of people who like building things will be less sympathetic to environmental concerns when those concerns are 'don't build that, leave the world untainted by human hand'- there's a difference between polluting by building/placing something of value somewhere and polluting as a pure stupid ugly externality. Engineer-y people might be inclined to hate the latter but not the former.

The aspect of amateur astronomy culture that discouraged me was the awful code published in Sky & Telescope back in the late 80s or early 90s.

They used to have a policy that in order to be compatible with the least common denominator of their readers, they required published programs to be in BASIC. And not just BASIC, but basic BASIC, with line numbers.

As far as I was concerned, it was unreadable and obsolete since about 1985. It also probably influenced me away from ever learning Forth by association.

Not to mention, that when I got a book on astronomical computer algorithms, it turned out that the available implementations were in Fortran, which to my taste was as bad or worse.

Fortran is still popular in scientific computing, and modern compilers are pretty good.

Not only that, but modern compilers are insanely good at compiling numerical Fortran code. The very first optimizing compiler was for Fortran and it's consistently been on the forefront of compiler techniques ever since.

I know that's the cliche, but I don't think that something like VSOP87 would be noticeably faster compiled with Fortran vs. C, in the early 90s. If there even was a Fortran compiler available for Mac or Amiga, it was probably priced obscenely, too.

Well, that, and with modern machinery, a global investment economy, and so many construction jobs depending on infinite growth, "build that junk" is the no-brainer solution to everything. Problem is, just a couple "build that junk" people can do so much damage, unless checked by an unusual, overwhelming backlash, we're not slowing down in any measurable way any time soon.

> ...but apparently "fuck astronomers" is a popular opinion.

They know what they did.

(Leap seconds.)

fun fact - mars has great time zones. No silly country borders and also had them even before we had time zones on earth https://marscalendar.com/time-zones

We now know that light pollution also kills insects, which will in the long term also kill us.

Reducing it should therefore be a priority. Instead, it's increased worldwide, mainly thanks to cheap power LEDs.

Power lines still look like garbage, IMHO. After having lived some years in Germany where they are almost universally buried (except high voltage long-haul lines), I can't stop seeing them everywhere in the US. So ugly. Every sky and scene just spoiled with rickety old third-world "oh let's just put this here for now" trash. Like a scratch right across my eyeballs.

Not sure where in the USA you are looking. If it's in a seismically active region there could be factors other than cost and aesthetics. Here in Japan power lines are seldom buried for this reason.

I've been everywhere, man.

Although there are some areas where power (and comms) cables are buried, it is overwhelmingly common in the US for them to be pole-mounted.

That was simply SEO talking. There was no other way to shoehorn a link to their Starlink webpage into the article.

Astronomers, both amateur and professional, have a legit issue with starlink. SpaceX are even trying to mitigate the issue - because of astronomers pointing it out. So I can see nothing wrong in a magazine for hobby astronomers taking a jab at starlink.

According to the astronomer I talked to, starlink has a negligible impact on professionals. Some disruption at the beginning, but fairly easy to account for. There is already plenty of man made objects that need to be accounted for like the ISS, any of which could cause an issue but it’s a tiny fraction of data that’s impacted and therefore it can be removed fairly easily.

That said, amateur astronomers doing long exposure shots will likely be impacted.

Simply not true, starlink will have a real impact on research (see e.g. https://www.lsst.org/content/lsst-statement-regarding-increa... for the impact on LSST) and will make some science impossible to do. Ironically, amateur long exposure shots will be fine because amateur astronomy doesn’t rely on pixel-level brightnesses and you can easily subtract out streaks in a way that’s pleasing to the eye. Whether or not you think it’s justified, it’s not true to say this will not impact astronomy. Some science cases will be fine, others will be significantly impacted and still others will be SOL and impossible to do.

So the “Rubin Observatory is an extreme case for the sensitivity of astronomical observations to satellite constellations because of its unprecedented ability to repeatedly monitor the sky widely and deeply.”

And their worried about potentially losing as little as 0.3% of pixel level data, that sounds about right. I am not saying it’s impact is meaningless, just they could offset their impact with funding, rather than it being a massive issue on it’s own.

Why do you care? I'm not concern trolling, I just worry/(am curious about) that some people have a quasi-emotional connection with Musk's companies.

Trust but verify, as the saying goes.

That would be something... especially given that absolute zero, the lowest temperature possible when matter ceases movement is -273C.

It’s a funny typo. Always makes you wonder how much other stuff they get wrong that’s missed.

That’d be far beyond absolute zero temp of −273.15° so must be a typo.

-90°C got transcribed wrong (the degree symbol as another zero)

F’ing AI! They ruin everything

That’s with windchill.

This is also the main theme of the comments on the site. Is it possible that typos are comment bait?

"Feels like -900C"

At -900 C, Kelvin is dead.

In 2021 lord Kelvin is definitely dead.

"And I came to the land where the sun is a tarnished penny, where the wind is a whip, where two moons play at hot rod games"

Roger Zelazny, A Rose For Ecclesiastes

I remember Starry Night having the option to see the night sky from different planets. You know, in case you wanted to track the stars with a telescope, on Mars.

I can't say enough good things about Starry Night in terms of teaching me about Astronomy and the Universe early on. Being able to "go" to other star systems and see what the night sky looks like was essential for intuiting our "place" in the sky in a lot of ways, much like playing Kerbal solidified my intuition around basic orbital mechanics.

I pulled this up in Stellarium, and the only real difference is that you can see Phobos, Deimos, and Earth. It doesn't seem to simulate the atmosphere.

I also tried this in Gaia Sky, but I would need to tweak the settings. The faint stars are too bright, and the bright stars aren't bright enough.

Any other recommendations for exploring our neighborhood virtually?

Have you tried out Space Engine [0]? It's a lot larger than our local neighborhood, but it uses real data.

> Real celestial objects are also present if you want to visit them, including the planets and moons of our Solar system, thousands of nearby stars with newly discovered exoplanets, and thousands of galaxies that are currently known.

[0]: http://spaceengine.org/

> You would see two moons in that sky instead of one

Any pictures of this?

There are some videos (from pictures) of eclipses, which show both: https://www.youtube.com/watch?v=M_Kn3M2ierk

This one more zoomed out, but only with Phobos: https://www.youtube.com/watch?v=ViiriVhIhjE

Taking into account that the Sun itself is seen smaller than on Earth, we can already imagine the view. The main problem would be that "Phobos is one of the least reflective bodies in the Solar System, with an albedo of just 0.071.".

This makes me appreciate our moon.

How lucky we are to have a moon that is roughly the same size in the sky as the sun is -- aligned such that we occasionally get to see a perfect solar eclipse and the sun's corona with our naked eyes.

Also, it's more spherical than the moons of Mars.

Mars’ moons are more like asteroids though

Anything as big as the Moon is going to be spherical; if Mars' moons were large enough to totally eclipse the Sun, I expect they would be spherical too.

If you get far enough away from the sun you could potentially see a total eclipse with a lumpy moon. Or if the moon has a very low orbit. For Mars, Phobos is probably about as close to an eclipse-with-a-lumpy-moon as you could reasonably expect to get. I think it's not that far above the Roche limit where it would fall apart and turn into a ring, and if it were bigger it would tend to be less lumpy. Potentially you could stretch it into a pancake-shape which would better occlude the sun by spinning it, but I suppose that would also make it more likely to fall apart and turn into a ring.

> aligned such that we occasionally get to see a perfect solar eclipse and the sun's corona with our naked eyes.

Uh...don't do that. It'll end up being the last thing you see.

A total eclipse is perfectly safe to view with the naked eye. You just have to be carful you don't start too early or end too late...

Many references, but e.g., https://eclipse2017.nasa.gov/safety "Looking directly at the sun is unsafe except during the brief total phase of a solar eclipse (“totality”)..."

In fact I viewed the 1976 total eclipse in Oregon with binoculars.

It was a glorious sight, an experience of a lifetime.

I was on a hillside near The Dalles with other eclipse chasers. Many of us wore sunglasses and looked away from the sun before totality to get our eyes a bit dark-adapted. And then when someone called out "totality!" we turned around, took off the sunglasses and used our binoculars or telescopes if we had them, and viewed the corona directly.

And no, no eye damage.

I don't want to suggest this is a _good_ idea, but I spent a lot of time staring directly at the sun as a kid without any apparent damage to my eyes.

It's safe.

0.07 doesn't sound like a show stopper. The moon is 0.12, so Phobos reflects 40% less light for that reason. The sun being further away (1.5 AU) has a bigger effect due to the inverse square law - that costs 55% of the light. But the biggest effect would come from the fact that it's tiny, about 0.65% of the radius of the moon, orbiting 60x closer, which two factors combine to make it another 60% dimmer than the moon. Then there's the atmosphere which I expect to have a relatively small effect assuming good conditions on both Earth and Mars.

So overall I estimate it should be 0.6 x 0.45 x 0.4 = 0.1, or about one-tenth as bright as the moon, or apparent magnitude -10. That would make it far brighter than we see Venus or Jupiter, but makes me question the assertion in TFA that it would cast shadows - I don't expect many shadows on earth when the moon is one day old.

>Depending on the time of year, you might also see an ‘Evening Star’ shining in the lavender-hued twilight – Earth, a strikingly-bright spark of silvery blue, which at its best would blaze brighter than mag. –2.5.

Man, I'd love to see what Earth would look like from Mars thru an amateur telescope. I'm sure it'd be beautiful.

I would expect similar view to photos of Earth from Moon landings. I would share a tear or twenty if I ever had the chance to see it myself, either of those cases.

Such great highlights from Curiosity, Spirit and Opportunity woven into an enjoyable narrative. I had missed the noctilucent clouds and transit of Phobos. Now stoked for Perseverance on Feb 18th.

In terms of the day, Mars does not have total solar eclipses but Phobos(a moon on Mars) does have eclipses[1].

[1]: https://www.youtube.com/watch?v=OyZoD7BRTtg&feature=youtu.be

Ah, yes, amateur astronomy on Mars. Something we'll not be able to do in my lifetime sadly.

I am expecting light pollution to follow us there also

As I understand it, habitats would need to be under some ground, and there really isn't much to do outside. So what'd be the point of lighting the surface up?

Isn't light pollution due to bouncing off the atmosphere's content?

Ipso facto, no atmo => no light pollution looking up a circled lens?

The article mentions dust in the atmosphere being a problem.

Mars has enough atmosphere (and dust!) that there's stuff for light to bounce off of. e.g. the article notes that the dust actually produces longer twilights than on Earth, because dust scatters more light than Earth's relatively low-dust air.

Well, if you don't have a bunch of pedestrians wandering around outside and people don't generally drive to the store in single-occupant vehicles, you don't really have much need for streetlamps either.

Maybe at some point when the population gets large enough that you'd have imported problems from Earth like random people stealing the Martian equivalent of a CD player and catalytic converter off your rover in the middle of the night, then security lighting may be a thing.

The main use I can think of for outside lighting in the short term would be people doing construction work at night. That might actually be preferred from a radiation point of view; I know Mars doesn't have much protection from radiation, but I'm not sure how much comes directly from the sun versus random ambient radiation in space.

Another possible source of light pollution would be greenhouses with big windows that are lit with artificial light at night.

> Ah, yes, amateur astronomy on Mars. Something we'll not be able to do in my lifetime sadly

While that is true, think of all the things that are possible in your lifetime, that weren't to the people that came before you.

Instant video chat with people on the other side of the globe, the world's information in your pocket, personal transportation that doesn't eat hay, you're not dying from Polio, etc. etc. The list is enormous.

And, for what it's worth, one day in the future when people can d0 amateur astronomy on Mars, they could sit around and lament they can't do it on Pluto...

Personally, I think it's far more exciting that I can look up pictures of nonexistent persons as I will, than I would be to go to Mars.

Mars seems rather boring compared to the facilities offered in my neighborhood, not to mention poor connexion to YouTube.

> Something we'll not be able to do in my lifetime sadly.

Unless you have terminal cancer, there is a path that might allow it to happen.

Of all the things HN thinks might happen because 'optimism' this is a lousy one to chose to be mostly accurate on.

In the last few images, the passing of Phobos in front of the Sun looks like an eye.

I really wish we will be able to see some interesting Mars things in our lifetime...

Blue skies on Mars..

They already do get a little blue: just like how at sunset and sunrise you see red near the sun on Earth, on Mars sunset and sunrise come with a bit of blue at the horizon.

https://solarsystem.nasa.gov/news/925/what-does-a-sunrise-su...

We've seen tons of interesting Mars things in my lifetime!

Or do you mean in person?

The answer should be: nearly exactly the same, with the exception of being able to see Earth and not being able to see Mars.

I wonder if generations of humans born and raised on Mars might start adapting their eyes to blue wave lengths!

Not unless there's some sort of natural (or artificial) selection for it.

I’m not sure why but my mind went straight to “depression”. I imagine earthlings would suffer of seasonal affective disorder from seeing a pale gray/blue sky forever and no red or yellow sun above them.

Kind of like a perpetual winter

Full of tracking cookies

Didn't we send bots with cameras to mars?

Didn't you click the article to see that it has images from them?

I clicked on the article, and it showed me no images.

Is this serious - crawling with starlink sats? At night I'm really not noticing starlink sats even on earth. What I'm noticing is MASSSIVE light pollution.

For an article about looking up with the human eye at the stars, the hit on starlink sats is so weird.

Starlink is probably going to be what makes internet initially possible on marks, may even be part of the mars - earth backhaul network, probably spacex will be helping host space based observation platforms (no dust / no atmo). etc.

From linux/net/ipv4/tcp_timer.c:

I guess we'll have to use something other than TCP to talk to the University of Mars.

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