Size of Atlantis in the night sky over Earth

[gopher65]

I did a quick search and didn't turn up anything else about this topic. Hopefully I didn't miss a thread.

Atlantis was in Low Earth Orbit (LEO) for a while. I figure that they were probably 150km above the surface (~standard low earth orbit). At that distance an object 1.8 kilometres in diameter would be more than twice the size of the full moon in the sky. In addition, Atlantis is made of shiny metal, and, if you can believe the CGI, is outputting quite a bit of light of its own (for comparison the moon only reflects the sun's light), so it would almost certainly have been substantially brighter than the full moon in the sky.

And no one noticed this? An object twice the size of the full moon that was gleaming like a diamond for 5 minutes? .... heh. Riiiiiiiiiight.

This didn't cause me to dislike the episode, but I did chuckle at the fact that none of the people who make the show thought of this wee little inconsistency in the plot. Wouldn't it have been so much cooler if the battle had taken place hovering close over the lunar surface instead? That would have eliminated this issue.

Ah well. I still liked it.

[Jedi_Master_Bra'tac]

When I first heard the line "several commercial craft have spotted a huge fireball in the night sky", I thought that the game was up and they'd have to make the SG program public. Apparently not, unless they just cloaked ship so they wouldn't get loads of attention.

[GateFanSamJack]

Did anybody see how it looked like Atlantis would buzz Hawaii?

In the commentary for Unending, Amanda Tapping was joking about taking SG-1 to Hawaii for a reunion episode like they did in the Brady Bunch. The writer she was commenting with mentioned he's been advocating for Stargate: Hawaii to no avail. I was so hoping I'd been bogus-spoilered and they'd land outside Hawaii.

[Vala_M]

I did a quick search and didn't turn up anything else about this topic. Hopefully I didn't miss a thread.

Atlantis was in Low Earth Orbit (LEO) for a while. I figure that they were probably 150km above the surface (~standard low earth orbit). At that distance an object 1.8 kilometres in diameter would be more than twice the size of the full moon in the sky. In addition, Atlantis is made of shiny metal, and, if you can believe the CGI, is outputting quite a bit of light of its own (for comparison the moon only reflects the sun's light), so it would almost certainly have been substantially brighter than the full moon in the sky.

And no one noticed this? An object twice the size of the full moon that was gleaming like a diamond for 5 minutes? .... heh. Riiiiiiiiiight.

This didn't cause me to dislike the episode, but I did chuckle at the fact that none of the people who make the show thought of this wee little inconsistency in the plot. Wouldn't it have been so much cooler if the battle had taken place hovering close over the lunar surface instead? That would have eliminated this issue.

Ah well. I still liked it.

That is interesting, I didn't think of any of that.

Vala,

[gopher65]

And, of course, I didn't mention the Hive itself. That thing may have been dark(ish), but it was still 5km across its longest point. It would take up a large enough portion of the sky that you simply *couldn't* miss it.

[Alteran of Atlantis]

That's an interesting point. I'm sure a few people noticed Atlantis, especially when the city was entering the Earth's atmosphere. But they were probably hushed. Sneaky sneaky military...

That, or everyone thinks they're crazy...

[hedwig]

That's an interesting point. I'm sure a few people noticed Atlantis, especially when the city was entering the Earth's atmosphere. But they were probably hushed. Sneaky sneaky military...

That, or everyone thinks they're crazy...

I would think more than a few people noticed Atlantis and the hive ship. Especially the hive ship blowing up. And I don't think the military could hush them all up. And then there's Atlantis streaking through the atmosphere and splashing down in the Pacific. Cloaked or not, there would likely still be some kind of trail left in its wake in the atmosphere. Plus, there are all those government and civilian satellites in orbit snapping pictures of all sorts of stuff up there in space, and I'll bet a few of them got some really interesting pictures of what happened.

[Alteran of Atlantis]

I would think more than a few people noticed Atlantis and the hive ship. Especially the hive ship blowing up. And I don't think the military could hush them all up. And then there's Atlantis streaking through the atmosphere and splashing down in the Pacific. Cloaked or not, there would likely still be some kind of trail left in its wake in the atmosphere. Plus, there are all those government and civilian satellites in orbit snapping pictures of all sorts of stuff up there in space, and I'll bet a few of them got some really interesting pictures of what happened.

True. And Atlanis landed near San Fransisco. Come on, someone is going to notice a giant city streaking though the atmosphere, even if it was from a distance. They cloaked before they landed, but probably not before they cam within sight of land.

[dee]

oh ya, I could just picture it, sitting on the beach in his chair, bermuda shorts/brightly color shirt sipping his drink of spice rum (captain morgan of course) lazely watching john sheppard hit that big wave and teyla in her bikini.I could really get to like this place Todd says to himself.

[dee]

of course people had to haveseen it

[nx01a]

It was another one of those really big asteroids, like the ones that explode in Earth's atmosphere every few years. Well, the Stargate Earth.

[gopher65]

It was another one of those really big asteroids, like the ones that explode in Earth's atmosphere every few years. Well, the Stargate Earth.

The asteroid that exploded over Canada a few months ago -- the one that could be seen for hundreds of miles in every direction -- was less than a metre in radius (and about 10 tonnes). It lit up the night sky as it entered the atmosphere.

The city is about 2000 metres from end to end, if you include its shield perimeter. Being that big, as it came in it would literally be like another sun in the sky ... except way bigger. From 150 miles it would be about twice the size of the sun in the sky, and it would increase proportionately with the decrease in distance as it approached the surface.

Even though its closest approach was over the pacific, it still would have been impossible *not* to see this for anyone who was outside, even while it wasn't on closest approach.

This isn't a matter of "most people weren't looking up, and therefore didn't see a few twinkly dots in GEO disappear in small flashes of light", like previous stargate invasions (may) have been. This is "OMG! The WHOLE SKY IS FREAKING ON FIRE!", which is a tad different.

And it wouldn't be mistaken for a meteor. Any highschool nerd could tell everyone that a meteor big enough to look like that would have wiped out the planet. *Poof*, gone. There could be no coverup of something like this event.

As I said earlier, it would have been pretty easy for them to fix this inconsistency, but they didn't even think of it. This is why shows need a science advisor. They coolfy shows.

[Randar]

I don't exactly see how such a small thing can look so big...i mean Atlantis is what? at most 4 miles wide? how can something that small possibly look the size of the moon even in LEO...i suppose its true(given the size of the moon and its distance from Earth it probably compares in size)...but it still seems odd that something so small would be so noticeable.

[PG15]

No, his math checks out...

"Ok people, not to worry; that wasn't an alien ship in the sky, you guys just all suffered Mass hallucination. Yep, that's it."

[Ezis]

Taking into account that the ISS is traveling in an orbit of approximately 350km from the surface of the earth, and that it is 73mx93mx27.4m and on a clear night appears as a light streaking across the sky about the size of the head of a match, I'd say something that's approximately 16 times that size being half that distance from the surface of the planet, you're looking at it being 32x the size of a the head of a match. Taking into account that the shield surrounding Atlantis fully surrounds the city, i.e. it doesn't actually touch any of the surface area of the city, that's going to increase the size even more.

Since the shield basically glows when something comes into contact with it, like the atmosphere of a planet, that's going to seriously drop the value of the city's apparent magnitude as it will be generating it's own light, whereas the ISS relies on the sun's light being reflected back to Earth to allow us to see it streak in the sky.

That being said, I would be incredibly surprised if the city's re-entry wouldn't light up the sky, almost appearing like another Sun as it's coming in for a landing.

Another question I have to ask is this, when Sheppard landed the city on the new planet, he wasn't able to land the city without a major splashdown upon landing. That being said, I'd like to know how Beckett, not being as compatible with the chair as Sheppard, would have had enough control of the city to have a landing that didn't result in a massive wave covering the coast of San Francisco.