Explanation: What's that approaching? Astronauts on board the International Space Station in 2010 first saw it far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship. Finally, the object revealed itself to be the Space Shuttle Endeavour, and it soon docked as expected with the Earth-orbiting space station. Pictured here, Endeavour was imaged near Earth's horizon as it approached, where several layers of the Earth's atmosphere were visible. Directly behind the shuttle is the mesosphere, which appears blue. The atmospheric layer that appears white is the stratosphere, while the orange layer is Earth's Troposphere. Together, these thin layers of air -- collectively spanning less than 2 percent of Earth's radius -- sustain us all in many ways, including providing oxygen to breath and a barrier to dangerous radiations from space.
If the Space Shuttle and Space Station remain in the mesophere, is it inaccurate to refer to them with the 'Space' label?
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 6:44 am
by MarkBour
DL MARTIN wrote: ↑Sun Apr 17, 2022 6:14 am
If the Space Shuttle and Space Station remain in the mesophere, is it inaccurate to refer to them with the 'Space' label?
Then there's those "Starships" that fly from the "Starbase" in Boca Chica. Now that's what I call hyperbole.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 7:54 am
by Wolf
A cross the space divide
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 11:50 am
by orin stepanek
So the Space station is actually still in the atmosphere! So i imagine
adjustments must occasionally be made to keep it afloat!
Aw! Animals give real love; we all could learn!
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 12:27 pm
by De58te
DL MARTIN wrote: ↑Sun Apr 17, 2022 6:14 am
If the Space Shuttle and Space Station remain in the mesophere, is it inaccurate to refer to them with the 'Space' label?
You could also ask IF wishes were horses? The Space Station isn't in the mesosphere. It's is several hundred kilometres above that. The top of the mesosphere or mesopause is also generally considered The Kármán line, or the edge of outer space at 100 kilometres above sea level. The Space Station is about 400 kilometres up.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 1:27 pm
by Ironwood
Don't forget the thermosphere and exosphere are layers of atmosphere above the mesosphere.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 1:38 pm
by Chris Peterson
orin stepanek wrote: ↑Sun Apr 17, 2022 11:50 am
shuttleAtm_nasa_960_ann.jpg
So the Space station is actually still in the atmosphere! So i imagine
adjustments must occasionally be made to keep it afloat! :roll:
It is... but it is not in any part of the atmosphere visible in this image. And yes, all satellites in low Earth orbit experience drag and have to have their orbits adjusted, or those orbits will decay.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 6:36 pm
by DL MARTIN
Thanks for the clarification regarding atmosphere and orbiting bodies. I was around when satellites were first introduced and they certainly moved the piece regarding research potential. With familiarity however, I've wondered just how appropriate it is to refer to them as being in Space since they seem very attached to Earth's gravity. I know this may seem picayune but this stuff is for sale and I wonder if the potential buyer is getting a straight story.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Sun Apr 17, 2022 7:16 pm
by Chris Peterson
DL MARTIN wrote: ↑Sun Apr 17, 2022 6:36 pm
Thanks for the clarification regarding atmosphere and orbiting bodies. I was around when satellites were first introduced and they certainly moved the piece regarding research potential. With familiarity however, I've wondered just how appropriate it is to refer to them as being in Space since they seem very attached to Earth's gravity. I know this may seem picayune but this stuff is for sale and I wonder if the potential buyer is getting a straight story.
"Space" isn't in any way defined by gravity. The physics of an orbiting satellite is exactly the same as that of the orbiting Moon. I don't think many people would argue that a trip to the Moon doesn't involve traveling through space!
This got me to thinking about a couple of famous comments:
"This is a little tiny blue skin that is 50 miles wide."
-- William Shatner
Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.
-- Carl Sagan
I can't begin to compare with the poetic and profound words of either man, but I had a thought looking at today's APOD and considering both quotes. In a way, Shatner is noting an added emphasis on Sagan, in terms of how tiny our realm of existence, of all life is on Earth.
From a distance, the globe of Earth looks small (cf. Sagan), but even that gives us too much credit (cf. Shatner). Our biosphere is more 2-dimensional than 3-dimensional. We're just in a verry narrow band on the surface of the globe. All of life exists between about 4.2 miles up and about 7 miles down from the sea-level point. (The tardigrade can live in extreme conditions, for example, still, not much of anything living has been found anywhere above about 22,000 feet. We found life at the Challenger Deep at the bottom of the Mariana Trench in the ocean. We've even found life quite a ways under the surface of the earth, both under the dry ground and under the ocean floor, but so far, nothing below about 7 miles below sea level, that I'm aware of.)
99.999% of humans can be found in a shell that is only about 3.1 miles in thickness, between sea level and 16,700 or so feet.
And as long as we're putting a tight bound on it, the 99.999% of us are further reduced to the 30% of the surface of the Earth that is land. And you could even toss out part of that, because over half of it is "not very habitable" (deserts, mountains, arctic regions). A common estimate, I can't verify its accuracy, is: 24.6 million mi2 out of 57.5 million mi2. So ...
We humans all live on a tiny, pale blue globe. A rocky planet that looks blue because it is 70% wet from a fairly thin layer of mostly-liquid water. And we only live on a sliver around its surface. And we only even live on about 15% of that surface, mainly. We're on the dry part, not the pretty blue part. We'd like you to come visit us, but only if you're nice.
-- Mark Goldfain
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Mon Apr 18, 2022 1:36 pm
by johnnydeep
MarkBour wrote: ↑Mon Apr 18, 2022 3:00 am
This got me to thinking about a couple of famous comments:
"This is a little tiny blue skin that is 50 miles wide."
-- William Shatner
Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.
-- Carl Sagan
I can't begin to compare with the poetic and profound words of either man, but I had a thought looking at today's APOD and considering both quotes. In a way, Shatner is noting an added emphasis on Sagan, in terms of how tiny our realm of existence, of all life is on Earth.
From a distance, the globe of Earth looks small (cf. Sagan), but even that gives us too much credit (cf. Shatner). Our biosphere is more 2-dimensional than 3-dimensional. We're just in a verry narrow band on the surface of the globe. All of life exists between about 4.2 miles up and about 7 miles down from the sea-level point. (The tardigrade can live in extreme conditions, for example, still, not much of anything living has been found anywhere above about 22,000 feet. We found life at the Challenger Deep at the bottom of the Mariana Trench in the ocean. We've even found life quite a ways under the surface of the earth, both under the dry ground and under the ocean floor, but so far, nothing below about 7 miles below sea level, that I'm aware of.)
99.999% of humans can be found in a shell that is only about 3.1 miles in thickness, between sea level and 16,700 or so feet.
And as long as we're putting a tight bound on it, the 99.999% of us are further reduced to the 30% of the surface of the Earth that is land. And you could even toss out part of that, because over half of it is "not very habitable" (deserts, mountains, arctic regions). A common estimate, I can't verify its accuracy, is: 24.6 million mi2 out of 57.5 million mi2. So ...
We humans all live on a tiny, pale blue globe. A rocky planet that looks blue because it is 70% wet from a fairly thin layer of mostly-liquid water. And we only live on a sliver around its surface. And we only even live on about 15% of that surface, mainly. We're on the dry part, not the pretty blue part. We'd like you to come visit us, but only if you're nice.
-- Mark Goldfain
Deep thoughts at this Easter time. To add to them: the tribe Hominini that we "humans" (homo sapiens) are members of has only been around for about 10 million years, which is a mere 1/450th of the time that the Earth has existed. And if you got all 7.6 billion of us together, standing shoulder to shoulder and back to front, our entire population would fit in a square only 41 miles on a side. Even worse, in total, we only account for about 1/9000th of the entire biomass of the Earth (with the total biomass itself being only one eleven billionth of Earth's mass)! Not very poetic, but still very sobering. Finally, to quote a famous song: "All we are is dust in the wind" -
Click to play embedded YouTube video.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Mon Apr 18, 2022 2:36 pm
by Wolf
MarkBour wrote: ↑Mon Apr 18, 2022 3:00 am
This got me to thinking about a couple of famous comments:
Whoa, Mark's and Johnny's fleeting profundities require some serious deep thinking. My attempt at a simple eggcorn regarding the obvious Easter-posted crucifixion-like Shuttle image seems much ado about nothing in retrospect.
Just remember too that within our thin-skinned bodies, we are our own microbiome of "around 30 trillion human cells, but our microbiome is an estimated 39 trillion microbial cells including bacteria, viruses and fungi that live on and in us."
MarkBour wrote: ↑Mon Apr 18, 2022 3:00 am
This got me to thinking about a couple of famous comments:
Whoa, Mark's and Johnny's fleeting profundities require some serious deep thinking. My attempt at a simple eggcorn regarding the obvious Easter-posted crucifixion-like Shuttle image seems much ado about nothing in retrospect.
Just remember too that within our thin-skinned bodies, we are our own microbiome of "around 30 trillion human cells, but our microbiome is an estimated 39 trillion microbial cells including bacteria, viruses and fungi that live on and in us."
You know, I never would have notice the cross allusion had you not mentioned it. I have to wonder if that really was the intent:
The Shuttle, Crucified
shuttle silhouette.JPG (14 KiB) Viewed 7503 times
Here's one more for you: our special humanness comes from a mere 6% difference in genes between us and chimpanzees (yes, that's four times more than the oft-quoted 1.6% figure).
Ok, two: and to top it all off, our "coding DNA" accounts for only 1% of all the DNA we have! One shudders at what surprises might lurk in that uncharted expanse...
MarkBour wrote: ↑Mon Apr 18, 2022 3:00 am
This got me to thinking about a couple of famous comments:
Whoa, Mark's and Johnny's fleeting profundities require some serious deep thinking. My attempt at a simple eggcorn regarding the obvious Easter-posted crucifixion-like Shuttle image seems much ado about nothing in retrospect.
Just remember too that within our thin-skinned bodies, we are our own microbiome of "around 30 trillion human cells, but our microbiome is an estimated 39 trillion microbial cells including bacteria, viruses and fungi that live on and in us."
Whoa, Mark's and Johnny's fleeting profundities require some serious deep thinking. My attempt at a simple eggcorn regarding the obvious Easter-posted crucifixion-like Shuttle image seems much ado about nothing in retrospect.
Just remember too that within our thin-skinned bodies, we are our own microbiome of "around 30 trillion human cells, but our microbiome is an estimated 39 trillion microbial cells including bacteria, viruses and fungi that live on and in us."
You know, I never would have notice the cross allusion had you not mentioned it. I have to wonder if that really was the intent:
Cross? Nonsense. It's obviously an Ewok.
Way to blow the mood, Chris.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Mon Apr 18, 2022 8:22 pm
by Wolf
MarkBour wrote: ↑Sun Apr 17, 2022 6:44 am
Then there's those "Starships" that fly from the "Starbase" in Boca Chica. Now that's what I call hyperbole.
Mark, yes, both hyperbole as well as hyperbola in those hyped and oftened photographed flights!
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Mon Apr 18, 2022 11:48 pm
by Wolf
johnnydeep wrote: ↑Mon Apr 18, 2022 3:34 pm
Way to blow the mood, Chris.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Tue Apr 19, 2022 4:15 am
by Guest
What causes the specific colors of the stratosphere and mesosphere? The troposphere is caused by blue light being scattered by Rayleigh scattering, so only red gets through, same mechanism that makes red sunsets. The mesosphere I can imagine also being Rayleigh scattering but why is the stratosphere white?
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Wed Apr 20, 2022 5:14 am
by MarkBour
Great additions to my musings, y'all. And I loved the Kansas video! Not only a great song, and appropriate to my musings, I think the title applied to the APOD itself very well.
Guest wrote: ↑Tue Apr 19, 2022 4:15 am
What causes the specific colors of the stratosphere and mesosphere? The troposphere is caused by blue light being scattered by Rayleigh scattering, so only red gets through, same mechanism that makes red sunsets. The mesosphere I can imagine also being Rayleigh scattering but why is the stratosphere white?
Too bad neufer is no longer with us to answer that one, I'm sure he'd have given a great explanation, since he was an expert on the ozone layer.
The stratosphere is home to the ozone layer, and it has vertically-stable layers of airmass, and a temperature inversion. Apparently, ozone is a pale blue, but its concentration is probably not high enough for that to be seen. The clouds are not in the stratosphere, but I wonder if it has enough water vapor to account for the whiteness, when viewed through an angle like this?
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Wed Apr 20, 2022 5:43 am
by MarkBour
MarkBour wrote: ↑Mon Apr 18, 2022 3:00 am
... All of life exists between about 4.2 miles up and about 7 miles down from the sea-level point. (The tardigrade can live in extreme conditions, for example, still, not much of anything living has been found anywhere above about 22,000 feet. We found life at the Challenger Deep at the bottom of the Mariana Trench in the ocean. We've even found life quite a ways under the surface of the earth, both under the dry ground and under the ocean floor, but so far, nothing below about 7 miles below sea level, that I'm aware of.) ...
The aforementioned Wikipedia article on the stratosphere showed me that the above statements need to be corrected.
Although the following records may be more "incidental" than really extending what should be considered habitat, the article mentioned three high altitude records that were news to me.
Apparently, bar-headed geese overfly Everest. So, that's 30,000 feet or more in altitude.
A vulture was encountered at 37,000 feet altitude, as the poor thing was ingested by a jet engine.
Bacteria have been detected on dust collected at 134,000 feet altitude.
So, that would push the upper limit as high as 25.5 miles above sea level. This would greatly extend the biosphere, though not the places of human dwelling. Then again, if we're talking about records, humans have been all of those places and higher, regularly living on the ISS and occasionally visiting the Moon. But these are super-rare records and I was just thinking about where we naturally can and do live.
MarkBour wrote: ↑Mon Apr 18, 2022 3:00 am
... All of life exists between about 4.2 miles up and about 7 miles down from the sea-level point. (The tardigrade can live in extreme conditions, for example, still, not much of anything living has been found anywhere above about 22,000 feet. We found life at the Challenger Deep at the bottom of the Mariana Trench in the ocean. We've even found life quite a ways under the surface of the earth, both under the dry ground and under the ocean floor, but so far, nothing below about 7 miles below sea level, that I'm aware of.) ...
The aforementioned Wikipedia article on the stratosphere showed me that the above statements need to be corrected.
Although the following records may be more "incidental" than really extending what should be considered habitat, the article mentioned three high altitude records that were news to me.
Apparently, bar-headed geese overfly Everest. So, that's 30,000 feet or more in altitude.
A vulture was encountered at 37,000 feet altitude, as the poor thing was ingested by a jet engine.
Bacteria have been detected on dust collected at 134,000 feet altitude.
So, that would push the upper limit as high as 25.5 miles above sea level. This would greatly extend the biosphere, though not the places of human dwelling. Then again, if we're talking about records, humans have been all of those places and higher, regularly living on the ISS and occasionally visiting the Moon. But these are super-rare records and I was just thinking about where we naturally can and do live.
The lower limit for life might need to be extended too. Life has been found 1.4 km below the North Atlantic sea floor!
https://earthsky.org/earth/stephen-giovannoni-discovers-deepest-yet-underground-life/ wrote:Even in this time of 7 billion human inhabitants, there are still frontiers being explored on Earth. One frontier is Earth’s deepest depths, which scientists are probing for signs of life. In late 2010, microbiologist Stephen Giovannoni and his research team discovered bacterial life deeper in the Earth’s crust than ever before, 1.4 kilometers below the sea floor in the North Atlantic. This discovery might have implications for life on other planets, such as Mars.
Re: APOD: Shuttle Over Earth (2022 Apr 17)
Posted: Mon May 09, 2022 3:04 am
by scotfree
Guest wrote: ↑Tue Apr 19, 2022 4:15 am
What causes the specific colors of the stratosphere and mesosphere? The troposphere is caused by blue light being scattered by Rayleigh scattering, so only red gets through, same mechanism that makes red sunsets. The mesosphere I can imagine also being Rayleigh scattering but why is the stratosphere white?
I think the answer here is that the dust in the mesosphere absorbs short wavelengths more than long wavelengths, so we perceive the color red. Higher in the atmosphere there's less dust so direct reflection off of water vapor dominates. Then the troposhere has less water vapor(?) so rayleigh scattering dominates and we perceive blue.
(Or at least I think that's what my dad's explanation would have been
Guest wrote: ↑Tue Apr 19, 2022 4:15 am
What causes the specific colors of the stratosphere and mesosphere? The troposphere is caused by blue light being scattered by Rayleigh scattering, so only red gets through, same mechanism that makes red sunsets. The mesosphere I can imagine also being Rayleigh scattering but why is the stratosphere white?
I think the answer here is that the dust in the mesosphere absorbs short wavelengths more than long wavelengths, so we perceive the color red. Higher in the atmosphere there's less dust so direct reflection off of water vapor dominates. Then the troposhere has less water vapor(?) so rayleigh scattering dominates and we perceive blue.
(Or at least I think that's what my dad's explanation would have been
Steve
Makes sense. So, the Russian flag has the right colors, but the wrong order. Netherlands has it better.
Shuttle Over Earth
Animals give real love; we all could learn! 
