Both voyagers recorded temperatures ranging from 54,000 to 90,000 degrees.
How doesn’t voyager melt?
No way anything man built can withstand those temperatures, they mean that voyager register space dust or gasses at those temperatures but didn’t cross it? Or something else?
The vacuum of space is cold. But the one molecule per square meter of space dust can be extremely hot. You can drop a match in a swimming pool and the water won’t change temperature at all.
Their analogy is just a touch backwards depending on how you’re visualizing it. It DOES touch the heat. It traveled through a huge region that was that hot. The match is an extremely hot particle and the pool is Voyager. Their point is a single molecule, even at 30,000 degrees, isn’t going to transfer much actual energy to the space craft.
The measured temperature is more of a function of directly detecting some lower temperature and cross-referencing density measurements. It’s not enough molecules to heat up the spacecraft to the same temperature, so figuring it out becomes a function of how much heat is being absorbed and radiated back out in relation to the detected density of particles. So per detected particle, it’s getting a lot of heat, but there aren’t enough particles to really heat the whole craft up much at all.
Despite what capitalists would like you to believe technology hasn’t changed all that much in 50 years. Sure there have been some novel technologies more recently like blue LEDs or CRISPR-Cas9. But the real advance since the 70s has been in miniaturization, allowing more things to be put in the same amount of space as before.
Also one point of clarification, Voyager is a space probe, not a satellite. Satellites orbit things and can be naturally occurring.
As to the sensing mechanism specifically I am not sure other than that it has to do with detecting a differential in energy, but the sensor in question is the Low Energy Charged Particle Instrument.
Technically even the Voyager probes are orbiting something. It isn’t a planet, and not even the sun anymore. It is orbiting Sagittarius A*, the black hole at the center of the Milky Way.
It has quite a few sensors for various particles and plasma/etc. “A single particle” isn’t as crazy as you might think. Even a human eye is chemically sensitive enough to see a single photon (though highly unlikely the brain would notice unless you’ve been living in a cave for a long while), and electronics can be made to be far more sensitive.
The ‘how’ might take a good bit of your own research because I’m running out of free time today, but for a loose example on photons (not particles), the YouTuber AlphaPhoenix built a 2,000,000,000 fps camera https://m.youtube.com/watch?v=o4TdHrMi6do The TLDW for how to sense individual particles is to have very good instruments to make clean signals, and then boost those small signals with good electronics. Of course NASA is going to design and build excellent electronics. Notice how AlphaPhoenix is using vaccuum tubes. A very old tech. The biggest factor that changes over time is how expensive and small electronics can be. As someone already said, the exact tech hasn’t actually changed that much. It’s mostly all the same theories, just refined and mass produced again and again.
Furthermore… I don’t think a vacuum can have a temperature, can it? Specifically in this context, when you’re contrasting the vacuum with the particles within it…
But isn’t ‘cold’ a measure of a particle’s energy, much the same as ‘hot’ is? Wouldn’t a true vacuum be neither hot nor cold? I mean, I get the analogy, but Isn’t the real issue that there’s not enough matter to transfer energy between things. So like, no matter how hot it is, it’s just not going anywhere? Or am I way off mark?
Space is “cold” because, compared to Earth, there’s no heat energy in the environment. Because there is nothing in the environment at all (mostly).
Space is also “hot” because compared to Earth, there’s no convenient environmental air or water you can use to dissipate heat through conduction or convection. All excess heat must be radiated, which is much, much slower than blowing atmospheric air over a heat exchanger.
The cold vacuum of space isn’t the lack of heat in matter. It’s the absence of matter. That rare molecule hitting the spacecraft will transfer thermal energy to it. But the effect will be practically nothing because it will be counteracted by the overwhelming mass of the craft which is being cooled by the vacuum of space and being heated on the inside by its nuclear reactor so that it doesn’t get too cold to operate.
And I’d guess what they’re asking is how a vacuum would cool something if there’s no matter providing collisions where energy transfer can happen. I.e., isn’t vacuum the ultimate insulator? If I understand correctly, objects in a vacuum cool by radiating only (i.e., energy leaving as photons), and perhaps we only think of space as cold because the absence of a medium (i.e., atmosphere) means no pressure and no additional energy being provided in said medium.
They used sensors to detect particle energy, which is what temperature measures, when they impacted. There are so very few particles out there that no significant heat transfer actually took place, despite the particles themselves having huge amounts of energy.
They both went directly through it. It envelopes the entire solar system as far as we know.
Temperature is the measure of the average kinetic energy in the particles of a material. So, if you have a particle traveling really really fast, especially relative to a spacecraft also traveling really really fast, when they collide there’s a lot of energy. But nobody would call that temperature in the everyday sense.
So yeah if you look at the whole kuiper belt and measure the average kinetic energy of the particle flying around at high speed, it would have a high temperature, but that’s not necessarily a useful piece of information, unless when you say “what’s the temperature of the kuiper belt” you mean “how much kinetic energy do these particles have, because I would like to build my satellite shielding to not be smashed in by the first one it encounters”.
How doesn’t voyager melt?
No way anything man built can withstand those temperatures, they mean that voyager register space dust or gasses at those temperatures but didn’t cross it? Or something else?
Basically like the sparks from a grinder. The individual sparks are glowing hot but they’re too small and too few to do any harm.
The vacuum of space is cold. But the one molecule per square meter of space dust can be extremely hot. You can drop a match in a swimming pool and the water won’t change temperature at all.
This explains the situation better but fails to explain how it detects these temperatures without touching them.
I assume its infrared cameras and the like. But this also implies the “wall of fire” is actually full of holes or its bound to collide with that heat.
Their analogy is just a touch backwards depending on how you’re visualizing it. It DOES touch the heat. It traveled through a huge region that was that hot. The match is an extremely hot particle and the pool is Voyager. Their point is a single molecule, even at 30,000 degrees, isn’t going to transfer much actual energy to the space craft.
The measured temperature is more of a function of directly detecting some lower temperature and cross-referencing density measurements. It’s not enough molecules to heat up the spacecraft to the same temperature, so figuring it out becomes a function of how much heat is being absorbed and radiated back out in relation to the detected density of particles. So per detected particle, it’s getting a lot of heat, but there aren’t enough particles to really heat the whole craft up much at all.
But how does a satellite built 50 years ago even detect the energy of that single particle in the vacuum of space? That’s mind boggling.
Despite what capitalists would like you to believe technology hasn’t changed all that much in 50 years. Sure there have been some novel technologies more recently like blue LEDs or CRISPR-Cas9. But the real advance since the 70s has been in miniaturization, allowing more things to be put in the same amount of space as before.
Also one point of clarification, Voyager is a space probe, not a satellite. Satellites orbit things and can be naturally occurring.
Fair. I’m still curious how it detects a single atom in the vacuum of space though
As to the sensing mechanism specifically I am not sure other than that it has to do with detecting a differential in energy, but the sensor in question is the Low Energy Charged Particle Instrument.
Thanks!
Technically even the Voyager probes are orbiting something. It isn’t a planet, and not even the sun anymore. It is orbiting Sagittarius A*, the black hole at the center of the Milky Way.
But yeah, probe is the more accurate term.
I had a feeling somebody was going to point that out…
It has quite a few sensors for various particles and plasma/etc. “A single particle” isn’t as crazy as you might think. Even a human eye is chemically sensitive enough to see a single photon (though highly unlikely the brain would notice unless you’ve been living in a cave for a long while), and electronics can be made to be far more sensitive.
https://science.nasa.gov/mission/voyager/instruments/ Gives a decent high level on the sensors these probes have.
The ‘how’ might take a good bit of your own research because I’m running out of free time today, but for a loose example on photons (not particles), the YouTuber AlphaPhoenix built a 2,000,000,000 fps camera https://m.youtube.com/watch?v=o4TdHrMi6do The TLDW for how to sense individual particles is to have very good instruments to make clean signals, and then boost those small signals with good electronics. Of course NASA is going to design and build excellent electronics. Notice how AlphaPhoenix is using vaccuum tubes. A very old tech. The biggest factor that changes over time is how expensive and small electronics can be. As someone already said, the exact tech hasn’t actually changed that much. It’s mostly all the same theories, just refined and mass produced again and again.
Very cool, thanks so much!
Furthermore… I don’t think a vacuum can have a temperature, can it? Specifically in this context, when you’re contrasting the vacuum with the particles within it…
If it’s not absolute zero, it has a temperature. There is radiation creating heat throughout the entire universe.
But isn’t ‘cold’ a measure of a particle’s energy, much the same as ‘hot’ is? Wouldn’t a true vacuum be neither hot nor cold? I mean, I get the analogy, but Isn’t the real issue that there’s not enough matter to transfer energy between things. So like, no matter how hot it is, it’s just not going anywhere? Or am I way off mark?
Space is “cold” because, compared to Earth, there’s no heat energy in the environment. Because there is nothing in the environment at all (mostly).
Space is also “hot” because compared to Earth, there’s no convenient environmental air or water you can use to dissipate heat through conduction or convection. All excess heat must be radiated, which is much, much slower than blowing atmospheric air over a heat exchanger.
The cold vacuum of space isn’t the lack of heat in matter. It’s the absence of matter. That rare molecule hitting the spacecraft will transfer thermal energy to it. But the effect will be practically nothing because it will be counteracted by the overwhelming mass of the craft which is being cooled by the vacuum of space and being heated on the inside by its nuclear reactor so that it doesn’t get too cold to operate.
And I’d guess what they’re asking is how a vacuum would cool something if there’s no matter providing collisions where energy transfer can happen. I.e., isn’t vacuum the ultimate insulator? If I understand correctly, objects in a vacuum cool by radiating only (i.e., energy leaving as photons), and perhaps we only think of space as cold because the absence of a medium (i.e., atmosphere) means no pressure and no additional energy being provided in said medium.
The craft radiates heat into the void. Not conduction but radiation.
They used sensors to detect particle energy, which is what temperature measures, when they impacted. There are so very few particles out there that no significant heat transfer actually took place, despite the particles themselves having huge amounts of energy.
They both went directly through it. It envelopes the entire solar system as far as we know.
The entire concept of temperature breaks down when there isn’t much material around. Nobody should be talking about the temperature of empty space.
That means you, satcom engineers!
Temperature is the measure of the average kinetic energy in the particles of a material. So, if you have a particle traveling really really fast, especially relative to a spacecraft also traveling really really fast, when they collide there’s a lot of energy. But nobody would call that temperature in the everyday sense.
So yeah if you look at the whole kuiper belt and measure the average kinetic energy of the particle flying around at high speed, it would have a high temperature, but that’s not necessarily a useful piece of information, unless when you say “what’s the temperature of the kuiper belt” you mean “how much kinetic energy do these particles have, because I would like to build my satellite shielding to not be smashed in by the first one it encounters”.