4 ms·

Agreed, but I believe Voyager is 18.5 light hours away, not 22. The article says it is 20 billion km away which is 18.5 light hours. However the article also s

Agreed, but I believe Voyager is 18.5 light hours away, not 22. The article says it is 20 billion km away which is 18.5 light hours. However the article also states signals take 22 hours to reach the spacecraft. Do radio waves travel slower than the speed of light even in the vacuum of space? I assume the waves do not spend the extra 3.5 hours in Earth's atmosphere!

ars 3y ago
The article is rounding up, and the parent comment is talking about Voyager 1. Specifically: Voyager 1 is 23.8 billion km (23.8 Tm), and Voyager 2 is 18.3 Tm.
- dylan604 3y ago
  For those that might not be aware, Voyager 2 launched before Voyager 1, so the distance discrepancy is not due to the further one being launched first
  - bragr 3y ago
    Voyager 2 was launched first but on a less direct trajectory out of the system which allowed it to visit Uranus and Neptune. Voyager 1 is going much faster https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
urubu 3y ago
There is an effect called dispersion, which causes different frequencies of electromagnetic radiation to travel through a medium at different speeds (lower frequencies => slower). It's strong enough to be noticeable in the case of pulsars (but probably insignificant inside the solar system).
sosodev 3y ago
I think it's because space isn't a perfect vacuum. The interstellar medium is a mix of gas and dust that slow down and weaken the signal. That effect is known as dispersion. With that said, it seems like the article might be inaccurate. That discrepancy seems too large to be explained by dispersion. I'm not an expert though. edit: I think the author got Voyager 1's distance mixed up with Voyager 2. Voyager 1 is ~22 (21.6) light hours away.
- hammyhavoc 3y ago
  Sounds more like ChatGPT got it mixed up.
hinkley 3y ago
Don't confused TTFB with message transport time. With a low bandwidth link, throughput becomes part of latency. Probably not 3.5 hours, but some fraction of that.

ars 3y ago

The article is rounding up, and the parent comment is talking about Voyager 1. Specifically: Voyager 1 is 23.8 billion km (23.8 Tm), and Voyager 2 is 18.3 Tm.

dylan604 3y ago
For those that might not be aware, Voyager 2 launched before Voyager 1, so the distance discrepancy is not due to the further one being launched first
- bragr 3y ago
  Voyager 2 was launched first but on a less direct trajectory out of the system which allowed it to visit Uranus and Neptune. Voyager 1 is going much faster https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/

urubu 3y ago

There is an effect called dispersion, which causes different frequencies of electromagnetic radiation to travel through a medium at different speeds (lower frequencies => slower). It's strong enough to be noticeable in the case of pulsars (but probably insignificant inside the solar system).

sosodev 3y ago

I think it's because space isn't a perfect vacuum. The interstellar medium is a mix of gas and dust that slow down and weaken the signal. That effect is known as dispersion. With that said, it seems like the article might be inaccurate. That discrepancy seems too large to be explained by dispersion. I'm not an expert though. edit: I think the author got Voyager 1's distance mixed up with Voyager 2. Voyager 1 is ~22 (21.6) light hours away.

hammyhavoc 3y ago
Sounds more like ChatGPT got it mixed up.

hinkley 3y ago

Don't confused TTFB with message transport time. With a low bandwidth link, throughput becomes part of latency. Probably not 3.5 hours, but some fraction of that.