3 ms·

>It's astonishing to me that Voyager knows where Earth is at all It's not that astonishing when you realize astral navigation is what sailors hundreds of years

>It's astonishing to me that Voyager knows where Earth is at all It's not that astonishing when you realize astral navigation is what sailors hundreds of years ago did to navigate the seas. Just look at the stars with a sextant and with some basic trigonometry you'll know where you are exactly. The Apollo space crew had to do that by hand and eyes using a sextant too when the astral navigation computer failed.

dcl 2y ago
Knowing your longitude is very difficult without a clock... Can't do it with just stars iirc.
- rbanffy 2y ago
  I think you can, with the Moon and where it is in relation to the Sun.
- fourgreen 2y ago
  You can determine your longitude without a clock, but achieving precision with this method is challenging. First, you need to observe the Moon's position relative to fixed stars, which gives you the UTC time. Then, observe the Sun's position relative to the horizon to determine the local time. By comparing the two, you can calculate your longitude.
  - monkeyfun 2y ago
    How are you going to usefully use this information if you wouldn't have an obvious way to know precisely how long it's been between whenever you lost track of the moon and stars and whenever the sun is clearly visible over the horizon?
- quesera 2y ago
  This is true and there's a fascinating history for Earth-bound (little v) voyagers! But Voyager does not have this particular problem. :)
secondcoming 2y ago
Does voyager have optical sensors that detect planets?
- deleted 2y ago
  [deleted]
quesera 2y ago
It would be astonishing if Voyager shipped in 1977 with computer vision capabilities that were capable of that level of object detection and discrimination and accuracy. Plus the detailed star maps for correlation. And all designed and built several years before launch! And in fact I think it's not possible. But orienting on Sol should be achievable. Even at 15 billion miles away, it's still surely the brightest thing in the sky. Presumably the orientation sensor is precisely in line with the parabolic antenna?

dcl 2y ago

Knowing your longitude is very difficult without a clock... Can't do it with just stars iirc.

rbanffy 2y ago
I think you can, with the Moon and where it is in relation to the Sun.
fourgreen 2y ago
You can determine your longitude without a clock, but achieving precision with this method is challenging. First, you need to observe the Moon's position relative to fixed stars, which gives you the UTC time. Then, observe the Sun's position relative to the horizon to determine the local time. By comparing the two, you can calculate your longitude.
- monkeyfun 2y ago
  How are you going to usefully use this information if you wouldn't have an obvious way to know precisely how long it's been between whenever you lost track of the moon and stars and whenever the sun is clearly visible over the horizon?
quesera 2y ago
This is true and there's a fascinating history for Earth-bound (little v) voyagers! But Voyager does not have this particular problem. :)

secondcoming 2y ago

Does voyager have optical sensors that detect planets?

deleted 2y ago
[deleted]

quesera 2y ago

It would be astonishing if Voyager shipped in 1977 with computer vision capabilities that were capable of that level of object detection and discrimination and accuracy. Plus the detailed star maps for correlation. And all designed and built several years before launch! And in fact I think it's not possible. But orienting on Sol should be achievable. Even at 15 billion miles away, it's still surely the brightest thing in the sky. Presumably the orientation sensor is precisely in line with the parabolic antenna?