toodoo213
New member
i've always been interested how astronomers calculated the distance, speed, and orbit of a space object, how did they?
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How can you find the distance and orbital trajectory for a planet
- Thread starter toodoo213
- Start date
One of the most historically important orbital determinations:
How Gauss Determined The Orbit of Ceres.
http://www.schillerinstitute.org/fid_97-01/982_orbit_ceres.pdf
Pictures, including a depiction of the night sky:
FIGURE 1.1. Positions of unknown
planet (Ceres), observed by
Giuseppe Piazzi on Jan. 2, Jan. 22,
and Feb. 11, 1801, moving slowly
counter-clockwise against the
‘sphere of the fixed stars.’
Another one: How Gauss did it:
http://aardvarkobs.com/html/how_gauss_did_it.html
http://en.wikipedia.org/wiki/Carl_Friedrich_Gauss
How Gauss Determined The Orbit of Ceres.
http://www.schillerinstitute.org/fid_97-01/982_orbit_ceres.pdf
Pictures, including a depiction of the night sky:
FIGURE 1.1. Positions of unknown
planet (Ceres), observed by
Giuseppe Piazzi on Jan. 2, Jan. 22,
and Feb. 11, 1801, moving slowly
counter-clockwise against the
‘sphere of the fixed stars.’
Another one: How Gauss did it:
http://aardvarkobs.com/html/how_gauss_did_it.html
http://en.wikipedia.org/wiki/Carl_Friedrich_Gauss
lalbanof
Member
I do wonder, however...
I think that to calculate the distance to the moon you proceed by triangulating two observations made at the same moment from different parts of the Earth.
With that, you have the size of the moon too.
To the Sun, once you have the orbit of the moon, you can proceed. Either triangulation, or using the fact that both bodies have the same angular area.
However, the masses would have required precise values for G. With the orbits, you have accelerations, and these gill give you G*M, where M is the mass of the central body, for example the Sun, or the Earth if the moon is the orbiting body. With that you can have the relation between the masses of Sun, Earth and Moon.
With observations on Earth's surface, above and below, you can have the mass of the Earth, once you have the G*M for Earth, because you know the mass of your test body.
How do you do calculate the distance between Sun and planets, before Newton? If anybody knows, how did they do it, then?
I think that to calculate the distance to the moon you proceed by triangulating two observations made at the same moment from different parts of the Earth.
With that, you have the size of the moon too.
To the Sun, once you have the orbit of the moon, you can proceed. Either triangulation, or using the fact that both bodies have the same angular area.
However, the masses would have required precise values for G. With the orbits, you have accelerations, and these gill give you G*M, where M is the mass of the central body, for example the Sun, or the Earth if the moon is the orbiting body. With that you can have the relation between the masses of Sun, Earth and Moon.
With observations on Earth's surface, above and below, you can have the mass of the Earth, once you have the G*M for Earth, because you know the mass of your test body.
How do you do calculate the distance between Sun and planets, before Newton? If anybody knows, how did they do it, then?
