Galileo discovered planet Neptune?

[BenBurch]

See also; http://books.google.com/books?id=Gn...fWwPMI&sa=X&oi=book_result&ct=result&resnum=3

 

[~enigma~]

Is this pseudo-history or is there a point to this tripe?

 

[JoeyDonuts]

It's a Galileo thread. That gives it a high likelihood of consisting mostly of self-aggrandizing based mostly on conjecture.

 

[BenBurch]

JoeyDonuts, well, unlike most of these, it is mostly correct. Appears to be likely he saw it, and did not realize what he saw. So it is not a discovery, really, but an observation.

 

[sphenisc]

Neptune has a orbital period of ~60,200 days (~165 years), which means it moves about 0.18 degrees during one month (very rough estimate, since I assume observing from the Sun, not Earth). Galileo's telescope had a field-of-view of about 0.25 degrees. Easily observable, if one has a fixed star as reference (and one could see the not very bright Neptune).

Galileo had already found blemishes on the Sun, and that Earth was not the center of the universe, and it got him enough trouble already. Finding a new planet? Foggedit!

Assuming observation from the Earth, there while be periods of switching from prograde to/from retrograde motion where Neptune will appear almost stationary and others where it is moving considerably faster than the "average" rate.

Interestingly, Galileo's drawings show that he first observed Neptune on December 28, 1612, and again on January 27, 1613. On both occasions, Galileo mistook Neptune for a fixed star when it appeared very close—in conjunction—to Jupiter in the night sky, hence, he is not credited with Neptune's discovery. During the period of his first observation in December 1612, Neptune was stationary in the sky because it had just turned retrograde that very day. This apparent backward motion is created when the orbit of the Earth takes it past an outer planet. Since Neptune was only beginning its yearly retrograde cycle, the motion of the planet was far too slight to be detected with Galileo's small telescope.

 

[Galileo]

It's a Galileo thread. That gives it a high likelihood of consisting mostly of self-aggrandizing based mostly on conjecture.

This is an awesome thread, I beg to differ.

 

[Galileo]

See also; http://books.google.com/books?id=Gn...fWwPMI&sa=X&oi=book_result&ct=result&resnum=3

Good find. It appears someone also spotted Neptune in 1822.

 

[TheDaver]

Galileo, it sounds like you want to be just like your idol, Galileo.

I should remind you that he’s dead.

Get to it.

Do not advocate suicide (or harm to another poster), even in jest.

Replying to this modbox in thread will be off topic  Posted By: Lisa Simpson

 

[Galileo]

Galileo, it sounds like you want to be just like your idol, Galileo.

I should remind you that he’s dead.

Get to it.

The spirit of Galileo will never die. Galileo lives!

 

[Wangler]

To put this into normal perspective - hold your pinky at arms length - that is 1 degree in the sky

Then move your pinky closer so that it subtends an angle greater than at arms length by the based upon the magification of his telescope: if his telescope magnified ten times then move your pinky closer to your eye, so that it appears ten times larger

- the movement he saw was 1/18 of that....

Thought I would clarify this a bit.......

 

[BenBurch]

Galileo, it sounds like you want to be just like your idol, Galileo.

I should remind you that he’s dead.

Get to it.

Do not advocate suicide (or harm to another poster), even in jest.

Replying to this modbox in thread will be off topic  Posted By: Lisa Simpson

I don't read it that way, Lisa. Not even close...

 

[Stellafane]

There were quite a number of pre-discovery observations of Neptune if I recall correctly.

True. In fact one was by John Herschel, son of Willian Herschel, discoverer of Uranus. Thus the two outer planets came an inch from being discovered by a father-and-son team. (What are to odds, right?) Herschel fils was magnanamous in his failure, however, saying that it was a far greater accomplishment to discover Neptune via mathematical calculation and deduction, while his discovery would have been more or less an accident.

 

[Beerina]

No chance..... there is no way he could have resolved Neptunes movement against the background stars in only one month of observation

You've studied the level of granularity and error deviation of Galileo's scientific records, and can report it was well above that needed to detect Neptune?


Links, please! This stuff fascinates me!

 

[I Ratant]

This is an awesome thread, I beg to differ.

.
It's the same as every other thread you post.
Clueless.
Noticing something moved in the sky is not the same as "discovering", which means making it public for others to observe and confirm.

 

[Damien Evans]

Galileo discovered planet Neptune?

Press Trust Of India

Melbourne, July 07, 2009



http://www.hindustantimes.com/Story...9&Headline=Galileo+discovered+planet+Neptune?

I've heard about this before, and while it is almost certain that Galileo did indeed see Neptune he didn't realise what it was and marked it down as a star, although he did note it shifted slightly in position.

With the equipment he had at his disposal he wouldn't have been able to see any detail of Neptune and would have found it visually indistinguishable from a dim star.

 

[Soapy Sam]

Just as well he didn't announce any such discovery. He might have found things even hotter by 1633.

 

[Mojo]

True. In fact one was by John Herschel, son of Willian Herschel, discoverer of Uranus. Thus the two outer planets came an inch from being discovered by a father-and-son team. (What are to odds, right?) Herschel fils was magnanamous in his failure, however, saying that it was a far greater accomplishment to discover Neptune via mathematical calculation and deduction, while his discovery would have been more or less an accident.

Much like Galileo's observation. Interesting that Galileo doesn't seem to have been able to make the conceptual leap between an observation of a star that moved and the possibility that it was a new planet.

 

[Mangoose]

It was very lucky for him that Neptune happened to have a near conjunction with Jupiter while he was observing the Jovian moons. He wouldn't have had another opportunity like that again until May 1626. But it looks like by that time he wasn't doing daily observations of Jupiter but had moved on to microscopal work.

 

[Galileo]

Much like Galileo's observation. Interesting that Galileo doesn't seem to have been able to make the conceptual leap between an observation of a star that moved and the possibility that it was a new planet.

Another way to identify a planet from a star is if you can resolve a bounded orb, rather than just a light point. I have not read the paper, but it is possible Galileo noticed this as well. Also, planets do not twinkle, only stars do.

It is possible likely that initially Galileo thought he just made a measurement error. By the time he realized it might be a planet, he might not have been to find it. Galileo's telescope had a very small field of view.

 

[paximperium]

I have not read the paper, but it is possible Galileo noticed this as well.

There is a theme here.

Also, planets do not twinkle, only stars do.

Please tell the folks here why stars "twinkle" and planets don't.

It is possible likely that initially Galileo thought he just made a measurement error. By the time he realized it might be a planet, he might not have been to find it. Galileo's telescope had a very small field of view.

So he didn't discover Neptune. Thanks for clearing that up.