Skip to main content
45 votes
Accepted

Why wasn't the planet Uranus recognized by ancient cultures?

The source of light that is Uranus was observed as far back as 128 BC. However it was misidentified as star as late as the 1760's. Then it was observed by Herschel in 1781, who also misidentified it,...
StephenG - Help Ukraine's user avatar
43 votes

Why is Uranus called a "green planet"?

I think your issue is linguistic not astronomical. The way a language cuts up the space of colours into discrete names is varies strongly from one language to another, and even from one dialect to ...
James K's user avatar
  • 123k
27 votes

Why wasn't the planet Uranus recognized by ancient cultures?

I like ScienceSnake's comment - a combination of faintness and its comparatively small apparent motion. It was observed in 1690 by John Flamsteed on several occasions, but because it moved so little ...
Bumptious Q Bangwhistle's user avatar
26 votes
Accepted

Are spacecraft visits to Uranus and Neptune hard to plan?

Uranus and Neptune are far - in orders of light-hours away. It took Voyager 2 nearly a decade to reach Uranus since its launch, costing almost $1B to build it in the first place. It's not that we can'...
4NT4R3S's user avatar
  • 1,015
17 votes

Why is Uranus called a "green planet"?

This answer looks into why Uranus is "green" or at least greener compared with Neptune's blue. Both planets have similar atmospheric compositions and would ordinarily be expected to show ...
Oscar Lanzi's user avatar
  • 1,121
15 votes

Why wasn't the planet Uranus recognized by ancient cultures?

It would require a lucky coincidence As noted by others, Uranus is faint and easy to misidentify as a fixed star. However, Bourtembourg 2013 claims that Uranus was observed already in 128 BC by ...
Martin Modrák's user avatar
8 votes

Why is Uranus called a "green planet"?

This is just a mere illusion. In reality, the peak wavelength is actually between green and blue, that is slightly cyanish/turquoise. The reason this happens is because the atmosphere of Uranus ...
Arjun's user avatar
  • 1,464
6 votes

Why is Uranus called a "green planet"?

A convenient pattern Uranus’ color is somewhere between green and blue. Since a lot of space trivia is in the purview of elementary education, and since patterns are useful for memorizing, it’s ...
Spencer Joplin's user avatar
5 votes
Accepted

Why are heavier hydrocarbons not present in lower part of Uranian atmosphere?

Methane is more abundant in the thermosphere and the stratosphere. On the stratosphere, the Wikipedia article you cite says The most abundant stratospheric hydrocarbons after methane... Also note ...
ProfRob's user avatar
  • 153k
5 votes

Why is Uranus called a "green planet"?

Although both Uranus and Neptune exhibit a color palette ranging from deep blue to pale green, there is a prime difference in the atmospheric composition which determines the color difference. In the ...
Nilay Ghosh's user avatar
  • 4,477
3 votes

Why are heavier hydrocarbons not present in lower part of Uranian atmosphere?

No knowledge on the subject, but I'd venture from looking through that article that it could well be the same reason lighter $O_2$ has peak concentrations in the troposphere on Earth, while heavier $...
JeopardyTempest's user avatar
3 votes
Accepted

Why is Neptune a darker blue than Uranus?

According to a new study the images of Neptune that we usually see are colour-enhanced to pick out features and that actually Uranus and Neptune are pretty much the same colour. https://phys.org/news/...
sno's user avatar
  • 1,456
1 vote

Are spacecraft visits to Uranus and Neptune hard to plan?

They're expensive for sure, and you will be giving something up if you plan and build for such a mission. Since Voyager, the priorities haven't aligned for any such mission to be chosen over other ...
BowlOfRed's user avatar
  • 2,085

Only top scored, non community-wiki answers of a minimum length are eligible