Uranus and Neptune Flashcards
Waht is the rotation period of Neptune in hours
16.1 hours
Who calculated the position of Neptune (and in what year)
Whose lead did he follow
Urbain Leverrier in 1846
following a lead from John Couch Adams
How many moons is Uranus known to have
What makes up the three main groups
28
5 Major moons
13 small inner moons
9 small outer moons
1 other one not clear about yet. The latest moon was found in 2024
What is the mass of Neptune (in Earth masses)
What is the gravity at the surface (earth =1)
- 1
- 1
Who discovered Uranus, and in what year
What did he originally call it
When did the same astronomer discover Uranus’s two largest moons
William Herschel in 1781
Georgium Sidus (‘Georgian Star’)
Discovered the largest moons in 1787
What is the average cloud top temperature of Neptune
-201 degrees C
In what year was Pluto demoted
2006
What is the mean cloud-top temperatures on Uranus
How cold can it get
- 197C degrees
but. . it can reach -224C making it the coldest planet in the solar system
Who nearly discovered Neptune
What is the similar story behind Uranus
Galileo in 1612. He drew it behind Jupiter, but thought it was a star
Uranus was first seen in 1690 by John Flamstead who entered it in his star catalogue. it was seen another 22 times before it was discovered to be a planet
What is the mean distance of Neptune from the Sun in AU
30.1
Who came up with the name Uranus (and when)
Johann Bode in 1850
Herschel had called it Georgium Sidus (George’s Star)
What are the major moons of Uranus in order of distance from the planet (closest first), and in order of size
Miranda, Ariel, Umbriel, Titania, Oberon
In size order
Titania, Oberon, Umbriel, Ariel, Miranda
What is odd about Uranus’s magnetic field
Its off-centre and massively lopsided
What is the rotation period of Uranus in hours
17.2
Which famous English brewer discovered Umbriel and Ariel
William Lassell in 1851
Who discovered Triton and when
William Lassell in 1846 just 17 days after the discovery of Neptune
It took more than a century before another moon was found there.
What is the gravity of Uranus at the equator (with Earth =1)
0.89
How many moons does Neptune have
16
Two discovered in 2024
What provides the blue colour to Neptune’s atmosphere
methane
What is the equitorial diameter of Uranus in km
51,118 km
What is the mean distance of Uranus from the Sun in AU
19.2
After Triton, what are Neptune’s two next biggest moons
any idea how small?
Proteus (c.400km diameter)
Nereid (c.340km in diameter)
How does Triton rank in solar system moons (what is its diameter)
7th
2700km
What is the axial tilt of Uranus
What does that mean for its direction of rotation
98 degrees
It means that like Venus it rotates in a retrograde motion
How many rings does Neptune have,
when was their existance confirmed
Who are they named after
5
confirmed at the arrival of Voyager 2 in 1989
astromers who were central to Neptune’s discovery
When was Uranus’s ring system first discovered
How many rings does Uranus have (how many different types?)
1977, by a a flying observatory on a C141A Starlifter
Uranus has 13 rings, all as dark as coal
There are 11 inner rings and 2 outer rings, discovered later by Hubble in 2005.
What is the axial tilt of Neptune
28.3 degrees
What is the orbital period of Uranus in years
84.3
When did astonomers realise Uranus was straying from its predicted orbit
1843
Who first observes Neptune
Johann Galle
What is the equitorial diameter of Neptune
49,528km
What is the Mass of Uranus(in units of Earth Mass)
14.5
What is the orbital period of Neptune
164.8 years
What is odd about its heat output - what does this mean
Unlike other gas giants, it gives off less than it recieves, suggesting it may have been cooled suddenly by an immense impact (possibly the one that left it on its side)
Name of most significant feature?
Miranda (moon of Uranus)
Some of the weirdest geology in the solar system, including Verona Rupes, a 20-kilometer-high scarp that is the tallest cliff in the Solar System,
Who
William Herschel (1738 - 1822)
Why are Uranus and Neptune described as Ice Giants
What are the ices?
An ice giant is a giant planet composed mainly of substances heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur.
They consist of only about 20% hydrogen and helium in mass, as opposed to the gas giants (Jupiter and Saturn), which are both more than 90% hydrogen and helium in mass.
The atmospheres, however, are predominantly hydrogen and helium
Funny definition of ice, but there you go (Because during their formation Uranus and Neptune incorporated their material as either ices or gas trapped in water ice, the term ice giant came into use- Today, there is very little ice left in Uranus and Neptune.)
Today the ices refer to water, ammonia and methane
Why does methane in the atmosphere give a bluish hue to Uranus and Neptune
Why is Neptune so vividly blue given it has the same atmospheric methane content as Uranus
The atmospheric methane absorbs red light
The more intense colouring of Neptune is a mystery - something else must be contributing, but what it is is unknown.
Why are there such violent storms on Neptune
Differential rotation of the atmosphere
The equatorial zone rotates slow than the planet’s magnetic field
but the polar zone rotates faster than the magnetic field
These differences are the most pronounced in the solar system
When will Triton eventually collide with Neptune?
Why?
3.6billion years
Its retrograde orbit and relative proximity mean it suffers tidal deceleration.
