Download Astronomy 100 -- Worksheet #7 THE JOVIAN PLANETS 1) The

Astronomy 100 -- Worksheet #7
THE JOVIAN PLANETS
1) The Jovian planets, also called the _____________________, are _____________,
_____________, _____________, and _____________.
They are characterized by
_____________ densities (like water), _____________ distances from the Sun, _____________
moons, cool _____________, and rapid _____________. These planets are also much
_____________ (larger/smaller) than the terrestrial planets.
2) The largest planet in the solar system is _____________.
3) Saturn was long thought to be the only planet with rings, but in the last 3 decades, ring systems have also been discovered around _____________, _____________, and _____________.
4) In contrast to the rotation of the terrestrial planets, the Jovian planets all undergo
_____________ rotation, which leads to their _____________ shape.
5) Jupiter’s atmosphere exhibits high and low pressure systems, along with storms which persist
for hundreds of years. Because of Jupiter’s rapid rotation, these high and low pressure systems
are seen to wrap around the planet as dark and light _____________.
6) Jupiter’s atmosphere is made up primarily of _____________ gas, with some helium,
methane, and amonia as well. An atmosphere made up of these 4 gases is also known as a
_____________ atmosphere.
7) Jupiter has more than 16 satellites, the largest 4 of which were discovered by
_____________. The satellite _____________ was observed by the Voyager spacecraft to have
active volcanos, and is believed to have a molten interior due to the tidal forces from Jupiter.
8) The planet with a density lower than that of water is _____________. This planet would float
in a bathtub, if there were one big enough.
9) Saturn has a spectacular _____________ system which surrounds the planet. These are composed of _____________ and _____________ which orbit Saturn in elliptical orbits with periods
which obey Kepler’s _____________ Law.
10) Saturn has more than 18 satellites, one of which is surrounded by an atmosphere. This satellite, _____________, has an atmosphere made mostly of nitrogen and has a similar density to
Earth’s atmosphere.
11) In the year 1780, the number of known planets in our solar system was _____________.
12) In 1781, the planet _____________ was discovered by accident by Sir William Herschel,
and originally it was not known whether it was a _____________ or a _____________.
-213) Today, we know that this planet is large, low density, cold, rapidly rotating, and has 15 satellites -- it is therefore classified as a _____________ planet.
14) The planet Uranus is unique in that its _________________________ lies in the plane of the
ecliptic. Consequently, its ring system and satellites lie in the plane of
____________________________.
15) An 8th planet was suspected in the 1830’s based on deviations of the orbit of Uranus from
the predictions following Newton’s Law of Gravity. If these deviations were due to the gravitational pull of an outer planet, the deviations in Uranus’s orbit could be used to calculate the location of the 8th planet. By such a method, the planet _____________ was eventually discovered
in 1846 after it was mathematically predicted by astronomers in England (John Adams) and
France (Urbain LeVerrier).
16) The planet Neptune is large, low density, rapidly rotating, with 8 known satellites and a
primitive atmosphere -- it is therefore classified as a _____________ planet.
17) In the early 1900’s, a 9th planet was suspected based on deviations of the orbit of Neptune
from the predictions following Newton’s Law of Gravity. If these deviations were due to the
gravitational pull of an outer planet, the deviations in Neptune’s orbit could be used to calculate
the location of the 9th planet. Unlike Neptune, however, searches for the 9th planet continued
for 25 years before success yielded the discovery of the planet _____________.
18) Pluto was a challenge to discover because this planet has an orbit which is oriented at an angle of _________________ relative to the ecliptic, unlike the much _____________ (smaller/larger) inclination angles of the orbits of the other planets.
19) The planet Pluto is so far from the Sun that we know little about this planet. It is cold and
low density like the _____________ planets, but it is also small with a solid surface and slow rotation like the _____________ planets. Pluto is unique.
20) The discovery of Pluto’s moon Charon is important because observations of the orbit of this
satellite indicate Pluto’s _____________.
21) The orbit of Pluto is so eccentric (= highly elliptical) that there are times when Pluto is closer to the Sun than ______________ ! On average, Pluto is ________ A.U. from the Sun, compared to Neptune’s distance of _________________ A.U., although in 1996 Pluto was closer
than __________ A.U. to the Sun.