ASTR 1040 8
The nucleus of a comet is a dirty snowball, a loose mixture of ice and dust about 10 km across. In the diagram of a comet orbiting the Sun, identify the comet's nucleus, coma, hydrogen envelope, ion tail, and dust tail.
A: Nucleus B: Coma C: Hydrogen Envelope D: ion tail E: dust tail
Jupiter's rapid rotation (every_____hours) produces powerful winds called______ streams, and we see these winds as the cloud belts that stretch around the planet. Winds in adjacent belts may blow in_______directions. As gas rises between the belts, it is spun into huge, whirling atmospheric vortices. The largest vortex, called_______the Spot, was discovered in 1664 and is larger than Earth. Convection in Jupiter's liquid metallic hydrogen interior combines with the planet's rapid rotation to generate a magnet field about 20,000 times______than Earth's.
Answer 1: 10 Answer 2: jet Answer 3: opposite Answer 4: Great Red Answer 5: stronger
Jupiter is the largest planet in our Solar System. It is slightly more than______times Earth's diameter, and_____times its mass. Jupiter's atmosphere consists mostly of hydrogen and helium, and hydrogen-rich gases such as methane (CH4),______ (NH3), and_____ (H2O). Deep within Jupiter, the compression created by its gravity presses molecules so close together that the gas changes to liquid hydrogen and, even deeper, liquid metallic hydrogen. Jupiter probably has a rock and iron_____about 18 times Earth's mass. Jupiter radiates________energy from its hot interior than it receives from the Sun! Also, Jupiter has a system of very faint________made of tiny particles of rock dust.
Answer 1: 11 Answer 2: 300 Answer 3: methane Answer 4:ammonia Answer 5: water Answer 6: metallic Answer 7: core Answer 8: more Answer 9: rings
About______years ago, a meteoroid about 50 meters in diameter hit Earth 40 miles east of Flagstaff, Arizona. Its impact vaporized tons of rock, which expanded and peeled back the ground, creating a crater (called Meteor Crater) about 1.2 kilometers across and 200 meters deep. The animals within 3 to 4 km of the impact site would have been subjected to winds exceeding 2000 km/hour and killed. A 50 percent casualty rate would occur between 9 and 14 km of the impact site due simply to bodies being picked up by the air blast and accelerated to a few to tens of kilometers per hour before being slammed back down again. Animals as far away as 16 to 24 km would have been injured severely. Vegetation would have been almost completely destroyed over an area of 800 to 1500 km2 around the Meteor Crater impact site. The graph below shows how often impacts of different sizes occur. An impact the size of the one that formed Arizona's Meteor Crater 50,000 years ago occurs roughly once every thousand years. In 1908, an asteroid broke up in our atmosphere over a largely uninhabited part of north-central Siberia, in a region known as Tunguska. The blast leveled trees out to a distance of 30 km, and two people were reportedly killed. More recently, on February 15, 2013, an asteroid exploded in the air in Chelyabinsk, Russia (coincidentally, also in Siberia). About 1,500 people were injured seriously enough to seek medical treatment. All of the injuries were due to indirect effects rather than the meteor itself, mainly from broken glass from windows that were blown in when the blast wave arrived. It is the largest known asteroid to have entered Earth's atmosphere since the 1908 Tunguska event. According to the graph below, an impact the size of the two Siberian events occurs roughly once every____years.
Answer 1: 50,000 Answer 2: 50 Answer 3: thousand Answer 4: few hundred
_____are small, generally rocky bodies that orbit the Sun. More than 100,000 asteroids orbit the Sun in the____belt between the orbits of____, stretching from 2 AU to 4 AU from the Sun. Just as the gravity of Saturn's moon Mimas maintains Cassini's division in Saturn's____ , Jupiter's gravity maintains the Cassini gaps in the asteroid belt. Most of the asteroids have diameters of less than a kilometer, but a few of them are very large. The largest,____, was the first to be discovered; it is about 1000 kilometers across and is now classified as a dwarf planet . The existence of stony and iron asteroids is strong evidence that the process of ____(heavier elements sinking and lighter elements rising) occurred in the larger bodies, with the heavy iron and nickel sinking to the core. After differentiation, collisions with neighboring asteroids broke up most of the large bodies. The fragments are what we see today: pieces of crust became___asteroids, and pieces of core became ______asteroids.
Answer 1: Asteroids Answer 2: asteroid Answer 3: Mars and Jupiter Answer 4: rings Answer 5:Kirkwood Answer 6: asteroid Answer 7: Ceres Answer 8: dwarf planet Answer 9: differentiation Answer 10: stony Answer 11: iron
The four Galilean moons of Jupiter (those discovered by____) were likely formed by a scaled-down version of the process that created the Solar System. In order of increasing distance, these moons are Io (closest),_____,_____, and ____ (farthest). They probably aggregated from______and gas that collected around Jupiter during its formation. Jupiter heated this orbiting debris, affecting the composition and density of the moons that formed from it. Such heating would melt ices and partially evaporate them so that the moons nearest Jupiter would have______ice and gas and therefore be denser , much as the Sun heated the solar nebula, thereby creating the difference between the terrestrial and outer planets. Evidence that Jupiter heated its moons comes from their density: the densest Galilean satellites are those nearest to Jupiter. The farther a Galilean moon is from Jupiter, the_______dense it is.
Answer 1: Galileo Answer 2: Io Answer 3: Europa Answer 4: Ganymede Answer 5: Callisto Answer 6: planetesimals Answer 7: less Answer 8: denser Answer 9: less
The number of surface craters found on the four Galilean satellites of Jupiter increases steadily from____, the innermost moon, to_____, the outermost moon. The reason for this is that______has the youngest surface, and_____has the oldest surface. Processes that are capable of covering craters are most important on the surface of_____, but are not as important on the more distant moons.
Answer 1: Io Answer 2: Callisto Answer 3: Io Answer 4: Callisto Answer 5: Io
These differences in the orbits of planets and comets have led astronomers to understand that comets come from two regions of the Solar System. Over 30,000 comet nuclei in the____belt orbit the Sun, extending out to about 50 AU from the Sun. Most of the short-period comets come from the Kuiper belt. Trillions of comets nuclei are found in the_____cloud, a spherical shell of comet nuclei that extends as much as 150,000 AU from the Sun (see Figure 11.19).
Answer 1: Kuiper Answer 2: Kuiper Answer 3: Oort
Where did the particles in Saturn's rings come from? A planet's ____ limit is the closest distance a moon can be to a planet. If a moon gets any closer than ______planetary radii, it will be torn apart by the planet's gravitational tidal force. All of Saturn's large moons are _____Saturn's Roche limit, and all of the rings are inside Saturn's Roche limit. Saturn's rings may be formed by the breakup of objects that stray ______ the Roche limit.
Answer 1: Roche Answer 2: 2.44 Answer 3: outside Answer 4: inside
Beyond Neptune's orbit are objects (probably surviving icy planetesimals) called Trans-Neptunian Objects (TNOs). Many of these TNOs orbit the Sun in the____ belt, which extends from beyond Neptune's orbit to perhaps 50 AU from the Sun. Relatively little is known about TNOs since only Pluto has been visited by spacecraft, although Neptune's moon___may be a captured TNO. Pluto and its moon ____are both TNOs.____is the second-largest known TNO. On July 14, 2015, NASA's New Horizons spacecraft flew by Pluto. When the first close-ups of Pluto's surface were received, astronomers were amazed to discover that the surface was free of craters and had prominent mountains. As you learned in Module 6, a surface with only a few craters is_____than a surface with many craters. This means that Pluto's____surface must be geologically____ Somehow mountains have been lifted up above the plains, and the plains continually renewed to cover the craters that must have formed there in the past. But exactly how did these events happen? These are new mysteries for astronomers to investigate. The largest known TNO is Eris . Like Pluto's orbit, its orbit is highly elliptical and highly inclined to the main disk of the Solar System. TNOs may have formed nearer the Sun, perhaps near Neptune, and were then ejected into their present orbits by successive____tugs exerted by the massive outer planets. In 2006 the International Astronomical Union came up with the designation_____to describe the larger TNOs like Pluto and Eris.
Answer 1: Trans-Neptunian Objects Answer 2: Kuiper Answer 3: Triton Answer 4: Charon Answer 5: Pluto Answer 6: younger Answer 7: young Answer 8: active Answer 9: Eris Answer 10: gravitational Answer 11: dwarf planet
Saturn's rings are composed primarily of water-ice. Particles in the darker rings may be rich in____compounds. These ring particles are relatively_____, only a few centimeters to a few meters across. Each ring particle orbits Saturn in its own individual orbit that obeys Kepler's laws. A gap in the rings called_____is caused by Saturn's moon____. (The discoverer of Cassini's division wrongly believed the gap was caused by another of Saturn's moons, Enceladus.) A ring particle in Cassini's division would orbit Saturn_____as fast as Mimas. This means that the ring particle would line up with Mimas every two orbits. The repeated tugs of Mimas' gravity thus keeps Cassini's division clear of particles.
Answer 1: carbon Answer 2: small Answer 3: Cassini's division Answer 4: Mimas Answer 5: twice Answer 6: clear of
Geological evidence indicates that, 65 million years ago, Earth experienced a huge impact. The relatively high abundance of the otherwise rare element iridium in a layer of clay laid down 65 million years ago suggests that the impacting body was an_____. The incoming body was about 10 km in diameter and traveling about 40,000 kilometers per hour when it slammed into Mexico's Yucatan Peninsula and left the crater, 180 km in diameter, that we see today. The blast sent huge amounts of dust and molten rock into the air. The molten rock raining down raised the surface temperature as high as that under a broiler and ignite global____. This was followed by months of darkness and intense cold caused by the dust shroud blotting out the Sun. The result was a mass extinction. Two-thirds of all the species on Earth died out, including the_____. This allowed small, furry______to rise and eventually dominate life on Earth.
Answer 1: iridium Answer 2: asteroid Answer 3: wildfires Answer 4: dinosaurs Answer 5: mammals
Titan, the________of Saturn's moons, is slightly bigger in diameter than the planet Mercury. Because Titan is so cold , gas molecules that leak from Titan's interior move relatively slowly and are unable to escape Titan's gravity. This immense moon therefore possesses its own atmosphere, which is mostly nitrogen. The clouds in Titan's atmosphere are made of_______(CH4). A probe, the Huygens lander, landed on Titan in 2005. On its way down, Huygens photographed river networks carved by flowing liquid_____. On the surface the lander found chunks of____
Answer 1: largest Answer 2: cold Answer 3: methane Answer 4: methane Answer 5: water ice
Although the asteroid belt is not crowded with asteroids, collisions do occur. The photo shows an asteroid collision observed in January, 2010. When asteroids collide, a smaller fragment (less than a few hundred meters across) is called a____. When a meteoroid plunges through our atmosphere, it heats and produces a streak of light called a _____(a "shooting star"). If a piece of rock reaches the ground intact, it is called a____. About 300 tons of extraterrestrial material, mostly dust, fall on Earth every day.
Answer 1: meteoroid Answer 2: meteor Answer 3: meteorite
Both Uranus and Neptune have a deep blue color. These planets are composed mostly of a hot mixture of water, ammonia, and methane surrounded by a thin atmosphere rich in hydrogen and hydrogen compounds such as_____(CH4). They look blue because of the methane in their atmospheres. Both planets have small cores of rock and iron. Both planets have a system of thin, dark rings that are probably rich in carbon particles or organic molecules. However, Neptune's ring particles are not distributed uniformly around the ring but are gathered into____
Answer 1: methane Answer 2: methane Answer 3: carbon Answer 4: arcs
Both Uranus and Neptune, and their moons, have unusual characteristics that can be attributed to violent events. Uranus axis of rotation lies nearly 8o below the plane of its orbit, so it rotates nearly on its side! Perhaps Uranus was struck by an enormous____ whose impact tilted the planet. However, both Uranus' and Neptune's magnetic fields are oriented in a direction similar to the magnetic fields of Earth, Jupiter, and Saturn. Uranus' moon____has a patchwork appearance that has been altered drastically since its formation, probably when it was shattered by impact with another large body. Neptune's moon _____orbits Neptune in a "backward" direction, and its orbit is highly tilted with respect to Neptune's equator. These observations indicate that_____came from the_____belt, and was captured by Neptune. This gravitational capture may explain why Neptune's outermost moon,______, follows a highly elliptical path that carries it far beyond Neptune's other moons.
Answer 1: planetesimal Answer 2: Miranda Answer 3: Triton Answer 4: Triton Answer 5: Kuiper Answer 6: Nereid
The orbits of comets around the Sun are different than the orbits of the planets in two ways. Although both planets and comets move in elliptical orbits around the Sun, the orbits of the____are nearly circular, while the orbits of the_____are highly elongated. The_____all orbit the Sun in the same orbital plane and in the same direction, while the____have orbit that are highly tilted with respect to the orbital plane. When Earth passes through the dusty debris strewn along a comet's orbit, the scattered material plunges into our atmosphere, producing a ____shower. The meteors appear to be coming from one point in the sky, called the_____.
Answer 1: planets Answer 2: comets Answer 3: planets Answer 4: comets Answer 5: meteor Answer 6: radiant
Saturn is the_____-largest planet in the Solar System. It is 9.5 times Earth's diameter, and 95 times its mass. Saturn and_____have similar hot interiors and similar compositions. Like Jupiter, Saturn radiates ______energy from its hot interior than it receives from the Sun. The difference in appearance between Saturn and Jupiter is due to____greater distance from the Sun and its consequently lower
Answer 1: second Answer 2: Jupiter Answer 3: more Answer 4: Saturn's
Io is covered with a rich red, yellow, and orange layer of______deposits. This colorful layer has been deposited by eruptions from______on Io's surface. Every 100 years Io ejects enough material to cover its surface to a depth of one meter, and any impact craters would quickly be covered. Europa is the smoothest object in the Solar System. The absence of large craters on its surface suggests that Europa's surface must be very_____. Europa's surface is almost pure frozen_____. It's slushy ice crust slowly flows like a ______, obliterating craters as they form. Below Europa's crust there may be an ocean of______water, perhaps 100 km deep. Ganymede and Callisto look somewhat like our own Moon, and are covered with____. However, unlike our Moon, the surfaces of Ganymede and Callisto are probably mostly______. Ganymede's surface is_____ heavily cratered than Callisto's, implying that craters in the smoother areas have been destroyed. Astronomers think that after Ganymede's surface solidified and was covered by infalling debris, a few large bodies may have hit it. These large bodies created basins that subsequently flooded with water from a liquid water ocean beneath its icy crust. The water then froze into a relatively smooth surface with few craters.
Answer 1: sulfur Answer 2: volcanoes Answer 3: young Answer 4: water Answer 5: glacier Answer 6: liquid Answer 7: craters Answer 8: ice Answer 9: less Answer 10: few
By looking at the diagram, you can tell which direction the comet is moving along its orbit.
False
