ASTRONOMY SCI 214 Week 4 - 5 PDF

Preview

Summary

Sample worksheet for the course ASTRONOMY....

Description

Week 4-5 Jovian Planets and Space Debris & Beyond Solar System Big Picture Week 4-5: Unit Learning Outcomes (ULO): At the end of the unit, you are expected to Develop critical thinking and foster comprehension which is relevant for higher learning in the field of Science, specifically to; a. Describe the features of the Jovian planets. b. Define the different space debris and describe its features. Big picture in Focus: ULOa. Describe the different features of the Jovian planets.

Metalanguage In this unit, features of the Jovian planets are discussed. Essential Knowledge Composition Jupiter, Saturn, Uranus and Neptune collectively make up the group known as the Jovian planets. The general structures of the jovian planets are opposite those of the terrestrial planets. Rather than having thin atmospheres around relatively large rocky bodies, the Jovian planets have relatively small, dense cores surrounded by massive layers of gas. Made almost entirely of hydrogen and helium, these planets do not have solid surfaces. THE JOVIAN PLANETS

Rotation HOW ROTATION AFFECTS PLANET SHAPES

Unlike the spherical shapes of terrestrial planets, the Jovian planets are all slightly oblong. The Jovian planets rotate much faster than any of the terrestrial worlds. Gravity by itself would make a planet spherical, but their rapid rotation flattens out their spherical shapes by flinging material near the equator outward. Observations of clouds at different latitudes suggest that the Jovian planets rotate at different speeds near their equators than near their poles. JOVIAN "DAYS" 

Jupiter : 10 hours

 

Saturn : 10 hours Uranus : 16-17 hours



Neptune : 16-17 hours

Moons and rings After size, perhaps the most noticeable difference between the Jovian and terrestrial planets involves moons and rings. The terrestrial planets are nearly isolated worlds, with only Earth (1 moon) and Mars (2 moons) orbited by any moons at all. In contrast, many moons and rings orbit each of the Jovian planets. All four Jovian planets have rings, although only Saturn's rings are easily visible from Earth. Rings are composed of countless small pieces of rock and ice, each orbiting its planet like a tiny moon. The rings look flat because the particles all orbit in essentially the same plane. The rings are located closer to the planets than any of their moderately sized or large moons, but the inner edge of the rings is still well above the planet's cloud tops.

JUPITER AND ITS MOONS.

SATURN’S RING AND MOONS. ATMOSPHERES Cloud altitude in Jovian Planet Atmospheres The atmospheres of Jupiter and Saturn are made almost entirely of hydrogen and helium, although there is some evidence they contain hydrogen compounds. Uranus and Neptune are made primarily of hydrogen compounds, with smaller traces of hydrogen, helium, metal and rock. The most common hydrogen compounds are methane (CH4), ammonia (NH3), and water (H2O). The farther away a planet is from the Sun, the cooler its atmosphere will be. This means that the same gases will condense to form clouds at different altitudes on different planets because the condensation of a gas requires a specific amount of

pressure and temperature. Ammonia, ammonium hydrosulfide and water make up the 3 cloud layers of Jupiter and Saturn. You can see from the graph to the right that these condense at lower altitudes in Saturn's atmosphere than they do in Jupiter's atmosphere. INTERIOR The cores of all four Jovian planets are made of some combination of rock, metal and hydrogen compounds. Jupiter and Saturn have similar interiors, with layers extending outward of metallic hydrogen, liquid hydrogen, gaseous hydrogen, and topped with a layer of visible clouds. Unlike Jupiter and Saturn, Uranus and Neptune have cores of rock and metal, but also water, methane and ammonia. The layer surrounding the core is made of gaseous hydrogen, covered with a layer of visible clouds similar to Jupiter's and Saturn's.

Jovian Plant Interior

Just like the terrestrial planets, the deeper you go, the hotter and denser it gets. An increase in temperature and density means an increase in pressure.

Jupiter’s Density Let’s check Short answer questions 1. What almost entirely Jovian planets are made of? 2. The Jovian planet with the most visible ring. 3. What composes the ring of a Jovian planet? 4. What elements are more abundant in Jupiter and Saturn? Uranus and Neptune? 5. What comprises the cores of a Jovian planet? 6. What are the distinguishing feature of Uranus’ and Neptune’s core to Jupiter’s and Saturn’s core? 7. The surrounding of a Jovian planet’s core is made of? Let’s analyze Discuss your answers in 5 – 10 sentences. 1. What does an increase in temperature and density means if you go deeper in a Jovian planet’s core? 2. Why does the atmosphere becomes cooler as it gets farther from the sun? In a nutshell If you are going to choose among the Jovian planets to live in, what planet will you choose? Why? Record a 1 – 2 minutes video of yourself explaining your answer.

Big picture in Focus: ULO. Define the different space debris and describe its features. Space Debris and Beyond Solar System What Are Meteorites? A meteorite is the term given to a piece of a comet or asteroid that falls into the Earth’s atmosphere and survives to hit the surface. These objects come in three easy-to-remember categories: stony, metallic and stony metallic. Stony meteorites, as the name implies, are made from rocky material not all that different from what's found in the ground on our planet. These objects are the most common type of meteorites and are thought to represent leftover fragments from the creation of our solar system. Such meteorites often contain organic, or carboncontaining, compounds, the molecular basis of living organisms, and sometimes even traces of water, suggesting that the ingredients for life may have originated before our world was born. Metallic meteorites contain mostly iron and nickel, while stony-metallic meteorites are made from both rocky and metallic material. Asteroids Asteroids, sometimes called minor planets, are rocky remnants left over from the early formation of our solar system about 4.6 billion years ago.The current known asteroid count is: 992,191 Most of this ancient space rubble can be found orbiting the sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta—the largest at about 329 miles (530 kilometers) in diameter - to bodies that are less than 33 feet (10 meters) across. The total mass of all the asteroids combined is less than that of Earth's Moon. Most asteroids are irregularly shaped, though a few are nearly spherical, and they are often pitted or cratered. As they revolve around the sun in elliptical orbits, the asteroids also rotate, sometimes quite erratically, tumbling as they go. More than 150 asteroids are known to have a small companion moon (some have two moons). There are also binary (double) asteroids, in which two rocky bodies of roughly equal size orbit each other, as well as triple asteroid systems. Composition

The three broad composition classes of asteroids are C-, S-, and M-types. 

 

The C-type (chondrite) asteroids are most common, probably consist of clay and silicate rocks, and are dark in appearance. They are among the most ancient objects in the solar system. The S-types ("stony") are made up of silicate materials and nickel-iron. The M-types are metallic (nickel-iron). The asteroids' compositional differences are related to how far from the sun they formed. Some experienced high temperatures after they formed and partly melted, with iron sinking to the center and forcing basaltic (volcanic) lava to the surface.

Jupiter's massive gravity and occasional close encounters with Mars or another object change the asteroids' orbits, knocking them out of the main belt and hurling them into space in all directions across the orbits of the other planets. Stray asteroids and asteroid fragments slammed into Earth and the other planets in the past, playing a major role in altering the geological history of the planets and in the evolution of life on Earth. Scientists continuously monitor Earth-crossing asteroids, whose paths intersect Earth's orbit, and near-Earth asteroids that approach Earth's orbital distance to within about 45 million kilometers (28 million miles) and may pose an impact danger. Radar is a valuable tool in detecting and monitoring potential impact hazards. By reflecting transmitted signals off objects, images and other information can be derived from the echoes. Scientists can learn a great deal about an asteroid's orbit, rotation, size, shape, and metal concentration. Asteroid Classifications Main Asteroid Belt: The majority of known asteroids orbit within the asteroid belt between Mars and Jupiter, generally with not very elongated orbits. The belt is estimated to contain between 1.1 and 1.9 million asteroids larger than 1 kilometer (0.6 mile) in diameter, and millions of smaller ones. Early in the history of the solar system, the gravity of newly formed Jupiter brought an end to the formation of planetary bodies in this region and caused the small bodies to collide with one another, fragmenting them into the asteroids we observe today. Trojans: These asteroids share an orbit with a larger planet, but do not collide with it because they gather around two special places in the orbit (called the L4 and L5 Lagrangian points). There, the gravitational pull from the sun and the planet are balanced by a trojan's tendency to otherwise fly out of the orbit. The Jupiter trojans form the most significant population of trojan asteroids. It is thought that they are as numerous as the asteroids in the asteroid belt. There are Mars and Neptune trojans, and NASA announced the discovery of an Earth trojan in 2011. Near-Earth Asteroids: These objects have orbits that pass close by that of Earth. Asteroids that actually cross Earth's orbital

path are known as Earth-crossers. As of June 19, 2013, 10,003 near-Earth asteroids are known and the number over 1 kilometer in diameter is thought to be 861, with 1,409 classified as potentially hazardous asteroids - those that could pose a threat to Earth. Comets As theorized by astronomer Gerard Kuiper in 1951, a disc-like belt of icy bodies exists beyond Neptune, where a population of dark comets orbits the Sun in the realm of Pluto. These icy objects, occasionally pushed by gravity into orbits bringing them closer to the Sun, become the so-called short-period comets. Taking less than 200 years to orbit the Sun, in many cases their appearance is predictable because they have passed by before. Less predictable are long-period comets, many of which arrive from a region called the Oort Cloud about 100,000 astronomical units (that is, about 100,000 times the distance between Earth and the Sun) from the Sun. These Oort Cloud comets can take as long as 30 million years to complete one trip around the Sun. Each comet has a tiny frozen part, called a nucleus, often no larger than a few kilometers across. The nucleus contains icy chunks, frozen gases with bits of embedded dust. A comet warms up as it nears the Sun and develops an atmosphere, or coma. The Sun's heat causes the comet's ices to change to gases so the coma gets larger. The coma may extend hundreds of thousands of kilometers. The pressure of sunlight and high-speed solar particles (solar wind) can blow the coma dust and gas away from the Sun, sometimes forming a long, bright tail. Comets actually have two tails―a dust tail and an ion (gas) tail. Most comets travel a safe distance from the Sun―comet Halley comes no closer than 89 million kilometers (55 million miles). However, some comets, called sungrazers, crash straight into the Sun or get so close that they break up and evaporate. Let’s check Short answer questions: 1. What are the three categories of meteorites? 2. Describe an asteroid briefly. 3. Describe each of the types of asteroid’s composition following: a. C – type b. S – type c. M – type

4. What changes an asteroid’s orbit? 5. Explain each of the following asteroid classifications: a. Main asteroid belt b. Trojans c. Near – Earth Asteroids Let’s analyze what do you think will happen of the following events occur? 1. No asteroid belts 2. No gravitational pull from the sun. 3. No gravitational pull from the planets. In a nutshell If you were to rewrite the theory on the extinction of the dinosaurs due to asteroid collision, what would you want to write instead?...