Solar System Formation Study Guide PDF

**Solar System Formation Study Guide.** **Important note:** Instead of cutting and pasting answers below from the PowerPoint which many of you did last time: a). First, read the content involved with each question, b). memorize what you need to know for the question asked (not word for word), c...

**Solar System Formation Study Guide.** **Important note:** Instead of cutting and pasting answers below from the PowerPoint which many of you did last time: a). First, read the content involved with each question, b). memorize what you need to know for the question asked (not word for word), c). put it into your own words, as if you had to teach it, d). answer the questions below e\. Submit the study guide 1\. What is the Nebular Hypothesis? What were the reasons why this idea was formulated many years ago? In other words, what basic observations regarding the planets lead early scientists and philosophers to create such an idea? -The Nebular Hypothesis is a hypothesis suggesting the origin of our Solar System and others as well. This theory suggests that the solar system formed from a large cloud of gas and dust. Early observations that led to this idea included the similarities in the orbits of planets, their motion in the same plane, and the presence of other nebulae in space. 2\. Briefly, according to the *Nebular Hypothesis*, how do stars and planets form? -According to the Nebular Hypothesis, stars and planets form when a nebula collapses under its own gravity, leading to the formation of a rotating disk of material. Inside of this disk, matter clumps together to form stars and planets. 3\. Why are cold, dark, molecular clouds the place of star and planet birth? Why not hot, bright clouds (nebulae)? -Cold, dark molecular clouds are ideal for star and planet formation because they are dense and shielded from any radiation. Hot and bright nebulae are often too energetic, making it harder for the matter to clump together. 4\. What is a star cluster? -A star cluster is a group of stars that are physically related or share the same origin, having formed at the same time and location. They are bound together by gravity. 5\. What was the approximate composition of the solar nebula (the nebula that formed the solar system)? -The solar nebula primarily consisted of hydrogen, helium, and a smaller amount of heavier elements like carbon or oxygen. 6\. What was the force that caused the solar nebula to collapse to form the Sun and planets? In other words, how does a cloud collapse? -The solar nebula collapsed due to gravitational forces. As the gas and dust particles were pulled together by gravity, they began to increase in their density as well as their temperature. 7\. What is the **most direct evidence,** available today that planetary systems form from revolving disks of gas and dust. -The most direct evidence we have available today comes from making observations of protoplanetary disks around young stars. These disks are rotating collections of gas and dust that eventually form planets. These observations also offer more evidence that the Nebular Hypothesis is a viable explanation. 8\. About how old is our Solar System? -Our Solar System is approximately 4.6 billion years old. 9\. What is a proplyd? -A proplyd is a protoplanetary disk, which is a rotating disk of gas and dust surrounding a young star where planets can form. 10\. What type of *event* do astronomers think triggered the formation of our solar system? -Astronomers believe that a nearby supernova explosion may have triggered the collapse of the solar nebula, providing the necessary shock ways in order to form our solar system. 11\. What is Hydrostatic equilibrium? -The Hydrostatic equilibrium is the balance between gravitational forces pulling inward and pressure forces pushing outwards in a star, which then allows for it to keep its size and stability. 12\. What is the process by which stars create energy? -Stars create their energy through nuclear fusion, primarily by fusing hydrogen into helium in their cores. 13\. Briefly, what is the proton- proton chain -The proton-proton chain is a fusion process in stars like the Sun, where hydrogen nuclei combine to form helium, releasing energy in the form of light and heat. 14\. Why do astronomers think electrostatic force was involved at the *beginning* of planet Formation. Why not explain the whole process using gravity? -Early on in planet formation, electrostatic forces helped particles stick together. Gravity only was significant later on as larger bodies formed, but at first, the smaller particles needed to overcome their motion and clump together. 15\. What is accretion? -Accretion: the coming together of small things to make them larger, usually by gravity. gas and dust in the protoplanetary disk clump together to form larger bodies, eventually leading to planet formation. 16\. How do terrestrial and giant planets differ? List as many ways as you can think of. -Terrestrial Planets: rocky , smaller, thinner atmosphere, closer to the sun -Giant Planets: gas giants, much larger, thick atmospheres, farther away 17\. Why do **rocky** planets exist closer to the Sun, while **gas** planets exist farther out? -Rocky planets form closer to the Sun where it is hotter, allowing the heavy materials to condense. Gas giants form farther out because the temperatures are cooler, allowing gases to accumulate. ONLY METAL AND ROCK CAN EXIST NEAR THE SUN! the young sun also influenced the distribution of materials. 18\. Why are the cores of planets mostly metal, and the crusts mostly rock? -the cores of planets are mostly metal due to the sinking of heavier materials during the differentiation process, the lighter materials form the crust. 19\. Why is Jupiter so much more massive than the other planets (How do we think this happened)? What is the "snow-line"? -Jupiter is more massive because it formed in a region with plenty of material for it to take. The "snow-line" is the distance from the Sun beyond which it was cool enough for ices to condense, helping these giant planets gather more and more mass. Jupiter formed around here, and the icy cores that formed had a huge size and huge amount of gravity, hydrogen and helium were pulled on top giving a solid core yet a gassy atmosphere. 20\. According to theory, why are Uranus and Neptune less massive than Jupiter and Saturn? -Uranus and Neptune are less massive because they formed in a region with less material available and were not able to accumulate as much gas as Jupiter and Saturn had. 21\. How did terrestrial planets differentiate? In other words, why are these planets layered Into core, mantle, and crust. How did this happen? -Terrestrial planets differentiated due to melting from heat generated by impacts and radioactive decay, allowing denser materials to sink to the center and lighter materials to rise. 22\. Why are the densest materials of planets found in their cores? -The densest materials are found in cores because they simply sink under the gravity during that differentiation process while lighter materials remain in the outer layers. 23\. Why didn't asteroids collect together to form a large planet? Where is the asteroid belt located? -Asteroids did not collect together into a larger planet due to the gravitational influence of Jupiter, which disrupted their formation. The asteroid belt is located between Mars and Jupiter. 24\. The asteroid belt is theorized to have lost a lot of mass? How did this happen? -The Asteroid belt lost mass due to collisions between the asteroids that broke them apart, along with the gravity from nearby planets. 25\. With respect to Solar System exploration, why is the study of asteroids important? -Studying asteroids helps us understand the building blocks of the solar system, the processes of planet formation and it can provide knowledge into the early solar system conditions. 26\. Hydrogen and helium (not all of helium) were produced in the big bang, but how about heavier elements? Where are they made? How about the heaviest elements, like metals. -Heavier elements are primarily formed in stars through nuclear fusion and during supernova explosions. The heaviest elements are created during these explosive events.