Grades 9-12 or Adult Sophisticated Learner
As the planets were getting larger and larger, there were still a lot of diffuse gases and rocky particles present in the disk of material around the Sun. These rocky particles ranged in sizes from very small clumps of rock to being bigger than many of our modern-day asteroids. They contained different kinds of minerals, gases, and some even contained water in the form of ice. We know from modern studies of meteorites, asteroids, and comets that some of these materials in the early solar system even contained simple chemical compounds such as formaldehyde, ammonia, and amino acids. These compounds were synthesized via chemical reactions in the giant molecular cloud and pre-solar nebula from which the Solar System originally formed. (See 1.1, 1.2)
The young planets were continually bombarded by these smaller chunks of rock, which in turn “delivered” water, gases, and carbon-containing compounds (organics) to the early Earth – critical components to the chemical reactions that would ultimately give rise to life. It was during this time of heavy bombardment of Earth that the Moon formed. The current theory about how Earth’s moon formed is that an extremely large chunk of rock, about the size of Mars (and nicknamed Theia), collided with the young Earth. Material was blasted off Earth’s surface but didn’t go far because of Earth’s gravitational pull and eventually coalesced to form the Moon. Thus, Earth-Moon relationship has been in effect almost since the time of Earth’s formation. The Moon’s gravitational pull on Earth influences the behavior of oceans (tides) but may also have played a role in the development of plate tectonics, a process critical to the cycling of elements and potentially necessary for the evolution of life as we know it.
The bombardments continued, and more organics, gases, and water were “delivered” to Earth. However, the continual impacts removed so many asteroids and comets that the period of heavy bombardment slowed, and Earth began to change. Water and gases, such as carbon dioxide, were emitted from volcanoes to form the early atmosphere. As Earth continued cooling, much of that steam may have condensed and contributed to the formation of global oceans. In a relatively short period of time after Earth had formed, it could have been habitable for life as we know it and definitely contained the raw materials and energy needed to give rise to life.
Disciplinary Core Ideas
ESS2.B: Plate Tectonics and Large-Scale System Interactions: Plate tectonics is the unifying theory that explains the past and current movements of the rocks at Earth’s surface and provides a framework for understanding its geologic history. (ESS2.B Grade 8 GBE) The solar system consists of the Sun and a collection of objects of varying sizes and conditions — including planets and their moons — that are held in orbit around the Sun by its gravitational pull on them. This system appears to have formed from a disk of dust and gas, drawn together by gravity.
LS4.C: Adaptation: Changes in the physical environment, whether naturally occurring or human induced, have thus contributed to the expansion of some species, the emergence of new distinct species as populations diverge under different conditions, and the decline – and sometimes the extinction – of some species. (HS-LS4-6)
PS2.A: Forces and Motion: Newton’s second law accurately predicts changes in the motion of macroscopic objects. (HS-PS2-1) *Momentum is defined for a particular frame of reference; it is the mass times the velocity of the object. (HS-PS2-2) *If a system interacts with objects outside itself, the total momentum of the system can change; however, any such change is balanced by changes in the momentum of objects outside the system. (HS-PS2-2, HS-PS2-3)
PS2.B: Types of Interactions: Newton’s law of universal gravitation and Coulomb’s law provide the mathematical models to describe and predict the effects of gravitational and electrostatic forces between distant objects. (HS-PS2-4) *Forces at a distance are explained by fields (gravitational, electric, and magnetic) permeating space that can transfer energy through space. (HS-PS2-4,HS-PS2-5)
PS1.B: Chemical Reactions: Chemical processes, their rates, and whether or not energy is stored or released can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy. (HS-PS1-4),(HS-PS1-5)
ESS1.C: The History of Planet Earth: Although active geologic processes, such as plate tectonics and erosion, have destroyed or altered most of the very early rock record on Earth, other objects in the solar system, such as lunar rocks, asteroids, and meteorites, have changed little over billions of years. Studying these objects can provide information about Earth’s formation and early history. (HS-ESS1-6)
Patterns: Different patterns may be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations of phenomena. (HS-PS2-4) Systems and System Models- When investigating or describing a system, the boundaries and initial conditions of the system need to be defined. (HS-PS2-2)
Big Ideas: Rocks, asteroids, comets and other material left over after planetary formation in space repeatedly crashed into the early Earth. These rocky particles transported water, gases, and carbon-containing compounds (organics) to the early Earth – critical components to the chemical reactions that would ultimately give rise to life. Impact with a Mars sized object led to the formation of Earth’s moon. Slowing of the bombardment allowed for a cooler Earth and the accumulation of water. Water and gases released through volcanoes contributed to the formation of the oceans and atmosphere. The liquid water supply and the right atmosphere helped create the environmental conditions on early Earth to support early life.
Boundaries: By the end of 12th grade, students learn how Newton’s second law accurately predicts changes in the motion of macroscopic objects. No details of quantum physics or relativity are included at this grade level.
6-12 A New Spin on Solar Wind: The Moon, Magnetosphere, and ARTEMIS. In this activity (2-3 lessons), students work in small groups to build their own model of the Sun-Earth-Moon system. Students use the model to demonstrate how the Earth is protected from particles streaming out of the Sun (solar wind) by a magnetic shield called the magnetosphere, and that the Moon is periodically protected from these particles as it moves in its orbit around the Earth. University of California, Berkeley/NASA. http://cse.ssl.berkeley.edu/artemis/epo-classroom-g69_NewSpinSolarWind.html
6-12 Astrobiology Math. This collection of math problems provides an authentic glimpse of modern astrobiology science and engineering issues, often involving actual research data. Students explore concepts in astrobiology through calculations. Relevant problems include Albedo and Heat Balance (page 43) and The Moon’s Atmosphere! (page 37). NASA. https://www.nasa.gov/pdf/637832main_Astrobiology_Math.pdf
7-9 SpaceMath Problem 8: Making a Model Planet. Students use the formula for a sphere, and the concept of density, to make a mathematical model of a planet based on its mass, radius and the density of several possible materials (ice, silicate rock, iron, basalt). [Topics: volume of sphere; mass = density x volume; decimal math; scientific notation] https://spacemath.gsfc.nasa.gov/astrob/Week14.pdf
7-12 SciJinks: How did the Atmosphere Form? This informational web article allows students and teachers to read about how the atmosphere of Earth changes through three main stages, including very early Earth. This information supports the continued story of how Earth became a habitable planet. NOAA/NASA. http://scijinks.gov/atmosphere-formation/
8-10 SpaceMath Problem 449: A simple model for the origin of Earth’s ocean water. Students create a simple model of the arrival of water to Earth using three sizes of cometary bodies and their arrival rates. [Topics: volume of a sphere; rates of change] https://spacemath.gsfc.nasa.gov/earth/8Page22.pdf
9-11 SpaceMath Problem 302: How to Build a Planet from the Inside Out. Students model a planet using a spherical core and shell with different densities. The goal is to create a planet of the right size, and with the correct mass using common planet building materials. [Topics: geometry; volume; scientific notation; mass=density x volume] https://spacemath.gsfc.nasa.gov/astrob/6Page72.pdf