ESS 1 Stars and Big Bang Theory

The brightness of a star.

The temperature of a star's surface.

The amount of matter in a star.

A shift in the light from distant galaxies towards the red end of the spectrum.

The faint microwave radiation that fills the universe, believed to be leftover radiation from the Big Bang.

The planets Mercury, Venus, Earth, and Mars. These planets are smaller, denser, and rocky.

The planets Jupiter, Saturn, Uranus, and Neptune. These planets are larger, less dense, and gaseous.

The estimated age of the universe is about 13.7 billion years old, and Earth is estimated to be about 4.5 billion years old.

A celestial object composed of gas, dust, and billions of stars held together by gravity.

A giant ball of hot gas that generates energy through nuclear fusion.

A small, rocky object that orbits the Sun.

A large, icy object that orbits the Sun and leaves a trail of gas and dust.

An area of space containing gas and dust, primarily hydrogen and helium, where stars are formed.

The process that powers stars, where light atomic nuclei fuse together to form heavier nuclei, releasing energy in the process.

A number that measures how circular or elliptical an orbit is. A value of 0 represents a perfectly circular orbit, while a value closer to 1 indicates a more elongated ellipse.

A closed curve where the sum of the distances from any point on the curve to two fixed points called foci is constant.

Rocks are dated by measuring the amount of radioactive isotopes remaining in a sample, then comparing this amount to the original amount the rock started off with.

The time it takes for half of the unstable isotopes in a sample to decay into stable isotopes.

Atoms of the same element that have the same number of protons but different numbers of neutrons. Some are unstable and break down.

Fossils that are easily recognizable, widespread, and existed for a relatively short period of time, allowing scientists to date rocks.

The order of geologic time units from longest to shortest, showing the history of the Earth.

Less dense materials rise to the surface, while denser materials sink. This process plays a key role in plate tectonics.

Fossils provide evidence of how species have evolved and adapted to their environments over time.

The presence of marine fossils on all continents provides strong evidence supporting the theory of continental drift.

The layer of the Earth's interior where convection primarily occurs. It's a semi-solid layer that flows slowly.

The process where denser oceanic plates dive beneath less dense continental plates.

A plate boundary where two plates move towards each other, resulting in collisions. This can lead to mountain formation, volcanoes, and earthquakes.

A plate boundary where two plates move apart, creating new crust. This can lead to the formation of mid-ocean ridges and volcanoes.

A plate boundary where two plates slide past each other horizontally, causing earthquakes. The San Andreas Fault is a prime example.

Seismic waves that travel through the Earth by compressing and expanding the material they pass through. They are faster than S-waves and can travel through solids, liquids, and gases.

Seismic waves that travel through the Earth by shaking the material perpendicular to the direction of wave travel. They are slower than P-waves and can only travel through solids.

The transfer of heat through the movement of fluids, such as air or water. Hotter fluids rise, while cooler fluids sink, creating a circular flow.

Large volcanic eruptions can send CO2 into the atmosphere, leading to global warming. The ash released can block sunlight, causing crops to fail and potentially leading to food shortages.

Volcanic ash deposits contain fossils and minerals that can be used to determine their age. These deposits help scientists understand the timing of past life and geological events.

Volcanic eruptions release ash into the atmosphere, blocking sunlight and potentially causing global cooling. However, the release of CO2 can also contribute to global warming.

Large asteroid impacts can cause tsunamis, earthquakes, and, if the asteroid is large enough, mass extinctions.

The gravitational pull of other planets can influence the trajectory of asteroids, potentially diverting them away from Earth and protecting it from impacts.

The law of superposition states that in undisturbed rock layers, the oldest layers are found at the bottom and the youngest layers at the top.

The law of original horizontality states that undisturbed sedimentary rock layers are originally deposited horizontally.