The Universe
What is the most accepted theory about the origin of the universe?
The Big Bang Theory
What is the name of the only star in our solar system?
The Sun
What process led to the formation of the Earth and other inner planets?
Planetesimal accretion
What are 3 examples of direct methods used to study Earth's crust?
Mines, geological drills, or volcanic eruptions.
What rock is the oceanic crust primarily made of?
Basalt
Name two types of galaxies.
Spiral-shaped and elliptical-shaped galaxies.
How many planets are there in the solar system?
What materials made up the planetesimals that formed Earth?
Silicates and metals such as iron and nickel.
What rock, expelled during volcanic eruptions, helps scientists understand the composition of Earth's mantle?
Peridotite.
What is the name of the discontinuity that separates the Earth's crust from the mantle?
Mohorovicic’s discontinuity.
What is a nebula? And give one example.
A nebula is a huge mass of gas and dust that may form stars or celestial bodies. An example is the Crab Nebula.
What are the two types of planets in our solar system, and what distinguishes them?
The inner (rocky) planets and the outer (gas) planets. Inner planets are smaller, more dense, and closer to the Sun. Outer planets are larger, less dense, and surrounded by rings.
What protects Earth from harmful solar winds?
Earth's magnetic field
How do meteorites help scientists study Earth's interior layers?
Because they have a composition similar to Earth's three main layers: core, crust, and mantle.
According to the geodynamic model, what layer of the Earth is responsible for the movement of lithospheric plates?
The D'' layer (part of the mesosphere).
What elements make up stars, and what do they produce?
Stars are made up of hydrogen and helium, and they produce energy and matter.
Why was Pluto reclassified as a dwarf planet?
Because it is not able to sweep up its orbit of asteroids and comets.
Due to extreme heat during Earth's early formation, the planet melted, and its components were ordered by density, with the less dense materials near the surface and the denser materials towards the core.
What does a positive gravimetric anomaly indicate about the presence of materials beneath the surface?
It indicates the presence of heavy metallic minerals.
Why can S waves not pass through the outer core?
Because the outer core is in a liquid state.
What happens when a star dies after burning all of its chemical elements?
The star evolves according to its size, potentially forming a white dwarf, neutron star, or black hole.
How was the solar system formed, and what role did a supernova play?
It was formed when a nebula collapsed due to the explosion of a supernova. The gases and dust began to concentrate and rotate, forming the solar nebula or protoplanetary disk, which eventually led to the formation of the Sun and planets.
What are the two celestial events that contributed to the formation of Earth's atmosphere and hydrosphere?
Volcanic eruptions and collisions with meteorites
Explain how seismic waves are used to study Earth's interior, and differentiate between P waves and S waves.
Seismic waves help study Earth's interior by showing how wave speed changes as they pass through different layers. P waves (primary) are faster and can travel through both solid and liquid materials, while S waves (secondary) are slower and can only travel through solid layers.
What is the difference between the outer core and the inner core in terms of their states and the effects of pressure and temperature?
The outer core is in a liquid state due to high temperatures, which prevent S waves from passing through. The inner core, despite having higher temperatures, remains solid due to the immense pressure that keeps the materials in a solid state.