Astrology Exam 2

How is the light gathering power of a telescope determined?

its aperture size; a larger aperture allows the telescope to collect more light, making it more effective for observing faint objects.

What are the main types of visual telescopes?

refracting telescopes, which use lenses to gather light, and reflecting telescopes, which use mirrors.

Why are reflecting telescopes preferred over refracting telescopes?

because they avoid chromatic aberration, can be made larger and are generally more cost-effective for large apertures.

What is chromatic aberration?

different wavelengths of light being refracted at slightly different angles, causing colored fringes around images.

Where is the best place to put a telescope on the surface of the earth?

high altitudes in remote locations, away from light pollution and atmospheric disturbances.

What does resolution mean?

the ability to distinguish between two close objects and resolve fine details in the image.

What are the limitations of ground-based telescopes?

atmospheric distortion, light pollution, and varying weather conditions that can affect observations.

What are the advantages of using a radio telescope? Why is it challenging for a radio telescope to have good resolution?

ability to observe celestial objects in cloudy weather and to explore longer wavelengths. due to the longer wavelengths of radio waves, which limit angular resolution.

What is radio interferometry?

uses multiple radio antennas working together to simulate a larger aperture, improving resolution and sensitivity of radio observations.

Why is it useful to put telescopes in space?

to avoid Earth's atmosphere

What can be studied with higher energy X-ray or gamma ray telescopes?

can study extremely energetic phenomena, such as black holes, neutron stars, supernovae, and the cosmic background radiation.

How many planets are there in the Solar System?

eight

How many dwarf planets are there?

five

Who are the members of the terrestrial planets?

Mercury, Venus, Earth, and Mars.

Who are the members of the Jovian planets?

Jupiter, Saturn, Uranus, and Neptune.

What are the characteristics of terrestrial planets?

rocky, have solid surfaces, are smaller, and have higher densities and fewer moons.

What are the characteristics of Jovian planets?

have thick atmospheres, are larger and less dense, and have many moons and ring systems.

What are the properties of asteroids?

rocky or metallic objects; they vary in size and composition.

What are the properties of comets?

icy bodies that release gas and dust

What are the properties of meteors?

streaks of light produced

What is the composition of terrestrial planets?

silicate rocks and metals, with solid surfaces and a metallic core.

What is the composition of Jovian planets?

hydrogen and helium, with possible metallic hydrogen interiors and thick atmospheres.

What is differentiation?

process by which a planet's materials separate based on density, leading to a layered structure with a core, mantle, and crust.

How did the Solar System form?

gravitational collapse of a region within a large molecular cloud, known as the solar nebula, leading to the formation of the Sun and planets.

What is a solar nebula?

rotating cloud of gas and dust from which the Solar System formed, consisting of hydrogen, helium, and heavier elements.

What is a circumstellar disk?

a rotating disk of dense gas and dust surrounding a newly formed star, where planets and other celestial bodies can form.

What is Earth made of?

solid rock, metals, water, and gases, primarily silicate rocks, and a metallic core of iron and nickel.

What is found on the surface that is crucial for life?

Water, carbon, nitrogen, and phosphorous.

How are we able to determine the interior structure of Earth?

seismic wave analysis, studying how these waves travel through different materials during earthquakes.

What are the major layers of Earth’s interior?

crust, mantle, outer core, and inner core.

How does Earth produce a magnetic field?

movement of molten iron and nickel in its outer core, generating electric currents.

What are plate tectonics?

large-scale movements of Earth's lithosphere, which is divided into plates that float on the semi-fluid asthenosphere.

What is convection?

heat transfer within fluids (liquids and gases) where warmer, less dense material rises, and cooler, denser material sinks.

What is the layer of the atmosphere where all the weather occurs?

troposphere.

What is the chemical composition of Earth’s atmosphere?

nitrogen (78%), oxygen (21%), argon (0.93%), carbon dioxide (0.04%), and trace amounts of other gases.

How did oxygen form in Earth’s atmosphere?

photosynthesis by cyanobacteria and plants

What is the greenhouse effect? How does it regulate Earth’s temperature?

trapping of heat in Earth's atmosphere by gases, which keeps the planet warm enough to support life.

What is the primary greenhouse gas?

carbon dioxide (CO2), although water vapor also plays a significant role.

Why does Earth have so few craters but the Moon has so many?

its surface is constantly being reshaped by erosion and tectonic activity

How do large impact events disrupt life on Earth?

causing mass extinctions, altering climates, creating tsunamis, and leading to widespread fires and geological changes.

How does the Moon’s density compare to Earth’s?

3.34 g/cm³ compared to 5.52 g/cm³.

The Moon’s composition is similar to what layer of Earth?

Earth's mantle.

What are maria?

large, dark, basaltic plains, formed by ancient volcanic eruptions.

What is the process by which impact craters are formed?

meteoroids, asteroids, or comets collide with the surface of the Moon, creating depressions.

What is the likely origin of the Moon? How did it form?

Giant Impact Hypothesis, suggesting the Moon formed from debris after a Mars-sized body collided with early Earth.

How do the internal layers of Mercury compare to the layers of Earth?

large metallic core and a thin mantle, compared to thicker crust, mantle, outer core, and inner core.

How does Mercury’s rotational and orbital period compare?

59 Earth days and an orbital period of about 88 Earth days, resulting in a very slow rotation relative to its orbital speed.

How was the rotational period of Mercury measured?

by observing the motion of its surface features and through radar observations.