Moon phases, eclipses, Universal Law of Gravitation, Galaxies, Star Systems, and the Sun Test Review

What causes the phases of the Moon?

The Moon’s orbit around Earth and the reflection of sunlight

Why do solar eclipses not occur every month?

The Moon’s orbit is tilted relative to Earth’s orbit

How does a lunar eclipse differ from a solar eclipse?

A lunar eclipse occurs when Earth is between the Sun and Moon; a solar eclipse occurs when the Moon is between the Sun and Earth

What is the difference between the umbra and penumbra?

The umbra is the darkest part of a shadow, while the penumbra is the lighter outer region.

What happens to the gravitational force between two objects if their distance doubles?

It decreases to one-fourth of its original strength.

What is the equation for Newton’s Universal Law of Gravitation?

F = G(m1m2/r^2)

What is the primary source of the Sun’s energy?

Nuclear fusion in the Sun’s core.

What are the effects of the solar wind on Earth?

Causes auroras and can disrupt electronics and communications

Why does the Sun’s corona appear hotter than its surface?

Magnetic fields accelerate particles in the corona.

How does a barred spiral galaxy differ from a regular spiral galaxy?

It has a bar-like structure at its center.

What type of galaxy is the Milky Way?

 A barred spiral galaxy.

How does an open star cluster differ from a globular cluster?

Open clusters are younger and loosely bound; globular clusters are older and densely packed

What is the significance of Hubble’s Tuning Fork diagram?

It classifies galaxies based on their shape.

What are coronal mass ejections (CMEs) and their effects on Earth?

Large bursts of solar particles that can disrupt Earth's magnetic field.

What phase must the Moon be in for a solar eclipse to occur?

New Moon

What phase must the Moon be in for a lunar eclipse to occur?

Full Moon

What is the role of gravity in planetary orbits?

It keeps planets in orbit around the Sun

What will happen to the Sun after it exhausts its nuclear fuel?

 It will become a white dwarf.

What are auroras, and how do they form?

Light displays caused by solar wind interacting with Earth's atmosphere.

What is a binary star system?

 A system with two stars orbiting a common center

Phases of the Moon

The different appearances of the Moon as seen from Earth, caused by the varying angles of sunlight reflecting off its surface as it orbits Earth

Umbra

1. The central, darkest part of a shadow, where all direct light is blocked; during an eclipse, this is where totality occurs.

Penumbra

The outer, lighter part of a shadow where only some of the light is blocked, causing partial eclipses

Solar Eclipse

 An astronomical event that occurs when the Moon moves between the Earth and the Sun, temporarily blocking sunlight and casting a shadow on Earth.

Lunar Eclipse

An event that happens when Earth moves between the Sun and the Moon, causing Earth's shadow to be cast on the Moon, making it appear darker or reddish

Gravity

The attractive force exerted between two masses; it governs the motion of celestial bodies and keeps planets in orbit around stars.

Newton’s Universal Law of Gravitation

A scientific law stating that every mass attracts every other mass with a force proportional to their masses and inversely proportional to the square of their distance.

Orbital Path

The continuous trajectory that an object follows around another celestial body due to gravitational forces, such as the Moon orbiting Earth

Core (of the Sun)

The innermost region of the Sun where nuclear fusion occurs, generating immense energy that powers the Sun and emits light and heat

Photosphere

The outermost visible layer of the Sun’s surface that emits the light we see; it has a temperature of approximately 5,500°C (9,932°F)

Corona

The Sun’s outermost atmospheric layer, extending millions of kilometers into space, visible as a halo during a total solar eclipse.

Solar Wind

A continuous flow of charged particles (plasma) released from the Sun’s corona, which can influence Earth's magnetic field and cause auroras.

Coronal Mass Ejection (CME)

A powerful eruption of plasma and magnetic fields from the Sun’s corona, capable of causing geomagnetic storms on Earth.

Solar Prominence

A large, bright, loop-shaped structure of plasma that extends from the Sun’s surface, often associated with sunspot regions.