Galaxies and the Universe

What are the main types of galaxies?

• Spiral, elliptical, irregular, and barred spiral

• Cylindrical, spherical, and conical

• Red, blue, and green

• Flat, round, and oval

What is an irregular galaxy?

• A galaxy with a distinct spiral shape.

• A galaxy that does not have a distinct regular shape, often appearing chaotic and lacking a defined structure.

• A galaxy that is primarily composed of old stars and has little gas and dust.

• A galaxy that is formed by the collision of two or more galaxies.

What is a light year?

• A unit of time used in astronomy.

• The distance that light travels in one year, approximately 5.88 trillion miles (9.46 trillion kilometers).

• A measure of the brightness of a star.

• The speed at which light travels in a vacuum.

What is the observable universe?

• The observable universe is the part of the universe that we can see and measure, limited by the distance light has traveled since the Big Bang.

• The observable universe is the entire universe that exists beyond our perception.

• The observable universe is a theoretical concept that cannot be measured.

• The observable universe is the region of space that is visible from Earth at any given time.

What is an elliptical galaxy?

• A type of galaxy with a spiral shape and young stars.

• A type of galaxy that has an ellipsoidal shape and lacks the distinct features of spiral galaxies, often containing older stars.

• A galaxy that is primarily composed of gas and dust, forming new stars.

• A type of galaxy that is irregular in shape and has no defined structure.

What is dark matter?

• A type of matter that emits light and is visible to the naked eye.

• A type of matter that does not emit, absorb, or reflect light, detectable only through its gravitational effects.

• A form of energy that powers stars and galaxies.

• A type of matter that can be seen with powerful telescopes.

What is a barred spiral galaxy?

• A type of galaxy with no defined structure.

• A type of spiral galaxy that has a central bar-shaped structure made of stars, with spiral arms extending from the ends of the bar.

• A galaxy that is completely elliptical in shape.

• A type of galaxy that only contains gas and dust.

What is dark energy?

• A force that causes the universe to contract

• A mysterious force that is causing the acceleration of the universe's expansion

• A type of matter that makes up 32% of the universe

• A phenomenon that only occurs in black holes

What characterizes a spiral galaxy?

• A spiral galaxy is characterized by its flat, rotating disk containing stars, gas, and dust, along with a central concentration of stars known as the bulge.

• A spiral galaxy is primarily composed of dark matter and has no visible stars or gas.

• A spiral galaxy is a type of galaxy that is completely irregular in shape and lacks any defined structure.

• A spiral galaxy is characterized by its elliptical shape and a lack of rotation.

What is a blue shift in the context of astronomy?

• A phenomenon where light waves are stretched as an object moves away from the observer.

• A change in light frequency that occurs when an object is stationary relative to the observer.

• A blue shift occurs when an object in space, such as a star or galaxy, is moving toward the observer, causing the light waves to compress and shift toward the blue end of the spectrum.

• A visual effect caused by atmospheric conditions that makes stars appear bluer.