15 Questions
What is a galaxy?
A collection of stars, planets, nebulae, gases, dust, and other cosmic matter bound together by gravity
How do galaxies form according to the most widely accepted model?
From clouds of dust and cosmic matter coming together and rotating around a central axis
What is the approximate number of galaxies estimated to exist in the universe?
Over 200 billion galaxies
What does gravity do in relation to galaxies?
Attracts matter towards the center of a mass or an object
How are light-years defined?
The distance traveled by light in one year
What distinguishes irregular galaxies from elliptical and spiral galaxies?
Lack of a distinct shape
How do elliptical galaxies differ from spiral galaxies in terms of star composition?
Predominantly composed of older, dimmer stars
Which feature distinguishes spiral galaxies from elliptical and irregular galaxies?
Central disk surrounded by spiral arms
What is a common characteristic between elliptical and irregular galaxies?
Older, dimmer stars
How do irregular galaxies differ from elliptical galaxies in terms of dust content?
Characterized by significant amounts of interstellar gases
What is the main difference between elliptical and spiral galaxies?
Elliptical galaxies are older and have stars rotating in random orbits, while spiral galaxies are younger and have stars forming actively.
What process causes the birth of a star in the solar nebular theory?
Gravitational forces compacting matter at the center
Why do elliptical galaxies sometimes appear dim compared to other galaxy types?
They have very little dust and gas.
What causes some elliptical galaxies to look like one giant star?
Optical illusion from uniform light emission
How do barred spiral galaxies differ from normal spiral galaxies?
Barred spiral galaxies have a large bar of stars running through the center.
Explore the formation and characteristics of galaxies in the universe. Learn about stars, planets, nebulae, gases, dust, and other cosmological elements that make up galaxies.
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