Habitable Zones
What does the term "habitable" mean when describing a planet?
A planet that has the necessary conditions to support life, such as maintaining liquid water on its surface.
What is the starting point of a star's life cycle?
A nebula, which is a clump of gas in space.
What happens when light passes through a prism?
It separates into a spectrum of colors, like a rainbow.
What is a comet made of, and what causes its tail?
Ice and dust; its tail forms when it nears the Sun and points away from it.
What shape is a planet’s orbit around the Sun?
An ellipse.
What is the "Goldilocks Zone"?
It is the distance from a star where conditions are just right for liquid water to exist on a planet's surface.
What happens to small or medium-sized stars at the end of their life cycle?
They expand and then collapse into white dwarfs.
What causes light to fan out into a band of colors?
Shorter wavelengths (blue and violet) bend more than longer wavelengths (red and orange).
Where are most asteroids found?
In the Asteroid Belt (between Mars and Jupiter) or the Kuiper Belt (beyond Neptune).
What does Kepler’s First Law state about a planet's orbit?
Each planet’s orbit is elliptical, with the Sun at one focus.
Name three characteristics a planet must have to be considered habitable.
Liquid water, a stable atmosphere, and a steady energy source from a star.
What determines how long a star will live?
Its mass or gas; larger stars live shorter lives, and smaller stars live longer lives.
What tool do scientists use to determine the composition of stars?
A spectroscope.
What’s the difference between a meteor and a meteorite?
A meteor burns up in Earth’s atmosphere, while a meteorite hits the ground.
What does Kepler’s Second Law describe about a planet’s motion?
The line joining a planet and the Sun sweeps equal areas in equal time intervals.
Why is the Sun essential for Earth's habitability?
The Sun provides light, heat, and energy
What is the role of gravity and fusion pressure in a star's stability?
Gravity pulls atoms inward, while fusion pressure pushes outward. The balance between these forces maintains stability.
How does a spectroscope help identify elements in the Sun?
Each element absorbs specific wavelengths of light, creating a unique "fingerprint" in the spectrum.
What are the criteria for a celestial body to be classified as a planet?
It must orbit the Sun, be mostly round, and have cleared its orbit of other objects.
According to Kepler’s Third Law, how is the orbital period related to the distance from the Sun?
There’s a direct relationship—the farther a planet is, the longer its orbital period.
What elements make up most of the Sun, and how do they contribute to its energy production?
Hydrogen (75%) and helium (24%). Energy is produced through nuclear fusion, where hydrogen converts to helium.
What is the maximum element the Sun can produce through fusion?
Oxygen.
Why is spectroscopy critical for studying celestial objects?
It reveals the chemical composition and physical properties of stars and planets.
Define the terms "perihelion" and "aphelion."
Perihelion is when a celestial object is closest to the Sun; aphelion is when it is farthest from the Sun.
How does the eccentricity of an orbit affect its shape?
A higher eccentricity means the orbit is more elongated; a lower eccentricity means it’s closer to a circle.