ASVAB General Science part 4

What are middle clouds?

Clouds that form at medium elevations in the atmosphere.

At what altitude do middle clouds occur?

Approximate altitude:

2,000–7,000 meters
(about 6,500–23,000 feet)

What are middle clouds made up of?

Liquid water droplets

What are altocumulus clouds?

Middle-altitude clouds that appear as:

• Gray-white patches

• Rounded groups or rolls

• Small, fluffy cloud clusters

What are the characteristics of altocumulus clouds?

• Made mostly of liquid water droplets

• Often appear in groups or waves

What are altostratus clouds?

Middle-altitude clouds that appear as:

• Gray or blue-gray sheets

• A broad layer covering much of the sky

What are the characteristics of altostratus clouds?

• Can block sunlight

• Often associated with approaching storms

Which clouds occur at 2,000–7,000 meters?

Middle clouds

Which middle cloud type appears as a gray sheet?

Altostratus

Which middle cloud type appears as puffy groups?

Altocumulus

What are low clouds

Clouds that form closest to Earth's surface.

At what altitude do low clouds occur?

Approximate altitude:

Earth's surface – 2,000 meters
(about 0–6,500 feet)

What are the characteristics of low clouds?

• Usually made of liquid water droplets

• Often appear thick and gray

• Can produce precipitation

What are stratus clouds?

Low, flat clouds that form a continuous layer across the sky.

What are the characteristics of stratus clouds?

Example?

• Gray and fog-like appearance

• Cover much or all of the sky

• Made of water droplets

• Often produce light rain or drizzle

Example:

• A cloudy, overcast day

What are stratocumulus clouds?

Low clouds that combine features of stratus and cumulus clouds.

What are the characteristics of stratocumulus clouds?

• Low-lying

• Lumpy or bumpy appearance

• Gray cloud groups or rolls

• Usually produce little precipitation

What are nimbostratus clouds?

Thick, dark gray clouds associated with steady precipitation.

What does the prefix “nimbus” mean?

Rain-producing cloud

What are the characteristics of nimbostratus clouds?

• Uneven cloud bases

• Cover large areas of the sky

• Produce:

  • Continuous rain

  • Snow

What altitude do low clouds occur?

Below 2,000 meters

Which low clouds look like a gray blanket?

Stratus

Which clouds produce steady rain or snow?

Nimbostratus

How is matter in the universe organized?

Matter in the universe is arranged in a hierarchy from smaller structures to larger structures:

1. Stars

2. Galaxies

3. Clusters of Galaxies

4. Superclusters

5. Great Wall of Galaxies

Memory Trick:

"Stars Gather Clusters, Super Great"
Stars → Galaxies → Clusters → Superclusters → Great Wall

What are stars?

A massive object made mostly of hot gases that produces its own light and energy through nuclear reactions.

What are the characteristics of stars?

Example?

Characteristics:

• Made mostly of hydrogen and helium

• Produces energy through nuclear fusion

• Some stars have planetary systems

Example:

• The Sun is a star

What are galaxies?

A large collection of stars, gas, dust, and other matter held together by gravity.

Galaxies may contain:

Example of galaxies?

• Millions to trillions of stars

• Planetary systems

• Nebulae and other objects

Example:

• The Milky Way galaxy contains our Solar System

What are galaxy clusters?

A group of galaxies held together by gravity.

What are superclusters?

A much larger structure made of multiple galaxy clusters.

What is the organization of clusters and superclusters?

Galaxies → Clusters → Superclusters

Clusters collect galaxies; superclusters collect clusters.

What is the Great Wall of galaxies?

One of the largest known structures in the universe.

It is:

• A massive arrangement of galaxies

• Made from many galaxy groups and clusters

• Part of the large-scale structure of the universe

How old is the universe?

Estimated to be about:

13.8 billion years old

How do scientists estimate the age of the universe?

Scientists estimate the age of the universe using:

• Expansion of the universe

• Cosmic background radiation

What is the universe made of?

• Dark Energy — about 73%

• Cold Dark Matter — about 23%

• Regular Matter — about 4%

What is Dark Energy?

• A mysterious form of energy

• Associated with the accelerating expansion of the universe

What is Cold Dark Matter?

• Matter that does not emit or absorb light

• Detected through its gravitational effects

What is Regular Matter?

The matter we can observe:

• Stars

• Planets

• Humans

• Gas and dust

Universe Organization Chart

Smallest → Largest:

⭐ Star
⬇
🌌 Galaxy
⬇
🌌🌌 Galaxy Cluster
⬇
🌌🌌🌌 Supercluster
⬇
🌐 Great Wall of Galaxies

What is the largest structure listed?

Great Wall of galaxies

What is the composition of the Sun?

Hydrogen (H) — 70%

Helium (He) — 28%

Other elements (metals) — 2%

• Carbon

• Oxygen

• Iron

• Other trace elements

What element is the fuel for nuclear fusion reactions and is the most abundant element in the Sun?

Hydrogen

What element is created when hydrogen atoms fuse together?

Helium

Why is the Sun important in the solar system?

• Is located at the center of the solar system

• Provides light and heat energy

• Controls the movement of planets through gravity

• Contains more than 99.8% of the total mass of the solar system

Because the Sun has so much mass, its gravity keeps ____ in orbit.

• Planets

• Moons

• Asteroids

• Comets

What process produces energy in the Sun?

Nuclear Fusion

Nuclear Fusion occurs when:

• Hydrogen atoms combine

• They form helium

• Energy is released as heat and light

Process of Nuclear Fusion.

Hydrogen → Helium + Energy

What are the planets in our solar system?

Inner Planets (Terrestrial Planets):

1. Mercury

2. Venus

3. Earth

4. Mars

Outer Planets (Jovian Planets):

5. Jupiter

6. Saturn

7. Uranus

8. Neptune

What are the inner planets (Terrestrial Planets):

1. Mercury

2. Venus

3. Earth

4. Mars

What are the outer planets (Jovian Planets):

1. Jupiter

2. Saturn

3. Uranus

4. Neptune

What are terrestrial planets?

The four inner planets closest to the Sun.

What are the characteristics of terrestrial planets?

Small
Dense
Rocky surfaces
Made mostly of metals and rock
Few or no moons
No rings

What are Jovian planets?

Four outer planets located beyond the asteroid belt.

What are Jovian planets also called?

Gas giants

What are the characteristics of Jovian (gas) planets?

Large size
Low density
Many moons
Have rings
Mostly made of gases

What is the asteroid belt?

A region of rocky objects located between:

Mars and Jupiter

What does the asteroid belt separate?

It separates:

• Inner terrestrial planets

• Outer Jovian planets

What are dwarf planets?

Smaller planetary bodies that orbit the Sun but do not meet all requirements to be considered full planets.

Important dwarf planets include:

• Ceres

• Pluto

• Haumea

• Makemake

• Eris

Most dwarf planets are located beyond Neptune in the:

Kuiper Belt

Solar System Order

From closest to farthest from the Sun:

☀ Sun
⬇

1. Mercury

2. Venus

3. Earth

4. Mars
   ⬇
   Asteroid Belt
   ⬇

5. Jupiter

6. Saturn

7. Uranus

8. Neptune
   ⬇
   Kuiper Belt (Dwarf planets)

Where is the asteroid belt located?

Between Mars and Jupiter

Which planets have rings?

All Jovian planets

Which planet is the largest?

Jupiter

What is waxing?

The period when the Moon’s visible illuminated area increases.

When does waxing occur?

It occurs during the two weeks when the Moon changes from:

New Moon → Full Moon

During waxing:

• The Moon appears to grow brighter each night

• More of the Sun-lit side becomes visible from Earth

Examples of waxing phases:

• Waxing crescent

• First quarter

• Waxing gibbous

What is waning?

The period when the Moon’s visible illuminated area decreases.

When does waning occur?

It occurs during the two weeks when the Moon changes from:

Full Moon → New Moon

During waning:

• The Moon appears to shrink or become less visible each night

• Less of the Sun-lit side is visible from Earth

Examples of waning phases:

• Waning gibbous

• Third quarter

• Waning crescent

Where does the Moon’s light come from?

Reflected sunlight

When does the Moon go from full moon to new moon?

Waning

When does the Moon go from new moon to full moon?

Waxing

What are the waxing phases of the Moon?

IN ORDER:

1. New Moon

2. Crescent Moon

3. First Quarter Moon

4. Gibbous Moon

5. Full Moon

Which phase of moon is not illuminated from earth’s view?

New Moon

New Moon Characteristics.

• The beginning of the waxing cycle

• The Moon is not illuminated from Earth's view

• The Moon rises and sets with the Sun

• The side facing Earth is mostly dark

Memory:

"New = no visible light."

Crescent Moon Characteristics.

• A small sliver of the Moon is illuminated

• Less than half of the Moon is visible

• The illuminated area begins increasing

Memory:

"Crescent = curved sliver."

First Quarter Moon Characteristics.

• Half of the Moon appears illuminated

• The Moon is about one-quarter through its orbit

• The Moon is highest in the sky around sunset

• It appears due south at the meridian (Northern Hemisphere)

Memory:

"Quarter = half-lit appearance."

(The name comes from being one-quarter through the Moon's orbit, not because only one-quarter looks lit.)

Which phase of moon appears due south at the meridian (Northern Hemisphere)?

First Quarter Moon

Gibbous Moon Characteristics.

• More than half of the Moon is illuminated

• Lighted portion continues increasing

• Appears larger and rounded, similar to a football shape

Memory:

"Gibbous = getting bigger."

Full Moon Characteristics.

• The entire visible face of the Moon is illuminated

• The Moon rises around sunset

• The Moon sets around sunrise

Memory:

"Full Moon = full sunlight facing Earth."

Which phase of moon rises around sunset and sets around sunrise?

Full Moon

Which Moon phase occurs when the entire visible surface is illuminated?

Full Moon

Which phase comes after the first quarter?

Gibbous

During which phase does the illuminated portion increase?

Waxing

Waxing grows:

New → Crescent → Quarter → Gibbous → Full.

What are the waning phases of the Moon?

The waning phases occur after the Full Moon when the visible illuminated portion of the Moon decreases.

Order of the waning phase:

Full Moon → Waning Gibbous → Third Quarter → Waning Crescent → New Moon

Waning Gibbous Definition.

The waning phase that occurs after the Full Moon.

Characteristics of Waning Gibbous.

• More than half of the Moon is still illuminated

• The left side appears lit

• The illuminated portion decreases each night

• Rises after sunset

• Sets after sunrise

Third Quarter Moon Definition.

The waning phase that appears half illuminated.

Why is the Third Quarter Moon called “Third Quarter”?

This is due to how the Moon is about three-quarters of the way through its orbit, not because three-quarters is lit.

Characteristics of Third Quarter Moon.

• Half of the Moon is visible from Earth

• The left half is illuminated

• Rises around midnight

• Sets around noon

Waning Crescent Definition.

The waning phase that occurs just before the New Moon.

Characteristics of Waning Crescent.

• Only a small sliver of light remains visible

• The illuminated portion continues shrinking

New Moon Definition.

The end of the waning cycle and beginning of the waxing cycle.

Characteristics of New Moon.

• The Moon appears dark from Earth

• The illuminated side faces away from Earth

• Rises and sets with the Sun