Comprehensive Earth and Space Science: Light, Solar System, and Energy

What is the speed of light in kilometers per second?

300,000 kmps

What is a light year?

The distance covered by light in one year, approximately 9.5 trillion km or 6 trillion miles.

How many galaxies are estimated to be in the universe?

At least 200 billion galaxies.

What is the diameter of the Milky Way Galaxy?

About 100,000 light years.

How long ago did the solar system and the Sun form?

Approximately 4.6 billion years ago.

What is the average distance between Earth and the Sun?

150 million km.

What is perihelion?

The point when Earth is closest to the Sun, occurring on January 3rd at 147 million km.

What is aphelion?

The point when Earth is farthest from the Sun, occurring on July 4th at 152 million km.

What is nuclear fusion?

A process where hydrogen atoms are fused to form helium, releasing large amounts of energy.

What is the plane of the elliptic?

The plane along which the Earth travels during its orbit.

What is the tilt of Earth's axis relative to the plane of the elliptic?

23.5 degrees.

What is solar wind?

Clouds of electrically charged particles emitted by the Sun.

What causes sunspots?

Magnetic storms on the Sun.

How large are sunspots compared to Earth?

Sunspots are more than 12 times Earth's diameter.

What is the activity cycle duration of sunspots?

11 years.

What is the effect of solar wind on Earth's magnetosphere?

It is deflected toward Earth's poles, with only a small portion entering the atmosphere to produce auroras.

What are some weather effects associated with sunspot cycles?

Sunspot cycles correspond to wet/dry cycling in the western US from 1740 to 1998.

What are flares, prominences, and coronal mass ejections?

They are associated with magnetic storms that produce solar wind.

What is the significance of changes in eccentricity of Earth's orbit?

They affect the timing of perihelion/aphelion and are implicated as a cause of past glaciations.

What is the diameter of the solar system?

Approximately 11 hours in diameter.

How far is the Moon from Earth?

About 1.28 seconds away, or 384,000 km.

What is the planetesimal hypothesis?

A theory describing the evolution of the solar system, stating that planets formed by the accretion of planetesimals ejected by the Sun.

What is the magnetosphere?

The magnetic field surrounding the Earth resulting from internal processes within the Earth's core.

How does the magnetosphere interact with solar wind?

It deflects the solar wind towards the poles, leaving little to enter the atmosphere.

What phenomenon is produced by the interaction between solar wind and the magnetosphere?

Auroras, including the Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights).

Where are auroras most often and clearly seen?

At high latitudes due to the deflection of solar wind poleward.

What is energy?

The ability to do work.

What are the two main classifications of energy?

Kinetic energy (in use) and potential energy (not yet used).

What is the standard unit of energy?

Joule (J), where 1 J = 0.239 calories.

What is the rate of energy flow measured in?

Watt (W), where 1 W = 1 J/s.

What types of energy does the Sun emit?

Electromagnetic Radiation (EM).

What is conduction?

Molecule to molecule transfer of heat, flowing from warm to cold.

What is convection?

Energy transfer by vertical movement and physical mixing, such as boiling water.

What is radiation?

Energy propagated without a medium, such as solar radiation.

What is the speed of light?

300,000 km/s.

What is the electromagnetic spectrum?

The range of all types of EM radiation, grouped based on wavelength.

What determines the quantity of EM radiation emitted by an object?

Amplitude, which is the wave height.

What determines the quality of EM radiation?

Wavelength, which is the distance between crest and trough.

What portion of the EM spectrum is of greatest interest to humans?

Shortwave, visible, and infrared radiation.

What is the relationship between temperature and energy emission?

Total energy emitted by an object is a function of temperature; hotter objects emit shorter average wavelengths.

What is the average wavelength of solar radiation?

0.45 micrometers (um), primarily in the visible portion.

What is the average wavelength of outgoing radiation from Earth?

8 micrometers (um), concentrated in infrared wavelengths.

Which gases absorb almost all shortwave radiation?

Ozone (O3) and oxygen (O2).

What percentage of solar output is made up of gamma rays, X-rays, and UV radiation?

7%.

What is the reason for unequal receipt of insolation from the equator to the poles?

Sphericity of the Earth.

What is the thermopause?

The outer boundary of Earth's atmosphere.

What is the sub-solar point?

The point on Earth's surface where the Sun's rays are perpendicular to the surface (90 degrees).

What is insolation?

Intercepted solar radiation arriving at the top of Earth's atmosphere and reaching Earth's surface.

How does the angle of the Sun's rays affect energy receipt on Earth?

A direct angle results in more concentrated energy, while an oblique angle results in more diffuse energy.

What is the solar constant?

The average amount of energy reaching the top of Earth's atmosphere, approximately 1372 W/m².

How much greater is the receipt of insolation at the thermopause over the equator compared to the poles?

2.5 times greater annually.

What is the significance of the Sun's altitude?

It is the angle above the horizon, with 0 degrees at sunrise/set and 90 degrees (zenith) directly overhead.

What is declination in relation to the Sun?

The latitude of the sub-solar point, which migrates between 23.5°N and 23.5°S.

Which U.S. state experiences the sub-solar point?

Hawaii.

What is global net radiation?

The difference between incoming radiation (insolation) and outgoing longwave radiation.

Where is the highest surplus of net radiation found?

Over the equatorial and tropical regions, especially the equatorial south Pacific.

What is the net radiation deficit poleward of 36°?

Poles lose more energy to space than they gain.

How does day length vary with latitude?

Constant day length occurs only along the Equator; the range increases poleward.

What is the effect of the Sahara Desert on net radiation?

It acts as a net sink, with clear skies leading to large longwave losses.

What is the duration of Earth's complete revolution around the Sun?

365.25 days (1 year).

How does axial tilt influence seasonality?

It is key to seasonal changes; without tilt, no seasonal variations would occur.

What are the four cardinal dates marking significant points in the seasons?

Summer Solstice (June 21), Fall Equinox (Sept 22), Winter Solstice (Dec 21), Spring Equinox (March 21).

What happens at the Arctic Circle during the Summer Solstice?

The North Pole experiences 24 hours of light.

What happens at the Antarctic Circle during the Winter Solstice?

The South Pole experiences 24 hours of darkness.

What occurs during the Spring Equinox?

It occurs on March 21st.

What is a Solstice?

A Solstice occurs when the sub-solar point is furthest from the Equator, at 23.5° N/S.

What are the Tropics?

Regions of Earth where the sun is directly overhead at noon during the solstices.

What drives Earth's physical and biological systems?

Solar energy.

How does the Magnetosphere affect Earth?

It influences the amount and type of energy received by the Earth.

What causes the uneven distribution of energy from the equator to the poles?

The sphericity of the Earth, the revolution of the Earth around the Sun, and the rotation of the Earth on its tilted axis.

What is the role of the Magnetosphere?

It acts as a membrane that protects organic life from harmful ionizing radiation.

What happens to atmospheric density and pressure with altitude?

Both density and pressure decrease with altitude.

What is the altitude range of the Exosphere?

It extends to 32,000 km from the top of the atmosphere.

What are the three criteria to examine the atmosphere?

Composition, temperature, and function.

What is the sea level pressure in different units?

1 kg/m², 1013.2 mb, or 101.32 kPa.

What is the Heterosphere?

The outer atmosphere, extending 80 km (50 mi) outwards, where gases are sorted by gravity.

What is the Homosphere?

The inner atmosphere from the surface to 80 km (50 mi), where gases are evenly blended.

What is the height range of the Troposphere?

From the Earth's surface to about 18 km (11 mi).

What is the temperature behavior in the Stratosphere?

Temperature increases with altitude and the stratopause is at 50 km (0°C).

What characterizes the Mesosphere?

It ranges from 50 km to 80 km, where temperature decreases with altitude and the mesopause is at 80 km (−90°C).

What is the significance of the Tropopause?

It acts as a cap between the Troposphere and Stratosphere.

What is the average cooling rate in the Troposphere?

6.4°C/km (3.5°F/1000 ft).

What are noctilucent clouds?

Clouds that occur in the Mesosphere.

What is the environmental lapse rate?

The actual local lapse rate of temperature in the atmosphere.

What percentage of the atmosphere's mass is found in the Troposphere?

90% of the atmosphere's mass.

What is the role of gravity in the atmosphere?

Gravity compresses air near the surface, increasing density.

What is the thermosphere and its altitude range?

The thermosphere is an atmospheric layer roughly the same as the heterosphere, extending outwards to about 80 km and reaching the thermopause at 480 km.

What is the primary function of the ionosphere?

The ionosphere absorbs cosmic rays, gamma rays, X-rays, and some UV rays.

How does temperature change with altitude in the thermosphere?

Temperature increases with altitude in the thermosphere.

What is the ozonosphere and its role?

The ozonosphere is part of the stratosphere where ozone (O3) absorbs UV energy and converts it to heat energy.

What is the thickness of the ozone layer at sea level?

The ozone layer is approximately 3 mm thick at sea level.

What are chlorofluorocarbons (CFCs) and their impact on the ozone layer?

CFCs are inert compounds that migrate and are primarily responsible for the depletion of the ozone layer.

What are the main sources of natural pollutants in the atmosphere?

Natural sources of pollution include volcanic eruptions, wildfires, and dust storms.

What is anthropogenic pollution and its primary characteristic?

Anthropogenic pollution is primarily an urban phenomenon, resulting from human activities.

What percentage of the global population lived in urban areas by 2010?

By 2010, approximately 51% of the global population (3.4 billion people) lived in urban areas.

What are the four types of anthropogenic pollution?

The four types of anthropogenic pollution include carbon monoxide, photochemical smog, industrial smog and sulfur oxides, and particulates.

What is acid deposition and its forms?

Acid deposition occurs in forms such as rain, snow, dust, and aerosols that enter surface and ground waters.

How is acid deposition measured on the pH scale?

Acid deposition is measured on a logarithmic pH scale, where a decrease of 1 unit represents a tenfold increase in acidity.

What are the natural pH levels of rainwater?

Natural rainwater has a pH of about 5.6, making it slightly acidic.

What chemical reactions contribute to acid deposition?

CO2 and H2O form carbonic acid, while NOx and SOx are converted to nitric and sulfuric acids in the atmosphere.