Solar Energy to Earth & the Seasons; Earth's Atmosphere PGS 45-58; 66-73

Nebula

A large, slowly rotating and collapsing cloud of dust and gas from which our Solar System formed.

Protosun

The early sun that grew in mass at the center of the solar nebula, drawing more matter to it.

Protoplanets

Smaller bodies of accreting material that swirled at varying distances from the center of the solar nebula.

Planetesimal Hypothesis

The theory explaining how suns condense from nebular clouds and form planetesimals that can develop into protoplanets.

Light-year

A unit of measurement for distance in space, equivalent to the distance light travels in one year, approximately 9.5 trillion kilometers.

Perihelion

The point in Earth's orbit where it is closest to the Sun.

Aphelion

The point in Earth's orbit where it is farthest from the Sun.

Solar Wind

Clouds of electrically charged particles emitted continuously by the Sun, primarily composed of hydrogen nuclei and free electrons.

Sunspots

Dark spots on the surface of the Sun, caused by magnetic storms, that vary in size from 10,000 to over 160,000 km.

Solar Cycle

The periodic variation in the Sun's activity and appearance over time, averaging about 11 years from maximum to maximum.

Coronal Mass Ejections (CMEs)

Massive bursts of solar wind and magnetic fields rising above the solar corona or being released into space.

Electromagnetic Spectrum

The range of all electromagnetic energy wavelengths, which includes solar radiation.

Wien's Displacement Law

A law stating that all objects radiate energy in wavelengths related to their surface temperatures.

Axial Tilt

The angle of Earth's axis which influences seasonal variations and affects the Sun's altitude above the horizon.

Insolation

The amount of sunlight reaching a given area, which is affected by the angle at which sunlight strikes the Earth's surface.

Aurora Borealis

The northern lights, a natural light display caused by charged solar wind particles interacting with Earth's atmosphere.

Aurora Australis

The southern lights, similar to the aurora borealis, occurring in the Southern Hemisphere.

Solar Dynamics Observatory (SDO)

A NASA mission that provides detailed observations of solar activity and phenomena.

Kepler Telescope

An orbiting telescope that has discovered thousands of exoplanets outside our Solar System.

Orbital Speed of Earth

The speed at which Earth travels around the Sun, approximately 107,280 km/h.

Solar Mass

The mass of the Sun, which generates the immense pressure and temperature required for nuclear reactions.

Solar Energy

Energy emitted by the Sun, including solar wind and radiant energy, essential for life on Earth.