space physics

Solar System

Consists of one star (the Sun), eight planets, dwarf planets, moons, and other objects such as asteroids and comets.

Natural Satellite

A celestial body that orbits a planet (e.g., the Moon).

Dwarf Planet

A planet-like object that orbits the Sun but does not meet all criteria to be a full planet.

Order of Planets

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Nebula

The first stage in the life cycle of a star, consisting of a cloud of gas and dust pulled together by gravity.

Protostar

Formed after a nebula, where temperature increases as particles collide.

Main Sequence Star

A star that is stable due to the balance between gravity and thermal expansion from fusion.

Red Giant or Supergiant

What a main sequence star becomes after running out of hydrogen.

Planetary Nebula

Formed when a low-mass star sheds its outer layers after the red giant phase.

White Dwarf

The hot, dense core left behind after a low-mass star dies.

Black Dwarf

A cooled white dwarf that no longer emits significant heat or light.

Supernova Explosion

What happens to high-mass stars after the red supergiant phase.

Neutron Star or Black Hole

What a supernova can leave behind, depending on the mass.

Gravitational Force

The reason why planets orbit stars.

Centripetal Force

Required to keep an object in circular orbit.

Velocity in Orbit

Constantly changing due to the change in direction.

Geostationary Orbit

An orbit in which a satellite stays above the same point on Earth, taking 24 hours.

Low Polar Orbits

Used for Earth observation and weather monitoring.

Red-Shift

The stretching of light waves from distant galaxies, making them appear redder.

Evidence for Universe Expansion

Provided by red-shift.

Big Bang Theory

The idea that the universe began from a very small, hot, dense point around 13.8 billion years ago.

Evidence Supporting Big Bang Theory

Includes red-shift and cosmic microwave background radiation (CMBR).

Cosmic Microwave Background Radiation (CMBR)

Low-energy radiation from the early universe, a remnant of the Big Bang.

Fates of the Universe

Can continue expanding forever, slow down and stop, or collapse back in (Big Crunch).

Fate of the Universe Determination

Based on the amount of mass and the effect of dark energy.