Solar System Flashcards
Nebula
a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
Solar Nebula
Our solar system began forming within a concentration of interstellar dust and hydrogen gas called a molecular cloud. The cloud contracted under its own gravity and our proto-Sun formed in the hot dense center.
Nuclear Fusion
a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
Sunspot
a spot or patch appearing from time to time on the sun’s surface, appearing dark by contrast with its surroundings.
Astronomical Unit
a unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.
Terrestrial Planets
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars.
Prograde Rotation
Having a rotational or orbital movement that is the same as most bodies within a celestial system. In our solar system, prograde movement for both rotating and orbiting bodies is in a counterclockwise direction when viewed from a vantage point above the Earth’s north pole. Compare retrograde.
Retrograde Rotation
All eight planets in the Solar System orbit the Sun in the direction that the Sun is rotating, which is counterclockwise when viewed from above the Sun’s north pole. Six of the planets also rotate about their axis in this same direction. The exceptions—the planets with retrograde rotation—are Venus and Uranus.
Gas Giant
a large planet of relatively low density consisting predominantly of hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune.
Satellite
In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as Earth’s Moon.
Phase
a distinct period or stage in a process of change or forming part of something’s development.
Eclipse
Eclipse is an integrated development environment used in computer programming, and is the most widely used Java IDE. It contains a base workspace and an extensible plug-in system for customizing the environment
Comet
A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail.
Asteroid
When found, asteroids were seen as a class of objects distinct from comets, and there was no unified term for the two until “small Solar System body” was coined in 2006.
Asteroid Belt
The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets.
