Astronomy

Astronomy

The study of everything outside the Earth's atmosphere, closely related to physics, chemistry, and geology.

Ancient Astronomy

Practical uses included creating calendars, religious ceremonies, navigation, and timing agricultural activities.

Heliocentric Theory

Proposed by Anistarchus, suggesting the Sun is the center of the Universe, later forgotten.

Geocentric Theory

Ptolemy's model from the 2nd AD, placing Earth at the center of the Universe.

Elliptical Orbits

Johannes Kepler's discovery that planetary orbits are elliptical, with the Sun at one focus.

Thermonuclear Fusion

The process by which stars produce energy, converting hydrogen into helium.

Solar System

Comprises the Sun, planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune), asteroids, meteors, and comets.

Sun

A second-generation star with a diameter 110 times that of Earth, undergoing differential rotation.

Sunspots

Cooler regions on the Sun's surface, part of solar activity.

Solar Wind

A stream of charged particles emitted by the Sun, affecting space weather.

Positive Effects of the Sun

Provides heat and light, influences weather, and supports photosynthesis.

Negative Effects of the Sun

UV light can cause skin cancer and disrupt electrical networks.

Solar Eclipse

Occurs when the Moon is positioned between the Earth and the Sun, can be total or partial.

Terrestrial Planets

Earth-type planets including Mercury, Venus, Earth, Mars, characterized by being small and solid.

Gas Giants

Jupiter-type planets including Jupiter, Saturn, Uranus, Neptune, characterized by being large and gaseous.

Mercury

Closest planet to the Sun with an orbit period of 87 days and a rotation period of 59 days.

Venus

The hottest planet with surface temperatures around 460°C and a retrograde rotation.

Mars

Smaller than Earth, has seasons, and two moons.

Jupiter

750 million km from the Sun

Uranus

Notable for its retrograde rotation and extreme axial tilt of 98°.

Neptune

The coldest planet with faint rings and fast winds.

Pluto

Classified as a dwarf planet and a Kuiper Belt Object.

Asteroids

Found in the asteroid belt between Mars and Jupiter, with diameters less than 1,000 km.

Comets

Composed of ice and dust, often referred to as "dirty iceballs."

Meteors

Space debris that burns up in the atmosphere, known as "shooting stars."

Earth's Revolution

The elliptical orbit around the Sun taking approximately 365.25 days, causing seasonal changes.

Earth's Rotation

The spinning of Earth on its axis, taking 24 hours, resulting in day and night cycles.

The Moon

The second brightest object in the sky, orbits Earth monthly, and has no atmosphere.

Moon's Terrain

Comprises highlands (heavily cratered and old) and maria (smooth and younger).

Impact Theory

Suggests the Moon formed from debris after a large object collided with Earth.

Saturn

known for its rings that where discovered by Galileo Galilei