All the bodies in the sky and the space between them The Universe All the bodies in the sky and the space between them

Types of Stars Sun: a yellow star, middle aged and hot Sirius: a white star, very young and very hot Aldebaran: an orange star, old and not very hot Rigel: a blue star, the hottest & youngest Betelgeuse: a red star, very old and cold Very large hot balls of gas that radiate heat and light.

Planet A very large round object that moves around a star, illuminated by the light from that star.

Satellite satellites planet A big ball that revolves around a planet, illuminated by the light from a star.

Comet Halley’s comet bright tail Close-up image of Halley’s comet A smaller object revolving around a star with a bright tail of gas and dust.

Constellation of Orion Betelgeuse, red star Aldebaran, orange star Sirius, white star Rigel, blue star A group of stars as we can see them from the Earth.

The Milky Way A large number of star systems that form the band of pale light across the night sky. The galaxy that we belong to.

A star and the planets and smaller bodies that orbit it. The Solar System A star and the planets and smaller bodies that orbit it.

The Sun The yellow star that is the source of heat and light for the planets in the solar system.

Venus The second planet from the sun, similar in size to the Earth, very luminous and visible as a “big star”.

The Earth The third planet from the sun on which we live, similar in size to Venus. The blue planet.

Mars Venus Mars The fourth planet from the sun, smaller than the Earth. The red planet. We can see it smaller than Venus.

Jupiter Jupiter satellites The fith planet from the Sun. It’s as big as a small star. It has got many satellites, four of them as big as planets.

Saturn The sixth planet from the Sun, much bigger than the Earth and sorrounded by rings. One big moon.

The rotation of the Earth: days and nights When the Earth rotates one half receives light and heat from the Sun (day). The other half is in the shadow (night)

The revolution of the Earth. Tilt Angle of inclination of the rotation axis = 23.5 degrees The Earth orbits the Sun (revolution) and its axis of rotation is tilted and the Sun’s rays do not reach the Earth in the same way. This tilt causes the different seasons.

Summer solstice The Sun’s rays are almost vertical in the northern hemisphere (directly over Tropic of Cancer). That’s why it is very hot. It’s on June 21st. It’s the longest day of the year.

Autumn Equinox The Sun’s rays are vertical over Equator. The days get shorter. It gets cooler. It’s on September 21. Days and nights are the same length.

Winter solstice The Sun’s rays are almost vertical in the southern hemisphere (directly over Tropic of Capricorn). That’s why it is very cold. It’s on December 21st. It’s the shortest day of the year.

Spring Equinox The Sun’s rays are vertical over Equator. The days get longer. It gets warmer. It’s on March 21. Days and nights are the same length.

The Moon The only Earth’s satellite. It orbits the Earht in a revolution movement.

Rotation and revolution ot the Moon The moon’s rotation and revolution take the same time, 28 days. That’s why we can see always the same side.

Full Moon Full moon is a lunar phase that occurs when the moon is on the opposite side of the earth from the sun

New Moon New moons occur when the Moon is between the Earth and Sun. The phase of the Moon in which the side facing Earth is dark and unilluminated.

Eclipse of Sun An eclipse of the Sun can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow falls upon Earth's surface, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon.

Eclipse of Moon An eclipse of the Moon (or lunar eclipse) can only occur at Full Moon, and only if the Moon passes through some portion of the Earth's shadow.

Sample of pictures test

Sample of Reading Com. Test