Our Solar System

The Sun Our Sun is a medium-sized yellow star in the middle of its life cycle. Its the center of our Solar System and holds objects in orbit by gravitational pull. More than 1,000,000 Earths can fit inside the Sun. It’s fueled by nuclear fusion of small atoms to form larger ones, and it’s the only source of energy in the solar system. It has features: sun spots, solar flares, and prominences.

Mercury Terrestrial planet with a solid rocky surface Covered with craters Extreme temperatures (from -170 ºC up to 467 ºC) Thin atmosphere so its temperatures vary by day and night Fastest planet to revolve around the Sun, thus named Mercury No moons … why not?

Venus Terrestrial planet with a solid, rocky surface Earth’s “twin” in size Extremely hot temperatures (470 ºC) due to thick atmospheric cloud cover and green house effect. Retrograde motion (it rotates clockwise) No moons … why not?

Earth Terrestrial planet with a solid, rocky surface Frozen caps at North & South Poles Capable of supporting life due to [C], 70% water, and protective atmosphere Seasons due to axis tilt 1 Moon: Luna where we have landed multiple times and sent more than 70 spacecraft

Earth’s Moon “Luna” The moon acts like a mirror; it reflects sunlight to Earth Phases of the moon occur as the moon revolves around Earth and reflects sunlight. Tides -- high tide and low tide -- are caused by the moon’s gravitational pull

Mars Terrestrial planet with a solid, rocky surface Red surface due to [Fe] Enormous active volcanoes and dust storms Thin atmosphere Frozen polar caps like Earth Liquid water once? 2 Moons: Phobos and Deimos

Asteroids Made of rock, minerals, and rare elements More than 100,000 orbit in the “Asteroid Belt” between Mars and Jupiter Could collide with Earth, but probably won’t The largest asteroid named Ceres is a dwarf planet Moons: a few asteroids have moons!

Meteors or “Shooting Stars” Pieces of rock that are falling toward Earth are meteors They glow brightly as they burn up due to fluid friction Called “meteoroids” if they are far away, “meteors” if they have a bright tail, and “meteorites” once they hit Earth

Jupiter The largest “gas giant” with no solid surface Faint rings Made of elements [H] and [He] with a hot, solid core of [Fe] -- almost a star! “Red Spot” is a massive storm 60+ Moons: the four largest are named Io, Europa, Ganymede, Callisto, but there are more…

Saturn Second largest gas giant without a solid surface Famous for bright, icy rings that we can see from Earth with a telescope. The rings have large divisions. Mostly made of elements [H] and [He] Less dense than water! 60+ Moons: Titan and Phoebe and more, some orbit in the gaps of the rings

Uranus Gas giant without a solid surface Made of elements [H] and [He] and water, ammonia and methane Bluish reflection due to methane (CH 4 ) gas Faint rings, but the brightest clouds Axis is turned “sideways” so it has wild seasons Retrograde motion 27 Moons: Ariel and more…

Neptune Gas giant without a solid surface Bluish reflection due to methane (CH 4 ) gas but more vivid than Uranus Six faint rings Farthest planet from the Sun, usually 13 Moons: Triton is the largest and 12 more…

Dwarf Planets & Plutoids Ceres is the largest asteroid in the asteroid belt Pluto has a solid, icy surface, 3 moons, and it orbits in a tilted plane. Charon is the largest moon of Pluto. Makemake is smaller than Pluto, but farther Haumea is similar to Pluto in size and rotates the fastest Eris is larger than Pluto, but farther away More to be discovered…

Comets Made of rock, ice and dust Comets consist of a head, coma, and two tails that point away from the Sun “Short-period” comets come from the “Kuiper Belt” and orbit the Sun every 200 years or less “Long-period” comets come from the “Oort Cloud” and take longer to orbit the Sun

Stars like our Sun Stars are classified in many ways: by color and temperature, mass, age in life cycle, brightness and…

The Life Cycle of Stars Stars age through a life cycle that includes many stages.

Galaxies Galaxies are groups of billions of stars, usually classified by their shape: spiral, elliptical, or irregular. Spiral: like our Milky Way Galaxy Elliptical Irregular (or chaotic)