OUR SOLAR SYSTEMS OTHER OBJECTS FOLDABLE FOLDABLE SETUP

OUR SOLAR SYSTEM’S OTHER OBJECTS FOLDABLE

FOLDABLE SETUP Our Solar System’s Other Objects Dwarf Planets Asteroids Comets Meteoroids

DWARF PLANETS • IN 2006, THEINTERNATIONAL ASTRONOMICAL UNION ADOPTED “DWARF PLANET” AS A NEW CATEGORY • DEFINED AS AN OBJECT THAT ORBITS THESUN, HAS ENOUGH MASS AND GRAVITY TO FORM A SPHERE, AND HAS OBJECTS SIMILAR IN MASS ORBITING NEAR IT OR CROSSING ITS ORBITAL PATH

DWARF PLANETS CONT’D. • FIVE DETERMINED DWARF PLANETS THUS FAR • 1. CERES • SMALLEST DWARF PLANET, ORBITS IN THE ASTEROID BELT, 945 KM DIAMETER • 2. PLUTO • PERIOD OF REVOLUTION IS 248 YEARSA, VERAGE TEMPERATURE OF -230° C, THREE KNOWN MOONS –CHARON (LARGEST), HYDRA, NIX • 3. ERIS • LARGEST DWARF PLANET, THREE TIMES FARTHER FROM THESUN THAN PLUTO IS, ONE MOON –DYSNOMIA • 4. MAKE • DESIGNATED IN 2008, SMALLER THAN PLUTO BUT YET ONE OF THE LARGEST OBJECTS IN THE KUIPER BELT, AVERAGE TEMPERATURE - ABOUT 30 K (− 243. 2 ° C) • 5. HAUMEA • DESIGNATED IN 2008, ALSO IN THE KUIPER BELT, ELONGATEDSHAPE, RAPID ROTATION

DWARF PLANETS

ASTEROIDS • PIECES OF ROCK AND ICE • USUALLY NOT SPHERICAL • MOST ORBIT THE SUN IN THE ASTEROID BELT • LOCATED BETWEEN THE ORBITS OFMARS AND JUPITER • HUNDREDS OF THOUSANDS DISCOVERED • LARGEST, PALLAS, IS OVER 500 KM IN DIAMETER

COMETS • MIXTURES OF ROCK, ICE, AND DUST • LOOSELY HELD TOGETHER BY GRAVITATIONAL ATTRACTION BETWEEN PARTICLES • ORBIT THE SUN IN LONG ELLIPTICAL ORBITS • STRUCTURE • SOLID, INNER PART IS ITS NUCLEUS • AS IT MOVES CLOSER TO THESUN, IT ABSORBS THERMAL ENERGY AND CAN DEVELOP A BRIGHT TAIL • HEATING CHANGES THE ICE TO GAS • ENERGY PUSHES SOME OF THE GAS AND DUST AWAY FROM THE NUCLEUS AND MAKES IT GLOW • THIS PRODUCES THE BRIGHT TAIL AND GLOWING NUCLEUS, CALLED A COMA

METEOROIDS • METEOROID – SMALL, ROCKY PARTICLE THAT MOVES THROUGH SPACE • METEOR – STREAK OF LIGHT IN EARTH’S ATMOSPHERE MADE BY A GLOWING METEOROID • METEORITE – A METEOROID THAT STRIKES A PLANET OR MOON