Science Test - Solar System

Dec. 2025

geocentic modle

Earth is at the center of the solar system

heliocentric model

Earth and other planets revolve around the sun

ellipse

an oval shape

solar system

consists of the planets, the sun, their moons, and a variety of smaller object

astronomical unit

the average distance between Earth and the sun, 150,00 kilometers

planet

must have been round, orbit the sun, and have cleared out the region of the solar system along its orbit

dwarf planet

an object that orbits the sun and has enough gravity to be spherical, but not cleared out the area of its orbit

planetesimal

the formation of rock and ice that has formed a small body

core

The central region of the sun

nuclear fusion

hydrogen atoms join to form helium

radiation zone

a region of very tightly packet gas where energy moves mainly in the for of electromagnetic radiation

convection zone

the outermost layer of the sun’s interior

photosphere

The inner layer of the sun’s atmosphere

chromosphere

The middle layer of the sun’s atmosphere

corona

The outer layer of teh suns atmosphere that looks like a white halo around the sun

solar wind

made up of electrical particles from the sun

sunspot

areas of gas on the sun’s surface that are cooler than the gasas around them

Prominences

huge loops of gas

solar flares

eruptions of loops of gas

terrestrial planets

the inner planets

inner planets

small and dense and have a rocky surface

Mercury

smallest terrestrial planet and closest to the sun

Venus

has a thick atmosphere, an unusual pattern of rotation, and the hottest surface of any planet

Earth

has liquid water and a sustainable temperature range and atmosphere for living things to survive

Mars

though Mars is mostly too cold for liquid water, it does have water ice now and shows evidence of intermittent seasonal flowing water today as well as liquid water in the past

greenhouse effect

Trapping heat in the atmosphere

gas gaint

the four outer planets

outer planets

they are much larger and more massive than Earth, and they do not have a solid surface

rings

a thin disk of small particle ice and rocks

Jupiter

the largest and most massive planet

Saturn

has the most spectacular rings of any planet

Uranus

axis of rotation is tilted of an angle of about 90 degrees from the vertical

Neptune

a cold, blue planet. It’s atmosphere contains visible clouds

asteroid belt

a region of the solar system between mars and Jupiter

Kuiper belt

region beyond Neptunes orbit extends about 100 times Earth’s distance from the sun

Oort cloud

Beyond the Kuiper belt stretches about 1,000 times the distance between the sun and Neptune

comet

loose collections of ice, dust, and small rocky particles whose orbit can be very long

asteroid

rocky objects, most of which are too small and too numerous to be considered a planet of dwarf planet

meteoroide

chucks of rock and dust smaller than asteroids

meteor

a small streak of light when a meteoroide enters Earth’s atmosphere

meteorite

meteoroids that crash into Earth