Astronomyy Reading and Concepts

1. Read the text “Understanding the Solar System”. Visit the next page:
http://www.astronomy.com/News-Observing/Intro%20Sky/Discover%20the%20Solar%20System/2010/08/Understanding%20the%20solar%20system.aspx

Write in three paragraphs with your own words the 3 main ideas of the text.

2. Astronomy questions

Study the next concepts related with astronomy. Prepare for the monthly exam

asteroid: a small, rocky body that orbits a star

asteroid belt: the zone in which most asteroids orbit the sun, located between the orbits of Mars and Jupiter

astronomical unit: the average distance from Earth to the sun, equal to about 93,000,000 miles (150,000,000 km)

astronomy: the branch of science concerned with objects beyond Earth

aurora: the emission of light when charged particles from the solar wind slam into and excite atoms and molecules in a planet’s upper atmosphere

aurora australis: the southern lights; see definition for aurora

aurora borealis: the northern lights; see definition for aurora

binary star: a system of two stars that orbit a common center of gravity; also known as a double star

black hole: a region of space where gravity is so powerful that not even light can escape; black holes can form either from the death of high-mass stars or in the cores of galaxies

comet: a small piece of ice and rock that orbits a star usually in a highly elongated orbit; long-period comets have orbital periods longer than 200 years, short-period comets have orbital periods less than 200 years

comet nucleus: a solid, compact mass of rock and ice that heats up when exposed to sunlight and releases gas and dust

constellation: one of the 88 patterns of stars in the sky, often named for a mythological god, hero, or animal

cosmic background radiation: microwave radiation that permeates the universe and represents the still-cooling heat generated from the Big Bang

cosmology: the branch of science concerned with the structure and evolution of the universe

cosmos: a synonym for universe

dust: tiny particles floating in space

elliptical galaxy: a gravitationally bound system of stars in a spherical or elliptical shape with no spiral structure

galaxy: an enormous gravitationally bound assemblage of millions or billions of stars

light-year: the distance light travels in one year, equivalent to approximately 5.9 trillion miles (9.5 trillion km)

moon: a smaller body orbiting a larger body; often refers to Earth’s moon

morning star: the planet Venus when it appears in the morning sky

nebula: a cloud of interstellar gas and dust; some nebulae represent stellar nurseries, others represent stellar graveyards

neutron star: the collapsed, extraordinarily dense, city-sized remnant of a high-mass star

nova: an explosion on the surface of a white dwarf that is accreting matter from a companion star, which causes the system to temporarily brighten by a factor of several hundred to several thousand

parsec: the distance an object would have to be from Earth so that its parallax when viewed from two points separated by 1 AU would be one arcsecond; equal to 3.26 light-years

planet: a large rocky or gaseous body that orbits a star

planetary nebula: a glowing shell of gas ejected by a dying, low-mass star

plasma: a gas that has been heated to a state where it contains ions and free-floating electrons; also known as ionized gas

protostar: a cloud of hot, dense gas and dust that is gravitationally collapsing to form a star

pulsar: a rapidly rotating neutron star that bathes Earth in regular pulses of electromagnetic radiation

quasar: the highly energetic core of a young galaxy thought to be powered by a supermassive black hole; short for quasi-stellar object

radio telescope: a telescope designed to detect radio waves coming from space

red giant: a cool star near the end of its life cycle that has expanded to a size of a few dozen to a hundred times the diameter of the sun

red supergiant: a cool, massive star near the end of its life that has expanded to a size from a hundred to a thousand times the diameter of the sun

satellite: a small body that orbits a planet or asteroid

solar system: the system containing the sun and all the smaller bodies in orbit around it

star: a self-luminous sphere of hot gas held together by gravity; ordinary stars generate energy by nuclear fusion in their cores

stellar wind: a stream of electrically charged subatomic particles given off by stars

sublimate: the transition of a solid substance evaporating into a gas without passing through a liquid phase

supernova: the cataclysmic explosion of a star

telescope: a tubed instrument used to brighten and magnify the view of astronomical objects (telescopes gather more light than the eye)

white dwar: the dense, collapsed, Earth-sized remnant of an intermediate-mass star like the Sun