Astronomy Science vocabulary Comets meteoroids asteroids phases of

Astronomy Science vocabulary: Comets, meteoroids, asteroids, phases of the moon, eclipses

Comets n n Often referred to as “Dirty snowballs”, comets are a small body of ice, rock and cosmic dust Comets move around the Sun in Elliptical orbits When a comet passes close enough to the sun, solar radiation heats the water ice so that the comet gives off gas and dust in the form of a long tail Comets always point away from the sun

Comet’s Tail

Comets Halley’s comet becomes visible to the unaided eye every 76 yrs as it nears the Sun. n n The Sun converts some of its gases into charged particles (ions), which stream away forming an ion tail. Scientists learned about Comets by studying Haley’s comet as it passed by Earth in 1986. They took pictures and used space probes

Asteroids n n Asteroids are small rocky bodies in orbit around the sun. Most asteroids have orbits that lie between the orbits of Mars and Jupiter Asteroid Ida is 55 miles long & orbits in the asteroid belt n Dangerous to us?

Meteoroids n n n Meteoroids are similar to Asteroids but much smaller in size. If a meteoroid enters the Earth’s atmosphere, it is called a meteorite. A Meteoroid entering the Earth’s atmosphere travels at great speeds, which heats up its surface and melts.

Meteors n n This melting makes the meteoroid glow red hot and give off tons of light. We see this as “a shooting star”. The bright streak of light caused by a meteoroid or comet dust burning up in the atmosphere is called a meteor.

Meteor Showers n 1. 2. 3. Question on video: What are the biggest culprits that cause meteor showers? Why do the tiny particles begin to glow as they pass through the Earth’s atmosphere? What is the best time to see meteor showers? n http: //www. teachersdomain. org/resource/ess 05. sci. ess. eiu. meteorshower/ n “Meteor Showers” occur when Earth passes through the dusty debris left behind in the orbit of a comet

Phases of the moon 1. New moon None of the moon is visible Crescent Moon Less than half of the Earth facing side of the moon is visible 2. Quarter Moon Exactly half of the Earth-facing side of the moon is visible 3. Gibbous Moon More than half of the Earth-facing side of the moon is visible 4. Full Moon The entire Earth facing side of the moon is visible

Waxing & Waning n n n http: //www. teachersdomain. org/resour ce/ess 05. sci. ess. eiu. mphase/ If the part of the moon that we see from the Earth is INCREASING, we say the moon is WAXING. If the part of the moon that we see from the Earth is DECREASING, we say the moon is WANING.

Eclipses – Where R U ? n n n Eclipses occur when the shadow of an object in the sky (ex. Moon, Earth) falls on another object Two types of Total Eclipses: ¡ Lunar Eclipse – Moon is hidden ¡ Solar Eclipse – Sun is hidden Sometimes only a part of the Sun or Moon is hidden and this is a Partial Eclipse

Lunar Eclipse ¡ ¡ Occurs when the Moon passes through some portion of the Earth’s shadow. The shadow caused by an eclipse is an UMBRA The moon appears red as it receives some light reflected off the Earth. Happens at night

Next Lunar eclipse in US n April 14 -15 th in 2014

Solar Eclipse n n Next in US on August 17 th, 2017 Occurs at New moon, when the Moon passes between the Sun and the Earth Happens during the day.

Corona n n n The outer atmosphere of the Sun is called the Corona. It is the only part of the Sun seen during a total eclipse. Solar eclipses can cause serious damage to the eyes if observed directly.

Complete the worksheet n Draw the positions of the Moon, Sun and Earth during a Lunar eclipse and a Solar eclipse