THE SUN, EARTH, & MOON Phases of the Moon Som omething thing - - PowerPoint PPT Presentation
THE SUN, EARTH, & MOON Phases of the Moon Som omething thing to Thi o Think k Abou out! t! Rotation: When an object rotates, it spins on its axis The Earth makes one complete rotation on its axis every 24 hours The Moon
Phases of the Moon
■ Rotation: – When an object rotates, it spins on its axis
■ The Earth makes one complete rotation on its axis every 24 hours ■ The Moon makes one complete rotation in approximately 28 days
■ Revolution: – When an object Revolves, it moves around another object
■ The Earth revolves around the Sun ■ The Moon revolves around the Earth
■ The Sun is the center of the solar system ■ The Earth rotates on its axis every 24 hours – Cause of day and night on Earth ■ The Earth has one moon – The moon makes one complete revolution around the Earth every 28 days
■ The Moon is: – Earth’s only natural satellite – Approximately 384,400 km [238,855 miles] away from the Earth ■ Is the orbit of the Moon around the Earth perfectly circular? – No, the orbit of the moon is not a perfect circle.
■ When the moon is at the closest point [perigee] the moon is 225,804 miles away from the earth ■ When the moon is at the most distant point [apogee] the moon is 251,968 miles away from Earth
Apollo 15 astronaut Jim Irwin on the Moon with the first Lunar Roving Vehicle. Jim Irwin was the 8th man to walk on the Moon
■ The Moon is not a star and does not give off light – The Moon reflects light from the Sun ■ The Moon is rotating on its axis and revolving around the Earth – The position of the Moon changes during the 29 and ½ day lunar cycle
■ As the Moon revolves around the Earth: – The shape of the Moon appears to change ■ Do you think that the shape of the moon actually changes? – Study the images of the lunar cycle before you answer
■ Only the side of the moon facing the sun can reflect sunlight. ■ During much of the lunar cycle we can only see a portion of the sunlit moon ■ What do you think we see during a ‘new moon’? ■ What do we see when the moon is a crescent?
The outside images are what we see when we look up at the moon from Earth The portion of the moon facing the sun reflects sunlight
■ Green lines represent portions of the Moon we cannot see from Earth ■ White areas of the Moon are what we see from the Earth
■ When the Moon is said to be ‘Waxing’ – The sunlit part of the Moon at any time befor
– The sunlit part of the Moon we see is getting larger
■ When the Moon is said to be ‘Waning’ – The sunlit part of the Moon at any time after a full Moon – The sunlit part of the Moon we see is getting smaller
■ During a new moon, we do not see the moon in the sky – The dark side of the moon is facing the Earth – The other side of the moon is very bright and facing the sun ■ Can you find the new moon in the picture to the right?
■ When we see the ‘waxing crescent moon’ a thin sliver or crescent of the moon is visible. – When we are able to see a bit more of the moon, we say the moon is waxing. ■ Can you find the waxing crescent moon in the picture to the right?
■ About one-week after the new moon, the moon has completed about one- quarter of its orbit around the Earth. – We are able to see
side of the moon. Actually, that is a quarter of the moon. ■ Can you find the waxing quarter moon in the image
■ As the moon continue nues to orbit the Earth, h, we are re able to s see more of the bright ht portion
the moon. – The gibb bbous mo moon is nearly y a full l mo moon – We call l it a waxing mo moon be because we can see mo more
moon fro rom m Earth. ■ Can you find d the waxing xing gibbous s moon in the image ge on the right? t?
■ When the moon is full, l, we are able to see the half of the moon n illum umin inat ated ed by the sun un. – The Su Sun, Earth th and d Moon n are nearly rly in a str traig ight t line. ne. ■ What other er time me during ing the moon’s orbit are the Sun, Earth, th, and Moon nearly rly in a straight raight line? e?
■ The waning ng gibbo bous us moon n is nearly rly a full moon n but we are seeing ing less ss of the moon. n. – We say th the moon n is wani ning ng and nd we call l th the mo moon n a g gibbo bbous us mo moon n beca cause use it t is nearly arly full ■ Can you find the e waning ng gibbous bbous moon
n the image age to the right? ght?
■ The portio tion n of the moon lit t by the sun un is growing wing smaller aller. – The left t half of th the mo moon n is illu lumin minated ed by th the sun ■ Can you find the e last t quarter er of the moon
the image age on the right? ght?
■ As the moon n appear ars s to be be smaller ller and nd small ller er in n the sky, , it is called ed the wanin ing g cresc scen ent. t. – The waning ing crescen scent t moon n will ll cont ntinu inue to appear ar smaller ler and smaller ler with th each day. ■ Can you find the e waning ng cresc scen ent t moon n in the image age on the right ht?
■ How is the Waxing Crescent Moon different from the Waning Crescent Moon? ■ If you looked into the night sky during the New Moon, would you expect the stars to be more or less visible in the night sky?