Physical science

• Eclipse - an astronomical event that occurs when the Sun, Moon, and Earth are aligned.
• Ecliepo - a Greek word of eclipse which means 'cease to exist'
• Twice a year, every 6 months - occurance of eclipse
• Shadow regions - Umbra and Penumbra
• Umbra- region of total shadow
• Penumbra - region of partial shadow
• 2 types of eclipse;

  •Solar eclipse

  •Lunar eclipse
• Solar eclipse - the position of moon is between the sun and earth. It occurs during daytime specifically new moon. It last for some minutes only. Then the moon cast it's shadow on the earth.
• Types of solar eclipse;

  1. Partial Solar eclipse - the moon covers only portion of the sun
  2. Total Solar Eclipse - moon completely covers the sun. When the totality begins or ends there is a diamond ring effect. It last in an average of 2-3 min.
• Type of solar eclipse;

  3. Annular solar Eclipse - there is a ring of sunlight around the moon.

  It occurs during apogee.
• Lunar Eclipse - the Earth is between the Sun and Moon. It occurs at night specifically during full moon. Earth cast it's shadow on the moon. It last for how many hours.
• Types of Lunar Eclipse;

  1. Total Lunar Eclipse - moon enters in the earths umbra. It has vibrant red color. And it takes 6 hours form the start to finish.
  2. Partial Lunar Eclipse - moon partially enters the umbra and part of it asses on the penumbra. It has a coppery glow color.
• Predicting Eclipse - astronomers use the Saros Cycle.
• Saros Cycle - from Greek word Saros meaning repetition.  One cycle is equally to 18 years and 11 1/3 days.
• Apogee and Perigee - distance form the earth to the moon.
• Apogee - the orbital point of greatest distance from Earth
• Perigee - orbital point of closest approach to Earth.
• 384,404 km - average distance from moon to the earth
• 356,334 - closest approach (Perigee)
• 406,610 km - Farthest (apogee)
• The phases of the moon are the results of varying viewing angles throughout the month.
• Common misconceptions is that phases of the moon are caused by the shadow of the earth
• Half of the moon is always lit up by the sun. As the moon orbits the earth, we see different parts of the lighted area.
• The revolution of the moon around the earth makes the moon look as if it is changing shape in the sky
• Phases of the moon - caused by the different angles from which we see the lighted part of the Moon's surface
• The moon passes through four major shapes during a cycle that repeats itself every 29.5 days.

  It follo one another in the same order;

  1. New moon
  2. First quarter
  3. Third quarter
  4. Full moon
• New moon - Lighted side of the moon faces away from the earth. Means that the sun, earth, and moon are almost in a straight line, with the moon in between the sun and the earth. The moon that we see looks very dark.
• First quarter moon - the right half of the moon appears lighted and the left side of the moon appears dark. During the time between the new moon and first quarter moon, the part of the moon that appears lighted gets larger and large every day, and will continue to grow until the full moon.
• Full moon - the lighted side of the moon faces the Earth. This means that the earth, sun, and moon are nearly in a straight line, with the earth in the middle. The moon that we see is very bright from the sunlight reflecting off it.
• Third (Last) Quarter Moon - sometimes called third quarter. The left half of the moon appears lighted, and the right side of the moon appears dark. During the time between the full moon and the last quarter moon, the part of the moon that appears lighted gets smaller and smaller every day. It will continue to shrink until the new moon, when the cycle starts all over again.
• Waxing Crescent Moon - this moon can be seen after the new moon, but before the first quarter moon, the crescent will grow larger and larger every day, until the moon looks like the first quarter moon.
• Waxing - means increasing, or growing larger.
• Waxing gibbous moon - this moon can be seen after the first quarter moon, but before the full moon. The amount of the moon that we can see will grow larger and larger every day.
• Waning Gibbous Moon - this moon can be seen after the Full Moon, but before the last quarter moon. The amount of the moon that we can see will grow smaller and smaller every day.
• Waning - means decreasing or growing smaller
• Waning crescent moon - this moon can be seen after the last quarter moon and before the new moon. The crescent will grow smaller and smaller every day, until the moon looks like the new moon.
• Phases of the Moon

  • New
  • Waxing Crescent
  • First Quarter
  • Waxing Gibbous
  • Full Moon
  • Waning Gibbous
  • Third Quarter
  • Waning Crescent
• Blue moon - when two full moons occur in a single month the second full moon called a blue moon
• Why does the blue moon happen?

  The moon orbits the earth every 27.3 days, or roughly 13 times a year, this means that once ( sometimes twice) per year the full moon will make its appearance twice in the same month . This second full moon is refered to as a "blue" moon.
• Is the moon blue during blue moon?

  There have been occasions when the moon has appeared to be blue in hue. This isn't an astronomical phenomenon. Instead, it is caused by dust or smoke high in the earth's atmosphere.