Context: Eclipses, the celestial body phenomenon with socio-cultural significance, have a wide influence on human activities. In this article, we are going to explore the different types of eclipses that occur in the Sun's solar system.
Solar Eclipses:
- Solar Eclipse happens when the Moon gets in the way of the Sun’s light and casts its shadow on Earth. That means during the day, the Moon moves over the Sun, and it gets dark. A solar eclipse happens at a new moon when the moon passes between the sun and Earth.
- This can happen in two ways:
- A total eclipse, when the Moon completely covers the Sun.
- A partial eclipse, when the Moon does not completely cover the Sun.
Lunar Eclipses:
- Lunar Eclipse happens at full moon, when the Earth, Sun and Moon align in space, with Earth between the Sun and Moon.
- During a lunar eclipse, Earth gets in the way of the Sun’s light hitting the Moon. That means that during the night, a full moon fades away as Earth’s shadow covers it up.
- The Moon can also look reddish because Earth’s atmosphere absorbs the other colours while it bends some sunlight toward the Moon.
- Sunlight bending through the atmosphere and absorbing other colours is also why sunsets are orange and red.
Phases of the Moon:
- The day on which the whole disc of the moon is visible is known as the full moon day.
- Thereafter, every night the size of the bright part of the moon appears to become thinner and thinner.
- On the fifteenth day the moon is not visible. This day is known as the ‘new moon day’.
- The next day, only a small portion of the moon appears in the sky. This is known as the crescent moon.
- Then again, the moon grows larger every day. On the fifteenth day once again, we get a full view of the moon.
Blood Moon
- This is not a new phenomenon; it is an informal term used in the case of a full lunar eclipse. When the Earth comes between the Sun and the Moon, light bends. While passing through the Earth's atmosphere, it scatters because the high-wavelength red component of light deflects the least, giving the illusion of the Moon being red, as happens with the Sun during sunrises and sunsets.
Lunar Eclipse not occurring on every new moon and full moon day: The Reason
- For an eclipse to happen the moon should be at one of the nodes made by the ecliptic plane, which does not happen on every new moon and full moon days as shown in the figure. So, we do not have a Lunar eclipse on every new moon and full moon.
Key Terms:
| Eclipse | In simple terms, an eclipse happens when a planet or a moon gets in the way of the Sun’s light. Here on Earth, we can experience two kinds of eclipses: solar eclipses and lunar eclipses. |
| Ecliptic Plane | The ecliptic plane is defined as the imaginary plane containing the Earth’s orbit around the sun. ·In the course of a year, the sun’s apparent path through the sky lies in this plane. ·The planetary bodies of our solar system all tend to lie near this plane.  |
| Line of Nodes | ·The plane of the Moon's orbit is inclined at a mean angle of 5.145° to the plane of Earth's orbit around the Sun. ·The intersection of these planes defines two points or nodes on the celestial sphere. ·The node where the Moon's path crosses the ecliptic from south to north is the ascending node, while the node where the Moon's path crosses the ecliptic from north to south is the descending node.  |
| Stars | Star, any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. |
| Satellites | Natural SatellitesA satellite is anything that orbits around a larger object. A natural satellite is any celestial body in space that orbits around a larger body. Moons are called natural satellites because they orbit planets. Artificial SatellitesAn artificial satellite is an object that people have made and launched into orbit using rockets. There are currently over 3,000 active satellites orbiting the Earth. The size, altitude and design of a satellite depend on its purpose. |
| Orbit | In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. |