Udupi, Apr 16: With the last New Moon on April 11, the moon will appear half-lit in the evening sky on Friday as it follows the Sun towards the western horizon. If observed around 5 pm, people will notice a small tiny shining dot very close to the Moon. This is Mars, the red planet.
As time passes, within a few minutes, the red planet will disappear all of a sudden appearing nowhere in the sky. This is the Lunar Occultation of Mars which will be visible for the people of India only.
The Moon moves across the sky each night being, close to the Earth, covering half a degree of width in the sky. While on this path, there are rare occasions when the Moon will pass in front of a star and cause occultation. An occultation is like a total solar eclipse when the moon covers the object completely and the object disappears from the sky for an hour and a half as the Moon makes its way across the sky. We see the stars appearing to pass behind the moon, disappearing on one side and reappearing on the other.
All planets in the solar system move around the Sun in almost a disk-like structure. When viewed from Earth, these planets and the Sun, all move along a line called the ecliptic. The moon also moves close to this line as its orbital plane is 5 degrees inclined. As the Moon moves across the sky, moving eastward with each passing day, the moon will pass above or below a planet and the sun every month. While we know the passes next to the Sun as new moon days, the passes very close to these planets are called the conjunction of the moon with these planets. Each month Moon passes very close to Mars with only a few degrees of space between the two as viewed from earth. As we see the pair from the Earth, this space between them, vary from place to place and during certain lunar conjunctions with mars, depending upon where one observes this from, the Moon will appear to pass in front of Mars and cause an eclipse of Mars, which we call Lunar Occultation of Mars.
In the past few months, such occultations have occurred but were visible only from certain parts of Earth. With the previous lunar occultations visible from Africa and South America respectively, this month’s lunar occultation will be visible from across the country.
In the evening, due to the blue scattering of the sky, the dark part of the moon will appear blue and around 5 pm, one can try and observe mars disappearing behind the moon behind the darker side. Because the darker side appears blue, it appears as if mars will vanish from the sky around 5:08 pm (at Udupi and Dakshina Kannada). As the sun sets, and darkness arrives, around 6:55 pm, the red planet will reappear from the bright side of the moon, completing the occultation.
Due to the nature of orbits of the Moon, Earth and Mars around the Sun, these events occur in a seemingly irregular pattern. In countries like Indonesia, due to time difference, the disappearance of Mars will also be visible in the dark night sky, while, in India, the disappearance may be difficult sight with the naked eye. However, the reappearance of Mars will be clearly visible and must not be missed. If you miss this event, there is no Lunar Occultation of Mars occurring again in the near future. While many lunar occultations will occur, none of them will be visible in India. Therefore, this event is not to be missed.
Poornaprajna Amateur Astronomers’ Club wishes that everyone witnesses this beautiful eclipse and enjoy the view with clear skies.