Astronomical Events: Waiting for a partial eclipse on July 17

In the early morning of July 17, 2019, Vietnamese people will have the opportunity to observe an interesting astronomical phenomenon in the year: Partial Moon. The following article will provide you with important information to help you observe this phenomenon.

Why is there a lunar eclipse?

True Moon is a phenomenon that occurs when the Moon, Earth and Sun lie on a straight line (or near straight line) and the Moon passes through the Earth's shadow. At that time, the Moon is facing the Sun across the Earth, so the eclipse only happens on the full moon. Due to the distance between the Moon, Earth and the Sun, the Earth's shadow is actually divided into two regions: the shadow and the shadow.

Explain lunar eclipse: When the Moon enters the shadow area (penumbra), the half-moon eclipse will take place.When the Moon enters the shadow region (umbra), the lunar eclipse appears.The total lunar eclipse occurs when the Moon lies completely in the shadow.(Photo: NASA).

Because of this partition, the lunar eclipse is divided into three categories, corresponding to three phases. The first is the half-moon eclipse - which happens when the Moon passes through the dark half of the Earth. At this point, the Moon is only slightly darker, so the semi-dark eclipse is often less sought after than the other two types. After moving through the shadow area, the Moon will go to the shadow area. At the time of the Moon between these two regions, we can observe partial eclipse. At that time, the full moon would lose a part like a giant piece of biscuits bitten by someone. And the most anticipated period - the total eclipse - occurs when the Moon passes through the shadow of the Earth and is completely obscured. However, the Moon did not "disappear" but appeared with enchanting red light.

Moonlight part.(Photo: Justin Sullivan / Getty Images).

Not every single moon has a lunar eclipse. Because the Moon's orbit is tilted 5 degrees above the zodiacal plane, the Moon, Earth and Sun are not always on a straight line. The intersection between the apparent path of the Sun and the Moon is called a node, only when the Moon passes through this node can we observe the lunar eclipse.

Moonlight part of July 17, 2019

This July, the Moon will pass through the upper node and a 'partial eclipse' will occur. This eclipse can be observed throughout Europe, Africa, Central Asia and the Indian Ocean region. In Vietnam, we can also observe this phenomenon.

Places that can observe the eclipse partially this time.(Photo: In-the-sky.org).

Details of the eclipse process are as follows: (time has been converted to VN time):

1. Moonlight half-dark start: 01:43:51
2. Partial eclipse begins: 03:01:43
3. True maximum eclipse: 04:30:44
4. Partial eclipse ended: 05:59:39 (not observable in Vietnam)
5. Half-moon eclipse ends: 07:17:38 (not visible in Vietnam)

In Hanoi, the Moon will set at 05:28, while in Ho Chi Minh City it is 05:44 , which means that we will not be able to observe the end of the lunar eclipse this time.

Moon real part at maximum, at 04:30:44.Now the Moon is very low, near the west-southwest horizon.(Image simulated on Stellarium software).

Unlike solar eclipses, the eclipse observation area is quite wide and the observation time is relatively long. Moreover, we can absolutely observe with the naked eye. Choose a quiet place, a clear view of the west and less light pollution to have the most favorable observation.

When will the next eclipses occur?

There were two eclipses in 2019. A full lunar eclipse occurred in January but was not observed in Vietnam, and the second time was a partial lunar eclipse on July 17. In 2020 there are four eclipses, all of which are half-moon eclipses, in which Vietnam can observe lunar eclipses in January, June and November. The next full lunar eclipse we have observations take place on November 8, 2022.

1. There will be a half-moon eclipse in Vietnam