The BA Planetarium Science Center is inviting the public, students and sky lovers to monitor the phenomenon on Mercury’s transit across the sun for free on Monday, the 9th of May starting from 12:30 pm. There will be observations by telescopes at the Bibliotheca Alexandrina to monitor the phenomenon of Mercury’s transit  across the sun using special solar filters. We strongly advise you not to look at the sun by the naked eye during the transit.

On Monday the 9th of May, at 1:12 pm exactly, a rare astronomical phenomenon will occur, which is the transit of Mercury across the Sun and it is called “Inferior Conjunction”. This phenomenon will be observed by astronomers and rare phenomena lovers from most of the countries around the world. This phenomenon occurs when the planet Mercury comes between the Earth and the Sun. if this occurs with the moon, this phenomenon is called lunar eclipse. But if this happens with the inner planets, Mercury or Venus, the phenomenon is called a transit. On the day of the transit, astronomical calculations have confirmed that the coordinates of Mercury with the Sun in front of the Earth are equal. Most of the inhabitants of Earth will be able to watch Mercury while its transit across the Sun. The last time this phenomenon occurred was in November 2006.

Facts and numbers related to the phenomenon of Mercury’s transit:

• During the transit, Mercury will appear as a tiny black glossy dot in front of the Sun.
• The transit will start from the eastern side to the western side of the Sun.
• The first contact between Mercury and the Sun will be from the eastern side of the Sun at 1:12 pm exactly.
• The entire planet will enter the circumference of the Sun at 1:15 pm.
• The planet will be in the middle of the transit trip in front of the Sun at 4:57 pm exactly.
• The planet will begin to exit the Sun from its western side at 8:39 pm. (This stage will not be seen in Egypt)
• The last contact between Mercury and the Sun will be at 8:42 pm. (This stage will not be seen in Egypt)
• The phenomenon will continue to fully occur for seven hours and half; starting from the first contact until the moment of the farewell.
• Mercury occupies an area of 1/157 of the size of the Sun during the transit. Due to its small size, and error may occur in the calculation of time ±2 minutes.
• The next Mercury’s transit will occur on November 11 2019, and the next will on November 12 2032.
• Mercury’s transit phenomenon usually occurs in May and November only.
• This phenomenon occurs in November more than it happens in May; it occurs 67% but in May it occurs 33% more.
• It is not a must that all the inhabitants of Earth will be able to watch the transit phenomenon.
• This time the transit was longer by two and half hours than the transit that occurred in 2006.
• This transit will be visible in most of Western Europe, Northern and Western Africa, the north-eastern America and most of the Atlantic Ocean islands.
• Of course, this phenomenon will not be visible in the countries that will happen to be at night during the occurrence of the transit, such as eastern Russia, China, Japan, Korea, the Philippines and other countries.
• Historically, Johannes Keppler the first to predict the phenomenon of the transit of Mercury; even though who died before the occurrence of this phenomenon. He predicted that a transit will happen on November 7 in 1631, but he died on 15 November 1630; one year before the transit’s occurrence.

Astronomical information and figures about Mercury:

• The scientist and astronomer Ptolemy was the first to monitor Mercury in 265  BC when the planet was related to the second-brightest star in Scorpius.
• The first observations of Mercury using telescopes was during the 18th century were conducted by the scientist Sir William Herschel.
• The Russian spacecraft “Mariner 10” reached Mercury 3 times in 1973, 1974, and 1975 and was able to photograph the planet.
• Mercury has no moons orbiting it.
• The atmosphere of Mercury was very thin because it is very near to the sun.
• Mercury is the smallest planet in  the solar system.
• Mercury cannot be seen during night but it can be seen before sunrise or after sunset and not for a long period of time.
• This planet was named after the messenger of commerce of the Romans, but the Greeks named it Apollon.
• The closest distance from the Sun is 46 million kilometers and is called gutter and the speed of rotation around the sun reaches 59 kilometers per second.
• The farthest distance from the sun is 70 million kilometers which is called the apogee and the speed of rotation around the sun would reach 39 kilometers per second.
• The closest distance from Earth is 80 million kilometers.
• The farthest distance from the Earth is 219 million kilometers.
• Mercury’s size is 1/14 of the Earth’s size and Mercury’s mass is 1/25 of that of the Earth.
• The temperature on Mercury reaches 220 degrees during the day.
• The temperature on Mercury reaches 27 degrees at night.
• The length of the day on Mercury equals 59 Earth days.
• The length of a year on Mercury equals 88 Earth days.