What is Mercury s greatest western elongation? What does Mercury s greatest western elongation mean

The great elongation is the maximum angle between the planet and the Sun as seen from the Earth. Mercury and Venus travel between the east and west sides of the Sun in conjunction cycles. They have a certain limit to their elongation to the east or west of the Sun, and their maximum elongation is called the "great elongation".

How to observe?

Mercury has a great eastern elongation and a great western elongation, which is called the eastern elongation if it is located in the east of the Sun and the western elongation if it is located in the west of the Sun. At great eastern elongation, Mercury appears above the western horizon at dusk; At the western distance, it appears in the low eastern sky at dawn. It is only possible to see Mercury at its maximum angular distance from the Sun, known as the "Great Distance".

Although Mercury has 6 major elongations this year, there are only two best observation conditions for people in the Northern Hemisphere and high latitudes, including this one.

Observation time

In the early hours of the 12th or 13th, Mercury can be looked for near the eastern horizon, rising at about 4:30 a.m. Mercury will rise before the Sun, and if the Sun has risen and you haven't seen it, it's no fun.

About 30-60 minutes after sunset is more suitable for observation, specifically according to the sky, the sky is dark, but not completely dark is the best. The time of Mercury's greatest western elongation is 18:17.

Place of observation

After talking about the time, let's talk about the location. Good weather is an important factor in viewing Mercury's western elongation, and the open area with no light source pollution, high atmospheric transparency, and no obstruction is an ideal observation location. For example, the top of a hill or the roof of a building. Remember it must be east!!

Precautions

Since Mercury is at a low level above the horizon, only a dozen degrees high, don't tilt your neck and look around the top of your head. In addition, it will be affected by atmospheric jitter on the ground, and it is also necessary to pay attention to distinguish it from the light on the ground. If possible, observations can be made with the help of binoculars.

Mercury's greatest western elongation means that Mercury appears to the west of the Sun. Due to its proximity to the Sun, Mercury is often obscured in the Sun's brilliance and has only a few brief observable opportunities each year, making it the most difficult of the eight planets in the solar system to observe.

It is only when the angular distance between Mercury and the Sun reaches its maximum, known as the "great elongation", that the public has the best chance of witnessing Mercury. Mercury is called the "greatest eastern elongation" to the east of the Sun and the "greatest western elongation" to the west of the Sun. (from Encyclopedia).

The exact time of Mercury's greatest western elongation in 2018.

Mercury appears low in the east at dawn.

On March 14, 2014, Mercury will have its greatest western elongation, but unfortunately, the horizon is too low for observation.

On September 12, 2017, astronomical experts introduced that the "western elongation of Mercury" will occur, and the public is expected to catch a glimpse of Mercury, which is rarely seen on weekdays, in the mornings before and after the elongation

This year, there are four major western elongations of Mercury, which is located west of the Sun and is seen low in the east at sunrise. The distance from the Sun is3° and.

The western elongation of the water model Bixing refers to the appearance of Mercury in the west of the Sun. Due to its proximity to the Sun, Mercury is often lost to the Sun's brilliance and has only a few brief observable opportunities each year, making it the most difficult of the eight planets in the solar system to observe.

It is only when the angular distance between Mercury and the Sun reaches its maximum, known as the "great elongation", that the public has the best chance of witnessing Mercury. The absence of Mercury in the east of the Sun is called the "Great East Elongation" and the "Great West Elongation" in the west of the Sun. At the "greatest eastern elongation", Mercury can be found above the western horizon at dusk; Mercury appears low in the east at dawn.

Mercury, one of the eight planets of the solar system. The closest planet to the Sun in the solar system, the smallest planet, the planet with the greatest eccentricity of orbit, and the planet with the largest temperature difference between day and night are all about it. Mercury's orbital period is days, its rotation period is days, and its two weeks of revolution is almost equal to the time of three weeks.

Mercury is relatively small, and the two moons, Ganymede and Titan, are both larger than Mercury.

Mercury is a small planet that we can't usually observe, not because it's too far away or too small, but because it's so close to the Sun. Although it has a strong ability to reflect the sun's rays, it is so close to the sun that it spends most of its time being overwhelmed by the sun's intense brilliance. Only when the elongation between Mercury and the Sun is at its maximum can we see it shining brightly in the sky.

With a telescope, you can see that it resembles a half-moon and a sweet potato, like a first and last quarter moons. When the elongation angle between Mercury and the Sun is the largest, it is called the Mercury elongation.

When Mercury is on the east side of the Sun, it is the greatest eastern elongation of Mercury, and we can see Mercury on the western horizon when the Sun sets in the west; When Mercury is on the western side of the Sun, it is the greatest western elongation of Mercury, and we can see Mercury on the eastern horizon before sunrise at dawn. The earth in the picture rotates from west to east, with the position of the earth "dusk" in the east and the position of "morning" in the west.

Mercury's great elongation is a great time to observe Mercury, but it is short-lived. At the great eastern elongation of Mercury, Mercury can be seen in the low sky to the west, when the sun has set in the west, and Mercury does not last long in the sky, and it will also set in the west after a while; At its greatest western elongation, Mercury is visible in the east just before sunrise. However, after sunrise, the sun's rays will drown out Mercury again.

Due to the large eccentricity of Mercury's orbit, the distance difference between its perihelion and aphelion is also clearly visible. Mercury is 47 million kilometers from the Sun at perihelion and about 70 million kilometers at aphelion. If Mercury's great elongation coincides with Mercury's aphelion, then the elongation between Mercury and the Sun will be greater, and Mercury will be observable for a longer time.

But it won't take more than two hours at a time.

Mercury's conjunction period with Earth is 116 days, which is more than the time it takes for Mercury to orbit the Sun. Therefore, Mercury must appear at the greatest eastern and western elongations at each conjunction. The Earth has 3 116 days in a year, so we can see Mercury's great elongation about 6 times a year.

So does Mercury rise in the west at sunrise or east at sunset? No, this is absolutely impossible. Because Mercury's orbit is on the inner side of the Earth, it is unlikely that the Earth will appear between the Sun and Mercury.

The same is true for Venus, which is also on the inner side of the Earth. So, if you see a bright star in the west before dawn or in the east after sunset, that star can't be Mercury or Venus. Similarly, on Mars, it is impossible to see the Earth rising in the east after sunset or the Earth appearing in the west in the sky before sunrise.

The maximum angle between the planet and the Sun as seen from the Earth. It is often used to describe the angle between Mercury or Venus and the Sun.

The planets (Mercury and Venus) travel between the east and west sides of the Sun in conjunction cycles, and their elongation to the east or west of the Sun has a certain limit: their maximum elongation is called the "great elongation". That's the best time to observe planets on Earth.

It is divided into east distance and west distance. At the greatest eastern elongation, the inner planets appear in the western sky after sunset: conversely, at the greatest western elongation, they appear in the eastern sky before sunrise.

The great elongations of Mercury and Venus, respectively "28 degrees" and "48 degrees". The magnitude of the angle of the row is determined by the distance of the planets from the Sun and the distance from the Sun to the Earth. Great elongations are usually the clearest time to observe the planets in the interior, because the planets are far from the Sun and are not affected by the sun's rays.

Resources.

Let's start by explaining the "large distance". We know that there are two large planets in the Earth's orbit - Venus and Mercury. Because they orbit inside the Earth.

So we look like they're always "wandering" around the sun, always close to the sun. Venus is a little better, especially Mercury is hard to see. Always drowning in the rays of the sun.

So when is the best time to observe them? Of course, when they are the furthest from the Sun (Kishi means the farthest we can see in the past), right? This timing is called "great distance", which means the greatest distance from the sun.

Just think about it, and you know that this great distance will appear on both sides of the sun. Then the great distance in the east is called "east distance", and the east distance is that it sets a little later than the sun after dusk; In the west, it is called "western elongation", and western elongation is that the planet rises a little earlier than the sun.