Planet Venus High in the Sky

 
On January 10, 2025, Venus will reach its Greatest Eastern Elongation. Venus, the brightest "star" in the evening western skies, outshines everything else. Just after sunset, in the evening twilight, it is easy to spot this diamond in the sky.

Greatest Elongation refers to the largest angle formed between Earth, the Sun, and a planet—in this case, Venus. On this day, Venus will appear 47 degrees away from the Sun as seen from Earth. As both Earth and Venus orbit the Sun, the angle between Venus and the Sun (as viewed from Earth) changes. When the planets align with Venus between Earth and the Sun, the angle is zero, an event known as Inferior Conjunction. Since Venus orbits closer to the Sun and moves faster than Earth, this angle increases, eventually reaching a maximum of 47 degrees. After this point, the angle begins to decrease until it reaches zero again. When Venus aligns on the far side of the Sun relative to Earth, this is called a Superior Conjunction.

At Greatest Eastern Elongation, Venus will display a nearly half-phase and will set late in the evening. As the days pass, the angle between the Sun and Venus will gradually reduce, but Venus's apparent size will increase. The phase will change from half to a crescent as the distance between Venus and Earth decreases.

At Greatest Elongation, Venus's angular size will be 24.6 arcseconds, with the planet located 101,742,566 km from Earth. As Venus continues to approach Earth, its angular size will increase to 46 arcseconds by the end of February, while its distance decreases to 53,967,713 km. Venus will be closest to Earth on March 22, 2025, at a distance of 41,977,162 km, just before reaching Inferior Conjunction on March 23, 2025.

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Mercury in the evening Sky

In the evening sky, low in the horizon, if we carefully look we can find the smallest planet in our solar system. After sunset, in a place where there are no obstruction like buildings or trees, in this unobstructed view of the western horizon we can spot planet mercury. Since mercury orbits close to the sun we can only find the planets close to the horizon in evening or morning skies.

During its orbit around the sun there are two favorable points where we can observe the planet. This is the maximum separation of angle between Sun and planet. This point of maximum separation is called Greatest elongation. For planet mercury this greatest elongation angle is between 18 degrees to 28 degrees. This is the reason why most people miss the planet, since it is so close to horizon.

On November 6^th the planet will reach greatest elongation giving us a good opportunity to catch a glimpse of this planet with naked eye, binoculars and telescopes. The angle for this elongation is 23 degrees, this means just after sunset the planet will be 23degrees above western horizon.

Spot planet after sunset in western sky.

The planet will be at a magnitude of -0.2, although it is bright the drawback is that it is immersed in twilight making it difficult to spot but as twilight fades its easy to spot.

With a telescope we can see the gibbous phase of mercury with an angular size of 6min of arc. The planet will be in half phase on 11^th of November and from there on the illuminated side of mercury will start decreasing. This is a nice time to see and enjoy and also understand the phases and orbit of mercury. Since the planet is coming closer to earth the angular size will keep increasing and it will be 9mins of arc before the planet sinks into the glare of the sun and then reach inferior conjunction on 27^th of November.

Clear Skies.

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