Translartion. Region: Russians Fedetion –
Source: Novosibirsk State University – Novosibirsk State University – The planet that people have observed since ancient times, leaving evidence both in written sources and in earlier petroglyphs, is, of course, one of the most noticeable and bright planets in the sky – Venus.
Different peoples called it by different names, and among other names, the most commonly used were the Morning Star and the Evening Star, because sometimes this special planet can be observed both in the morning and in the evening.
This year we will have the opportunity to see Venus both in the morning and in the evening from March 17 to 25 in central Russia: Moscow, Nizhny Novgorod, Kazan, Yekaterinburg, Novosibirsk and Krasnoyarsk. This visibility of the planet is called “double visibility” and is possible during inferior conjunctions of Venus, that is, when the planet is between the Earth and the Sun at the same ecliptic longitude. At this moment, these space objects are located close to each other on the celestial sphere like a “parade of planets”. There are two possible options: Venus is located in the sky above the Sun or below, since the planet’s orbit has an inclination to the ecliptic of 3.4°. If Venus is located above the Sun, it sets behind the horizon later than the Sun and is visible in the evening. But on these same days, it also rises before the Sun, when it is still relatively dark, and can be seen early in the morning. This is a simple explanation of “double visibility”.
A more complex explanation, understandable to amateur astronomers, is given by Mikhail Maslov, an engineer at the Vega observatory at NSU:
— This possibility arises because Venus is visually noticeably higher than the ecliptic — the line in the sky that is the projection of the plane of the Earth’s orbit. This position results in the inferior conjunction of Venus passing as if “above the Sun” from the position of an observer on Earth, and the elongation of the planet does not decrease to near-zero marks. Due to this, Venus rises above the horizon before the Sun, which creates a certain morning period of visibility, and on the same day sets after the Sun, which also creates evening visibility. Thus, during the day, Venus can be seen both in the morning and in the evening.
It is worth noting that this visibility is quite poor, since Venus during the conjunction with the Sun is still quite close to it in the sky, but interested observers can, nevertheless, try to record such a situation by observing Venus in the morning and evening, taking the necessary precautions due to the presence of the bright Sun at a small angular distance.
Venus will be visible in the evening just after sunset, low above the western horizon, and in the morning just before sunrise above the eastern horizon. These conditions repeat every 8 years. After March 25, we will be able to see Venus only in the mornings.
With a good, even amateur telescope, in the period from March 17 to 25, both “owls” in the evenings and “larks” in the mornings will be able to try to see both the changes in the phases of Venus and the “horns” of Venus. The tips of the “horns” are precisely the signs of the atmosphere of Venus, which is very dense relative to the atmosphere of the Earth.
On March 20, the vernal equinox will occur, when the length of day and night will be equal and the length of daylight hours will begin to increase. On the days of the vernal and autumnal equinoxes, the Sun is located strictly perpendicular to the Earth’s equator, and at this moment both hemispheres of the planet are illuminated equally, the time of daylight becomes equal to the time of night.
Author: Alfiya Nesterenko, head of the Vega observatory at NSU.
Photo by: Egor Konyaev, engineer at the NSU Vega Observatory. The photo of Venus was taken on February 26, 2025.
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