How Long Is A Day On Mercury (And Why)?

How Long Is A Day On Mercury (And Why)?

Exact Answer: 58d 15h 30m

Mercury is one of the most uncommon (usual) planets in the universe. The place of mercury is extremely close to the sun. Being the closest to the sun still mercury is not the hottest. The days in mercury planets are around 58d 15h 30m long. The atmospheric condition in mercury is virtual non-existence. The temperature of mercury is not fixed, as it may go from hot to cold.

The temperature of mercury can be sometimes extremely hot and cold depending on many conditions. The length of one year on the planet mercury would be around 88 days. The nights and days in mercury are very unusual just like the plant. The slow rotation of the planet makes the day last longer.

In simple terms, if you stand on the surface of the planet (mercury), then it would take a long time (176 earth days) to see the sun rising.

How Long Is A Day On Mercury

How Long Is A Day On Mercury?

Days On Mercury How Long Is A Day On Mercury
1 day58.646 earth days
2 days117.292 earth days

The mercury has eccentric orbits as compared to any other solar planet. The orbital period of mercury is not constant or stable, as it depends on the position of mercury in the orbit. The speed of mercury increases when the distance of this planet is very less from the sun. The speed would come down if the planet is at a very far distance from the sun.

The time taken by the mercury to take one single orbit (of the sun) is around 88 days. Many astronauts believe that mercury is quite close and locked to the sun. The astronomer also considers the earth very closely Locked with the moon. The days on earth would be shorts compared to that of mercury. A single day in mercury would take 58 earth days according to science.

The solar day (in mercury) would be around 176 days. This is because of the slow rotation (sidereal) and rapid velocity (orbital velocity). The night and day cycle (ratio) of the mercury could be different for the polar regions. The Polar Regions (cratered polar regions) stay (exists) in the perpetual shadow state.

The temperature of this region would be on the cool side. Radar bright images are captured from this place in mercury. Many scientists and astronauts believed that it may be a sign of water (ice) there. The days in mercury are very long as compared to earth days. The rotation speed of mercury is extremely slow as compared to the earth’s rotation speed.

This makes a huge difference in making the days in mercury quite long.

Why Is A Day On Mercury This Long?

The mercury has no weather conditions like clouds, winds, and rains. The rotation speed and the climatic condition of mercury are extremely different. The days of mercury are not the same as compared to the planet earth. The main reason is the slow rotation that takes more time for mercury to complete one rotation.

The days of mercury would be extremely long, as it would take more time than earth to see the sun once. The days of mercury are quite hot when the planet is near to the earth. Nights of mercury would be quite cool (as the temperature would be less). The day and night cycles of mercury would be unusual and different.

Nobody can expect the length of days in mercury to be the same as on earth, as there are many differences. The atmospheric conditions of mercury are not constant (unstable) and this may be a reason for no lives in mercury.


Mercury is quite an old planet in the solar system with a wide view of the sun. The between the mercury and sun is very little (short). The mercury is seen closest to the sun. The days of mercury are longer as compared to the days of earth. It would take around 1407.5 hours for the completion of the day in mercury.


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Hi! I'm Nidhi.

Here at the EHL, it's all about delicious, easy recipes for casual entertaining. So come and join me at the beach, relax and enjoy the food.

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