When is mercury traveling the slowest

But when talking about a gas giant in the outer reaches of the solar system, the concept of seasonal change doesn't quite mean the same as on Earth. Seasonal variations are strong on Saturn and each season lasts more than 7 years.

That's a long winter! When the Cassini spacecraft began its revolutionary mission to Saturn and its largest moon, Titan, Saturn was two years into its northern fall season. When it arrived at Saturn in , it will have just become northern winter on the ringed planet. Uranus has a relatively circular orbit, so it remains at about the same distance from the Sun throughout its long year.

But the axis of Uranus is tilted by 98 degrees! This causes year-long seasons and unusual weather, although one thing that is certain: it is always cold. For nearly a quarter of the Uranian year equal to 84 Earth years , the sun shines directly over each pole, leaving the other half of the planet plunged into a long, dark winter.

Uranus has a deep atmosphere of mostly hydrogen and helium. Absorption of red light by methane in the atmosphere gives the planet its bluish color. Early visual observers reported Jupiter-like cloud belts on the planet, but when the Voyager 2 spacecraft flew by in , Uranus appeared virtually featureless.

The Northern Hemisphere of Uranus is just now coming out of the grip of its decades-long winter. As the sunlight reaches some latitudes for the first time in years, it warms the atmosphere and triggers gigantic springtime storms comparable in size to North America with temperatures of ?

F below zero. By the year , the sun will be shining directly over Uranus' equator, which will produce more evenly distributed sunlight and the ability to see features at all latitudes on Uranus.

Neptune has an axial tilt of But this gas giant doesn't really experience appreciable seasonal variation, although its seasons last for more than 40 years! Because Pluto is so far away, virtually nothing is known about its seasons. However, because of its tilt of nearly degrees and the highest eccentricity of any planetary orbit even at its great distance from the Sun, weather variations are expected to be significant -- perhaps enough to result in far greater changes in its atmospheric pressures than even that of Mars.

It is possible that the very thin atmosphere of Pluto may entirely freeze and fall as snow to Pluto's surface as it gets farther and farther from the Sun. Extraterrestrial weather and seasons are harsh and may be rather unpredictable.

So, as we contemplate the different times of year on Earth, and may lament about the coming of a long, hot summer or a cold harsh winter, take a quick mental tour of our solar system. Suddenly, having to water the garden or scrape ice off of a windshield doesn't seem so bad. Science Features. Scientists believe that Jupiter's Great Red Spot is actually a hurricane that has been raging for more than years within the planet's atmosphere.

The tilt of the Earth is the primary reason for the differences in weather we observe between summer and winter. Mars' winds were strong enough to give the rover Spirit a good cleaning. SSE Home. Weather, Weather, Everywhere? Awards and Recognition. Solar System Exploration Roadmap. Jupiter is the fastest spinning planet while Venus is the slowest. Venus takes Earth days to complete one rotation on its axis, making it the slowest of all planets. Venus Venus, which is floating higher each evening in twilight, low in the west, is the slowest-spinning body in the known universe.

In fact, Venus takes Earth days to rotate once on its axis — the slowest rotation of any planet — and its rotation is retrograde to its orbital path. Combined with its orbital period, this means that a single solar day on Venus the time between one sunup to the next is Earth days. Venus, which is floating higher each evening in twilight, low in the west, is the slowest-spinning body in the known universe. This means that Jupiter has the shortest days of all the planets in the solar system.

Venus rotates once every days —- by far the slowest rotation period of any of the major planets. A Venusian sidereal day thus lasts more than a Venusian year versus Mercury has wildly swinging temperatures , but only at thin atmosphere to trap heat on the planet, while the atmosphere of Venus creates a runaway greenhouse effect that elevates its temperature higher than Mercury.

Because Mercury is so close to the sun, the Hubble Space Telescope, which has captured images of a number of bodies in the solar system, cannot photograph the planet's rocky surface.

Because Mercury lies between Earth and the sun, it undergoes phases much like the moon. However, the phases of Mercury are more difficult to detect than the phases of Venus, which also orbits between the Earth and the sun. Italian astronomer Galileo Galilei could detect the phases of Venus with his telescope, but not the phases of Mercury. Like Venus, Mercury also undergoes transits , passing between the Earth and the sun about 13 times each century.

But the inclination of Mercury's orbit is such that a transit does not occur every time the two planets pass. Mercury only crosses the sun once every seven years. Astronomers used transits to help calculate the distance to Earth from the sun. Venus' transits are significantly more rare, occurring only once every years. If you were in a place that had bad weather, for example, you missed your chance and had to wait for the next one," Joseph Gurman said in a statement.

The constant motions of planets around the sun means that the distance between Earth and Mercury is in constant flux. When both planets are on opposite sides of the sun, they can achieve their maximum distance of million miles million kilometers.

When they are at their closest, they are only 48 million miles