What are the clouds of the other planets in the solar system like?
On planets with an atmosphere in the solar system we find clouds similar to those on Earth, not only made of water, but of many other compounds.
![Jupiter Clouds Jupiter Clouds](https://services.meteored.com/img/article/nubes-de-otros-planetas-1721512121868_1024.jpg)
If we ask you if there are clouds on planets other than Earth, your answer will surely be yes, since the beautiful images of the different planetary atmospheres that have been providing us for quite some time with the space probes that we have been sending through the solar system, as well as the large telescopes, are well known. The doubt, however, arises when consulting the definition of cloud.
The World Meteorological Organization (WMO) - the highest authority in the matter - in its International Cloud Atlas defines a cloud as "a hydrometeor consisting of tiny particles of liquid water or ice, or both, suspended in the atmosphere and that, in general, do not touch the ground. They may also contain larger liquid water or ice particles, as well as non-aqueous liquid particles or solid particles from, for example, industrial gases, smoke or dust."
The unusual beauty of Jupiter's clouds in great detail. pic.twitter.com/lITXCKUoIL
— Curiosity (@MAstronomers) June 21, 2024
It is a definition applicable only to clouds that form in the Earth's atmosphere, so to refer to those that are formed in other celestial bodies (planets, satellites) or on Earth under certain conditions, the particles that form them are not necessarily formed of liquid or solid water, but can have their origin in the condensation of gases other than water vapor.
The clouds of the gas giants
The planets called "gas giants" are Jupiter, Saturn, Uranus and Neptune, and they owe their name both to their large size - with respect to that of the Earth - and to the fact that they are almost entirely made up of gases, so we can affirm that each of them forms a gigantic atmosphere. It is dominated by gases such as hydrogen and helium, many lighter than nitrogen and oxygen that make up almost all of the Earth's atmospheric medium.
![Saturn Clouds. Saturn Clouds.](https://services.meteored.com/img/article/nubes-de-otros-planetas-1721512170633_1024.jpg)
Jupiter's gigantic ocean of hydrogen and helium is completed with small amounts of phosphorus and sulphur compounds, as well as methane, ammonia, water vapour, carbon monoxide or hydrogen cyanide, among others. The clouds resulting from the condensation of all these gases have different shades.
The rapid Jovian rotation causes them to be distributed latitudinally forming bands parallel to the equator, alternating those of whitish colour with those of brown tones. Interspersed between them appear a series of ovals, which are large stormy systems, highlighting among all of them the Great Red Spot.
Saturn's atmosphere is similar to that of Jupiter, although the proportion of helium (the second most abundant gas after hydrogen) is lower. We also find traces of methane, water vapour, ammonia, propane and phosphines, among other gaseous compounds. Depending on the level of pressure, we find clouds of ammonia, water and other compositions, which as a whole adopt yellowish tones.
Saturn's hexagon is a persistent approximately hexagonal cloud pattern around the north pole of the planet
— Science girl (@gunsnrosesgirl3) May 4, 2024
NASA
pic.twitter.com/A9L8XtbT4X
The observation of its speed of displacement has allowed us to deduce one of the singularities of the planet of the rings: intensities of the reigning winds of up to 1800 km/h, slightly lower than those detected in the high atmosphere of Neptune.
One of Saturn's moons is Titan and has a dense atmosphere. On its surface there is an ocean of liquid methane and clouds of great vertical development develop that leave strong downpours of methane. High clouds formed by hydrocarbon crystals are also formed.
In Neptune we find high clouds of hydrogen, helium and methane, as well as durable stormy systems (formed by convective clouds), similar to those of Jupiter.
To complete this quick tour of the clouds of the gas giants, we have the ones that are formed in Uranus and Neptune. In the first of them, the hydrogen/helium ratio is 83/15, to which must be added 2% of methane and trace gases. It is the coldest atmosphere in the entire solar system and depending on the altitude we find clouds of methane or ice crystals.
The dense cloud layer of Venus
The surface of Venus remains hidden from observation from satellites and telescopes, due to the dense atmosphere that surrounds the planet. Consisting mostly of CO2, we find in it thick clouds of sulphuric acid and sulphur. The surface atmospheric pressure is about ninety times greater than the terrestrial one. The total and permanent coverage of those "large-thicss" clouds results in a powerful greenhouse effect, with temperatures close to 500 ºC on the infernal surface.
![Venus Venus](https://services.meteored.com/img/article/nubes-de-otros-planetas-1721512213365_1024.jpg)
The clouds are distributed in several layers, presenting different nature and characteristics depending on the atmospheric level. At about 50 km of altitude there is one about 5 km thick, made up of crystals of sulphur compounds, chlorine and sulphuric acid. Above, up to an altitude of about 80 km there is another pair of well-defined layers. In the lower of the two, water and several very corrosive acid compounds are mixed, such as hydrochloric, while in the upper one we find a mist of sulphur dioxide.
Martian clouds analogous to terrestrial clouds
Mars is known as the red planet because of the ferrosilicates that cover its dusty surface. The particles of iron oxide, of intense reddish colour, are dragged and elevated by gigantic storms of dust that spread those iron aerosols largely in the atmosphere, clouding it. The result is a sky similar to the one that the haze gives us on Earth, especially when it is intense and greatly reduces visibility.
More clouds from the surface of Mars. On Sol 2417 the Curiosity rover photographed these clouds looming over the evening twilight. The NAVCAM images were carefully mosaiced and hand colored to suggest the possible visual appearance. A daytime panorama supplied the foreground. pic.twitter.com/VYMKC2awO0
— Donald E Davis (@DDAVISSPACEART) June 9, 2019
Although there is often talk of clouds of dust, referring to both those of our planet and those of Mars, the nature of these clouds (constituted by lythometeores) is different from that of the clouds to which we are dedicating this article, which are not lacking in the Martian skies. Seen from the ground, they have an a salmon colour, similar to that of the Earth's twilight.
The atmosphere of Mars is much dimmer than ours, with the pressure on its surface being up to a hundred times smaller. As with Venus, its atmosphere is mostly constituted (95.3%) by CO2 dioxide, although the greenhouse effect on the planet is minimal.
![Ice clouds on Mars Ice clouds on Mars](https://services.meteored.com/img/article/nubes-de-otros-planetas-1721512252178_1024.jpg)
In the Martian atmosphere, water vapour is a minority trace gas, despite which, the prevailing conditions favour its condensation and reverse sublimation, relatively frequently forming clouds of appearance and composition similar to those of the Earth.
We have both high clouds formed of ice crystals (equivalent to the cirrri that are formed on Earth), and convective clouds (clusters), which do not usually reach great altitudes, but whose formation is largely dictated by insolation. Fogs and cloud bands associated with gravity waves are also part of the Mars cloud sample.