"How's the weather" is usually a topic of conversation that gets shuffled away into small talk, but weather is anything but small, especially in space.
On Earth, we are used to hearing about large storms like cyclones, with their damaging winds and flooding rains, or thunderstorms with their lightning, but these weather events don't only occur on Earth, they happen on other planets too.
But with such different atmospheres the weather is even more extreme than what we experience on Earth.
On Venus, its thick atmosphere is nearly 90 times the pressure of ours, and made of unfriendly gases like sulphur dioxide. Meaning that when it rains, the rain is made of sulphuric acid, something so acidic that it removes water from other things, causing burns and all sorts of damage - even taking an umbrella wouldn't help you much on Venus!
The size of the storms that we see on other planets is mind boggling.
On Jupiter, there is the famous Great Red Spot, something that has been visible to us on Earth for hundreds of years (since the invention of the telescope), and is a cyclone type event occurring in the atmosphere of Jupiter.
The Great Red Spot is a bit bigger than the entire size of the Earth, with the winds reaching over 430km/h. The clouds on Jupiter flow in bands (which we see as its stripes), either eastward or westward, and the Great Red Spot is between 2 of these bands, causing its anti-clockwise rotation.
Within these cloud bands on Jupiter, we have even been able to detect lightning.
Neptune also has big storms, similar to the Great Red Spot on Jupiter, called dark spots and first observed by Voyager 2 in 1989. Neptune's dark spots are not long lived like the Great Red Spot on Jupiter, but instead form and disappear every few years. Some of the planets manage to have wild weather without having much of an atmosphere.
Mercury has very little atmosphere, but what it does have is called an exosphere - meaning instead of an atmosphere it has a thin layer of particles that it has captured during solar flares or ejections from the Sun.
Even Mars has dramatic winds and planet wide dust storms, despite having less than 1 per cent of the pressure of the Earth's atmosphere. The dust storms on Mars are so extreme that it makes it difficult to communicate with rovers, and the rovers can get their solar panels covered in dust, which happened to the NASA rovers Spirit and Opportunity throughout their lifetimes; but luckily that dust was blown off by another wind, allowing them to recharge.
So next time you are having a small talk conversation about the weather, spice it up with some space weather, because there's nothing small about that!
- Brad Tucker is an astrophysicist and cosmologist at Mount Stromlo Observatory, and the National Centre for the Public Awareness of Science at ANU.
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