Many planets have an atmosphere that is poisonous, at least for us. All the gas giants, for a start. Mercury has almost no atmosphere. This would not exactly be poisonous, but it isn't exactly health, either... You would still need to keep your spacesuit on, if you venture outside the ship. Venus is also toxic for us - and, it is extremely hot. Mars' atmosphere isn't fit for humans, either.
Venus. It has a very thick atmosphere, mainly Carbon Dioxide (96.5%) and some Nitrogen (around 3.5%). Due to the large mass of the atmosphere, the surface pressure is 93 bar or 9.3 Mega pascals (MPa), 93 times that of earth surface pressure.
Jupiter is the planet that has the heaviest atmosphere. It is one of the gas giants and is the largest planet in the solar system.
venus
venus
Gas giant
venus
A Gas Planet.
Its A gas giant planet. -Pets Jaques
jupitar
Jupiter is the largest and most massive planet.
No. The planet Mercury does not have an atmosphere.
A Gas Planet.
A "Gas Giant" planet.
Its A gas giant planet. -Pets Jaques
That is commonly called a gas giant.
Mercury has no real atmosphere as the planet is too close to the sun and is not massive enough.
The Gas Giants have a deep gas atmosphere and earth have a not so deep atmosphere
jupitar
Venus and the four outer planets all have a very thick and massive atmosphere.
probes =)
The mass of the planet. It's not clear cut, since there has to be gas around in the area to provide the atmosphere, but the planet (or moon) need to be massive enough to provide sufficient gravity for the gas molecules not to escape into space.
there hobos!
There is no simple relationship, but the general tendency is that more massive planets have more gravitational attraction, and are able to maintain a denser atmosphere. The amount of atmosphere a planet has may also depend on it closeness to the Sun / to the planet's star, and to its evolutionary history.