The sea wasp box jellyfish is perhaps the most deadly variety. This translucent sea-dweller may not look all that menacing, but it is the most venomous animal on planet Earth. Box jellyfish are deadly to many different animals, not the least of all, us. If you get stung by one of these animals, you are very likely to die.
Earth and Mars Conjunction: On the opposite end of the scale, Mars and Earth can be 401 million km apart (249 million miles) when they are in opposition and both are at aphelion. The average distance between the two is 225 million km. When Mars and Earth are at their closest, you have your launch window.
Earth is on the inside track, and so it gets around more quickly. Sometimes itâs close to Mars, when itâs making a pass, and other times itâs far away, at the other side of the track. The minimum distance from the Earth to Mars is about 54.6 million kilometers. The farthest apart they can be is about 401 million km. The average distance is about 225 million km. SpaceKids on SPACE.com provides simple, straightforward answers to really big cosmic questions.