Space (said final frontier) is really, really dangerous. People might liken travelling through it to those 16th and 17th Century ships trying to get round the Cape of Good Hope. But that has nothing on space.
We have a spaceship, about the size of a medium range car (almost certainly a Tesla) circling the sun right now but unlike a Tesla it is travelling at 330,000 miles an hour. By 2025 it will be travelling at 430,000 miles per hour. It can go this fast because it is also in orbit with Venus and gets a slingshot effect every time it orbits. It also gets some pretty phenomenal pictures of Venus. Its last orbit took to within 520 miles of the planet (and picked up on some weird radio signals along the way).
So we should be pretty proud that we can go that fast. And rightly so.
Yet when and if we get towards the centre of our galaxy a whole new realm of space opens up.
Things get hot and things get fast.
NASA spotted a neighbouring sun that makes ours look like it is having a nap. It has, according to NASA, ‘a hair trigger temper’, rather like the guy in the corner of that Glasgow pub your parents told you never to go into. When it has one of its outbursts, it becomes 14,000 times brighter than normal.
That is one heck of a temper and you wouldn’t want to be around when it got angry.
Further out, or into, space, things get really wild. There is such a whirlpool of forces at the centre of the galaxy that stars are being ejected from it, really fast.
One such star, bigger than our sun, has been ejected from a vast black hole in the centre of our galaxy and is travelling at 3.7 million miles per hour. Just to put that into perspective, so that we don’t get nervous it might be about to arrive, it was thrown out about the time we stood on two feet for the first time (about half an hour before we got our first backache).
Now that Voyager is beyond our solar system, we are getting data that shows that, instead of a smooth ride to Betelgeuse, there is a lot of turbulence. In fact our solar system might be one of the quieter neighbourhoods in space.
To us novices, space is dangerous (and no one can hear you scream). Even Mr Musk has said that getting to Mars is not the hard part. The hard part is building stuff when you get there. People will die, he said, but it will be worth it, he said.
With all that speed and all those stars flying around, the ride into real space will not be easy.
Maybe that is why those aliens want to come and visit. Maybe they need a peaceful holiday.
Either that or alien civilisations took one look outside at the roiling madness that is space and decided to stay home and watch YouTube like everyone else.