Scientists at NASA are becoming increasingly concerned at what they say is "a major change in the set-up of the Solar System", after photographic images were transmitted back to Earth from a little-known satellite which is something to do with getting better TV reception.
The satellite, part of the 'Twilight Zone' project, sent the images back to NASA last Thursday, showing that the eight planets are moving closer and closer together, and, indeed, closer to the Sun
The planets are so close together, that it will soon be easy to touch them, and it might even be possible to step from one world to another.
In the past, and up until very recently, the distance from the Sun to the Solar System's outermost planet, Neptune, had been measured at 4.4757 billion km. Now, though, the two objects are thought to differ in distance by as little as 150,000 km - and are still closing on each other.
Similarly, Earth is now only a 'short hop' from Mars, and it's thought that the pair may soon be so close together, that Earthlings might be able to organize 'exchange visits' with Martians.
But the big news is that, although the eight planets used to almost always be in different parts of the Solar System on their vastly-unsimilar orbits, they are now perfectly aligned in a straight line as in the picture above.
This could mean big trouble, because, if one of them crashes into another, there will, almost certainly, be a right old mess.