The planets don't actually "align" in the sense of being perfectly in a straight line. It's a misconception that comes from the fact that we sometimes see several planets close together in the sky.

Here's why:

* Perspective: From our viewpoint on Earth, the planets appear to move across the sky in different paths. Sometimes these paths bring planets close together, creating an apparent alignment.

* Orbital Planes: The planets in our solar system don't orbit in exactly the same plane. This means they are never perfectly aligned in 3D space.

However, there are times when planets appear close together in the sky:

* Conjunctions: When two or more planets are relatively close together in the sky from our viewpoint. These can be quite spectacular events.

* Planetary Alignments: While not a perfect alignment, sometimes several planets appear in a relatively small area of the sky. This can be considered a "planetary alignment" from a visual standpoint.

There's no set date for a perfect alignment:

* No True Alignment: A true, perfectly aligned position of all planets in our solar system is extremely unlikely and has never happened in recorded history.

* Future Predictions: Predicting such an event is difficult due to the complex gravitational interactions between the planets.

Instead of waiting for a perfect alignment, keep an eye out for planetary conjunctions and close groupings of planets in the sky. These are common and offer beautiful astronomical sights!

You can find information about upcoming planetary conjunctions and other astronomical events on websites like NASA's website or other astronomy websites.