Here's what's important to understand:
* "Alignment" is relative: What we perceive as "alignment" depends on our viewpoint from Earth. There's no single point in space where all planets will perfectly line up.
* No perfect alignment: It's extremely rare for all planets in our solar system to be perfectly aligned in a straight line. The orbits of planets are tilted at different angles, making a perfect alignment nearly impossible.
* "Planetary conjunctions": What we often refer to as "alignment" are actually planetary conjunctions. This is when two or more planets appear close together in the sky from our perspective on Earth. These conjunctions happen fairly frequently, with some occurring every few months.
So, to answer your question, how often planets "align" depends on what you consider "alignment."
* Conjunctions of two planets: Relatively common, happening every few months.
* Conjunctions of three or more planets: Less frequent, but still happen on a regular basis.
* "Perfect" alignment of all planets: Extremely rare, likely not happening within our lifetimes.
Remember, the positions of planets are constantly changing, and what appears to be an alignment from Earth might look completely different from another vantage point in space.
