* Size Comparison: You're asking about the planet closest in *size* to the Sun. The Sun is a star, vastly larger than any planet in our solar system.

* No Planet Close in Size: No planet comes even close to the Sun's size. The Sun is so large that it would take over 1 million Earths to fill it up!

What you might be thinking of:

* Closest to the Sun: That would be Mercury, the planet that orbits closest to our star.

* Largest Planet: That would be Jupiter, the largest planet in our solar system, but still incredibly small compared to the Sun.

Let me know if you have any more questions!