Surface of the sun

Question

At what altitude from the surface of the sun does space begin?

Answer 1

Not exactly sure what you are asking. The Sun's surface is indistinct. The layer that we typically call the "surface" is the photosphere. Above the photosphere is the chromosphere and the corona. The chromosphere extends approximately 2100 km above the photosphere. According to NASA, the corona has no outer boundary (which basically means the corona is variable; there can be a coronal hole where the corona is absent, or there can be helmet streamers that extend far out into space.