What is the Sun’s atmosphere?
The layers of gas that surround a star or planet are known as its atmosphere. The Sun has several layers of atmosphere. The three outer layers are known as the photosphere, which is the Sun’s visible surface; the chromosphere, which is above the photosphere; and the corona – the Sun’s outer layer. The corona extends millions of miles into space and can only be seen from Earth during a solar eclipse – when the Moon is directly in front of the Sun. It is this the part of the Sun’s atmosphere that the Parker Solar Probe will be exploring.