1. Earth passed through an old supernova remnant? What would happen to Earth and life on it? 2. The Sun were an M-type star, rather than a G-type star? Assuming that Earth orbiting the M-type star had...

1. Earth passed through an old supernova remnant? What would happen to Earth and life on it?

2. The Sun were an M-type star, rather than a G-type star? Assuming that Earth orbiting the M-type star had the same composition and orbital distance that it has today, what would be different on Earth?