If Orion (M42) was only 4LYs away

[glend]

My son sent me this link of how our night sky would look if Orion (M42) was only 4 light years away:

http://www.iflscience.com/space/amazing-gif-shows-what-it-would-look-if-orion-nebula-was-only-4-light-years-away

This would obviously impact astronomy in a major way and loss of darkness would seriously affect DSO astronomy.

What other impacts do you see, for example would radiation from this nebula have prevented life on earth?

[tlgerdes]

I remember someone saying to me something similar if the Tarantula Nebula was just in our galaxy, let alone 4LY away.

[tlgerdes]

"The Tarantula is 100 times farther than the famous stellar nursery, the Orion Nebula in our own Galaxy. If the Tarantula Nebula was in our Galaxy, the distance of the Orion Nebula (remote only 1 350 light-years), it would cover an area twice as large as the Big Dipper almost a quarter of sky and be visible even in daylight. "
src = http://www.astronoo.com/en/articles/nebula-tarantula.html

"If it were as close to the solar system as the Orion Nebula (http://www.constellation-guide.com/orion-nebula-messier-42/), the Tarantula Nebula would be so bright that it would cast shadows. The Orion Nebula (http://www.constellation-guide.com/orion-nebula-messier-42/), while more famous, especially in the northern hemisphere, is only a hundredth the size of 30 Doradus."
src = http://www.constellation-guide.com/tarantula-nebula-30-doradus/