What cosmic catastrophes could wipe out life on earth?

Question

What cosmic catastrophes could wipe out life on earth?

Answer 1

If my mom makes that casserole again, it might just do it.

Answer 2

None of the above answers are correct except the supernova.  

Life on earth is extremely robust.  It is found in the deepest mines and at the bottom of the sea- five miles down.  It is in Antarctica and in boiling sulfur springs.

What could possibly wipe out all life on Earth?  A really nearby supernova - but there are no candidate stars that are close enough (>100 light years).  

Not even a huge asteroid would wipe out all life on earth.  The dominate life form on Earth is single celled life.  It is in just too many places to be effected by most single events (except maybe the casserole).

Answer 3

A very large asteroid sticking the planet.

A burst of radiation from a close by magnestar or super nova explosion.

Answer 4

Humans stand a far greater chance of wiping out life on earth than any cosmic catastrophe.

Answer 5

Obama in the Whitehouse.

Answer 6

Well right now, all of the media attention is on the Hadron Collider, which is supposed to be turned on in August.  Theoretical Physicists insist nothing will go wrong and that all the precautions have been taken to avert any disaster.

I don't doubt that they've built in many safety factors.  My concern is with acts of God, like EARTHQUAKES!  Switzerland is home to a host of earthquakes, albeit minor, yet the danger is still there.  Can you stop a supercollider in a nanosecond?  I sure hope they can guarantee that in writing.  If light can't even escape a black hole, how in heaven are we going to escape it--we'll all be torn in half.  As for probability, that's like playing Russian roulette with a loaded gun.  The flip side of probability is surety.

This $5.8 billion project should just be put on the backburner for now imo.  Until we have an Earth 2 and Earth 3 on the moon and Mars, this experiment should be put on hold.  We need contingency backups in case this baby blows.  I say pay them the big bucks to halt the experiment until we can actually duplicate people, animals, plants and vegetation on other moons and planets.  Either that, or dismantle this contraption and do it offline on another moon, the Earth is for babies and pets.

Answer 7

1. Very large meteor or comet impact

2. Nearby supernova

3. Gamma ray burst

Answer 8

1. A nearby supernova.

2. A magnetar pointing at us.

3. A very large, powerful coronal mass ejection (from the sun) hits the earth while the planet's magnetic field is down.

4. A large object (>10 km) his the earth.

5. A larger object (> 100 km) hits the moon.

6. The sun ages to become a red giant.

7. A rogue star or planet passes through the solar system, disrupting the orbit of the Earth, or other major planets.

8. A rogue black hole, or neutron star, or stellar cinder passes near the Earth, sucking us in, or breaks up the planet due to tidal friction.

9. An advanced civilization decided to terraform the Earth for their own uses.