The dust storms as tall as mount olympus. And that freaking mountain is like many times bigger than the baby mount everest. And how big is the wind storm...well it cover,,,,,,,the entire planet. The ENTIRE planet. Its pretty harsh out there.
Thanks to my spamming of Discovery and Nat Geo
Why I say earth is safer unrelated to us is:
1. Atmosphere. Slows down the entering projectile.
2. Most surface occupied by ocean water a very neutral substance.
3. Atmosphere again contains mostly neutral Nitrogen. (I hope they have space suits though)
4. Humans. Most likely will kill the aliens but never take the first step as curiosity comes first and aggresion later.
5. Protection from solar wind (which is pretty bad ass if you dig deeper)
6. A surface temperature which is ideal for most organisms hopefully aliens but can be sure. Should try the antarctic and mount fuji for holidays, aliens.
Also my friend every planet has varied forms of climate including our sun 11year cycle if memory serves. Jupiter is the worst I agree but relatively earth is the mildest. Plus we got resorts