Or they could be so far away that we never got a signal from them yet.<p>I can see how hard it is for life to survive and see that Mars and Venus are two examples of the planet going the wrong way to not support life. That not having enough greenhouse gas to keep warm or having too much of it can kill off life.<p>I then remembered that the Earth is in-between ice ages.
<a href="http:&#x2F;&#x2F;www.astrobio.net&#x2F;topic&#x2F;solar-system&#x2F;earth&#x2F;swinging-between-ice-ages&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.astrobio.net&#x2F;topic&#x2F;solar-system&#x2F;earth&#x2F;swinging-be...</a><p>That the Earth has gone through climate changes over time, and right now as we burn fossil fuels we are changing the Earth and making things worse for us.<p>If aliens existed they might have had an ice age were they died or they burned fossil fuels until they made their planet inhabitable for them as well.<p>We need to focus on our planet and making sure we don&#x27;t wipe ourselves out.