<story><title>Water found on a potentially life-friendly alien planet</title><url>https://www.nationalgeographic.com/science/2019/09/first-water-found-in-habitable-exoplanets-atmosphere-hubble-kepler-k2-18b/</url></story><parent_chain><item><author>nothis</author><text>&amp;gt; I&amp;#x27;m looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them).&lt;p&gt;I just realized I have no real concept of how many stars there even are within, say, a 100 light year radius of our sun (I guess that&amp;#x27;s a more realistic thing to find out than the number of planets).&lt;p&gt;A quick search provided some estimates and they&amp;#x27;re kinda... disappointingly low, at around 20000 stars. That&amp;#x27;s a number where some &amp;quot;1% of 1% of 1%&amp;quot; kinda filter quickly ends up in a scenario where a planet fitting all our criteria might simply never be in reach. For something more &amp;quot;realistic&amp;quot; (I know, heh!) like 20 light years, there are only 150 solar systems. I&amp;#x27;ve seen different numbers and have no idea how they&amp;#x27;re calculated but for the usual astronomic scales which quickly go into &amp;quot;billions&amp;quot; territory, it seems we&amp;#x27;re kinda stuck with a comparably small list of candidates.</text></item><item><author>transreal</author><text>With a planet this large, visiting it would be a one way trip due to the &amp;quot;The Tyranny of the Rocket Equation&amp;quot; [0].  I&amp;#x27;m looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them).&lt;p&gt;[0] - &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.nasa.gov&amp;#x2F;mission_pages&amp;#x2F;station&amp;#x2F;expeditions&amp;#x2F;expedition30&amp;#x2F;tryanny.html&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.nasa.gov&amp;#x2F;mission_pages&amp;#x2F;station&amp;#x2F;expeditions&amp;#x2F;exped...&lt;/a&gt;</text></item></parent_chain><comment><author>newsbinator</author><text>&amp;gt; That&amp;#x27;s a number where some &amp;quot;1% of 1% of 1%&amp;quot; kinda filter quickly ends up in a scenario where a planet fitting all our criteria might simply never be in reach.&lt;p&gt;It might cheer you up to think that&amp;#x27;s the only reason the human race happens to be the one in our neighborhood that made it into space, without being stepped on by an Old One.</text></comment>
<story><title>Water found on a potentially life-friendly alien planet</title><url>https://www.nationalgeographic.com/science/2019/09/first-water-found-in-habitable-exoplanets-atmosphere-hubble-kepler-k2-18b/</url></story><parent_chain><item><author>nothis</author><text>&amp;gt; I&amp;#x27;m looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them).&lt;p&gt;I just realized I have no real concept of how many stars there even are within, say, a 100 light year radius of our sun (I guess that&amp;#x27;s a more realistic thing to find out than the number of planets).&lt;p&gt;A quick search provided some estimates and they&amp;#x27;re kinda... disappointingly low, at around 20000 stars. That&amp;#x27;s a number where some &amp;quot;1% of 1% of 1%&amp;quot; kinda filter quickly ends up in a scenario where a planet fitting all our criteria might simply never be in reach. For something more &amp;quot;realistic&amp;quot; (I know, heh!) like 20 light years, there are only 150 solar systems. I&amp;#x27;ve seen different numbers and have no idea how they&amp;#x27;re calculated but for the usual astronomic scales which quickly go into &amp;quot;billions&amp;quot; territory, it seems we&amp;#x27;re kinda stuck with a comparably small list of candidates.</text></item><item><author>transreal</author><text>With a planet this large, visiting it would be a one way trip due to the &amp;quot;The Tyranny of the Rocket Equation&amp;quot; [0].  I&amp;#x27;m looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them).&lt;p&gt;[0] - &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.nasa.gov&amp;#x2F;mission_pages&amp;#x2F;station&amp;#x2F;expeditions&amp;#x2F;expedition30&amp;#x2F;tryanny.html&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.nasa.gov&amp;#x2F;mission_pages&amp;#x2F;station&amp;#x2F;expeditions&amp;#x2F;exped...&lt;/a&gt;</text></item></parent_chain><comment><author>flukus</author><text>On the plus side there are more moons than planets and many of them may be habitable. We&amp;#x27;ve barely started looking at extra solar Jupiter like planets because of the much longer orbital periods.</text></comment>