Super-Earths 'in the billions'
"There could be many billions of planets not much bigger than Earth circling faint stars in our galaxy, says an international team of astronomers."
<?xml version="1.0" encoding="UTF-8"?>
<!--Xholon Workbook http://www.primordion.com/Xholon/wb/ (C) Ken Webb Wed Mar 28 2012 21:11:42 GMT-0400 (EDT)-->
<XholonWorkbook>
<Notes><![CDATA[
Xholon
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Title: Super-Earths 'in the billions'
Description: "There could be many billions of planets not much bigger than Earth circling faint stars in our galaxy, says an international team of astronomers."
Url: http://www.bbc.co.uk/news/science-environment-17532470
InternalName:
YoutubeId:
Keywords:
My Notes
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A story by BBC science correspondent Jonathan Amos reports on recent observations and calculations about the possible number of Earth-like planets in our galaxy. This workbook will work through the simple math mentioned in the BBC article.
Try this::
Click the Run button above. This will open an small overlay on this browser page.
Click on the MilkyWay and other nodes, to explore the structure (very simplified) of the Milky Way galaxy.
Select and copy the 4 lines of JavaScript in the editor below. Paste these into the textarea in the overlay.
OR you can use drag and drop.
Press the Submit button.
]]></Notes>
<script implName="lang:python:inline:"><![CDATA[
#print "height = 12.34 m"
]]></script>
<script implName="lang:javascript:inline:"><![CDATA[
var redDwarfs = 160e9; // "there may be 160 billion red dwarf stars in our galaxy"
var pSuperEarthHz = 0.4; // "about 40% of all red dwarf stars have a super-Earth orbiting in the habitable zone"
var superEarthsHz = redDwarfs * pSuperEarthHz;
print("\n" + superEarthsHz);
// result: 64000000000
]]></script>
<_-.XholonClass>
<!-- domain objects -->
<PhysicalSystem/>
<Galaxy>
<MilkyWay/> <!-- our galaxy -->
</Galaxy>
<Star>
<YellowDwarf> <!-- see: http://en.wikipedia.org/wiki/G-type_main-sequence_star -->
<Sun/> <!-- our Sun is a small yellow star -->
</YellowDwarf>
<RedDwarf/> <!-- a red star that's smaller and dimmer than our Sun -->
</Star>
<Planet>
<Earth/>
<SuperEarth/> <!-- a planet that is "one to 10 times the mass of the Earth" -->
</Planet>
<RedDwarfs/>
</_-.XholonClass>
<xholonClassDetails>
</xholonClassDetails>
<PhysicalSystem>
<MilkyWay>
<Sun>
<Earth multiplicity="1"/>
</Sun>
<RedDwarfs>
<SuperEarth multiplicity="64"/> <!-- 64 billion -->
</RedDwarfs>
</MilkyWay>
</PhysicalSystem>
<Blockbehavior implName="lang:python:inline:"><![CDATA[
# This works if pasted in as a last child of Block.
#height.incVal(0.02)
#print("Python wants something to do. Height:" + str(height))
]]></Blockbehavior>
<Blockbehavior implName="lang:javascript:inline:"><![CDATA[
// This works if pasted in as a last child of Block.
//height.incVal(0.02);
//print("JavaScript wants something to do. Height:" + height + "\n");
]]></Blockbehavior>
<Blockbehavior implName="lang:webEditionjs:inline:"><![CDATA[
//this.bindPorts(this.parent());
//this.height.incVal(0.02);
//print("JavaScript wants something to do. Height:" + this.height.attr('val') + "\n");
]]></Blockbehavior>
<Blockbehavior implName="lang:bsh:inline:"><![CDATA[
// This works if pasted in as a last child of Block.
//height.incVal(0.02);
//System.out.print("Java/Beanshell wants something to do. Height:" + height + "\n");
]]></Blockbehavior>
<Blockbehavior implName="lang:jruby:inline:"><![CDATA[
#require 'java'
# This works if pasted in as a last child of Block.
#$height.incVal(0.02)
#puts "Ruby wants something to do. Height: #{$height}"
]]></Blockbehavior>
<Blockbehavior implName="lang:groovy:inline:"><![CDATA[
// This works if pasted in as a last child of Block.
//height.incVal(0.02);
//System.out.print("Groovy wants something to do. Height:" + height + "\n");
]]></Blockbehavior>
<SvgClient><Attribute_String roleName="svgUri"><![CDATA[data:image/svg+xml,
<svg width="430" height="40" xmlns="http://www.w3.org/2000/svg">
<!-- super Earth's are very hard to see -->
<text x="10" y="15" width="430" height="40" style="fill:AliceBlue">It's a pterodactyl. It's a starship. It's a Super Earth!</text>
</svg>
]]></Attribute_String><Attribute_String roleName="setup">${MODELNAME_DEFAULT},${SVGURI_DEFAULT}</Attribute_String></SvgClient>
</XholonWorkbook>