New solar system theories may have little room for other "Earths"

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <b> <h1 class="title"><font face="Arial" size="4">New solar system theories may have little room for other "Earths"</font></h1> </b> <p class="title"><font face="Arial" size="1">Posted August 3<br> World Science staff</font><b><font size="2"><span style="FONT-FAMILY: Arial; mso-fareast-font-family: Times New Roman; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA"><br> <br> New theories may be needed to explain how solar systems we've found beyond our own formed, and those theories may dim hopes for "Earth-like" planets, a research group says. </span></font></b></p> <p class="title"><b><font size="2"><span style="FONT-FAMILY: Arial; mso-fareast-font-family: Times New Roman; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">Traditionally, researchers have tried to whittle down planet formation theories to a single one that most researchers can agree on and that fits most or all solar systems. There is reasonable agreement on the outlines of a theory for our own, but newly found solar ones are so systematically different from ours that they may require a completely separate model, say the researchers, from Hubble Space Telescope and Cambridge University. </span></font></b></p> <p class="title"><b><font size="2"><span style="FONT-FAMILY: Arial; mso-fareast-font-family: Times New Roman; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">The group wrote a paper on the subject to appear in the Monthly Notices of the Royal Astronomical Society. The most widely accepted theory for our solar system, they explain, involves material clumping to form rocky, possibly Earth-like planets, some of which acquire a gas coating to form giant planets like Jupiter. </span></font></b></p> <p class="title"><b><font size="2"><span style="FONT-FAMILY: Arial; mso-fareast-font-family: Times New Roman; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">A theory to explain the the other known solar systems - which differ in that they have giant planets much closer to their sun, among other things - might not include this rocky planet step, the researchers write, and thus "would have difficulty in producing terrestrial-type planets."</span></font></p> </b> </body>