Astronomy Future files

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" rowspan="2" width=210 BGCOLOR="#9999FF" TEXT="#080000" bgproperties="fixed" background="09376ba3.gif"> <bR> </td> <td valign="top" colspan=2 height=90 BGCOLOR="#99CCFF" TEXT="#080000" bgproperties="fixed" background="09476bc1egdyqn.gif"> <div> <FONT SIZE="5" COLOR="#FFFFCC" FACE="Arial" ><B>José Flor Web Site</B></FONT><B>   |   </B><A HREF="index.htm" TARGET="_top" TITLE="José Flor Web Site"><U><B>home</B></U></A></div> <div> <B>Astronomy Future files</B></div> <div> Back to: <<A HREF="space_exploration.htm" TARGET="_top" TITLE="Space exploration"><U><B>Space exploration</B></U></A><B>></B></div> </td> </tr><tr> <td valign="top" height=390 colspan=2 BGCOLOR="#99CCFF" TEXT="#080000" bgproperties="fixed" background="09476ba3.gif"> <div> Astronomy Future files</div> <div> <B>Other planetary systems</B></div> <div> It is very likely that most stars are born with their own systems of planets. But such planets are so hard to see in even the most powerful telescopes because they are so far away. Only a few giant planets have been detected circling other stars.</div> <div> Disc of dust, looking just as our solar system would have looked when it was only a few hundred million years old, heve been discovered circling some nearby stars, such as the bright stars Vega and Fomalhaut. There are big holes in the middle of the discs, probably 'swept clean' by young orbiting planets that we are not able to detect.</div> <bR> <div> <B>The end of the universe</B></div> <div> Astronomers think that long after the Sun has faded into darkness, other stars will be born from the gas clounds scattered though the Galaxy. But eventually the gas will be used up and starbirth will cease after a million million years. Yet the smallest, faintest stars may shine for 100 times longer than this. Much later, some of the dead stars will be swallowed into black holes growing at the heart of each galaxy, but most will escape from their galaxies and wander through space. The universe will have become a cold, dark place. No one knows whether life will evolve into a form that can survive into this distant future.</div> <bR> <div> <B>Crossing the solar system</B></div> <div> Present-day journeys to the outer solar system take years, and new types of propulsion are needed. A slow, steady thrust continued for months or years could build up a large final speed. One possibility is nuclear energy; another is the 'light-yacht', which would have large sails and would be pushed along by the pressure of sunlight. A stronger thrust could be provided by atoms of antimatter, which are 'mirror-image' versions of ordinary atoms. When matter and antimetter collide, both vanish with the release of huge amount of energy. If large amount of antimatter could be made and safely stored, it could drive a spacecraft across the solar system at high speeds.</div> <bR> <div> <B>What if an asteroid hit the Earth?</B></div> <div> If an asteroid 1 kilometer across hit the Earth, it would blast a big area and create huge waves in the oceans and the ground itself. A dust cloud would be formed that would last for years, cooling the whole Earth. Humans would probably not survive. Many scientists believe that an impact like this - or the vast amount of dust it would have caused - wiped out the dinosaurs and thousand of other animal and plant species 65 million years ago.</div> </td> </tr></table></body>