<blockquote><font class="small">In reply to:</font><hr /><p>do you guys think there can be a planet above or under earth ...maybe a light year down or a light year up..because i thought that when scientist are lookin at space they just look straight up... itd be weird if there was a planet right ontop of the earth and the exact place couple light years up...always been wonderin whats way above or way ontop of the earth in outer space<p><hr /></p></p></blockquote><br /><br />Yep, there can be planets where we can't see them -- and stars too! In fact, when astronomers talk of the "missing mass" of the universe, they're talking not about some exotic weird matter, but simply about matter that they can't see. "Dark matter" is matter that isn't shining any light on Earth. This may be simply because there's a big huge dust cloud in the way.....<br /><br />There isn't really an "up" in space. "Up" is a relative term. For you and me, it's stuff that's above our heads when we're standing. But if I'm in the United States and you're in Australia, that's a completely different part of the sky. In fact, my "up" is your "down", and vice versa. Weird, huh? But true. We think of "up" as being the opposite of the direction that gravity is pulling us, because we can sense that constant force with the organs of balance in our middle ears, the semicircular canals.<br /><br />Astronomers can observe any part of the sky that has nothing between it and the telescope. So if an astronomer has a 20" Dobsonian telescope and takes it out in the middle of the Arizona desert, he or she can anything except for the stuff hidden by the Earth itself. That is, everything above him or her. <img src="/images/icons/wink.gif" /> But if he or she then flies to an observatory high up in the Chilean Andes, he or she can see completely different stuff just by moving around the Earth. And of course if that astronomer then books time on the Hubble Space Telescope, he or she can arrange to see almost any part of the <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>