Star Shade To Help Astronomers Find Earth-like Worlds!

[carlsagan]

A star shade called an Occulter is being proposed to blot out the bright light from stars and reveal any small pinpoints of light around those stars which could be earth-like worlds. Until now the only exo-planets discovered have been gas giants comparable in size to Jupiter. The brightness of the parent star essentially drowning out the light from anything smaller. But by launching an Occulter to cover these stars scientists hope to identify terrestrial worlds and even oceans on their surfaces. <br /><br />Nasa is so excited at this idea that they've already approved a 400 million dollar grant to look into it. It could even be included as part of the James Webb Space Telescope package planned to be launched as a replacement for Hubble.

 

[drwayne]

"Nasa is so excited at this idea that they've already approved a 400 million dollar grant to look into it."<br /><br />Reference? <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

If you are going to talk about things such as this, including "facts" such as NASA grants, then primary sources are a VERY good idea. For a NASA grant, a NASA or other governmental site would be a primary source. Am enthusuast site would not be.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[harmonicaman]

Yeah; this ingenious scheme has been bandied about for a couple of years by NASA’s Institute for Advanced Concepts (NIAC). The New Worlds Imager (NWI) system design is currently being studied at the University of Colorado at Boulder.<br /><br />Their goal is to explore the feasibility of using a large-scale camera obscura to obtain pictures of exosolar planets.<br /><br /><i>"The basic building block of the New Worlds Imager is a pair of spacecraft, a starshade and a collector, that function together as a single pinhole camera. The starshade serves as the pinhole for the camera, though the entire shade will be a kilometer (0.6 miles) or more in diameter, with a hole about 10 meters (10 yards) across punched in the center. The collector holds a telescope with a primary mirror the same size as the pinhole: 10 meters. To guarantee the best images, the starshade and collector need to be separated by about 200,000 km, or about half the distance from the Earth to the Moon. Two starshade-collector pairs, their images combined in a central combiner spacecraft, form the New Worlds Imager."</i> (NASA)<br /><br />There are several competing ideas for the NWI; but this system (pdf. file with graphics and maths) seems to be promising and is the best presentation I could find on the internet... <br /><br />Other ideas just utilize a simple big screen or balloon to block out the star's light, but the pin hole camera idea seems to be a major refinement -- but it is more complicated...

 

[carlsagan]

"primary sources are a VERY good idea"<br /><br />My apologies. This is my first visit here.<br /><br />There is no internet source that I'm aware of so I'm afraid I cannot help you there. Perhaps something will be published in the next few days.<br /><br />There are however many websites describing what an Occulter is if you should require such references. I recommend trying the Encyclopedia Brittanica first.<br /> <br />

 

[jmilsom]

We were just discussing this in the context of astrobiology in the SETI forum. See below.<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=seti&Number=528093&page=0&view=collapsed&sb=5&o=0&fpart=<br /><br />Also, there was discussion of the 'Pinhole' Camera in space a while back in the SS&A forum. See below.<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=sciastro&Number=65281&page=&view=&sb=&o=&vc=1<br /><br />Here is a good NASA article on the subject from late last year:<br /><br />http://www.nasa.gov/vision/universe/newworlds/new_worlds_imager.html <div class="Discussion_UserSignature"> </div>

 

[3488]

Nice idea, but I think that as things are now, it belongs in fantasy land. How will the shade be kept in line? pointing is virtually impossible with such an unwieldy device.<br /><br />Nice idea, but does not work in reality. The TPF or a lunar observatory would do better. What about an occulting disk being fixed to the Hubble?? <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[harmonicaman]

<i>"...it belongs in fantasy land. How will the shade be kept in line? pointing is virtually impossible with such an unwieldy device."</i><br /><br />I agree that the engineering is formidable, but it might be the perfect application for an ion engine (or similar low thrust device). I foresee several occulters being placed at different parts of the sky to service one telescope. Since they are such unwieldy objects to maneuver, one occulter could be used at a time as the others are slowly being nudged into position. <br /><br /><i>"What about an occulting disk being fixed to the Hubble?"</i><br /><br />The camera obscura concept requires that the occulter pin-hole is placed at a great distance from the telescope to obtain optimum focus.

 

[3488]

Thats true. Several 'pinholes' for one giant telescope would work. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[drwayne]

Ran across this this evening:<br /><br />http://www.nature.com/nature/journal/v442/n7098/abs/nature04930.html <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

From here that is:<br /><br />http://arstechnica.com/journals/science.ars/2006/7/7/4565 <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[carlsagan]

The Times<br />July 6<br /><b> 'Star shade' that casts light on space.'</b><br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Nasa is so interested in the idea that it has backed the research with an initial study grant of $400,000 <p><hr /></p></p></blockquote>

 

[alokmohan]

Exacly .They are in fantasy land.Granting so much money for funny ideas.

 

[jmilsom]

As all the skeptics said when it was first proposed that man could fly to the moon. <div class="Discussion_UserSignature"> </div>

 

[carlsagan]

Submarines were a funny idea too. So was heavier than air flight.