<p>Astronaut photo of the confluence of the <a href="//commons.wikimedia.org/wiki/Mississippi_River" title="Mississippi River">Mississippi</a> and Ohio Rivers at <a href="//commons.wikimedia.org/wiki/Cairo,_Illinois" title="Cairo, Illinois">Cairo, Illinois</a>. 
</p><p><br></p>
<table class="infobox" style="float: left; width: 75%; text-align: left; font-size: 85%;line-height: 1.3em;"><caption style="margin-left:0px; font-size: 135%;"><span style="float:left;margin:5px; margin-top: 8px;"><img alt="International Space Station Insignia" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/S94-47164_ISS_Cupola_Artists_Rendering.png/34px-S94-47164_ISS_Cupola_Artists_Rendering.png" decoding="async" title="International Space Station Insignia" width="34" height="34" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/S94-47164_ISS_Cupola_Artists_Rendering.png/51px-S94-47164_ISS_Cupola_Artists_Rendering.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/S94-47164_ISS_Cupola_Artists_Rendering.png/68px-S94-47164_ISS_Cupola_Artists_Rendering.png 2x" data-file-width="3000" data-file-height="3000"></span><span style="line-height: 3.5em;">ISS Crew Earth Observations: <a rel="nofollow" class="external text" href="http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS012&amp;roll=E&amp;frame=15035"><b>ISS012-E-15035</b></a></span><span style="float:right;margin:7px;"><img alt="International Space Station Insignia" src="https://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/ISS_insignia.svg/30px-ISS_insignia.svg.png" decoding="async" title="International Space Station Insignia" width="30" height="37" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/ISS_insignia.svg/45px-ISS_insignia.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/ISS_insignia.svg/60px-ISS_insignia.svg.png 2x" data-file-width="800" data-file-height="990"></span>
</caption>

<tbody><tr><th colspan="2" style="line-height: 1.6em; font-size: 105%; text-align: left; background: #DDDDDD;">Identification
</th></tr><tr><th width="33%">Mission
</th>
<td>ISS012 (<a href="https://en.wikipedia.org/wiki/Expedition_12" class="extiw" title="en:Expedition 12">Expedition 12</a>)
</td></tr><tr><th><abbr title="A single letter E refers to images that were originally captured in digital form including electronic still camera (ESC) and High Definition Television (HDTV) images.">Roll</abbr>
</th>
<td>E
</td></tr><tr><th>Frame
</th>
<td>15035
</td></tr><tr><th>Country or Geographic Name
</th>
<td>USA-ILLINOIS
</td></tr><tr><th>Features
</th>
<td>CAIRO, MISSISSIPPI R., OHIO R.
</td></tr><tr><th><abbr title="Negative numbers indicate photos south of the equator.">Center Point Latitude</abbr>
</th>
<td>37.0° N
</td></tr><tr><th><abbr title="Negative numbers indicate photos west of the prime meridian.">Center Point Longitude</abbr>
</th>
<td>-89.2° E
</td></tr><tr><th colspan="2" style="line-height: 1.6em; font-size: 105%; text-align: left; background: #DDDDDD;">Camera
</th></tr><tr><th><abbr title="Calculated look angle away from a straight nadir (straight down below the spacecraft) view.">Camera Tilt</abbr>
</th>
<td>17°
</td></tr><tr><th>Camera Focal Length
</th>
<td>400 mm
</td></tr><tr><th>Camera
</th>
<td>Kodak DCS760C Electronic Still Camera
</td></tr><tr><th>Film
</th>
<td>3060 x 2036 pixel CCD, RGBG array.
</td></tr><tr><th colspan="2" style="line-height: 1.6em; font-size: 105%; text-align: left; background: #DDDDDD;">Quality
</th></tr><tr><th><abbr title="Ranges are 0-10%, 11-25%, 26-50%, 51-75% and 76-100% cloud cover.">Percentage of Cloud Cover</abbr>
</th>
<td>0-10%
</td></tr><tr><th colspan="2" style="line-height: 1.6em; font-size: 105%; text-align: left; background: #DDDDDD;">Nadir <span style="float:right;"><small><a href="https://en.wikipedia.org/wiki/Nadir" class="extiw" title="en:Nadir">What is Nadir?</a></small></span>
</th></tr><tr><th>Date
</th>
<td><span class="mw-formatted-date" title="2006-01-12">2006-01-12</span>
</td></tr><tr><th><abbr title="Greenwich Mean Time">Time</abbr>
</th>
<td>18:38:03
</td></tr><tr><th>Nadir Point Latitude
</th>
<td>37.2° N
</td></tr><tr><th>Nadir Point Longitude
</th>
<td>-88.3° E
</td></tr><tr><th>Nadir to Photo Center Direction
</th>
<td>West
</td></tr><tr><th><abbr title="Clockwise angle in degrees from north to the sun measured at the nadir point.">Sun Azimuth</abbr>
</th>
<td>190°
</td></tr><tr><th>Spacecraft Altitude
</th>
<td>185 nautical miles (343 km)
</td></tr><tr><th><abbr title="Angle in degrees between the horizon and the sun, measured at the nadir point.">Sun Elevation Angle</abbr>
</th>
<td>31°
</td></tr><tr><th>Orbit Number
</th>
<td>867
</td></tr><tr><th colspan="2" style="line-height: 1.6em; font-size: 105%; text-align: left; background: #DDDDDD;">Original image caption
</th></tr><tr><td colspan="2" style="line-height: 1.5em;">The Ohio River becomes a tributary of the Mississippi River directly south of Cairo, Illinois, a small city on the spit of land where the rivers converge (at center of this astronaut photograph). Brown, sediment-laden water flowing generally northeast to south from the Ohio River is distinct from the green and relatively sediment-poor water of the Mississippi River (flowing northwest to south). The color of the rivers in this image is reversed from the usual condition of a green Ohio and a brown Mississippi. This suggests that the very high rainfall in December 2005 over the Appalachians and the northeastern United States has led to greater-than-normal amounts of sediment in the rivers and streams of the Ohio River watershed. The distinct boundary between the two river’s waters indicates that little to no mixing occurs even 5-6 kilometers (3-4 miles) downstream.
<p><br>
Cairo became a prosperous port following the Civil War due to increased riverboat and railroad commerce. Small features visible in the image on the Ohio are river barges, which indicate the continued importance of Cairo as a transport hub. Flooding of the Ohio and Mississippi Rivers presents a continual danger to the city; this danger is lessened by the Birds Point-New Madrid Floodway that begins directly to the south of the river confluence. During major flood events, the floodway lessens flood stages upstream (such as at Cairo) and adjacent to the floodway. Part of the extensive levee system associated with flood control of the Mississippi River is visible in the image. Barlow Bottoms (image right), located in adjacent Kentucky, is a wetland bird-watching location that is replenished by periodic floods and releases of Ohio River water.
</p>
</td></tr></tbody></table><div style="clear:both;"></div>
ISS Crew Earth Observations experiment and the Image Science &amp; Analysis Group, Johnson Space Center, NASA
2006-01-12
<a rel="nofollow" class="external free" href="http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17177">http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17177</a>