Astronomy Picture of the Day
 Tetons and Snake River, Planet Earth
 Veins of Heaven
 Andromeda is the nearest major
 To some, it may look like a portal into the distant universe.
 One of the most identifiable nebulae in the sky,
|
The latest NASA "Image of the Day" image.
Ranger 7 took this image, the first picture of the moon by a U.S. spacecraft, on July 31, 1964 at 13:09 UT (9:09 AM EDT), about 17 minutes before impacting the lunar surface. The area photographed is centered at 13 S, 10 W and covers about 360 km from top to bottom. The large crater at center right is the 108 km diameter Alphonsus. Above it is Ptolemaeus and below it Arzachel. The terminator is at the bottom right corner. Mare Nubium is at center and left. North is at about 11:00 at the center of the frame. The Ranger 7 impact site is off the frame, to the left of the upper left corner.
The Ranger series of spacecraft were designed solely to take high-quality pictures of the moon and transmit them back to Earth in real time. The images were to be used for scientific study, as well as selecting landing sites for the Apollo moon missions. Ranger 7 was the first of the Ranger series to be entirely successful. It transmitted 4,308 high-quality images over the last 17 minutes of flight, the final image having a resolution of 0.5 meter/pixel.
Ranger 7 was launched July 28, 1964 and arrived at the moon on July 31, 1964.
> Moon Mission 50-Year Anniversary: A Vintage Look Back
Image Credit: NASA
NASA technologists have hurdled a number of significant challenges in their quest to improve a revolutionary observing technology originally created for the James Webb Space Telescope. This image shows a close-up view of the next-generation microshutter arrays -- designed to accommodate the needs of future observatories -- during the fabrication process.
Determined to make the Webb telescope's microshutter technology more broadly available, a team of technologists at NASA's Goddard Space Flight Center spent the past four years experimenting with techniques to advance this capability. One of the first things the team did was eliminate the magnet that sweeps over the shutter arrays to activate them, replacing it with electrostatic actuation. Just as significant is the voltage needed to actuate the arrays. By last year, the team had achieved a major milestone by activating the shutters with just 30 volts. The team used atomic layer deposition, a state-of-the-art fabrication technology, to fully insulate the tiny space between the electrodes to eliminate potential electrical crosstalk that could interfere with the arrays’ operation. They also applied a very thin anti-stiction coating to prevent the shutters from sticking when opened.
> Revolutionary Microshutter Technology Hurdles Significant Challenges
Image Credit: NASA/Bill Hrybyk
On July 26, 2014, from 10:57 a.m. to 11:42 a.m. EDT, the moon crossed between NASA’s Solar Dynamics Observatory (SDO) and the sun, a phenomenon called a lunar transit. A lunar transit happens approximately twice a year, causing a partial solar eclipse that can only be seen from SDO's point of view. Images of the eclipse show a crisp lunar horizon, because the moon has no atmosphere that would distort light. This image shows the blended result of two SDO wavelengths - one in 304 wavelength and another in 171 wavelength.
Image Credit: NASA/SDO
Tethys, like many moons in the solar system, keeps one face pointed towards the planet around which it orbits. Tethys' anti-Saturn face is seen here, fully illuminated, basking in sunlight. On the right side of the moon in this image is the huge crater Odysseus.
The Odysseus crater is 280 miles (450 kilometers) across while Tethys is 660 miles (1,062 kilometers) across. See PIA07693 for a closer view and more information on the Odysseus crater.
This view looks toward the anti-Saturn side of Tethys. North on Tethys is up and rotated 33 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 15, 2013.
The view was acquired at a distance of approximately 503,000 miles (809,000 kilometers) from Tethys. Image scale is 3 miles (5 kilometers) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .
Credit: NASA/JPL-Caltech/Space Science Institute
The Sunshield on NASA's James Webb Space Telescope is the largest part of the observatory—five layers of thin membrane that must unfurl reliably in space to precise tolerances. Last week, for the first time, engineers stacked and unfurled a full-sized test unit of the Sunshield and it worked perfectly.
The Sunshield is about the length of a tennis court, and will be folded up like an umbrella around the Webb telescope’s mirrors and instruments during launch. Once it reaches its orbit, the Webb telescope will receive a command from Earth to unfold, and separate the Sunshield's five layers into their precisely stacked arrangement with its kite-like shape.
The Sunshield test unit was stacked and expanded at a cleanroom in the Northrop Grumman facility in Redondo Beach, California.
The Sunshield separates the observatory into a warm sun-facing side and a cold side where the sunshine is blocked from interfering with the sensitive infrared instruments. The infrared instruments need to be kept very cold (under 50 K or -370 degrees F) to operate. The Sunshield protects these sensitive instruments with an effective sun protection factor or SPF of 1,000,000 (suntan lotion generally has an SPF of 8-50).
In addition to providing a cold environment, the Sunshield provides a thermally stable environment. This stability is essential to maintaining proper alignment of the primary mirror segments as the telescope changes its orientation to the sun.
The James Webb Space Telescope is the successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, the European Space Agency and the Canadian Space Agency.
For more information about the Webb telescope, visit: www.jwst.nasa.gov or www.nasa.gov/webb
For more information on the Webb Sunshield, visit: http://jwst.nasa.gov/sunshield.html
Photo Credit: NASA/Chris Gunn
Rob Gutro
NASA's Goddard Space Flight Center
|
