Archive for September 24th, 2009

View of Spain’s solar towers near Seville.

In a patchwork of agricultural fields outside Seville, Spain, two otherworldly towers rise above the plain. Nearby arrays of mirrors reflect light onto the towers, illuminating the water vapor and dust suspended in the air and creating visible beams. Within the towers, the thermal energy from the concentrated light creates steam, and the steam powers turbines to generate electricity. Known as PS10 and PS20, the mirror-tower networks are part of a larger project intended to meet the energy needs of some 180,000 homes—roughly the energy needs of Seville—by 2013, without greenhouse gas emissions.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured this false-color image of PS10 and PS20 on August 29, 2009. Red indicates vegetation, shades of brown indicate bare ground and/or fallow fields, and blue indicates water. Human-made structures appear in shades of blue-gray. PS10 and PS20 appear as approximate circles punctuated by towers on their southern ends. Although less conspicuous than the circular arrays, rectangular arrays of mirrors operate south of the towers.

The mirrored heliostats that make up the arrays track the Sun’s position throughout the day and send concentrated energy to the nearby towers. A BBC correspondent who ascended PS10 in the spring of 2007 recorded sauna-like temperatures and searing ladder rungs near the tower’s top, and a mirror-illuminated glow to the entire area. PS20 began operating two years later.

As this image shows, the network for PS20 is larger than that for PS10. The tower sizes and energy capacities differ as well. Reaching a height of 115 meters (approximately 380 feet), PS10 is powered by 624 heliostats. Reaching a height of 165 meters (approximately 540 feet), PS20 is powered by 1,255 mirrored heliostats. PS20 was designed to produce twice the energy of its smaller, 11-megawatt neighbor. The towers both produced more energy than expected during trial tests. Although not the world’s first power towers, PS10 and PS20 became the first project executed on such a large scale.

Also an aerial view of the towers.

Time lapse video of Ares 1-X lightning tower buildup.

If you haven’t heard, NASA has confirmed water on the surface of the moon. Article from JPL below with link.

My take away from all this, we still don’t know everything about the moon. Also this while great doesn’t invalidate LCROSS’s mission. Which just so you know, is in 14 more days. NASA has a nifty impact clock here along with other information.

These images show a very young lunar crater on the side of the moon that faces away from Earth, as viewed by NASA's Moon Mineralogy Mapper on the Indian Space Research Organization's Chandrayaan-1 spacecraft. Image credit: ISRO/NASA/JPL-Caltech/USGS/Brown Univ.

PASADENA, Calif. — NASA scientists have discovered water molecules in the polar regions of the moon. Instruments aboard three separate spacecraft revealed water molecules in amounts that are greater than predicted, but still relatively small. Hydroxyl, a molecule consisting of one oxygen atom and one hydrogen atom, also was found in the lunar soil. The findings were published in Thursday’s edition of the journal Science.

NASA’s Moon Mineralogy Mapper, or M3, instrument reported the observations. M3 was carried into space on Oct. 22, 2008, aboard the Indian Space Research Organization’s Chandrayaan-1 spacecraft. Data from the Visual and Infrared Mapping Spectrometer, or VIMS, on NASA’s Cassini spacecraft, and the High-Resolution Infrared Imaging Spectrometer on NASA’s Epoxi spacecraft contributed to confirmation of the finding. The spacecraft imaging spectrometers made it possible to map lunar water more effectively than ever before.

The confirmation of elevated water molecules and hydroxyl at these concentrations in the moon’s polar regions raises new questions about its origin and effect on the mineralogy of the moon. Answers to these questions will be studied and debated for years to come.

“Water ice on the moon has been something of a holy grail for lunar scientists for a very long time,” said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. “This surprising finding has come about through the ingenuity, perseverance and international cooperation between NASA and the India Space Research Organization.”

From its perch in lunar orbit, M3′s state-of-the-art spectrometer measured light reflecting off the moon’s surface at infrared wavelengths, splitting the spectral colors of the lunar surface into small enough bits to reveal a new level of detail in surface composition. When the M3 science team analyzed data from the instrument, they found the wavelengths of light being absorbed were consistent with the absorption patterns for water molecules and hydroxyl.

JPL Article

This deliberately over-exposed image shows Goddard Laser Ranging Facility shooting the Lunar Reconnaissance Orbiter with a laser. More details can be found below along with a link to the full article.

Image Credit: Tom Zagwodzki/Goddard Space Flight Center

On certain nights, an arresting green line pierces the sky above NASA’s Goddard Space Flight Center in Greenbelt, Md. It’s a laser directed at the moon, visible when the air is humid. No, we’re not repelling an invasion. Instead, we’re tracking our own spacecraft.

28 times per second, engineers at NASA Goddard fire a laser that travels about 250,000 miles to hit the minivan-sized Lunar Reconnaissance Orbiter (LRO) spacecraft moving at nearly 3,600 miles per hour as it orbits the moon.

The first laser ranging effort to track a spacecraft beyond low-Earth orbit on a daily basis produces distance measurements accurate to about four inches (10 centimeters). For comparison, the microwave stations tracking LRO measure its range to a precision of about 65 feet (20 meters).

“Current lunar maps are not as accurate as we’ll need to return people safely to the moon,” said Ronald Zellar of NASA Goddard, team lead for the LRO laser ranging system. “In order to make an accurate map, first you need to know where you are. Knowing the precise range to LRO is necessary for its instruments to produce much more accurate maps, with errors reduced to the size of humans or rovers.”

“A further benefit of laser ranging to LRO is that it can improve knowledge of the moon’s orientation and gravity, which are central to understanding its interior structure and to precision navigation,” said Gregory Neumann, a Geophysicist at NASA Goddard.

Full Text

Hopefully you folks aren’t sick of all the Australian dust pictures, so here are two more at least. This time an image from NASA’s Terra and Aqua satellite.

On the morning of September 24, 2009, the dense dust that had covered eastern Australia the previous day blew south over the Tasman Sea towards New Zealand. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this photo-like image of the storm on September 24, at 11:10 a.m., New Zealand time (23:10 UTC on September 23). The dust plume is still densely concentrated in this image, attesting to the strength of the winds. The plume is clearly entrained in the storm system that brought the winds to Australia in the first place. The plume underlies the storm clouds, sharing their fish-hook shape.

The image covers approximately 2,300 kilometers (1,429 miles) from north to south, about the same distance from New York City to the center of Kansas in the middle of the United States. The lower half of New Caledonia Island is visible along the top edge of the image. Hidden by clouds, the northern shore of New Zealand’s South Island is outlined in the lower right corner of the image. A few hours after Terra MODIS captured this image, the MODIS instrument on the Aqua satellite observed the northern half of the plume extending along the east coast of Australia to the northern tip of Queensland’s Cape York Peninsula on September 24. The straight-line distance between the far northern edge of the plume on September 24 and the southern edge is about 3,450 kilometers (2,700 miles), roughly equivalent to the distance between New York City and Los Angeles.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC. Caption by Holli Riebeek.

By the early afternoon of September 24, 2009, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this image, the thick dust that had covered the eastern shore of Australia the previous day stretched in a long plume from northern Queensland to New Zealand. This image shows the northern portion of the plume off the coast of Queenland. The tan dust is densely concentrated in a compact plume that mirrors the coastline. The gem-like blue-green Great Barrier Reef is visible beneath the plume near the top of the image where the tan dust mingles with gray-brown smoke from wildfires.

Earlier in the day, Terra MODIS imaged the southern portion of the dust plume near New Zealand. The straight-line distance between the far northern edge of the plume, shown in this image, and the southern edge captured in the Terra MODIS image is about 3,450 kilometers (2,700 miles), roughly equivalent to the distance between New York City and Los Angeles.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC. Caption by Holli Riebeek.

While Discovery is checked over and processed for its next mission, Atlantis moves ahead with its next flight to ISS.

The external fuel tank for space shuttle Atlantis’ STS-129 mission is lowered between the solid rocket boosters stacked on the mobile launch platform in high bay 2 of NASA’s Kennedy Space Center in Florida. Photo credit: NASA/Jim Grossmann

Many of you have already seen the image from the previous day, when dust hung over the east coast of Australia. With a new day, the MODIS Rapid Response Team takes another look. This time with the Aqua satelltie.

Below you can see the dust which has lifted from the coast of Australia and blown out to sea.