We all know the basics of the Diurnal Cycle – day and night, sunrise and sunset. And we are all aware that during the day, the Sun is the most luminous object in the sky, to the point that it completely obscures the stars. And at night, the Moon (when it is visible) is the most luminous object, sometimes to the point that it can make gazing at the Milky Way and Deep-Sky Objects more difficult.
This dichotomy of night and day, darkness and light, are why the Moon and the Sun were often worshiped together by ancient cultures. But at times, the Moon is visible even in the daytime. We’ve all seen it, hanging low in the sky, a pale impression against a background of blue? But just what accounts for this? How is it that we can see the brightest object in the night sky when the Sun is still beaming overhead?
The ISS, from the shuttle mission in May 2010. Credit: NASA
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Last month the International Space Station partner agencies met to discuss the continuation of space station operations into the next decade and its use as a research laboratory. They also did a little forward thinking, and talked about some unique possibilities for the station’s future, including the potential for using the space station as a launching point to fly a manned mission around the Moon. I don’t know what our readers think, but my reactions is: this is just about the coolest idea I’ve heard in a long while! I’m having visions of a Star Trek-like space-dock, only on a smaller scale! In an article by the BBC’s Jonathan Amos, the partners said they want the ISS to become more than just a high-flying platform for doing experiments in microgravity, but also hope to see it become a testbed for the next-generation technologies and techniques needed to go beyond low-Earth orbit to explore destinations such as asteroids and Mars.
“We need the courage of starting a new era,” Europe’s director of human spaceflight, Simonetta Di Pippo, told the BBC News. For sending a mission to the Moon from the ISS, De Pippo said, “The idea is to ascend to the space station the various elements of the mission, and then try to assemble the spacecraft at the ISS, and go from the orbit of the space station to the Moon.”
One “next-generation” activity that is already planned is conducting a flight test of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine on the ISS, which is the new plasma–based space propulsion technology, that could get astronauts to destinations like Mars much quicker than conventional rockets. NASA has sign a commercial Space Act with the Ad Astra company (which is lead by former astronaut Franklin Chang Diaz).
But starting a Moon mission from the ISS is really a far-reaching, kind of “out-there” concept. It would be reminiscent of Apollo 8, and be the first of a new philosophy of using the station as a spaceport, or base-camp from where travelers start their journey. The propulsion system would be built at the station then launched from orbit, just like space travelers have dreamed for decades.
Of course, this is just an idea, and probably an expensive proposition, but isn’t it wonderful that the leaders of the space agencies are even thinking about it, much less talking about it?
Of course, doing zero-g experiments would always be the main focus of the ISS, but just think….
With this type of mission, the future of spaceflight actually be as Canadian astronaut Chris Hadfield describes in the video below. “This is the great stepping off point of to the rest of the universe,” says Hadfield, who will be commanding an upcoming expedition on the ISS. “This is an important moment in the history of human exploration and human capability,… and the space station is a visible sign of the future to come.”
ARCA successfully launches the first Romanian space rocket, via balloon. Credit: ARCA
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A Romanian team aiming to send a rocket to the Moon via balloon successfully launched a test flight of their Helen 2 rocket, sending the first Romanian-made rocket system to 40,000 meters above the Earth. The Aeronautics and Cosmonautics Romanian Association (ARCA) team is vying for the Google Lunar X PRIZE, and tested the balloon/rocket system (sometimes called a ‘rockoon’) which launched from a Romanian naval frigate from the Black Sea. While the balloon and rocket worked great, the parachute and recovery system failed. But the team met their main objectives and were ecstatic.
A Romanian naval officer celebrates with a member of the ARCA team after the rocket fired successfully. Credit: ARCA
ARCA has a simple, “green” design. For getting the Moon, a super-huge balloon will carry a system of three rockets to about 18 km (11 miles). Then the first two rocket stages will fire and boost the system into low Earth orbit, and use the final stage to boost it to the Moon. The lander, the European Lunar Explorer (ELE) resembles a knobby rubber ball that uses its own rocket engine to ensure a soft landing. They consider their system to be green, as the rocket engine operates exclusively with hydrogen peroxide
The Helen rocket is lifted into the air by the balloon. Credit: ARCA
The balloon ascent took 40 minutes, bringing the system to an altitude of 14,000 m, at times raising the system at 120 km/h. When it reached that altitude, the flight controllers on the naval ship lit the rocket engines for 30 seconds, bringing it to 40,000 meters. From flight data transmitted to the control centers of ARCA and the Romanian civil aviation authority (ROMATSA) the team was able to confirm the successful flight trajectory, which had an error of only 800 m from the center of their safe trajectory.
A payload on board the capsule took pictures from the top of the trajectory.
An image sent down from the capsule from about 40,000 meters. Credit: ARCA
But at the capsule’s reentry, the parachute did not open, and a ship sent to try and find the capsule in the water was not able to find and retrieve it. But the ARCA team said they didn’t look for it for very long, since most data were transmitted by radio telemetry and satellite and recovery isn’t an objective of the Google Lunar X Prize Competition.
However, they were able to complete the successful launch of the first Romanian space rocket, as well as their first flight of the Google Lunar X Prize Competition. They also verified their rocket stabilization system, and reached the highest altitude ever by an object designed and built entirely in Romania.
A 'rainbow' appears on this image from the Lunar Reconnaissance Oribiter
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Even though it is not the mind-blowing experience of a double rainbow all the way across the sky, seeing a rainbow on the Moon is pretty unusual. This curious image from the Lunar Reconnaissance Orbiter shows a rainbow effect across 120 km of the lunar surface. And although water has recently been found on the Moon, water droplets have nothing to do with this rainbow. It comes from illumination conditions and viewing angles with having the Sun directly overhead of the LRO and the Moon.
“This image was acquired as the Sun was exactly overhead, allowing us to observe the ‘opposition surge,’said Brent Denevi, writing on the LRO Camera website. “This is a surge in brightness that occurs when the Sun is directly behind the observer because of two effects. First, there are no shadows seen on the surface, because each boulder and grain of soil’s shadow is hidden directly beneath it. Second, as the light reflects back to the observer it constructively interferes with itself.”
It is a very cool effect, giving the Moon a look having some unexpected color. Denevi said images that contain this type of effect are not just pretty, but useful, too. “They provide a huge new dataset for studying how light interacts with a particulate surface at different wavelengths,” he said. “Perhaps an esoteric-sounding field of study, but this data can help us understand the reflectance images and spectra we have of the Moon and other bodies throughout the Solar System.”
China successfully launched their second robotic mission, Chang’E-2, to the Moon. A Long March 3C rocket blasted off from Xichang launch center just before 1100 GMT on October 1. The satellite is scheduled to reach the Moon in five days, and so far, all the telemetry shows everything to be working as planned. It will take some time for Chang’E-2 to settle into its 100-km (60-mile) orbit above the lunar surfaces, although the China space agency also said the spacecraft will come as close as 15km above the surface during its mission in order to take high-resolution imagery of potential landing sites for Chang’E-3, China’s next lunar mission that will send a rover to the Moon’s surface, scheduled for 2013. Continue reading “China Launches Second Moon Mission”
LROC Wide Angle Camera (WAC) mosaic of the lunar South Pole region, width ~600 km. Credit: NASA/GSFC/Arizona State University.
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The lunar South Pole – a land of craters, shadows, intrigue and science! This wide-angle mosaic of the South Pole is one of the latest stunning images from the Lunar Reconnaissance Oribiter. The South Pole is the home of Cabeus Crater, where LCROSS impacted in 2009, as well as the Aitken Basin, which contains impact melt that will allow scientists to unambiguously determine the basin’s age, plus Shackleton crater, the region touted as the perfect place for future outposts and huge telescopes. The permanently shadowed regions in this crater wonderland could harbor reservoirs of ice and other volatiles contain a “priceless record of water composition dating back to the beginning of our Solar System, an incomparable dataset for astrobiology investigations,” said Mark Robinson, principal investigator for the Lunar Reconnaissance Orbiter Camera. “Additionally, these volatile deposits could serve as a tremendously valuable resource for future explorers.”
This is one of LROC’s first mosaics of the lunar South Pole, showing the region in all its glory. These mosaics are composed of several individual images taken by the wide-angle camera (WAC) on LRO that are stitched together. These big, beautiful images allow investigators to explore the geophysical and compositional properties of the lunar surface on a global or regional scale.
WAC South Pole mosaic showing locations of major craters. The impact site of the LCROSS spacecraft is marked with an 'X'. Credit: NASA/GSFC/Arizona State University.
All the mosaics from the WAC and the two Narrow Angle Cameras (NAC) and WAC mosaics are produced using a specialized image-processing package called ISIS, the Integrated System for Imagers and Spectrometers. ISIS has the unique capability for processing data from several NASA spacecraft missions and when it applies, scientists can put everything together to get the big picture.
As LRO passes over the pole every two hours, the LROC WAC snaps an image, and over a month, images covering the entire polar region are captured. This mosaic contains 288 images taken in one month; if you look closely, you can see where the month began and ended at about 90°E longitude and note how the lighting changed. This makes the rim of Shackleton crater appear to be slightly disjointed. This is caused by how the Sun came from opposite sides for portions of the mosaic, resulting in opposite sides of the crater’s wall being illuminated in some images. As the mission progresses, the WAC will capture the pole across the full range of seasons and we’ll see even more spectacular views of this region, as well as the entire Moon.
Many astronomers feel that the Moon would be an excellent location for telescopes, — both on the surface and in lunar orbit – and these telescope could help answer some of the most important questions in astronomy and astrophysics today. One proposal calls for a lunar orbiting low frequency antenna that could measure the signatures of the first collapsing structures in the early universe. Dr. Jack Burns from the University of Colorado, Boulder, discussed the idea for the Lunar Cosmology Dipole Explorer (LCODE) at the NASA Lunar Science Institute’s Lunar Forum this summer.
What makes the Moon so inviting is that the lunar far side is uniquely radio quiet in the inner part of the solar system, as the far side is always facing away from the Earth, and the Moon itself blocks out any interfering man-made signals from radio, TV and satellites.
In this radio quiet zone, astronomers could study the very early universe, back to less than half a billion years after the Big Bang, probing what is called the Dark Ages, before the first stars and galaxies formed.
LCODE would be a satellite orbiting the Moon carrying a single dipole antenna, kind of like your car antenna, Burns said, but it has two ends. “It flies around the Moon and we take data only when we are above the far side, the shielded zone where we are free of radio interference,” said Burns, “and that allows us, because it is so quiet there, to take measurements of these very faint emissions from this very early era in our universe’s history.”
Example of dipole antenna.
The orbiting dipole would allow scientists to look for these signals over the entire sky. If that is successful, the next stage would be to put an array of dipole antennas on the surface, perhaps even about ten thousand antennas, and use it as a radio interferometer that would “allow us to actually get some resolution to do some imaging,” Burns said, “and explore the composition of these structures in the early universe that eventually go on to form stars and galaxies.”
Other proposals for doing radio astronomy from the Moon would be to study the sun at low frequencies, below 10 megahertz. The sun emits very strong low frequency radio waves, and these are related to Coronal Mass Ejections, which produce very high energy particles which can interfere with satellites and could potentially be very harmful to future astronauts traveling in interplanetary space. “We hope to be able to image and to understand how these particles are accelerated,” Burns said.
The other interesting regions of the Moon from which to do astronomy would be the poles in permanently shadowed craters, which are very cold — only about 40 degrees above absolute zero – which would make an excellent site for infrared telescopes which need to be cooled down to very low temperatures.
Marius Hills region on the Moon, from LRO's Wide Angle Camera.
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Here’s a look at the Moon in a way we’ve never quite seen it before: a close up, but wide angle view. The Lunar Reconnaissance Orbiter camera actually consists of three cameras: there are two narrow-angle cameras which make high-resolution, black-and-white images of the surface, with resolutions down to 1 meter (about 3.3 feet). A third, a wide-angle camera (WAC), takes color and ultraviolet images over the complete lunar surface at 100-meter (almost 330-foot) resolution. However, the raw wide-angle images are somewhat distorted by the camera, but Maurice Collins, a Moon enthusiast from New Zealand, found that putting several images together in a mosaic removes a lot of the distortions and produces a much clearer image. The results are nothing short of stunning; here are a few example of Maurice’s handiwork, including this jaw-dropping image of the Marius Hills region of the Moon. Click on any of these images for a larger version on Maurice’s website, Moon Science
Copernicus Crater on the Moon, captured by LROC's wide angle camera. Image processing by Maurice Collins
Maurice told me that he has been studying the Moon for about ten years now, and he does telescopic imaging of the Moon from his backyard Palmerston North, New Zealand as well as study the various spacecraft data. “I found out how to process the WAC images from Rick Evans (his website is here ) for the Octave processing method, and I also use a tool developed by Jim Mosher for another quicker technique,” Maurice said. Several of Maurice’s images have been featured on the Lunar Photo of the Day website.
Aristarchus Crater, as seen by LROC's wide angle camera. Image processing by Maurice Collins
Other areas of lunar imaging work he has done is using the Lunar Terminator Visualization Tool (LTVT) to study the lunar topography from the Lunar Orbiter Laser Altimeter (LOLA) digital elevation model laser altimeter data.
“Using a previous DEM from the Kaguya spacecraft I discovered a new large (630km long) mountain ridge radial to the Imbrium basin which I have nicknamed “Shannen Ridge” after my 9 year old daughter,” he said. See the image of Shannen Ridge here.
Maurice said he is usually out every clear night imaging or observing the Moon with his telescope. Thanks to Maurice for his wonderful work, and for allowing us at Universe Today to post some of the images. Check out his complete cache of WAC mosaics at his website.
A false colour composite of the distribution of water and hydroxyl molecules over the lunar surface. Credit: ISRO/NASA/JPL-Caltech/Brown Univ./USGS
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The recent discovery of water on the Moon may have a serious impact on future plans for lunar based astronomy. Space scientists from the Chinese Academy of Sciences have calculated that the scattering caused by molecules vaporized in sunlight could heavily distort observations from telescopes mounted on the Moon.
“Last year, scientists discovered a fine dew of water covering the Moon. This water vaporizes in sunlight and is then broken down by ultraviolet radiation, forming hydrogen and hydroxyl molecules. We recalculated the amount of hydroxyl molecules that would be present in the lunar atmosphere and found that it could be two or three orders higher than previously thought,” said Zhao Hua, who presented his team’s results at the European Planetary Science Congress in Rome.
The research has particular implications for the Chinese Lunar lander, Chang’E-3, which is planned to be launched in 2013. An ultraviolet astronomical telescope will be installed on the Chang’E-3 lander, which will operate on the sunlit surface of the Moon, powered by solar panels.
“At certain ultraviolet wavelengths, hydroxyl molecules cause a particular kind of scattering where photons are absorbed and rapidly re-emitted. Our calculations suggest that this scattering will contaminate observations by sunlit telescopes,” said Zhao.
The Moon’s potential as a site for building astronomical observatories has been discussed since the era of the Space Race. Lunar-based telescopes could have several advantages over astronomical telescopes on Earth, including a cloudless sky and low seisimic activity.
The far-side of the Moon could be an ideal site for radio astronomy, being permanently shielded from interference from the Earth. Radio observations would not be affected by the higher hydroxyl levels.
A natural bridge on the Moon. Credit: NASA/GSFC/Arizona State University
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“Just when you think you have seen everything, LROC reveals a natural bridge on the Moon!” said Mark Robinson, Principal Investigator of the Lunar Reconnaissance Orbiter Camera (LROC), writing on the LROC website. “Who would have thought?” The natural bridge seen in this image is about 7 meters (23 feet) wide on top and perhaps 9 meters (30 feet) on the bottom side. Scientists estimate it would be a 20-meter (66-foot) walk to cross from one side to the other. While there are natural bridges here on Earth (which usually form as a result of wind and water erosion — see here for images of a natural bridge in Virginia in the US) how would such a natural structure form on the Moon? The answer might include another intriguing feature that has been found recently on the Moon: lava tubes.
Lunar bridge in 3-D. Image credit: NASA, GSFC/Arizona State University. Stereo image by Nathanial Burton-Bradford.
Robinson said the most likely way this feature formed is from a dual collapse into a lava tube. These are deep holes on the Moon that could open into vast underground tunnels, and could serve as a safe, radiation shielding habitats for future human lunar explorers.
There are actually a couple of these natural bridges that were found in just one region on the Moon, in the midst of an impact melt in the 15 km-wide King crater. Nathanial Burton-Bradford has created a few stereo images, which provide a unique perspective on these lunar bridges. Nathanial called the one below a “strange ‘twiglet’ ‘Monster Munch’ shape bridge.”
Another natural lunar bridge. Credit: NASA/GSFC/University of Arizona. Stereo image by Nathanial Burton-Bradford.
How can the lunar scientists be certain this feature really is bridge over a cavern? Look closely at the top image and in the pit on the west or left side, there is a small crescent of light on its floor. That patch of light came from the east, under the bridge.
Although Robinson and his team do not know for certain the details of how the bridge formed, here’s one possible scenario: The impact melt that was thrown out of the crater pooled on the newly deposited ejecta and must be many tens of meters thick, allowing its interior to stay molten for a long time. As the local terrain readjusted after the shock of the impact, the substrate of this massive pool of melt was jostled to some degree. Local pressures built up and the melt moved around under a deforming crust. You can see that the south end of the bridge extends from a small local rise, shaped something like a blister. Perhaps some melt was locally pushed up forming the rise, then the magma found a path to flow away, leaving a void which the crusted roof partially collapsed.
The LROC team is working on making their own stereo images, but in the meantime, thanks to Nathanial Burton-Bradford for providing us with a preview!
