Chang’e 2 is now “liberated” from earth and lunar gravity

China’s lunar probe Chang’e 2 completed its mission orbiting the moon three months ago and has now reached Lagrange (liberation) Point L2.

It has now reached a point in space where neither the moon nor the earth’s gravity will affect the probe. This point is called L2. It’s the farthest a Chinese spacecraft has ever been.

Chang’e 2′s primary mission was to orbit the moon at only 100 kilometers from the surface, taking high resolution photos. After completing this, scientists decided that there was enough fuel to continue with the second part of the mission. But sending the probe from the moon was unprecedented. Similar missions has previously left directly from Earth, so keeping the satellite on course was a technological challenge.

Zhou Jianliang, Deputy Chief Designer, Measure & Control System of Chang’e 2, said, “The satellite faced various disruptions on its journey, which could have led it off course. We had planned four readjustments to keep it on track. But we only need(ed) to do it once since the first adjustment proved so accurate.”

China’s ambitious three-stage moon mission is steadily advancing. The next phase will be the launch of Chang’e-3 in 2013. The probe’s mission is to land on the moon together with a moon rover. In the third phase, the rover should land on the moon and return to Earth with lunar soil and stones for scientists to study. The Chang’e program was named after the legendary Chinese goddess who flew to the moon. With the progress in technology and experience from the Chang’e mission, sending a Chinese astronaut to the moon is now clearly feasible.

On Lagrange Points:

The Italian-French mathematician Joseph-Louis Lagrange discovered five special points in the vicinity of two orbiting masses where a third, smaller mass can orbit at a fixed distance from the larger masses. More precisely, the Lagrange Points mark positions where the gravitational pull of the two large masses precisely equals the centripetal force required to rotate with them. Those with a mathematical flair can follow this link to a derivation of Lagrange’s result (168K PDF file, 8 pages).

Of the five Lagrange points, three are unstable and two are stable. The unstable Lagrange points – labeled L1, L2 and L3 – lie along the line connecting the two large masses. The stable Lagrange points – labeled L4 and L5 – form the apex of two equilateral triangles that have the large masses at their vertices.

Lagrange Points of the Earth-Sun system (not drawn to scale!): NASA

 The easiest way to see how Lagrange made his discovery is to adopt a frame of reference that rotates with the system. The forces exerted on a body at rest in this frame can be derived from an effective potential in much the same way that wind speeds can be inferred from a weather map. The forces are strongest when the contours of the effective potential are closest together and weakest when the contours are far apart. In the contour plot below we see that L4 and L5 correspond to hilltops and L1, L2 and L3 correspond to saddles (i.e. points where the potential is curving up in one direction and down in the other).

A contour plot of the effective potential (not drawn to scale!): NASA

Solar effects will give increased volcanic and earthquake activity in the next 2 years

Solar effects are much more profound than many so-called climate scientists like to admit. It seems entirely plausible to me that earthquakes and volcanism are connected to solar events. This paper by Zhang from 1998 also associates increased Earthquakes with general increases in solar proton events.

http://www.springerlink.com/content/buvw2tq081013210/fulltext.pdf?page=1

Relationship between global seismicity and solar activities

Gui-Qing ZHANG

Vol. 11 No.4 (495~500)  ACTA SEISMOLOGICA SINICA  July, 1998

Beijing Astronomical Observatory, Chinese Academy of  Sciences, Beijing 100101, China

Abstract :

The  relations  between  sunspot  numbers and earthquakes  (M>6), solar 10.7cm  radio flux  and  earthquakes,  solar  proton events and earthquakes have been  analyzed in this  paper. It has been found that:

1. Earthquakes occur frequently around the minimum years  of  solar activity. Generally, the  earthquake  activities are  relatively less during the peak value years of  solar activity, some  say, a round the period when magnetic polarity  in the  solar polar regions  is reversed.
2. The earthquake frequency in the minimum period of  solar activity is closely related to the  maximum annual means of sunspot numbers, the maximum annual means of solar 10.7 cm radio flux and solar proton events of a whole solar cycle, and the relation between earthquake and solar proton events is closer than others.
3. As judged by above interrelationship, the period from 1995 to 1997 will be the years while earthquake activities are frequent. In the paper, the simple physical discussion has been carried out.

Piers Corbyn at WeatherAction comments:

“We now think that it is not just general solar proton event levels which point towards more earthquakes but that individual solar proton events exacerbate immediate earthquake (and associated volcanism) risk either directly or due to consequent storm activity and related surface pressure changes such as caused by our solar triggered and predicted Tropical Cyclone Atu which is currently centred North of New Zealand and heading closer.

There are also additional lunar effects on storm development and earthquakes & volcanism and for solar drivers it appears that the odd-even minima, particularly the later part i.e. the rising phase of even solar cycles – WHICH IS WHERE WE ARE NOW (early Solar Cycle 24) – are the most dangerous.

Prediction of individual Earthquakes is very hard but we are very confident of a continuing period of significantly enhanced earthquake and volcanic activity as well as extreme weather events for the coming one or two years, probably exceeding the levels of the most active extended periods in at least the last 100 years.”

Chinese Premier Wen Jiabao unveils Chang’e-2 pictures

Xinhua reports the success of the Chang’e-2 mission.

Chinese Premier Wen Jiabao Monday unveiled the first pictures of the moon’s Sinus Iridum, or Bay of Rainbows, marking the success of China’s Chang’e-2 lunar probe mission.

Chinese Premier Wen Jiabao attends an unveiling ceremony for pictures of the moon's Sinus Iridum, or Bay of Rainbows, taken and sent back by the Chang'e-2, China's second lunar probe, in Beijing, capital of China, Nov. 8, 2010. (Xinhua/Huang Jingwen)

The pictures were taken and sent back by the Chang’e-2, China’s second lunar probe, which was launched on October 1.

Chang’e-2 entered into its final 118 min orbit and formally started its mission of mapping the moon and preparing the way for Chang’e-3 on October 9th.

Lunar activity: Chang’e-2 starts mission and Nasa revives 2 satellites

Xinhua reports

Scientists successfully activated four attitude control engines on Chang’e-2 and sent the satellite into the orbit with a perilune of just 15 kilometer above the moon, according to a flight control official in Beijing. It will photograph the Bay of Rainbows region with its CCD cameras from Wednesday, according to the center.

NASA has revived 2 satellites that were dying and sent them to the moon creating the ARTEMIS mission:

A pair of NASA spacecraft that were supposed to be dead a year ago are instead flying to the Moon for a breakthrough mission in lunar orbit. ”Their real names are THEMIS P1 and P2, but I call them ‘dead spacecraft walking,’” says Vassilis Angelopoulos of UCLA, principal investigator of the THEMIS mission. “Not so long ago, we thought they were goners. Now they are beginning a whole new adventure.”

The story begins in 2007 when NASA launched a fleet of five spacecraft into Earth’s magnetosphere to study the physics of geomagnetic storms. Collectively, they were called THEMIS, short for “Time History of Events and Macroscale Interactions during Substorms.” P1 and P2 were the outermost members of the quintet. Working together, the probes quickly discovered a cornucopia of previously unknown phenomena such as colliding auroras, magnetic spacequakes, and plasma bullets shooting up and down Earth’s magnetic tail. These findings allowed researchers to solve several longstanding mysteries of the Northern Lights.

The mission was going splendidly, except for one thing: Occasionally, P1 and P2 would pass through the shadow of Earth. The solar powered spacecraft were designed to go without sunlight for as much as three hours at a time, so a small amount of shadowing was no problem. But as the mission wore on, their orbits evolved and by 2009 the pair was spending as much as 8 hours a day in the dark. ”The two spacecraft were running out of power and freezing to death,” says Angelopoulos. “We had to do something to save them.”

Because the mission had gone so well, the spacecraft still had an ample supply of fuel–enough to go to the Moon. “We could do some great science from lunar orbit,” he says. NASA approved the trip and in late 2009, P1 and P2 headed away from the shadows of Earth.

With a new destination, the mission needed a new name. The team selected ARTEMIS, the Greek goddess of the Moon. It also stands for “Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun.”

The first big events of the ARTEMIS mission are underway now. On August 25, 2010, ARTEMIS-P1 reached the L2 Lagrange point on the far side of the Moon. Following close behind, ARTEMIS-P2 entered the opposite L1 Lagrange point on Oct. 22nd. Lagrange points are places where the gravity of Earth and Moon balance, creating a sort of gravitational parking spot for spacecraft.

 

The ARTEMIS spacecraft are currently located at the L1 and L2 Earth-Moon Lagrange points: NASA

 

http://science.nasa.gov/science-news/science-at-nasa/2010/27oct_artemis/

 

Lunar crater “Cabeus” contains more water than the Sahara

The New York Times reports on the latest results from the $79 million Lcross mission. Last October, as it neared impact, the Lcross spacecraft released the empty second stage and slowed down slightly so that it could watch the stage’s 5,600-mile-per-hour crash into a 60-mile-wide, 2-mile-deep crater named Cabeus.

 

Debris ejected from the Cabeus lunar crater about 20 seconds after the Lcross impact: image Science / AAAS

 

A series of articles reporting the Lcross results appear in Friday’s issue of the journal Science.

Last November, the team reported that the impact had kicked up at least 26 gallons of water, confirming suspicions of ice in the craters. The new results increase the water estimate to about 40 gallons, and by estimating by amount of dirt excavated by the impact, calculated the concentration of water for the first time. The Sahara sands are 2 to 5 percent water, and the water is tightly bound to the minerals. In the lunar crater, which lies in perpetual darkness, the water is in the form of almost pure ice grains mixed in with the rest of the soil, and is easy to extract. The ice is about 5.6 percent of the mixture, and possibly as high as 8.5 percent of it, Dr. Colaprete principal investigator of NASA’s Lunar Crater Observation and Sensing Satellite —  Lcross - said.

In lunar terms, that is an oasis, surprisingly wet for a place that had long been thought by many planetary scientists to be utterly dry. If astronauts were to visit this crater, they might be able to use eight wheelbarrows of soil to melt 10 to 13 gallons of water. The water, if purified, could be used for drinking, or broken apart into hydrogen and oxygen for rocket fuel — to get home or travel to Mars.

Also surprising was the cornucopia of other elements and molecules that Lcross scooped out of the Cabeus crater, near the Moon’s south pole. Lying in perpetual darkness, the bottom of Cabeus, at minus 370 degrees Fahrenheit, is among the coldest places in the solar system and acts as a “cold trap,” collecting a history of impacts and debris over perhaps a couple of billion years.

“This is quite a reservoir of our cosmic climate,” said Peter H. Schultz, a professor of geological sciences at Brown University and lead author of one of the Science papers. “It reflects things that hit the Moon.”

By analyzing the spectrum of infrared light reflected off the debris plume, Dr. Schultz and his colleagues identified elements like sodium and silver.