Planet called Lunar
The Queen of Night
Since time immemorial, people
have gazed with wonder at the pale yellow orb that casts its soft radiance upon
the Earth. Throughout the ages, it has been clothed in a deep and glamorous
mystery, a thing of legend and romance. The coming of the spaceship has
replaced many of the old superstitions by an even greater sense of wonder. There
is hardly a person who was living at the time that will not remember the
dramatic moment of touchdown by the lunar module of Apollo 11 on the Sea of
Tranquillity. World-wide television recorded the event as Neil Armstrong and
'Buzz' Aldrin landed on the Moon. It was the twenty-first of July 1969 and the
hard and dedicated work of thousands of scientists and engineers had come to
fruition. Their one lonely companion Michael Collins orbited the little
world in the command module which was loaded with instruments carrying out
geological and photographic surveys over the lunar surface. Already
several manned flights had gone round the Moon and unmanned spacecraft had
already disturbed its ancient silence.
From the scarred and battered surface of a planet called Lunar
the first astronauts gazed into the black canopy of star spangled space and saw
within that alien sky the large blue and white globe that was their home.
Shining with a radiance of sixty full moons it went through its phases and
forever presented different aspects to the two silent figures who left the Lunar
Module to tread upon the surface of the Moon and gaze upwards with awe at the
planet from which they had come.
AS17-148-22727 (7 December 1972) --- This view of the Earth was
seen by the Apollo 17 crew as they travelled toward the Moon on their NASA lunar
landing mission. This outstanding trans-lunar coast photograph extends from the
Mediterranean Sea area to the Antarctica south polar ice cap. This is the first
time the Apollo trajectory made it possible to photograph the south polar ice
cap. Note the heavy cloud cover in the Southern Hemisphere. Almost the entire
coastline of Africa is clearly visible. The Arabian Peninsula can be seen at the northeastern edge of Africa. The large island off the coast of Africa is the
Malagasy Republic. The Asian mainland is on the horizon toward the northeast.
The Apollo 17 crew consisted of astronauts Eugene A. Cernan, mission commander;
Ronald E. Evans, command module pilot; and Harrison H. Schmitt, lunar module
pilot. While astronauts Cernan and Schmitt descended in the Lunar Module (LM) to
explore the Moon, astronaut Evans remained with the Command and Service Modules
Photograph credit NASA
Missions to the Moon
Between 1969-1972, there were six
successful manned missions to the Moon. Since the first lunar
landing there was only one dramatic failure. Although it never reached the
moon the three astronauts returned safely to Earth. The
dramatic rescue of the three astronauts is the subject of the famous film Apollo
Large Scale Map of Moon showing Landing Sites Courtesy NASA
The direct hyperlink to this site is given in this web-site in the section at
the end of this 'chapter'. This
web-site when accessed directly can be used to obtain magnified maps of the
individual landing sites
Picture credit to NASA Apollo 16.
Locked in synchronous
rotation, the Moon always presents its well-known near side to Earth. But from
lunar orbit, the Apollo astronauts also grew to know the Moon's far side. This
picture was taken from Apollo 16's mapping camera. It shows the eastern edge of
the familiar near side (top) and the strange and heavily cratered far side of
the Moon. Surprisingly, the rough and battered surface of the far side looks
very different from the near side which is covered with smooth dark lunar maria.
The likely explanation is that the crust is thicker on the far side, making it
harder for molten material from the interior to flow to the surface
The astronauts from each mission
left a number of important instruments on the surface that continued to
broadcast back to Earth the results of their findings for several years after
they had been installed. The name given to the collection of instruments was
'The Apollo Lunar Surface Experimental Package' or ALSEP
Some of the most important
experiments involved the use of instruments to: -
Measure and analyse the Solar
Measure Seismic Activity -
Measure for Traces of Possible
Measure any Magnetic Field
Geological Surveys and other observations were also carried from orbit during
the missions. In each mission, two of the astronauts landed on the surface and
one member of the crew remained on board the space vehicle.
Probably the most important
assignment during each mission for the astronauts was to carry out geological
surveys around the landing sites and to collect rock specimens. At the same
time as his two companions explored the landing site, one lonely companion
orbited the little world alone in the command module.
Altogether about 392 kilograms of rock samples were brought back to Earth by the
six missions. During the whole of the Apollo programme, rock samples were taken
from many different types of sites - for example the Mare or 'sea areas' and the
A list of the manned space
flights is given in the table below
Table 4.1. Apollo Missions to the Moon.
Date of Landing
Mass of Rock Samples
21 July 1969
Sea of Tranquillity
0.7° N Latitude
3.2° S Latitude 23.4°W
Abandoned Returned to
Unsuccessful see Film
3.7° S Latitude 17.5°W
3 kilometre Survey
Hadley Rill. Near
26.1° N Latitude
3.7° E Longitude
28 kilometre Survey
Mare Nectaris near
Crater of Descartes
9.0° S Latitude 15.5°E
27 kilometre Survey
Taurus- Littrow Mts
Sea of Serenity
20.2°N Latitude 30.8°E
35 kilometre Survey
Each succeeding mission grew more ambitious. The amount of rock
samples collected was more on each occasion and the distance travelled by the
astronauts and time spent on the Moon increased. The final mission was Apollo
17. Some idea of the nature of the mission can be seen from the photograph of
Commander Cernik in a 'moonmobile'
Apollo 17 Site of
Landing – The Taurus-Littrow Valley
map and information courtesy Acknowledgement NASA/Apollo17
NASA/Apollo17Astronaut Eugene A. Cernan, commander, makes a short checkout of
the Lunar Roving Vehicle (LRV) during the early part of the first Apollo 17
Extravehicular Activity at the Taurus-Littrow landing site. The Earth date
was 11 December 1972. The photograph was taken by scientist-astronaut Harrison
H. Schmitt, lunar module pilot. The mountain in the right background is the east
end of South Massif. While astronaut's Cernan and Schmitt descended in the Lunar
Module to explore the Moon, astronaut Ronald E. Evans,
command module pilot, remained with the Command and Service Module.
Apollo 17 was
the last of the Apollo series of moon landings. It was also the most
ambitious - the astronauts were on the Moon longer than any other Moon explorers
and the greatest number of rock specimens were collected. Harrison 'Jack'
Schmitt was the only 'scientist ' to ever visit the Moon and was a civilian.
Schmitt was the only geologist in the astronaut corps. Jack was born July
3, 1935 in Santa Rita, New Mexico, and grew up in the nearby town of Silver
City. He received a B.S. from Caltech in 1957 and then spent a year studying
geology at the University of Oslo in Norway. He received a Ph.D. in Geology from
Harvard University in 1964. Before joining NASA as a member of the first group
of scientist-astronauts in June 1965, he worked at the U.S. Geological Survey's Astrogeology Center at Flagstaff, developing geological field techniques that
would be used by the Apollo crews. Following his selection, Schmitt played a key
role in training Apollo crews to be geologic observers when they were in lunar
orbit and competent geologic field workers when they were on the lunar surface.
After each of the landing missions, he participated in the examination and
evaluation of the returned lunar samples and helped the crews with the
scientific aspects of their mission reports.
During their 75 hours on the
Moon, the crew of Apollo 17 set up ten scientific experiments and
collected a total of 120 kilograms of moon rock from 22 locations within the
Taurus-Littrow Valley. They spent 22 hours on the lunar surface and travelled a
total of 36 kilometres. They took a number of excellent photographs. The map
shows the landing area where these activities took place.
Taurus-Littrow Valley. Site of Apollo 17 Landing
for map NASA /Apollo 17
There were two main
geological objectives undertaken in the area. They were the collection of
samples of ancient rocks from the lunar highlands and the investigation of young
volcanic activity on the valley floor. The crew collected 741 individual rock
and soil samples, with a total mass of 111 kilograms. This include a deep
drill core that obtained material from 3 meters below the lunar surface.
Rocks from the floor
of the Taurus-Littrow Valley were found to be mostly mare basalts. They
consisted primarily of the minerals plagioclase and pyroxene and were formed
from molten lava. They had developed from material that melted at depths of at
least 130 to 220 kilometers below the surface. They then rose to the surface
before solidifying. Most of these Apollo 17 mare basalts formed between 3.7 and
3.8 billion years ago. They were found to contain large amounts of the element
titanium. The basalt layer is between 1.0 and 1.4 kilometers thick near the
Apollo 17 landing site. On quiet eruption the Mare basalts flowed easily across
the Moon's surface. Samples of an orange coloured glass were also obtained.
It is thought that the glass formed 3.64 billion years ago from material that
melted about 400 kilometers below the surface.
Lunar Highland Rocks
A variety of very
old rocks were collected from the mountains to the north and south of the
landing site. Some of these rocks had been melted by the heat of a large impact
and are referred to as impact melts. Studies of such rocks indicate that the
impact that formed the Serenitatis basin (the basin of which the Taurus-Littrow
is part) occurred 3.89 billion years ago. Other rocks obtained included norites,
troctolites, and dunites which were formed even earlier in the Moon's history.
Norite consists primarily of the minerals plagioclase and pyroxene. Troctolite
consists primarily of plagioclase and olivine, but small amounts of pyroxene are
also present. Dunite is nearly pure olivine. Many of these rocks originally
formed in the lower half of the Moon's crust and were later brought to the
Moon's surface by large meteorite impacts. They formed between 4.2 and 4.5
billion years ago (the solar system formed about 4.56 billion years ago).
The impact that produced the sea of serenity occurred during ther time of the
late heavy bombardments
The Soviet Lunar Programme
The Soviet Union also undertook an elaborate lunar programme.
It was a very long-running undertaking, with the first mission flying in 1959
and the last flying in 1976. The Luna missions were designed to collect
information about the Moon and its environment, not only for scientific purposes
but also to be used in the planning of future lunar missions including manned
landings. The series included flyby, lunar-orbiting, and soft-landing missions.
It also included three missions that removed samples of rock that were then
returned to Earth. They were obtained from areas not covered by the Apollo
landings. Selected Luna missions are noted in the list in the table..Although
the Luna program experienced many ups and downs and failed to lead to a manned
mission to the Moon, it achieved many “firsts.” Among them were the first flyby
of the Moon, the first impact on the Moon, the first photographs of the farside,
the first analysis of lunar soil, the first soft landing, the first lunar rover
deployment and the first return of a sample of moon rock to Earth.
Table 4.2 Russian Luna Programme
4 January 1959
First fly-by of the Moon
13 September 1959
First Photographs of the
7 October 1959
latitude 0.0 o longitude
20 September 1970
Sea of Fertility
0.7 o S
latitude 56.3 o E longitude
Samples returned to Earth
21 February 1972
Sea of Fertility 160
kms from Luna 16 site in Appolonius Mts
3.5 o N
latitude 56.5 o E longitude
Sample returned to Earth 30
18 August 1976
Sea of Crisis
12.7 o N
latitude 62.2 o E longitude
Sample returned to Earth 170
The Lunar Surface
Although the Moon has not suffered erosion by water or by wind the surface of
the Moon has changed considerably over geological time. The changes have been
brought about by the action of impact processes, volcanic activity and tectonic
activity in the very distant past . By far the most important are those that
have been caused by bombardment from meteorites and by the incessant and
prolonged action of the Solar Wind and cosmic radiation on the lunar surface.
of lunar rocks is split into a number of periods named after certain large
craters. The periods recommended by D.E.Wilhelms of the U.S, Geological Survey
1,200 million years age to present day
Period 3,300 million years ago to 1,200 million years ago
Period 3,850 million years ago to 3,200 million years ago
Period 3,920 million years ago to 3,850 million years ago
Pre-Nectarian Period Before
3,920 million years ago
One of the most recently formed
lunar craters is the Crater of Copernicus which is 96 kilometres in diameter and
is believed to have originated about 900 million years ago. The Copernican
Period covers from 1,200 million years ago up to the present day
Eratosthenes Crater is considerably older than Copernicus and the period covers
from approximately 3,200 million up to 1,200 million years ago.
The formation of the Imbrian
Basin was caused by a huge impact. It was a major event in lunar history. It
has given its name to a period lasting from about 3,850 million up to 3,200
years ago. Much of the volcanic activity, caused by the Moon's own internal
action, occurred during this period.
of photograph NASA/Apollo 11
As a result of
the changes that have occurred over these vast periods of geological time,a
blanket of loose material covers the surface of the Moon. It is referred to as
the'REGOLITH'. It consists of rock fragments, fine stones and dust. The word
'soil' isused for any material under one centimetre in diameter. The regolith is
of variabledepth. It covers the bedrock to a depth of 4 to 5 metres in the Mare
Areas and 10 metresor more in the Highland Regions. The regolith is loose and
the footprints of hemoonboots of the astronauts and the tracks of the
moonmobiles can clearly beseen in photographs taken during the missions. The
illustration shows a photograph of an astronaut’s boot-print in the regolith
taken on the Apollo 11 Mission.
Later Missions to the Moon
Since the Apollo Landings there have been no
further attempts to land people on the Moon. With the robot landings on
Venus, Mars and Titan and the astounding progress obtained by the Galileo and
Cassini missions and many more, some of the glamour of the moon landings has
perhaps faded a little. However the time will soon arrive in the next
decade when men and women will return to the moon and set up permanent bases
similar to the space station and to the Antarctic bases on our own planet.
The moon is however not being neglected. Three important
missions have been launched recently
are due to NASA for supplying the information of the Clementine Mission.
January 25, 1994, the Deep Space Program Science Experiment (DSPSE) (better
known as Clementine) was launched from Vandenberg Air Force Base, California, on
a mission designed to test lightweight miniature sensors and advanced spacecraft
components by exposing them, over a long period of time, to the difficult
environment of outer space. In addition to testing the various sensors,
Clementine was given the complex task of mapping the moon. The mission results
February 26 and April 22, 1994, Clementine was able to deliver more than 1.8
million digital images of the moon back to the Clementine ground network,
including the NRL satellite ground-tracking station located in Maryland. These
images were quickly accessible to the general public via the Internet and World
Wide Web. When scientists reviewed the data from Clementine, they made a major
scientific discovery: the possible existence of ice within some of the moon's
Pentagon announced on December 3, 1996, that radar data acquired by the
Clementine spacecraft indicated ice in the bottom of a crater on the South Pole
of the Moon.
1994, President Clinton cited Clementine as one of the major national
achievements in aeronautics in space. He stated "The relatively inexpensive,
rapidly built spacecraft constituted a major revolution in spacecraft management
and design; it also contributed significantly to lunar studies by photographing
1.8 million images of the surface of the Moon"
The Lunar Prospector
Thanks are due to NASA for information on the Lunar Prospector.
Beginning on January 15, 1998, Lunar Prospector spent one year mapping
the entire surface of the Moon from a distance of about 100 kilometers (60
miles). The data collected during this phase of the mission greatly improved on
the quality of data collected previously. Among the early returns from the
instruments were those from the Neutron Spectrometer indicating significant
amounts of water ice at the lunar poles.
Lunar Prospector's Flight Path to the
Moon Credit NASA
The Lunar Prospector crashed, as
planned, and several teams of researchers tried to detect that cloud,
but without success. Either there was no water, or there was not enough
water to be detected by Earth-based telescopes, or the telescopes were
not looking in precisely the right place. In any
event, no water was found from Prospector's impact.
In 2008, NASA plans to send a new
spacecraft to the Moon: the Lunar Reconnaissance Orbiter (LRO),
bristling with advanced sensors that can sense water in at least four
different ways. Scientists are hopeful that LRO can decide the question
of Moon water once and for all.
Our interest is not just scientific.
If we are indeed to build a base on the Moon, the presence of water
already there would offer a tremendous advantage in building and running
Smart - 1
European Space Agency sent a very novel kind of spacecraft to the Moon called
SMART-1 Those people who were fortunate enough to attend the recent 2007
European Astrofest Conference at Kensington Town Hall in London were entertained
by a most interesting lecture on SMART- I given by Dr Dave Heather from ESTEC
the European Space Agency Center at Noordwijk in the Netherlands.
Telescopic view of the whole
Moon seen from Earth Credit ESA SMART-1 Mission.
Caption SMART-1 is Europe's
first mission to the Moon. The scientists taking part have a 21st-Century view
of our companion in space, which makes our connection with it more intimate than
ever. The Moon is no longer seen merely as a satellite, but as the Earth's
daughter, forming in a double planet.
Thanks and credits are due to ESA
for the descriptions and details given in their web-site . A hyperlink is
given to the ESA website in the section of this web-site devoted to outside
Over 30 years after the last Apollo
mission visited the Moon in 1972, there is still much that we do not know about
our satellite. How was it created? What role did it play in the formation and
evolution of Earth? SMART-1 may help to answer these questions.
The main purpose of the SMART-1
mission is to flight-test the new solar-electric propulsion technology – a kind
of solar-powered thruster that is ten times more efficient than the usual
chemical systems employed when travelling in space. If all goes well, such a
system could be providing the propulsion system for future ESA missions into
deep space, such as BepiColombo.
SMART-1 will be leading the way in
the latest imaging techniques. Images taken from many different angles and X-ray
and infrared detection work will allow scientists to draw up new
three-dimensional models of the Moon’s surface.
SMART-1 will be looking at the
darker parts of the Moon's south pole for the first time. It will be mapping the
so-called Peak of Eternal Light, an eerie mountaintop that is permanently bathed
in sunlight, while all around are dark craters never touched by the Sun. These
craters are believed to harbour water-ice in the lunar soil. SMART-1 will also
help scientists to confirm if ice is present at the lunar poles, where the
temperature never rises above –170°C. Any water on the lunar surface would be
very helpful in the creation of permanent bases on the Moon.
is heading for the Moon using revolutionary propulsion techniques and carry a
battery of miniaturised instruments.
As well as testing new technology,
SMART-1 will make the first comprehensive inventory of key chemical elements in
the lunar surface. It will also investigate the theory that the Moon was formed
following the violent collision of a smaller planet with Earth, four and a half
thousand million years ago.
Scientists demand more from space
missions travelling to other worlds and beyond than ever before an, traditional
rocket technologies are beginning to show shortcomings. In response to this
need, ESA are developing a new type of engine, known as solar-electric
propulsion, or an 'ion' engine, which could mark a whole new era of space
exploration. Solar-electric propulsion does not burn fuel as chemical rockets
do; instead the technique converts sunlight into electricity via solar panels
and uses it to electrically charge heavy gas atoms, which accelerate away from
the spacecraft at high speed. This drives the spacecraft forwards. In a chemical
rocket, the burning fuel creates gases which are expelled relatively slowly
compared to ion thrusters. However, in an ion engine, the gas is ejected at high
velocity, which makes it much more efficient and requires less fuel.
Ion engines are very important
because their high efficiency makes previously impossible missions achievable.
Since they do not need to carry so much fuel, ion engines release room for more
scientific instruments. As technology continues to get smaller, the size of
instruments decreases and the overall size and mass of the spacecraft decreases,
further increasing efficiency.
Further away from the Sun, where
the light is weaker, a new power source, such as a nuclear reactor, would be
needed. This type of engine could take spacecraft to the Kuiper belt and even
farther away. The Kuiper belt extends beyond the planet Pluto. It is a dream
destination for many scientists because it contains comets that have been
undisturbed since the formation of the Solar System. Beyond Pluto is a
mysterious realm of magnetic fields and rarefied gases known as interstellar
space. Solar-electric propulsion would make such a mission possible because an
ion engine can run almost constantly, so that eventually it outperforms any
chemical rocket on such long flights.
SMART-1 was launched from Kourou, French Guiana, on 27
September 2003. After launch, SMART-1 uses its ion drive to spiral out from the
Earth until the Moon's gravity catches it and pulls it towards the Moon. The
final operational orbit is a polar elliptical orbit, ranging from 300 to 10 000
kilometres above the Moon's surface.
The SMART-1 project is being driven
by a team at ESTEC in Noordwijk in the Netherlands. The industrial prime
contractor is the Swedish Space Corporation (SSC) through its Science Systems
Division. Some 15 subcontractors and suppliers from six European countries are
involved in building the spacecraft. For the science and technology payload,
co-investigators come from nine European countries, from ESA and from the United
The solar-electric primary
propulsion that has been selected is a Stationary Plasma Hall-effect thruster,
the PPS-1350 developed by SNECMA, France.
The European Space Agency's Science Programme encompasses, in
addition to the ambitious 'Cornerstone' and medium-sized missions, recently
dubbed 'flexi-missions', small relatively low-cost missions. These have been
given the generic name SMART - 'Small Missions for Advanced Research in
Technology'. Their purpose is to test new technologies that will eventually be
used on bigger projects.
SMART-1 is the first in this
programme. Its primary objective is to flight test Solar Electric Primary
Propulsion as the key technology for future Cornerstones in a mission
representative of a deep-space one. ESA's projected BepiColombo mission to
explore the planet Mercury could be the first to benefit from SMART-1's
demonstration of electric propulsion. Another objective is to test new
technologies for spacecraft and instruments.
The planetary objective selected
for the SMART-1 mission is to orbit the Moon for a nominal period of six months.
It is the first time that Europe sends a spacecraft to the Moon. The project
aims to have the spacecraft ready early in 2003 for launch as an Ariane-5
auxiliary payload. In addition to the use of solar electric primary propulsion
to reach Earth's natural satellite, the spacecraft will carry out a complete
programme of scientific observations in lunar orbit.
Shape of Things to Come
European Space Agency's SMART-1 craft, currently orbiting the Moon, is expected
to shed additional light on lunar topography. NASA has plans for a robotic
reconnaissance effort in 2008 that would provide more information on polar
illumination. Meanwhile, India's first mission to the Moon, planned for 2007,
would pack a U.S.-made radar instrument designed to pin down the locations of
planned to set up a future moonbase will be set
up near one of the poles. One particular
area that is receiving attention is a spot near
the rim of Shackleton Crater close to the South
Pole that is almost permanently sunlit. It is
also close to a dark region where, if we are
lucky, there might be water. For a small
colony of space men and women this would provide
water for drinking, and oxygen for breathing by
electrolysis and perhaps for the growth of
plants in a small hydroponic farm. We must
however remember that such water resources if
they exist at all may be very limited.
The artists impressions of the moonbases of the
future are Credit to NASA.
In the recent
February 2007 edition of Astronomy Now there is an interesting article by
William Harwood based on an interview with NASA Administrator Mike Griffin on
the future of the exploration of the Moon entitled 'Fly me to the Moon'.
It is well worth reading.
Although it was
published sixteen years there is a very comprehensive book entitled 'Lunar
Sourcebook - A user's guide to the Moon'. It was edited by Grant.
H.Heinken, David.T.Vaniman and Bevan.M.French. There is a foreword
It was published
in by the Cambridge University Press in 1991 (ISBN Number 0-521-33444-6).
There are over 700 pages of scientific details of work done on the Moon and on
moon rocks. It will be of particular interest to geologists and
Lunar Chemistry, Mineralogy and Petrology are dealt with in another section of
the web-site hyperlinked to this one