Moon

The spring 2019 faculty-student special event “Apollo 10: Fly me to the Moon” was held at 7 pm on Wednesday May 22 to celebrate the 50th anniversary of the Apollo Moon missions with a program on Apollo 10 and 11, the origin and co-evolution of the Moon and Earth, and the influence of the Moon on life on Earth. Poster talks, videos, and posters and videos were also available. The ultimate question in the evolutionary history of Earth is how did a cold dilute cloud of gas and dust evolve into astronauts driving on the moon of a planet orbiting a star?

near side and far side of Moon and Apollo 10 rocket launch

Near Side of Moon

Far Side of Moon

7 pm May 22, 2019

This webpage is under construction, but the embedded videos and other materials are very informative.

Flyer for Apollo 10: 50th Anniversary special event May 22

Apollo Missions - Four Embedded Videos

Apollo 11 moon mission animated

https://www.youtube.com/watch?v=8VvfTY-tVzI

It Took 83 Engines to Get to the Moon

https://www.youtube.com/watch?v=F2c9LPNRonQ

1969 Apollo 10 NASA - dress rehearsal for the lunar landing

https://www.youtube.com/watch?v=pb0bV5CPIUM

Apollo 10 nearly crashes on the Moon

https://www.youtube.com/watch?v=g5N2pygq42A

Two embedded videos: Where did the Moon come from?

Where Did The Moon Come From? - Do We Really Need the Moon?

Preview - BBC Two https://www.youtube.com/watch?v=c0FCE4H0Dro

Where did the Moon come from? A new theory

TED Talk by Sarah T. Stewart https://youtu.be/7uRPPaYuu44

The Earth and Moon are like identical twins, made up of the exact same materials -- which is really strange, since no other celestial bodies we know of share this kind of chemical relationship. What's responsible for this special connection? Looking for an answer, planetary scientist and MacArthur "Genius" Sarah T. Stewart discovered a new kind of astronomical object -- a synestia -- and a new way to solve the mystery of the Moon's origin.

Giant Impact Hypothesis for the origin of the Moon

Moon was produced by a head-on collision between Earth and a forming planet

UCLA-led research reconstructs massive crash, which took place 4.5 billion years ago

Stuart Wolpert | January 28, 2016

The extremely similar chemical composition of rocks on the Earth and moon helped scientists determine that a head-on collision, not a glancing blow, took place between Earth and Theia.

The moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia approximately 100 million years after the Earth formed, UCLA geochemists and colleagues report.

Scientists had already known about this high-speed crash, which occurred almost 4.5 billion years ago, but many thought the Earth collided with Theia (pronounced THAY-eh) at an angle of 45 degrees or more — a powerful side-swipe (simulated in this 2012 YouTube video). New evidence reported Jan. 29 in the journal Science substantially strengthens the case for a head-on assault.

The researchers analyzed seven rocks brought to the Earth from the moon by the Apollo 12, 15 and 17 missions, as well as six volcanic rocks from the Earth’s mantle — five from Hawaii and one from Arizona.

The key to reconstructing the giant impact was a chemical signature revealed in the rocks’ oxygen atoms. (Oxygen makes up 90 percent of rocks’ volume and 50 percent of their weight.) More than 99.9 percent of Earth’s oxygen is O-16, so called because each atom contains eight protons and eight neutrons. But there also are small quantities of heavier oxygen isotopes: O-17, which have one extra neutron, and O-18, which have two extra neutrons. Earth, Mars and other planetary bodies in our solar system each has a unique ratio of O-17 to O-16 — each one a distinctive “fingerprint.”

In 2014, a team of German scientists reported in Science that the moon also has its own unique ratio of oxygen isotopes, different from Earth’s. The new research finds that is not the case.

“We don’t see any difference between the Earth’s and the moon’s oxygen isotopes; they’re indistinguishable,” said Edward Young, lead author of the new study and a UCLA professor of geochemistry and cosmochemistry.

Young’s research team used state-of-the-art technology and techniques to make extraordinarily precise and careful measurements, and verified them with UCLA’s new mass spectrometer.

The fact that oxygen in rocks on the Earth and our moon share chemical signatures was very telling, Young said. Had Earth and Theia collided in a glancing side blow, the vast majority of the moon would have been made mainly of Theia, and the Earth and moon should have different oxygen isotopes. A head-on collision, however, likely would have resulted in similar chemical composition of both Earth and the moon.

“Theia was thoroughly mixed into both the Earth and the moon, and evenly dispersed between them,” Young said. “This explains why we don’t see a different signature of Theia in the moon versus the Earth.”

Theia, which did not survive the collision (except that it now makes up large parts of Earth and the moon) was growing and probably would have become a planet if the crash had not occurred, Young said. Young and some other scientists believe the planet was approximately the same size as the Earth; others believe it was smaller, perhaps more similar in size to Mars.

Another interesting question is whether the collision with Theia removed any water that the early Earth may have contained. After the collision — perhaps tens of millions of year later — small asteroids likely hit the Earth, including ones that may have been rich in water, Young said. Collisions of growing bodies occurred very frequently back then, he said, although Mars avoided large collisions.

A head-on collision was initially proposed in 2012 by Matija Ćuk, now a research scientist with the SETI Institute, and Sarah Stewart, now a professor at UC Davis; and, separately during the same year by Robin Canup of the Southwest Research Institute.

Co-authors of the Science paper are Issaku Kohl, a researcher in Young’s laboratory; Paul Warren, a researcher in the UCLA department of Earth, planetary, and space sciences; David Rubie, a research professor at Germany’s Bayerisches Geoinstitut, University of Bayreuth; and Seth Jacobson and Alessandro Morbidelli, planetary scientists at France’s Laboratoire Lagrange, Université de Nice.

The research was funded by NASA, the Deep Carbon Observatory and a European Research Council advanced grant (ACCRETE).

Co-evolution of the Earth and the Moon

How Earth and the Moon interact - astronomytoday.com

The Earth is unique amongst the terrestrial planets in having a large satellite, the Moon, which, relative to the Earth, has the largest mass of any satellite-parent system. Numerous lines of evidence indicate that the Moon was derived from the Earth as the result of a singular impact event soon after the initial formation of the Earth. As a result, the subsequent evolution of the Earth and the emergence and development of life has been strongly influenced by the presence of the Moon.

This article will highlight and explain the key areas in which the Moon has both directly and indirectly influenced the emergence and evolution of life on the Earth, a process that has culminated in the development of an intelligent, technologically advanced species.

Tides

Perhaps the most obvious manifestation of the influence of the Moon on the Earth are the ocean tides, particularly the spring tides where the gravitational pull of the Sun and Moon combine to give the greatest effect. The regular rise and fall of sea level creates an unique environment in the Solar System, where life is exposed to both immersion in water and exposure to air in the space of a few hours. This interface between two distinct ecological niches is thought by many to be crucial in evolutionary terms.

This is an environment in which organisms can experience the stresses and strains of an alien world before safely returning to their aquatic habitat, such changes possibly promoting the alteration and/or migration of organisms from one environment to the other. Hence the presence of the Moon to cause tides may well have sparked the spread of organisms from the sea to the land.

The Moon also raises tides in the solid body of the Earth and in the past, when the Moon orbited much closer to the Earth than at present, these tides are estimated to have produced displacements in the Earth's solid surface of up to a kilometre. This would have produced intense stress and deformation within the Earth which, coupled with the decaying heat of accretion and the higher content of radioactive (U, Th and K) elements, would have greatly promoted melting of the early Earth. This melting may well have had an important role in the early differentiation of the Earth, in particular producing the earliest evolved crust, which would then be available for recycling by nascent plate tectonic processes.

Stable Axial Tilt

It is considered likely by many authors that the current circa 23.5 degree tilt of the Earth's axis of rotation is a relic of the oblique collision that produced the Moon. Furthermore it is argued that the presence of the orbiting Moon has, through a large part of geological time, stabilised this axial tilt or obliquity of the Earth. This has had important ramifications for life on the Earth as major and frequent shifts in this obliquity would have led to significant and rapid changes in the Earth's climate due to changes in insolation values at the poles and equator. A similar mechanism has been suggested to explain the apparent contradictions in the climate record of Mars.

The current relatively moderate axial tilt of the Earth ensures that the difference in heating between the poles and equator is sufficient to promote a healthy and diverse range of climatic zones without veering from one extreme to another (e.g. Snowball Earth hypothesis). In particular, the stability of the Earth's axial tilt produced by the Moon, coupled with the break up of the Pangean supercontinent in the late Mesozoic, produced a diverse set of climate zones (with their associated ecological niches) compared with what had gone before during the time of the dinosaurs. This helped set the stage for the rise of the mammals, including Man.

Metals

Perhaps one of the least obvious but most significant contributions from the Moon to life on Earth has been the gift of workable metal deposits at the surface of the planet. Ever since the first samples of lunar rock were returned by the Apollo astronauts and the geochemical data were made available, scientists have been intrigued by the relatively high abundance of siderophile and chalcophile metals in the silicate Earth compared with the Moon. Current theory suggests that if the Earth had once been entirely molten then these metals should have been locked up in the Earth's metallic core as the Earth cooled. The current abundance of these elements in the Earth's mantle should be much lower, similar to those of the Moon (part of which was derived from the Earth's original mantle).

Computer modelling of the collision between the Earth and the Mars-sized impactor shows that the bulk of the mantle of the impacting object and a proportion of the Earth's silicate mantle were ejected into Earth orbit and coalesced to form the Moon. However, the metallic core of the impactor was not ejected into orbit but instead fell into the main body of the Earth. This impacting core material, in some models, is the 'wedding ring' of metals deposited into the Earth's silicate mantle after collision and subsequently recycled into workable ore deposits by plate tectonic processes over geological time. Without this gift of metals, the so called 'late veneer', it is very unlikely that a technological civilization could have developed on the Earth.

Maths, Art and Eclipses

The Moon has also encouraged the development of intelligence in less quantifiable ways. What did primitive man make of the luminous orb that lit the night sky for half a month and changed its phase and brightness over 28 days? Did the regular procession of the lunar cycle combined with the wanderings of the planets and the stately progression of the stars and Sun with the seasons underpin and prompt thinking about the nature of the Universe? Certainly the earliest astronomers observed and calculated calendars based on those observations and planned their agriculture accordingly. The lore, mythology and literature of the Moon, from illuminating star-crossed lovers to turning men into werewolves, permeates human culture and society. When Galileo turned his telescope towards the Moon and recognized mountains, craters and 'seas', did this not spur humankind into thinking about the 'plurality of worlds'? In a perhaps more direct fashion, the Moon has spurred technological development. Clearly the 'Race to the Moon' which, arguably, helped prompt some of the most rapid advances in tracking, propulsion, electronics, life support and other high-technology industries as well as transform humanity's view of itself, could not have happened without a Moon!

Perhaps the most beautiful and eloquent symbol of our dependence on the Moon is that of the total solar eclipse, that chance coincidence of distance and angular size which not only allows us to see and understand the true extent of our star but also allowed the first observational confirmation of Albert Einstein's theories, which transformed our understanding of the Universe.

The conclusion reached is that the Moon, itself born in a unique and random event, has been essential for the emergence of intelligent life on Earth and as a result such intelligence is probably a very rare occurrence itself.

Author: Paul J. Henney

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Influence of the Moon on life on Earth - two articles

No Moon, no life on Earth, suggests theory

https://www.newscientist.com/article/dn4786-no-moon-no-life-on-earth-suggests-theory/ Anil Ananthaswamy

Without the Moon, there would have been no life on Earth.

Four billion years ago, when life began, the Moon orbited much closer to us than it does now, causing massive tides to ebb and flow every few hours. These tides caused dramatic fluctuations in salinity around coastlines which could have driven the evolution of early DNA-like biomolecules.

This hypothesis, which is the work of Richard Lathe, a molecular biologist at Pieta Research in Edinburgh, UK, also suggests that life could not have begun on Mars.

According to one theory for the origin of life, self-replicating molecules such as DNA or RNA emerged when small precursor molecules in the primordial “soup” polymerised into long strands. These strands served as templates for more precursor molecules to attach along the templates, creating double-stranded polymers similar to DNA.

But the whole theory fails without some way of breaking apart the double strands to keep the process going, says Lathe. It would take some external force to dissociate the two strands, he says.

Doubling up

As an analogy, he points to PCR, the technique used to amplify DNA in the lab. DNA is cycled between two temperatures in the presence of appropriate enzymes.

At the lower temperature of about 50 °C, single DNA strands act as templates for synthesising complementary strands. At the higher temperature of about 100 °C, the double strands break apart, doubling the number of molecules. Lower the temperature, and the synthesis starts again. Using this process, a single DNA molecule can be converted into a trillion identical copies in just 40 cycles.

Lathe believes that thanks to the Moon, something similar happened during Earth’s early years. Most researchers agree that the Moon formed five billion years ago from debris blasted off Earth in a giant impact.

A billion years later when life is thought to have arisen, the Moon was still much closer to us than it is now. That, plus the Earth’s much more rapid rotation, led to tidal cycles every two to six hours, with tides extending several hundred kilometres inland, says Lathe. Coastal areas therefore saw dramatic cyclical changes in salinity, and Lathe believes this led to repeated association and dissociation of double-stranded molecules similar to DNA.

When the massive tides rolled in, the salt concentration was very low. Double-stranded DNA breaks apart under such conditions because electrically charged phosphate groups on each strand repel each other.

But when the tides went out, precursor molecules and precipitated salt would have been present in high concentrations. This would have encouraged double-stranded molecules to form, since high salt concentrations neutralise DNA’s phosphate charges, allowing strands to stick together.

Unrelenting cycles

These unrelenting saline cycles would have amplified molecules such as DNA in a process similar to PCR, says Lathe. “The tidal force is absolutely important, because it provides the energy for association and dissociation [of polymers].”

Many researchers do not believe DNA and RNA were the first replicating molecules. Graham Cairns-Smith of the University of Glasgow, UK, thinks much simpler “genetic” material formed first, from the crystallisation of clay minerals.

But he says Lathe’s idea deserves attention. “Whatever the replicating entities were that started the evolutionary process, it would be significant that they lived in an environment in which the conditions were changing.”

If the theory is right, life could not have evolved on Mars, says Lathe. Phobos, the larger of Mars’s two Moons, is so small that the tidal forces it generates are just one per cent of those generated by our Moon. “Even if there was water on Mars, life could not have evolved there because these polymers could not have replicated,” he says.

Journal reference: Icarus (vol 168, p 18)

Without the Moon, Would There Be Life on Earth?

By driving the tides, our lunar companion may have jump-started biology--or at least accelerated its progression

By Bruce Dorminey on April 21, 2009 https://www.scientificamerican.com/article/moon-life-tides/

The ocean tides mirror life itself. Their ebb and flow pay homage to the cyclic nature of the cosmos along even the most secluded seashores. But is life itself also ultimately a fluke of the tides?
If so, life may ultimately owe its origins to our serendipitously large moon. The sun and wind also drive the ocean's oscillations, but it is the moon's gravitational tug that is responsible for the lion's share of this predictable tidal flux.
Our current Earth–moon system, according to the prevailing theory of lunar formation, reflects our solar system's early game of planetary billiards, when colliding planetary embryos created entirely new versions of themselves—in the case of our own planet, a disproportionately large natural satellite in close orbit.
It all started some 4.5 billion years ago when, as theory has it, our nascent Earth was blindsided by a Mars-size planetary embryo, believed to have spun Earth into its initial fast rotation of roughly 12 hours per day. The molten mantle thrown into orbit after the catastrophic lunar-forming impact quickly coalesced into our moon. Within a few thousand years, Earth cooled to an object with a molten surface and a steam atmosphere. Life emerged some 700 million years later, or about 3.8 billion years ago.
But four billion years ago a cooling Earth already had an ocean, but remained barren. The moon was perhaps half as distant as it is now, and as a result, the ocean tides were much more extreme.
At an average distance of 235,000 miles (380,000 kilometers), the moon is currently receding from Earth at a rate of 1.5 inches (3.8 centimeters) per year. As it does, Earth's own spin rate is slowing. And, in the process, roughly 10²⁰ joules of gravitational energy is shed into the oceans annually.*
Over the eons, all that energy has had an evolutionary impact.
"The oceans' tidal flow helps transport heat from the equator to the poles," says Bruce Bills, a geodynamicist at the NASA Jet Propulsion Laboratory in Pasadena, Calif. "Without the lunar tides, it's conceivable that climate oscillations from the ice age to the interglacial would be less extreme than they are. Such glaciations caused migrations of animal and plant species that probably helped speed up speciation."
Bills also points out that such tidal heat transfer could have also mitigated climate fluctuations. The problem in determining which "tidal forcing" scenario is correct, he says, is that climate researchers currently lack data spanning extremely long timescales. Even so, Peter Raimondi, an ecologist at the University of California, Santa Cruz, says the tools of evolution are also driven by the tides' influence on these intertidal regions.
"In a rocky intertidal area," Raimondi says, "it's very clear there are strong evolutionary pressures brought on by a changing environment over a short spatial scale. Without our moon, our marine environment would be much less rich in terms of species diversity."
But is the influence of the lunar tides actually responsible for life itself?
If life originated around deep ocean hydrothermal vents (so-called black smokers), then the lunar tides played a minor role, if any, says James Cowen, a biogeochemical oceanographer at the University of Hawaii at Manoa. If, however, life originated in tidal waters, he says, then tidal cycles could have played a major role.

Three terawatts (3 TW) are shed into the oceans continually.
Both DNA and RNA—the messengers of life as we know it—almost certainly were selected and evolved from a large diverse group of protonucleic acid molecules. But for DNA and RNA to evolve from this group of protonucleic acid structures, first they had to be able to replicate. That involved organizing their copying via cyclic assembly and dissociation.
"A lot of origin-of-life reactions involve getting rid of water," says Kevin Zahnle, a planetary scientist at the NASA Ames Research Center at Moffett Field, Calif. "So you look for means to concentrate your solutions. One way to do that is to throw water up on a hot rock, then have the waters recede and evaporate."
Molecular biologist Richard Lathe of Pieta Research, a biotech consultancy in Edinburgh, Scotland, contends that some 3.9 billion years ago, fast tidal cycling caused by the influence of our moon enabled the formation of precursor nucleic acids.
Lathe says that a 12-hour Earth day would have produced high tides "a little faster than every six hours."
He believes these lunar tides would have moved many miles inland, beyond the crashing waves driven by the sun or surface winds, and onto a vast, flat sandscape. Today, this sort of ocean cycling pervades the sandy flats surrounding France's famed tidal island of Mont-Saint-Michel, abutting the English Channel.
In the early Earth environment, Lathe notes that such fast lunar tidal oscillations would result in the highly saline low-tide environment that protonucleic acid fragments would have needed to associate and assemble complementary molecular strands.
Having bonded in pairs at low tide, these newly formed molecular strands would then dissociate at high tide, when salt concentrations were reduced, providing what Lathe terms a self-replicating system. Lathe believes that DNA would ultimately have arisen from such protonucleic acids.
If the lunar tides were a crucial part of evolution on our own planet, what of other ocean-bearing terrestrial planets without benefit of a significant nearby lunar neighbor? Would their prospects for life be diminished due to lack of tides?
"Odds of nucleic acids forming on Earth without the lunar tides would be much lower," Lathe says. By this accounting, he says that Mars, with its two puny moons, Deimos and Phobos, could not have formed life.
Within our own solar system, the moons of Jupiter have turned the idea of tidal influence on its head. On Jupiter's icy moon Europa, tidal heating, caused by the flexing of the satellite under the gravitational pull of the giant planet, is believed to maintain a large liquid water ocean below its frozen surface.
"Europa must have big tides, so it's my favorite for microbial life," says Max Bernstein, an astrochemist and program scientist at NASA Headquarters in Washington, D.C. "Europa is considered by many as the best place to find life in the solar system."
But even with strong tides, any evolutionary ambitions of microbes on Europa would soon be stymied by their harsh habitat. That is one reason why so much time and energy still goes into unraveling the mystery of life's origins on our own planet.
Our disproportionately large nearby moon certainly gave Earth an early tidal nudge. But unlike Venus and Mars, our moon's gravitational influence also helped ensure that Earth's spin axis and climate remained stable over long timescales. That's arguably just as important as our oceans' tidal ebb and flow.
Still, as Bruce Lieberman, a paleobiologist at the University of Kansas in Lawrence, points out: "I suspect that eventually life would have made land without the tides. But the lineages that ultimately gave rise to humans were at first intertidal."

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evolutionary history of the Moon

The evolutionary history of the Moon

This is a work in progress.

The evolutionary history of the Moon is inseparable from the evolutionary history of Earth. The Moon is remarkably large for an object orbiting a rocky planet. According to the Giant Impact Hypothesis, a Mars-size object named Theia impacted the proto-Earth. The impact increased the mass of the Earth by about 10% and formed a Moon whose mass is about 80 times less than Earth’s. Like the Earth’s orbit around the Sun, the Moon’s orbit around Earth is nearly circular.

The collision also tilted the Earth’s axis of rotation to values that vary around its current average of 23.45 degrees. The Earth’s axis of rotation is stabilized by the gravitational influence of the Moon, which also causes its precession, that is to say, it points to different “North stars” over the course of about 26000 years. The tilt and its stability help make the climate on Earth favorable for liquid oceans and for life.

The initial orbit of the Moon was very close to the Earth, but gravitational gradients across large bodies produce tidal effects that can transfer angular momentum from one body to another. Tidal friction and collisions dissipate rotational energy, but angular momentum is a conserved quantity of the Earth-Moon system as well as the original Earth-Theia system.

Within a few million years, the rotational period of the Moon increased to nearly 30 days, at which point it became tidally locked so that one side always faces Earth. The rotational angular momentum of the Moon is 30,000 times smaller than its orbital angular momentum.

The initial rotational angular momentum of the Earth after the Moon formed was about five times greater than the current value. In other words, the length of day was about five hours rather than 24 hours. A point on the Earth’s equator moved at a speed of more than 5000 mph rather than the leisurely 1000 mph or so today. The Earth transferred about 80% of its angular momentum to the Moon, not in terms of the rotation of the Moon, but in the Moon’s orbital angular momentum which depends on its mass and its orbital radius.

The same process that caused the Moon to be tidally locked to Earth slowed the Earth’s rotation and caused the Moon to recede to greater distances where its orbital angular momentum increased to be about four times the rotational angular momentum of Earth.

As a result of its Earthly origin, the composition of the Moon is very similar to the Earth, but without the massive iron core that formed deep in the Earth. In fact the Earth and Moon are isotopic twins. Recent computer simulations have indicated that large diameter donut shaped planets called synestias form from high energy, high angular momentum giant impacts.

To quote Stewart and Lock et al 2017: “Radiation causes condensation at the photosphere and torrential rain. Downwelling condensates penetrate deep into the synestia. Condensates rapidly accrete into a lunar seed. The synestia cools and contracts. The Moon grows by accreting condensates within the vapor of the synestia. The Moon separates from the condensing synestia. The synestia contracts inside the Roche limits and eventually falls below the corotation limit.”

The Moon is currently receding at the rate of about 4 cm per year. If that rate were constant for the past 4.5 billion years, then it was 180,000 km (or about 110,000 miles) closer when it formed. That is about half the current distance. This is also far greater than the Roche Limit which determines how close a body can form without being torn apart by tidal forces.

What factors determine the rate? Tidal braking depends on the diameter of a body, the mass and angular momentum of the object influencing it, and the elasticity of the body. A perfectly rigid body does not bulge. Apparently the thin layer of water covering much of the Earth’s surface produces most of the tidal braking because it is able to produce greater bulges than the underlying solid surface.

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