The moon itself cannot be explained.
Some say that it could be a captured
asteroid or stray moon, but if that were the case, the moon's rotation
and spin are wrong. Some say that it was formed at the same time as the
Earth, but if that were true, then it should be made up of
basically the same material that the Earth when it was formed. That does not
leave many options. The one idea that has popped up is that early in the
history of the Earth, a planet with a size larger
than Mars, slammed into the Earth, spewing material into orbit which condensed
to form the moon. The most interactive computer model reported in the Journal Nature, shows that this is a possibility, however this idea does have some faults. Click here to be taken to Natures Website Article.
First
of all, a collison of that magnitude would have shifted the Earth's orbit
tremendously. Second, the material thrown into space would more than likely
formed either a ring such as Saturn and Jupiter, or formed several smaller
moons and not one giant moon. The odds that it would form the one moon
would be extrordinary.
A group of scientist decided to test this theory and formed a computer
program which would simulate the "planetary collison" theory. So far, they have
yet to have it work successfully.
Another question arises about the Moon's surface. There are numerous "rays"
apparantly radiating from its craters. Science has long taught children in school
and the general public that these rays are the mass ejecta from the impact of the
meteors, astroids, and comets that slammed into the Moon's surface. However, there
are a few questions about them based on obsevation.
Some of these rays appear to have no parent crater, so where did these come
from?
Another question coming up by Astronomers is that some of these rays appear to
bend and wind around nearby craters. If the rays were formed by being ejected and then
randomly blasted out onto the surface, the matter would land reguardless of what land
formations were located below them....yet they appear to bend and curve.
As reported in the March 10, 2000 Washington Post-
They tested samples of quartz marbles called spherules which are formed from celestrial
impacts. They can be dated fairly easily by using the decay of potassium into argon gas as
an atomic clock. This is what placed the age at 400 million years. With the somewhat close
relation to the Cambrian Explosion, the theory has been suggested that the increased bombardment
brought diverse stresses to Earth and so brought diverse life forms to adapt to the changes.
Added to this is the Theory of Panspermia: that the seeds of life was brought from space.
This theory is still a hot debate and planetary geologist and moon expert Paul D. Spudis of the
Lunar and Planetary Institute in Houston illustrates this point, "It's fine analytical work, and
the interpretations are questionable, but not totally out to lunch, but I found the connection
to the Cambrian explosion to be quite forced." [Wash. Post March 10, 2000]
In the early development of Earth, the Sun shone with as much as 30%
less brightness than today. That means that there was up to 30% less
energy being emmitted by the Sun. You can experience this if you ever
been in a 1/3 solar eclipse, only imagine that it is always that bright
during the day.
Now the problem lies in the less energy being released because that would
have significantly cooled the Earth down, so much so that our early oceans
should have been frozen to ice. If the oceans were frozen, then no life could
have formed because the beginnings of us (according to science) was in the primordial
soup of the oceans. Only, there are no signs of the oceans being frozen
early on in history.
The Journal: Nature introduces an added problem. Mars at this same time
should have been frozen as well, yet astronomers currently believe that there
was flowing water on the surface of Mars. As we all know, Mars is even further away
from the Sun than we are and yet even it was able to keep warm enough to keep
liquid water around.
Scientists try to explain this by guessing that an early thick layer of gases kept the Earth warm
due to an escalated greenhouse effect. We see this happening today with the gas layer
around Earth keeping it 62 F higher than it would be without such a layer. In this
early past though, the lowered energy would mean that the Earth would have had to keep
itself 90 F higher to keep warm.
However, the large moon of Saturn, called Titan,
has a fairly thick cloud/gas layer
covering it which astronomers have long thought kept the moon at a warmer
temperature than it should be, but recent observations say otherwise. They
discovered that Titan is actually cooler than it should be (16 F less), which seriously
calls into question scientists explanation about early Earth.
Also, such high concentrations of these gases would have been left in the ancient soil.
Currently, there is no evidence of these gases being present in the soil in high concentrations.
Another possible solution is that the Sun originally had more mass than it does now and so
was actually warmer in the early days of the planets. Nature reports that researchers tried to
look at stars similar to the young Sun to see if they carry more mass, so they looked at p01 UMa. a
star in Ursa Major. They found about a 6% more mass than expected. A mass loss of 5 - 10 percent
could be enough to account for the liquid oceans. If the 6% found in the Ursa Major star is indicitive
of our Sun early on, then it could be just enough to keep Earth warm enough however, Mars would still
have been frozen. Plus the 6% is just inside the persentages needed to solve the puzzel. Not to mention
the margin of error which would be present in the data collecting which was not mentioned in the article.
So what kept Earth and Mars so warm with a 1/3 less warm Sun? Scientists do not know.
On to the statements and thoughts of the foremost astrophysicist of our time
and perhaps ever.....Stephen Hawking.
The Moon and the Evolution of Life
An analysis of Moon dirt brought back from Apollo 14 shows that the Moon came
under heavy comet/meteor bombardment around 400 million years ago. This corresponds
loosely with the age called the "Cambrian Explosion" (650 million years ago - 500 million years ago)
when a massive amount of new life forms developed on Earth.
The Faint Young Sun Paradox
...according to the July issue of Astronomy magazine and
the online Journal: Nature, Feburary 24, 2000.
Or
Go back to the Main Page.
