magine the shock of growing up in a loving
family with people you call "Mum" and "Dad" and then, suddenly,
learning that you are actually adopted!
This same sense of shock came as scientists
announced that the Sun, the Moon, our planet and its siblings,
were not born into the familiar band of stars known as the Milky
Way galaxy, but we actually belong to a strange formation with
the unfamiliar name of the Sagittarius Dwarf galaxy!
How can this be?
Using volumes of data from the Two-Micron All
Sky Survey (2MASS), a major project to survey the sky in
infrared light led by the University of Massachusetts, the
astronomers are answering questions that have baffled scientists
for decades and proving that our own Milky Way is consuming one
of its neighbors in a dramatic display of ongoing galactic
cannibalism. The study published in the Astrophysical Journal,
is the first to map the full extent of the Sagittarius galaxy
and show in visually vivid detail how its debris wraps around
and passes through our Milky Way. Sagittarius is 10,000 times
smaller in mass than the Milky Way, so it is getting stretched
out, torn apart and gobbled up by the bigger Milky Way.
A new infra red digital survey of the
entire sky was made in 2003. Teams from the universities of
Virginia and Massachusetts used a supercomputer to sort through
half a billion stars to create a -- NEW STAR MAP showing our
Solar System (yellow circle) to be at the exact nexus crossroads
where two galaxies are actually joining.
"It's clear who's the bully in the
interaction," said Steven Majewski, U.Va. professor of astronomy
and lead author on the paper describing the results.
"If people had infrared-sensitive eyes, the
entrails of Sagittarius would be a prominent fixture sweeping
across our sky," Majewski said. "But at human, visual
wavelengths, they become buried among countless intervening
stars and obscuring dust. The great expanse of the Sagittarius
system has been hidden from view."
Not any more. By using infrared maps, the
astronomers filtered away millions of foreground stars to focus
on a type of star called an M giant. These large,
infrared-bright stars are populous in the Sagittarius galaxy but
uncommon in the outer Milky Way. The 2MASS infrared map of M
giant stars analyzed by Majewski and collaborators is the first
to give a complete view of the Milky Way galaxy's meal of
Sagittarius stars, now wrapping like a spaghetti noodle around
the Milky Way. Prior to this work, astronomers had detected only
a few scattered pieces of the disrupted Sagittarius dwarf. Even
the existence of Sagittarius was unknown until the heart of this
nearest satellite galaxy of the Milky Way was discovered by a
British team of astronomers in 1994.
animation of the "marriage".
The fact that the Milky Way is seen in the
sky at an angle has always puzzled astronomers. If we originated
from the Milky Way, we ought to be oriented to the galaxy's
ecliptic, with the planets aligned around our Sun in much the
same angle as our Sun aligns with the Milky Way. Instead, as
first suggested by researcher
Perkins Erwin, the odd angle suggests that our Sun is
influenced by some other system. Together with data from the
Two-Micron All Sky Survey we now know what it is. We actually
belong to the Sagittarius Dwarf galaxy.
"We sifted several thousand interesting stars
from a catalog of half a billion," said co-author Michael
Skrutskie, U.Va. professor of astronomy and principal
investigator for the 2MASS project. "By tuning our maps of the
sky to the 'right' kind of star, the Sagittarius system jumped
We are from another galaxy in the process
of joining with the Milky Way. The Milky Way is actually not our
parent galaxy. The mystery of why the Milky Way has always been
sideways in the night sky has never been answered -- until now.
"This first full-sky map of Sagittarius shows
its extensive interaction with the Milky Way," Majewski said.
"Both stars and star clusters now in the outer parts of the
Milky Way have been 'stolen' from Sagittarius as the
gravitational forces of the Milky Way nibbled away at its dwarf
companion. This one vivid example shows that the Milky Way grows
by eating its smaller neighbors."
The study's map of M giants depicts 2 billion
years of Sagittarius stripping by the Milky Way, and suggests
that Sagittarius has reached a critical phase in what had been a
slow dance of death.
"After slow, continuous gnawing by the Milky
Way, Sagittarius has been whittled down to the point that it
cannot hold itself together much longer," said 2MASS Science
Team member and study co-author Martin Weinberg of the
University of Massachusetts. "We are seeing Sagittarius at the
very end of its life as an intact system."
Does this mean we are at a unique moment in
the life of our galaxy? Yes and no.
"Whenever possible, astronomers appeal to the
principle that we are not at a special time or place in the
universe," Majewski said. "Because over the 14 billion-year
history of the Milky Way it is unlikely that we would just
happen to catch a brief event like the death of Sagittarius, we
infer that such events must be common in the life of big spiral
galaxies like our own. The Milky Way probably dined on a number
of dwarf galaxy snacks in the past."
On the other hand, Majewski and his
colleagues have been surprised by the Earth's proximity to a
portion of the Sagittarius debris.
"For only a few percent of its 240
million-year orbit around the Milky Way galaxy does our Solar
System pass through the path of Sagittarius debris," Majewski
said. "Remarkably, stars from Sagittarius are now raining down
onto our present position in the Milky Way. Stars from an alien
galaxy are relatively near us. We have to re-think our
assumptions about the Milky Way galaxy to account for this
The new findings will help astronomers
measure the total mass of the Milky Way and Sagittarius
galaxies, and probe the quantity and distribution of the
invisible dark matter in these systems.
"The shape of the Sagittarius debris trail
shows us that the Milky Way's unseen dark matter is in a
spherical distribution, a result that is quite unexpected,"
"The observations provide new insights into
the nature of the mysterious dark matter," said Princeton's
Spergel. "Either our galaxy is unusual or the dark matter has
richer properties than postulated by conventional models."
Implications in Global Warming?
It has been postulated that this is the real
reason for both global warming since higher energy levels of the
Milky Way are almost certain to cause our Sun to burn hotter and
emit higher energies. Indeed, temperatures have been seen to
rise on virtually all the planets in our system. This seems
quite apart from any local phenomenon like greenhouse gases etc.
This grand turning is possibly the root cause
for the discontinuation of the Mayan calendar (the most accurate
on the planet) because the 'read-point' of the Pleiades star
cluster, which many believe the calendar was based upon, can no
longer be a constant as we begin to steer away from the earlier
Other changes happening in our system
The "marriage" of our birth galaxy with our
new adopted Milky Way galaxy is causing energy shifts that are
obvious just about everywhere. Here are some changes being
watched by scientists:
* A growth of dark spots on Pluto.
* Reporting of auroras on Saturn.
* Reporting of Uranus and Neptune polar
shifts (They are magnetically conjugate planets), and the abrupt
large-scale growth of Uranus' magnetosphere intensity.
* A change in light intensity and light spot
dynamics on Neptune.
* The doubling of the magnetic field
intensity on Jupiter (based upon 1992 data), and a series of new
states and processes observed on this planet as an aftermath of
a series of explosions in July 1994 [caused by "Comet" SL-9].
That is, a relaxation of a plasmoid train which excited the
Jovian magnetosphere, thus inducing excessive plasma generation
and it's release in the same manner as Solar coronal holes
inducing an appearance of radiation belt brightening in
decimeter band (13.2 and 36 cm), and the appearance of large
auroral anomalies and a change of the Jupiter - Io system of
Update Note: A stream of ionized
hydrogen, oxygen, nitrogen, etc. is being directed to
Jupiter from the volcanic areas of Io through a one million
amperes flux tube. It is affecting the character of
Jupiter's magnetic process and intensifying it's plasma
genesis.[Z.I.Vselennaya "Earth and Universe" N3, 1997 plo-9
by NASA data]
* A series of Martian atmosphere
transformations increasing its biosphere quality. In
particularly, a cloudy growth in the equator area and an unusual
growth of ozone concentration.
Update Note: Mars Surveyor Satellite
encountered an atmospheric density double that projected by
NASA upon entering a Mars orbit. This greater density bent
one of the solar array arms beyond the full and open stop.
This combination of events has delayed the beginning of the
scheduled photo mission for one year.
* A first stage atmosphere generation on the
Moon, where a growing natrium atmosphere is detected that
reaches 9,000 km in height.
* Significant physical, chemical and optical
changes observed on Venus; an inversion of dark and light spots
detected for the first time, and a sharp decrease of
sulfur-containing gases in its atmosphere.
* A Change in the Quality of Interplanetary
Space Towards an Increase in Its Interplanetary and
Solar-Planetary Transmitting Properties.
When speaking of new energetic and material
qualities of interplanetary space, we must first point out the
increase of the interplanetary domains energetic charge, and
level of material saturation. This change of the typical mean
state of interplanetary space has two main causes:
* The supply/inflow of matter from
interstellar space. (Radiation material, ionized elements, and
* The after effects of Solar Cycle 22
activity, especially as a result of fast coronal mass ejection's
[CME's] of magnetized solar plasmas.
What does it all mean?
We of the overarching Sagittarius Dwarf
Elliptical Galaxy have finally come down next to, and even with
the massively powerful spiral armed equatorial plane of the
Milky Way Galaxy.
In our movement through space, our Earth has
now fully begun to respond to the more powerful galactic
energies and electro-gravitational bias of the massive Milky
Way. We have reached the higher energy equatorial disc region of
the massive spiral arm. We have now been "adopted" by a new
system, a stronger and more powerful system, and we can expect
changes on almost every level of energy.
Whatever these changes are, they are all part
of the natural birth, death, rebirth and transformation of the
cosmos. As our knowledge of the universe grows, we cannot but
understand how much we do not understand. Such is life.
[For further reading we suggest you go to
Perkins Erwin's blog;
www.astro.virginia.edu which was the basis of this summary.]
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