The halo, which is a spherical cloud surrounding the disk, contains
about 2% as many stars as the
It contains old and cool
it has little gas and dust.
The Milky Way is a collection
of hundreds of billions of stars traveling through the Universe
together like a giant cloud
floating across the sky.
Our own star is the Sun. It is just one among the 750 billion to one
trillion stars that astronomers say compose the
Milky Way galaxy.
Our Solar System's Location in the Milky Way Galaxy
The sun is about
26,000 light-years from the center of the Milky Way
Galaxy, which is about 80,000 to 120,000 light-years
across (and less than 7,000 light-years thick). We
are located on on one of its spiral arms, out
towards the edge. It takes the sun (and our solar
system) roughly 200-250 million years to orbit once
around the Milky Way. In this orbit, we (and the
rest of the Solar System) are traveling at a
velocity of about 155 miles/sec (250 km/sec).
To reach the center of
the Milky Way Galaxy starting from the Earth, aim
toward the constellation Sagittarius.
Since we're inside the
Milky Way Galaxy and we've never sent a spacecraft
outside our Galaxy, we have no photographs of the
Milky Way Galaxy. Radio telescope data does,
however, let us know a lot about it.
The Milky Way galaxy is
about 100,000 light years in diameter
Size of the Milky Way
The disk of the Milky Way galaxy is about 100,000
light years in diameter (one light year is about 9.5
x 1015 meters), but only about 1000 light years
Our Galaxy contains about 200 billion stars. Most of
the stars are located in the disk of our galaxy,
which is the site of most of the star formation
because it contains lots
of gas and dust.
Astronomers believe they
see an extraordinarily powerful object — a black
hole — at the center of the Milky Way.
coordinates as seen from outside the celestial sphere. Ecliptic
longitude (red) is measured along the ecliptic from the vernal
equinox. Ecliptic latitude (yellow) is measured perpendicular to the
ecliptic. A full globe is shown here, although high-latitude
coordinates are seldom seen except for certain comets
Where is the ecliptic in relation to
the Milky Way?
The equator (or plane) of the Milky Way is tilted by about 60ş to
the plane of the ecliptic, the plane of the Earth’s orbit around the
The plane of the Earth’s orbit around the sun is called the
ecliptic. The plane of the ecliptic projected onto the stellar
sphere marks the sun’s annual path in front of the background stars.
Although the sun appears to move eastward through the stars at about
one degree per day, this apparent motion is really a reflection of
the Earth orbiting the sun.
What is the ecliptic?
The ecliptic is an important reference and is often highlighted on
sky charts. Because the planets of the solar system circle the sun
on nearly the same plane that the Earth circles the sun, the planets
are always found on or close to the ecliptic. The plane of the
moon’s orbit around Earth is only somewhat askew to the plane of the
ecliptic, so the moon is always found on or near the ecliptic, too.
new moon aligns with the ecliptic,
we have a total eclipse of the sun. When the full moon aligns with
the ecliptic, we have a total lunar eclipse.
Where is the ecliptic in
relation to the Milky Way?
The equator (or plane) of the Milky Way galaxy is tilted by about
60o to the plane of the ecliptic. Quite
by coincidence, the ecliptic intersects
the galactic equator on or near the June and December solstices. But
does that mean the Earth literally crosses the plane of the Milky
Way’s disk at these times? The answer is no!
Ecliptic Coordinate System
The ecliptic system was the principal coordinate system for ancient
astronomy and is still useful for computing the apparent motions of
the Sun, Moon, and planets.
The ecliptic system describes the planets' orbital movement around
the sun, and centers on the barycenter of the solar system (i.e.
very close to the sun). The fundamental plane is the plane of the
Earth's orbit, called the ecliptic plane. The system is primarily
used for computing the positions of
planets and other solar system bodies,
as well as defining their orbital elements.
The ecliptic coordinate system is a
celestial coordinate system commonly used for representing the
positions and orbits of Solar System objects. Because most planets
(except Mercury), and many small solar system bodies have orbits
with small inclinations to the ecliptic, it is convenient to use it
as the fundamental plane. The system's origin can be either the
center of the Sun or the center of the Earth, its primary direction
is towards the vernal equinox, and it has a right-handed convention.
It may be implemented in spherical or rectangular coordinates
The celestial equator and the ecliptic
are slowly moving due to perturbing forces on the Earth, therefore
the orientation of the primary direction, their intersection at the
Northern Hemisphere vernal equinox, is
not quite fixed. A slow motion of
Earth's axis, precession, causes a slow, continuous turning of the
coordinate system westward about the poles of the ecliptic,
completing one circuit in about 26,000 years. Superimposed on this
is a smaller motion of the ecliptic, and a small oscillation of the
Earth's axis, nutation. ...
NGC 4414, a typical spiral
galaxy in the constellation Coma Berenices, is about 55,000
light-years in diameter and approximately 60 million light-years
away from Earth.
A galaxy is a massive, gravitationally bound system that consists of
stars and stellar remnants, an interstellar medium of gas and dust,
and an important but poorly understood component tentatively dubbed
dark matter. The word galaxy is derived from the Greek galaxias (γαλαξίας),
literally "milky", a reference to the Milky Way galaxy. Examples of
galaxies range from dwarfs with as few as ten million (107) stars to
giants with a hundred trillion (1014) stars,each orbiting their
galaxy's own center of mass.
Galaxies contain varying amounts of star systems, star clusters and
types of interstellar clouds. In between these objects is a sparse
interstellar medium of gas, dust, and cosmic rays. Dark matter
appears to account for around 90% of the mass of most galaxies.
Observational data suggests that supermassive black holes may exist
at the center of many, if not all, galaxies. They are thought to be
the primary driver of active galactic nuclei found at the core of
some galaxies. The Milky Way galaxy appears to harbor at least one
Galaxies have been historically categorized according to their
apparent shape; usually referred to as their visual morphology. A
common form is the elliptical galaxy, which has an ellipse-shaped
light profile. Spiral galaxies are disk-shaped with dusty, curving
arms. Those with irregular or unusual shapes are known as irregular
galaxies and typically originate from disruption by the
gravitational pull of neighboring galaxies. Such interactions
between nearby galaxies, which may ultimately result in a merging,
sometimes induce significantly increased incidents of star formation
leading starburst galaxies. Smaller galaxies lacking a coherent
structure are referred to as irregular galaxies.
There are probably more than 170 billion (1.7 × 1011) galaxies in
the observable universe. Most are 1,000 to 100,000 parsecs in
diameter and usually separated by distances on the order of millions
of parsecs (or megaparsecs). Intergalactic space (the space between
galaxies) is filled with a tenuous gas of an average density less
than one atom per cubic meter. The majority of galaxies are
organized into a hierarchy of associations known as groups and
clusters, which, in turn usually form larger superclusters. At the
largest scale, these associations are generally arranged into sheets
and filaments, which are surrounded by immense voids.
10 Most Fascinating Galaxies
of our Universe – (Text & Photos)
Welcome to the Hubble
Universe: Galaxies & Nebula: A Cosmic Journey Through the Universe (
14 mins) !!!!!!!
- Nebula & Galaxies: A Cosmic Journey Through the Universe. A
documentary film by Rhawn Joseph, Ph.D.
Milky Way Ring
Inside the Milky Way - The Definitive
Guide to the Milky Way Galaxy
( 1 H: 31 mins)
Inside of the Milky Way - By Natgeo
The secrets of our home galaxy revealed with all new state oif the
art computer recreations from JPL and NASA.
National Geographic - Inside the
Milky Way (2010) Bluray 1080p
( 1Hr: 36 mins) - ( Not
From Stars being born, and super-massive black holes to Carl
or how to center yourself in the universe the CGI way
Since time immemorial, humanity has been transfixed by the Celeste,
trying to order the heavens, read the sky, and understand our place
in the universe — a place nested within the Milky Way galaxy, which
contains our Solar System. But what exactly is the Milky Way, how
did it come to be, and where is it going? That’s exactly what the
fascinating National Geographic documentary Inside the Milky Way
explores, using bleeding-edge technology to construct a 3D CGI model
of our galaxy and simulate everything from the formation of
super-massive black holes to how stars are born and die.
+++ many many phtos…
Infrared picture of the center of
the Milky Way galaxy
In this NASA photo of our Milky
Way galaxy, the dark patches in front of the brighter background are
opaque clouds of clumped dust grains known as dark nebulae.
Our own star is the Sun. It is
just one among the 750 billion to one trillion stars that
astronomers say compose the Milky Way galaxy.
Our Milky Way is about 100,000 light years in diameter.
Radioastronomy shows it to be a spiral shaped galaxy.
This enormous section of the Milky Way Galaxy
is a mosaic of images from NASA’s Wide-field Infrared Survey
Explorer, or WISE. - The Infrared Processing and Analysis Center is
a NASA data center managed by the Jet Propulsion Laboratory.
COBE Dipole: Speeding
Through the Universe
The Eternal Moving Universe!!!
Our Earth is not at rest. The Earth
moves around the Sun. The Sun orbits the center of the Milky Way
Galaxy. The Milky Way Galaxy orbits in the Local Group. The Local
Group falls toward the Virgo Cluster of Galaxies. But these speeds
are less than the speed that all of these objects together move
relative to the microwave background. In the above all-sky map,
radiation in the Earth's direction of motion appears "blueshifted"
and hence hotter, while radiation on the opposite side of the sky is
"redshifted" and colder.
The map indicates that the Local
Group moves at about 600 kilometers per second relative to this
primordial radiation. This high speed was initially unexpected and
its magnitude is still unexplained. Why are we moving so fast? What
is out there?
What is the estimated rate of speed that our Sun is
moving in relation to the center of the milky Way galaxy?
And is the whole Milky Way galaxy moving also?
The Sun orbits the center of the Milky Way at about 250 km/second
and it takes about 220 million years to complete an orbit.
The Milky Way is part of a group of galaxies known as the Local
Group. All of these are moving relative to each other due to
their gravitational interaction with speeds of around 100 km/s or
less. Calculating the velocities of the galaxies in the Local Group
is difficult because there are probably members that have not yet
been discovered because they are too dim or are obscured by the
plane of the Milky Way. The radial velocities relative to the Milky
Way are found by measuring Doppler shifts in the spectra of stars in
the galaxies. You will find more information at
The Local Group is also moving at about 600 km/second relative to
the cosmic microwave background.
Bursts of Gamma Rays from Center of Galaxy
NASA – Center of the Milky Way Galaxy - A Galactic
February 21, 2002: In the most suspenseful detective
stories, the mystery deepens even as the plot reveals more clues. So
has it been in real life for astrophysicists investigating the
center of our Milky Way galaxy. They hoped that NASA's Chandra X-ray
Observatory would reveal a long-suspected black hole there -- and
indeed it did. But Chandra's revelations have raised new questions
that baffle scientists perhaps even more than before.
A Galactic Center Mystery – Fermi Lab Map ( 2 mins)
- Galactic “Fermi Bubbles” - The Milky Way's
Mysterious Gamma Ray Lobes
Fermi telescope discovers new Giant
Structure in our Galaxy (w/
From end to end, the newly discovered gamma-ray
bubbles extend 50,000 light-years, or roughly half of the Milky
Way's diameter, as shown in this illustration. Hints of the bubbles'
edges were first observed in X-rays (blue) by ROSAT, a Germany-led
mission operating in the 1990s. The gamma rays mapped by Fermi
(magenta) extend much farther from the galaxy's plane.
Mysterious Gamma-Ray Bubbles in the Milky Way Part
1 ( 14 mins)
The Fermi Gamma-ray Space Telescope has produced a
string of stunning discoveries in its first two years, opening our
eyes to the high-energy Universe as never before. Video presentation
by Douglas Finkbeiner, Harvard
Mysterious Gamma-Ray Bubbles in the Milky Way Part 2 ( 14 mins)
Spitzer + Herschel: The Galactic
Center Revisited [720p] – Frequency
The Galactic Center Revisited
(Gallery Explorer) ( 3 mins)
Hiding behind the constellations Sagittarius and Scorpius is the
center of our own Milky Way galaxy,
over 25,000 light years away. This
patch of sky is mostly dark in visible light, shrouded by dust
clouds that lie between us and the Galactic center. But the infrared
vision of NASA’s Spitzer Space Telescope sees through the dust
showing us this strange and tumultuous region.
A gas cloud with several times
of the Earth is accelerating
towards a Supermassive black hole at the centre
of the Milky Way.
A black hole is a region of spacetime where gravity
prevents anything, including light, from escaping. The theory of
general relativity predicts that a sufficiently compact mass will
deform spacetime to form a black hole. Around a black hole there is
a mathematically defined surface called an event horizon that marks
the point of no return. It is called "black" because it absorbs all
the light that hits the horizon, reflecting nothing, just like a
perfect black body in thermodynamics. Quantum mechanics predicts
that black holes emit radiation like a black body with a finite
temperature. This temperature is inversely proportional to the mass
of the black hole, making it difficult to observe this radiation for
black holes of stellar mass or greater.
Objects whose gravity field is too strong for light to escape were
first considered in the
18th century by John Michell and Pierre-Simon Laplace. The first
modern solution of general relativity that would characterize a
black hole was found by Karl Schwarzschild in 1916, although its
interpretation as a region of space from which nothing can escape
was not fully appreciated for another four decades. Long considered
a mathematical curiosity, it was during the 1960s that theoretical
work showed black holes were a generic prediction of general
relativity. The discovery of neutron stars sparked interest in
gravitationally collapsed compact objects as a possible
Black holes of stellar mass are expected to form when very massive
stars collapse at the end of their life cycle. After a black hole
has formed it can continue to grow by absorbing mass from its
surroundings. By absorbing other stars and merging with other black
holes, supermassive black holes of millions of solar masses may
form. There is general consensus that supermassive black holes exist
in the centers of most galaxies.
Despite its invisible interior, the presence of a black hole can be
inferred through its interaction with other matter and with light
and other electromagnetic radiation. Matter falling onto a black
hole can form an accretion disk heated by friction, forming some of
the brightest objects in the universe. If there are other stars
orbiting a black hole, their orbit can be used to determine its mass
and location. These data can be used to exclude possible
alternatives (such as neutron stars). In this way, astronomers have
identified numerous stellar black hole candidates in binary systems,
and established that the core of our Milky Way galaxy contains a
supermassive black hole of about 4.3 million solar masses.
Supermassive black hole
supermassive black hole (SMBH) is the largest type of black hole, on
the order of hundreds of thousands to billions of solar masses.
Most—and possibly all—galaxies are inferred to contain a
supermassive black hole at their centers. In the case of the Milky
Way, the SMBH is believed to correspond with the location of
Supermassive black holes have properties which distinguish them from
lower-mass classifications. First, the average density of a
supermassive black hole (defined as the mass of the black hole
divided by the volume within its Schwarzschild radius) can be less
than the density of water in the case of some supermassive black
holes. This is because the Schwarzschild radius is directly
proportional to mass, while density is inversely proportional to the
volume. Since the volume of a spherical object (such as the event
horizon of a non-rotating black hole) is directly proportional to
the cube of the radius, the density of a black hole is inversely
proportional to the square of the mass, and thus higher mass black
holes have lower average density. Also, the tidal forces in the
vicinity of the event horizon are significantly weaker. Since the
central singularity is so far away from the horizon, a hypothetical
astronaut traveling towards the black hole center would not
experience significant tidal force until very deep into the black
Way's Giant Black Hole Spits Out Its Food
colossal black hole at the heart of the Milky Way galaxy is a messy
eater. Of all the gas that falls toward the black hole, 99 percent
gets spewed back out into space, new observations show, making the
black hole akin to a toddler whose food ends up mostly on the floor,
rather than his mouth.
The Milky Way's supermassive black hole, called Sagittarius A*
(pronounced "Sagittarius A-star"), contains the mass of 4 million
suns. Yet it's not getting much larger, according to the new
findings, which help explain why the object is surprisingly dim.
Although black holes themselves can't be seen, their immediate
vicinities usually emit strong radiation from the material falling
into them. Not so for Sgr A*, though, which has prompted a rash of
competing theories trying to explain its surprising lack of light.
[Strangest Black Holes In the Universe]
"There's been a debate for the last 20 years or so about what
actually is happening to the matter around the black hole," said
research leader Q. Daniel Wang of the University of Massachusetts,
Amherst. "Whether the black hole is accreting the matter, or
actually whether the matter can be ejected. This is the first direct
evidence for outflow in the accretion process." ...
Michio Kaku: Which Came First, the Galaxy or the
Dr. Michio Kaku is an American theoretical physicist,
the Henry Semat Professor of Theoretical Physics in the City College
of New York of City University of New York, a futurist, and a
"communicator" and "popularizer" of science. He has written several
books about physics and related topics; he has made frequent
appearances on radio, television, and film; and he writes extensive
online blogs and articles. He has written two New York Times best
sellers, Physics of the Impossible (2008) and Physics of the Future
(2011). He has hosted several TV specials for BBC TV, the Discovery
Channel, and the Science Channel.
At the heart of every galaxy like our own Milky Way
lies a Supermassive Black Hole, but scientists are unsure
which develops first.
Question: Are the supermassive black holes at the center of galaxies
involved in the formation of those galaxies? (Submitted by Andy
Well Andy, you ask a very touchy subject. What came
first, the chicken or the egg, the galaxy or the black hole?
We still don't know. First of all, if you want to see
the black hole at the center of our own Milky Way galaxy go out
tonight and look in the direction of Sagittarius. That is
where we have a super-massive black hole at the very center or our
own backyard, the Milky Way galaxy. It weighs two to three million
times the mass of our sun.
Now the latest theory about which came first is the following:
First, we think that out of the big bang came dark matter, invisible
matter. If I held dark matter in my hand it would literally ooze its
way right through my fingers, go right to the center of the earth,
go to China and then go back and forth between China and my hand.
That is dark matter. We think that dark matter begins to clump first
because of gravity, then matter was attracted to the clumpiness
creating the super-massive black hole and then later the galaxy
itself began to form. We have computer simulations about this, but
still the relationship is not yet clear.
Now remember, stars—we know almost everything about stellar
evolution. That is because the Pentagon has given us physicists
billions of dollars to model hydrogen bombs and a star is nothing
but a hydrogen bomb. However, a galaxy consists of over a hundred
billion stars, so it's much more difficult to tell which came first,
the black hole or the galaxy itself.
Black Holes Discovered 20 Billion times
the Sun's Mass -Michio Kaku ( 30 mins)
Theoretical physicist Dr. Michio Kaku commented on the discovery of
two gigantic black holes, as well as other science and space news.
The black holes have a staggering mass that is 20 billion times that
of our sun, and are 10 times the size of our solar system.
Intriguingly, he suggested that the billions of stars that fell into
such a black hole could be shot out the other end through a "white
hole" in a process like the Big Bang.
As the Solar System, orbits the
Milky Way galaxy follows a path
that travels above and below the
equator of the galactic plane.
Celestial Coordinate System
In astronomy, a celestial coordinate system is a coordinate system
for mapping positions on the celestial sphere. There are different
celestial coordinate systems each using a system of spherical
coordinates projected on the celestial sphere, in analogy to the
geographic coordinate system used on the surface of the Earth.
The coordinate systems differ only in their choice of the
fundamental plane, which divides the sky into two equal hemispheres
along a great circle. For example, the fundamental plane of the
geographic system is the Earth's equator. Each coordinate system is
named for its choice of fundamental plane.
Orientation of Astronomical
Orientation of the galactic, ecliptic and equatorial coordinate
systems, projected on the celestial sphere, showing the galactic
equator (black), north galactic pole (NGP), the ecliptic (orange),
north ecliptic pole (NEP), the celestial equator (blue) and north
celestial pole (NCP). Sun and earth not shown to scale but to
indicate sun's orbital direction around the galactic center and
earth's orbital direction around the sun.
Earth's pole lying immersed in
Earth Orbit Orientation Respecting
the Galactic Equator
With respect to the Milky Way star band, one may note that the
orbital path of the earth about the sun, from a visual perspective,
appears to ‘cross over the equator of the galaxy’ at about 60
degrees. In the diagram pictured (below), the observer is positioned
at the centre of the sun looking towards the centre of the Milky
Way. The ecliptic line as marked is of the path taken by the earth
in the course of a single year in orbit of the sun. The galactic
equator, as also marked, is a line of ‘best fit’ that places half of
the stars in one hemisphere and half in the other, as viewed from
the centre of the present solar system. It is a line determined
purely by statistical methods. The marked point (<) of the Milky Way
is the exact centre of the galaxy:
Our Sun transitioning over
Sun on Galactic Plane &
Earth's pole lying immersed in the
Just like the Earth orbits the Sun, the Sun itself is
part of the Milky Way galaxy. It takes about 220 million years for
the Sun to complete a single journey around the Milky Way. But the
Sun also bobs up and down as it travels in orbit around the center
of the galaxy. The oscillation takes a total of 64 million years to
complete. And there’s a moment when the Sun passes directly through
the galactic disk and there’s a perfect galactic alignment between
the Sun and the center of the galaxy.
When’s that galactic alignment going to happen? It’s
almost impossible to know exactly. The Milky Way is 100,000
light-years across, but only 1,000 light-years thick. So during the
course of that 64 million year cycle, the Sun rises above the
galactic plane 500 light-years, passes down through the galactic
plane, until it’s 500 light-years below and then comes back up
There has to be a moment when everything’s in perfect
alignment, but the timescales are so long that astronomers couldn’t
calculate it. Of course, this alignment with the center of the
galaxy doesn’t have an effect on the Earth or the Solar System, it’s
just like crossing an imaginary line in space, like traveling from
Canada to the United States in your car.
There’s another type of galactic alignment. This is
where the Earth, Sun and the center of the galaxy are in perfect
alignment from our perspective. This actually happens every year
during the winter solstice, on December 21st. Because of a wobble in
the Earth’s orbit, the positions of the constellations slowly shift
from year to year. The most perfect galactic alignment between the
Earth, Sun and the center of the Milky Way happened back in 1998,
but now we’re slowly shifting away from that alignment. In the
coming decades, the perfect alignment will shift to another day.
Earth Movement through the Galactic Plane
Earth & Sun Movement through Galactic Plane
Movement of Stars - and Planet Earth -
in the Milky Way Galaxy
Stars in the Milky Way galaxy (including the Sun)
move at different speeds around the galactic center and in different
displacements above or below the galactic plane :
· Old stars (such as the Sun) have high velocities and can move out
of the galactic plane.
· Young stars have low velocities and small displacements from the
· Giant molecular clouds (birthplaces of stars) also have low
velocities and stay relatively close to the galactic plane.
Motion of the Solar System with the Planets trough
the Milky Way Galaxy
Overall, the entire galaxy rotates clockwise (as viewed from
“galactic north”) at a roughly constant velocity of 160-220 km/sec:
· Relative to this velocity, the Sun
and its planetary system move around the galactic center at a
velocity of 17-22 km/sec, in a roughly elliptical orbit, with a
period of about 240 million years.
· The Sun and its planetary system
also move perpendicular to the galactic plane (up and down in a
harmonic fashion) with a period of 57-74 million years.
The Solar system, therefore, has two
main components of motion within the Milky Way galaxy:
1. A round-and-round motion around
the galactic center, and
2. an up-and-down motion across the galactic plane,
both taking place simultaneously.
An in-and-out motion (from the galactic center) due to its
elliptical orbit also gives the Solar system a third distinctive
component of motion in the galaxy. Another way to say all this is
that the Sun and its planets spiral through the Milky Way like a
Even Bigger Cosmic Motions
Not only does the Solar system move around the Milky Way galaxy, but
also the Milky Way galaxy moves around the center of a super-cluster
of 2,500 neighboring galaxies.
And this super-cluster of 2,500 galaxies (including the Milky Way)
is hurtling through space towards a point now known as “The Great
The Milky Way contains
100 billion Planets
The Milky Way contains 100 billion
New Nasa study reveals a Galaxy full of Planets
A detailed statistical study by Nasa scientists has revealed that
our Milky Way galaxy contains a minimum of 100 billion planets.
The discovery was made by a team of astronomers and is based on the
detection of three planets outside our solar system, called
The survey results show that our galaxy contains, on average, a
minimum of one planet for every star. This means that it's likely
there is a minimum of
within just 50 light-years of Earth.
Stephen Kane of NASA's Exoplanet Science Institute at the California
Institute of Technology and a co-author of the said: "Results from
the three main techniques of planet detection, including
Microlensing, are rapidly converging to a common result: Not only
are planets common in the galaxy, but there are more small planets
than large ones."
The technique of Microlensing means using one star as a magnifying
lens to brighten the light from a background star. The background
star's light will brighten further if there are planets orbiting the
foreground star, these planets would otherwise have been too faint
The study is based on observations taken over six years and it also
concludes that there are far more Earth-sized planets than the huge
Jupiter-sized bodies. A rough estimate points to around 10 billion
Mr Kane added:
"This is encouraging news for investigations into habitable (or
inhabited ) planets."
Scientists Puzzled by Region Outside Solar System
(AP Feb 2012) — A glimpse beyond our solar system
reveals the neighborhood just outside the sun's influence is
different and stranger than expected, scientists reported Tuesday.
One oddity is the amount of oxygen. There are more oxygen atoms
floating freely in the solar system than in the immediate
interstellar space, or the vast region between stars. Scientists
were unsure why, but they said it's possible some of the
life-supporting element could be hidden in dust or ice.
"We discovered this big puzzle — that the matter just outside of our
solar system doesn't look like the material inside," said David
McComas of the Southwest Research Institute in San Antonio, Texas.
The discovery came from NASA's Interstellar Boundary Explorer
spacecraft, which launched in 2008 to study the chaotic boundary
where the solar wind from the sun clashes with cold gases from
Circling 200,000 miles above Earth, the Ibex spacecraft spots
particles streaming into the solar system. A protective bubble
surrounding around the sun and planets prevents dangerous cosmic
radiation from seeping through, but neutral particles can pass
freely, allowing Ibex to map their distribution. The presence of
less oxygen outside the solar system should not have any bearing on
the search for Earth-like planets, scientists involved in the Exo-planet
There's plenty of oxygen in all the stars in the galaxy and in the
material out of which stars and planets form, Geoff Marcy of
University of California, Berkeley said in an email. While Ibex
probes the edge of the solar system from Earth orbit, NASA's
long-running, nuclear-powered twin Voyager spacecraft are at the
fringes. Launched in 1977, the spacecraft have been exploring the
solar system boundary since 2004.
Scientists have said it'll be months or years before Voyager 1 exits
the solar system and becomes the first manmade probe to cross into
Scientists puzzled by region outside solar
system ( 2 mins)
The exciting discoveries of Exo-Planets
Cosmic Journeys: The Search For
Earth-Like Planets ( 22 mins)
The search for Earth-like planets is reaching a fever-pitch. Does
the evidence so far help shed light on the ancient question: Is the
galaxy filled with life, or is Earth just a beautiful, lonely
aberration? If things dont work out on this planet Or if our itch to
explore becomes unbearable at some point in the future Astronomers
have recently found out what kind of galactic real estate might be
available to us. Well have to develop advanced transport to land
there, 20 light years away. The question right now: is it worth the
NASA's Kepler Mission
Discovery Summary, Dec. 2011 ( 3mins)
Exo-Plantes Scientists from NASA's Kepler mission have been busy
recently. The team has announced the discovery of Kepler-22b, its
first confirmed planet in the habitable zone of its solar system,
600 light years away. They have also been combing through light data
captured by the telescope and have released the latest number of
planetary candidates team members have identified. Staff and
scientists also got together (along with a special guest!) recently
to celebrate 1,000 days of science operations by the mission.
New Estimate for Alien Earths: 2 Billion in Our Galaxy Alone
Hubble team detects a Watery super-Earth enshrouded by Thick
Extrasolar Planets discovered
around the sStar Kepler 11
An artist's illustration of the
extrasolar planets discovered around the star Kepler 11
by NASA's Kepler Space Telescope.
Roughly one out of every 37 to one out of every 70 sunlike stars in
the sky might harbor an alien Earth, a new study reveals.
These findings hint that billions of Earthlike planets might exist
in our galaxy alone, researchers added.
These new calculations are based in data from the Kepler space
telescope, which in February wowed the globe by revealing more than
1,200 possible alien worlds, including 68 potentially Earth-size
planets. The spacecraft does so by looking for the dimming that
occurs when a world transits or moves in front of a star.
Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif.,
focused on roughly Earth-size planets within the habitable zones of
their stars — that is, orbits where liquid water can exist on the
surfaces of those worlds…
Massive Star ever found - R136a1
( Shown on Darker Blue)
Is about 265 times the mass of
Largest Star ever discovered,
compared to our Sun ( 1 mins)
Discovery Channel shows Earth, compared to the Sun, and then to a
few other massive stars in our own Milky Way
A newfound star has shattered the record
as the most massive stellar monster ever seen, astronomers announced
Weighing in at a whopping 265 times the mass of our sun, the
behemoth may have actually slimmed down since birth, when it likely
tipped the scales at 320 times the sun's mass.
The discovery could rewrite the laws of stellar physics, since it's
long been thought that stars beyond a certain mass would be too
unstable to survive.
"We are really taken aback, because up until now the astronomical
community at large has assumed that the upper size limit for stars
would be around 150" times the mass of the sun, said study co-author
Richard Parker, an astronomer at the University of Sheffield in the
"This giant could really revolutionize the way we think about how
stars form and die in clusters and galaxies."
The location of the Pleiades
on the Constellation Taurus.
A Spitzer image of the Pleiades
in infrared, showing the associated dust
The Pleiades Star System
In astronomy, the Pleiades, or Seven Sisters (Messier object 45 or
M45), is an open star cluster containing middle-aged hot B-type
stars located in the constellation of Taurus. It is among the
nearest star clusters to Earth and is the cluster most obvious to
the naked eye in the night sky. Pleiades has several meanings in
different cultures and traditions.
The cluster is dominated by hot blue and extremely luminous stars
that have formed within the last 100 million years. Dust that forms
a faint reflection nebulosity around the brightest stars was thought
at first to be left over from the formation of the cluster (hence
the alternate name Maia Nebula after the star Maia), but is now
known to be an unrelated dust cloud in the interstellar medium that
the stars are currently passing through. Astronomers estimate that
the cluster will survive for about another 250 million years, after
which it will disperse due to gravitational interactions with its