This particular rocket isn't destined for the space shuttle.The shuttle is being retired in 2010 after the completion of the International Space Station. It is an expensive ship to fly at almost five hundred million dollars a flight. It is expensive in lives too, having claimed fourteen astronauts. Space exploration is a dangerous business but flights to an orbital space station must be safe, routine and cheap.

The Russians have been using the Soyuz three man capsule since the sixties, upgrading and improving it, and it has proven very safe and costs one twentieth as much to fly as a shuttle. The debate about what to replace the shuttle with focused quickly on the tried-and true space capsule. The most advanced capsule vehicle last flown by the United States was the three man Apollo design.

It was Buzz Aldrin, second man on the moon, who first suggested that the tasks combined in the space shuttle program of shipping crew and cargo should be separated. The new ship's primary mission was to deliver six people to the space station and remain there as a life boat for up to six months.

The new ship, originally called the Crew Exploration Module, is now called Orion. Outwardly it looks like a large version of Apollo's command and service module used so brilliantly on lunar missions. But there are differences.

Orion will carry six astronauts, not three. The pilot and copilot operate controls based on a 767 cockpit, entirely digital and with powerful compting abilities; Apollo employed an analog computer with less calculating power than a digital watch or cellphone. The pilots recline on raised platforms on either side of the capsule. In the back of the vehicle is something lacking in Apollo; a toilet. The other four astronauts are strapped in between the pilots. Behind the command capsule is a service module with solar panels to provide power on extended trips and enough propulsion to allow for lunar missions.

The Orion is launched on top of a single space shuttle solid rocket booster. It carries a launch escape tower that can wisk the crew to safety if the boosters have any problems. A second stage atop that carries the ship to orbit. It uses engines developed for Apollo so no new engineering is required. While the first stage parachutes down to be reused. Orion itself can be used for at least ten missions.

When the mission is over, Orion parachutes down but with a difference. To save money in sea recovery operations, the ship normally lands on dry land like the Russian Soyuz, using airbags to soften the landing. That means the crew can land in Edwards Air Force base or Florida or many other places.

Yet the other mission of Orion is to return Americans to the moon by 2020. To accomplish this a massive unmanned cargo booster called Ares Five will be developed. It too is derived from space shuttle components. Using five expendable engines, two boosters, and a modified shuttle external tank this huge vehicle is larger and more powerful than the Saturn Five. It will place a booster into orbit carrying a four man lunar lander. Orion docks with this in orbit and it fires its engines, going on to the moon where it can remain for two weeks, carrying manned rovers and equipment. Unmanned versions can bring down compoents for a lunar base.

The discovery of what appears to be a lake of ice in the shadows of the moon's south pole means that it will be possible to refuel the lunar landers on the surface, allowing them to fly all over the moon to explore or to land large amounts of cargo from Earth without the need to carry fuel down for the return journey. A moonbase can create its own air and water

The actual design of the new lunar lander is not set. It will have a separate ascent and descent stage and the lower stage will probably resemble the Apollo vehicle closely but with some differences. The LM had only a single ascent or descent engine. This gave no margin of safety in the case of any failure. With the use of a three engine cluster it is possible to lose one engine and still fly. The descent module should be refuelable on site burning hydrogen and oxygen or perhaps oxygen and methane freed from lunar rock or ice. The ascent module from the original LM was made of aluminum so thin that yo could have perceided with a pen; this was to save weight. The new vehicle may employ an inflatable habitat which will expand after landing to a comfortable size, unfolding like a tent trailer. Unmanned versions of the lander will ship cargo the the moon's surface/ These would include such payloads as rovers to explore the surface and collect ore and ice, either manned or unmanned.

It has been argued that the Orion approach to lunar exploration is too low tech, that perhaps a ew approach to deep space exploration is what is required like the ill-fated X-33 spaceplane, a single stage to orbit vehicle, that was canceled because it was at the time technically infeasible. To reduce the cost of the new program Orion uses tried-and-true technology that is largely off the shelf or derivative, building on NASA's strength .

Finally the Ares vehicles can be used to take men to Mars, using the experience gained from moon missions. They can be used to expand the space station or build new ones. Meanwhile the Russians are retiring the Soyuz in favor of a six man space plane called the Clipper which will also travel to the ISS and perhaps join the USA in its exploration of the moon and Mars. The Clipper might be flown as easily on an Arres One rocket as a substitute for Orion, which would greatly increase the versatility of the program. Because of the simplicity of Ares One such a ship could be readied for flight very quickly for use as a rescue craft.

Triton

Triton is Neptune's largest moon. This picture was taken in 1989 by Voyager 2, the only Spacecraft to ever pass by it. Voyager, at that time, also found evidence for ice volcanoes on the eerie surface of windy, cold Neptune.

Earth Rise

This is a remarkably rare picture, taken from deep space. It catches the earth rising above the Moon's limb.

Europa

Beautiful Europa is one of the smallest of Jupiter's moon. Europa is about the size of our own Moon, and also keeps one face pointed towards her home planet, Jupiter. Hers is the smoothest surface in the Solar system, and is covered with ice crystals.

The Blue Snowball

This blue snowball is a planetary nebula. This simply means that it's a ring of dust and gas which were blown off after a large star imploded (or exploded). Some colours here were added to highlight the steady emission of ions.

Mercury

Mercury stands closest to the Sun than any other planet in our Solar System. As a result of this, it is difficult for observers from earth to photograph this particular planet. Here is a rare photo taken by Mariner 10 (after 3 "drive-bys" in 1974 and 1975).

A Star Is Born

An impressive picture of a cute, young star.

Crab Nebula

A fantastic shot of a star which exploded just under a thousand years ago.

Io's Surface

Io is one of my favourite moons of Jupiter. I've saved pictures of her before, but here it is clear that her surface is filled with volcanic activity. Io is the Solar System's most volcanically active body. Her surface is ever changing because of the constant lava flows.

*All of the images shown above have been taken from the Nasa Astronomy Picture of the Day Archive.

Other Works in This Series of Space Pictures

• 10 Most Awsome Pictures Taken From Outer Space
• Welcome to Makind s New Home in Space
• Pictures of Earth and Outer Space at Night
• A Handpicked Collection of Ultimate Space Pictures
• A Handpicked Collection of Ultimate Space Pictures 2

********************************************************************

When we think of the phrase, "Water, water, everywhere…and not a drop to drink", we need to take a second and third look at mankind's continuous search for water on Mars. We know with recently acquired proof there is water on this wonderful and mysterious red planet--we have seen it through images arriving from NASA's Phoenix digging for successful testing and we have seen it from images arriving from space that has shown evidence of such. This find has been so important that an additional NASA operational funding has been extended through September 30, 2008, adding five weeks to the original 90 mission days.

Why is finding water so important? It's not like we're going to rush off next week to Mars as we are running short down here on Earth-not like many of us did not see THAT coming as town and cities are on serious water rationing! Simply put-it is all about life. And life requires “liquid water”--life on Earth and possibly life on Mars--or even “somewhere out in space”.

The most important aspect of this little molecule of water is that it needs to be in a state of liquid in order to transport chemicals into and out-of cells. Things we have discovered-such as water ice and water vapor-do not have the ability we need to transfer these substances to any form of life. Proteins act as catalysts inside the cells of our body, with their proper functioning needing liquid water. But protein is not the only property important to life, as we know through our search for water.

The NASA Phoenix Lander is using a chemistry lab, TEGA, a microscope, a conductivity probe, and cameras to confirm the 2002 Mars findings regarding water ice on Mars. Being studied is the sky as well as the surface of Mars, using a Canadian laser beam instrument to observe the overhead clouds and dust, “which” according to the Canadian Space Agency is like using a 30-watt light bulb to offer the Earth a Martian laser show. Sounds pretty powerful to me!!

According to the latest NASA reports, Phoenix has completed a full-circle, color panorama of its surroundings at its landing site. “The details and patterns we see in the ground show an ice-dominated terrain as far as the eye can see,” said Mark Lemmon of Texas A&M University, lead scientist for Phoenix's Surface Stereo Imager camera. “They help us plan measurements we're making within reach of the robotic arm and interpret those measurements on a wider scale.”

 

 

 

The Aftermath of the Great Supernova

Picture Credit: Hubble Space Telescope

Sometimes stars explode and burst into - well I was going to say flames, but the correct term would be - gas. Not the smelly kind I hope, though no one is close enough to smell them.

When stars explode they are called supernovas, and in 1987 one such explosion occurred. This magnificent event was captured by the Hubble Space Telescope. The picture above shows what you could call a star (or stars) on the verge of death. Ahhh…

Jupiter

Picture Credit: NASA, JPL, NSSDC, Voyager

A picture of a very caramel-like surface of Jupiter, one of the Earth's planets. Jupiter has no solid surface, it is just a huge ball of gas - literally. It's the largest planet in the solar system, made up of mainly hydrogen and helium. The red-ish spot that you can see on this picture is a hurricane system steadily churning for at least 300 years within the clouds of Jupiter. The hurricane itself is so large that 3 Earths could fit inside it.

The Cat's Eye Nebula

Picture Credit: NASA, Hubble Space Telescope

When there is a cloud of gas and dust in Space, it is called by the very posh name - "Nebula". (I see a common theme of "gas" here). This particular nebula is called the cat's eye and is generally thought to be a cluster of stars surrounded by bulbs of gas.

Ida the Asteroid

Picture Credit: NASA, JPL, Galileo Project

Meet Ida. She is basically a large piece of rock (an asteroid) orbiting our sun. You can see her Moon Dactyl, on the right, which is about one mile across. Meanwhile, Ida herself, a giant potato, measures about 36 miles long and 14 miles wide. Ida is the first asteroid with her own little moon

The Mountains of Mars

Picture Credit: NASA,Viking Project

This is a picture of the largest of Mars' mountains. It's called Olympus Mons and was produced by a volcano. Olympus Mons is almost 15 miles high and more than 300 miles wide at the base. Keep in mind that Earth's largest volcano Mauna Loa in Hawaii is 5 miles high and about 12 miles wide by comparison.

The Face on Mars

Picture Credit: NASA,Viking Project

This picture shows what appears to be a human face on Mars (does it look a bit like George Washington?) This picture created quite a stir when it was first taken in 1976. People speculated that it was probably built by intelligent life living on Mars!

M31: The Andromeda Galaxy

Credit: The Electronic Universe Project

Our Galaxy, with our Moon, the Sun, the Earth and all our other planets and stars is called the Milky Way. Meanwhile, about 2 million light years away, there is another similar galaxy called Andromeda, and this is it. Ours and Andromeda (referred to as M31) are two of the largest known galaxies in Space. I thought that Andromeda looks like a giant lighted Frisbee.

Io: A Volcanic Moon

Credit: NASA, Voyager Project

This magnificent spectre you see here is one of Jupiter's four moons. This one is called Io. Io is about the size of our own Moon and she is said to be one of the most beautiful objects in our solar system. Io's surface is covered with many active volcanoes, and with each eruption, compounds are expelled in a variety of superb colours which is the reason for this pizza-like look

A Close-up of Io's Volcano

Credit: NASA, Voyager Project, Copyright Calvin J. Hamilton

And this is what one of the volcanoes looks like. Over 200 miles of colourful lava flows out from what is obviously a very hot volcanic vent.

The Sun Erupts

Credit: Skylab

The sun in all its glory was captured erupting a solar flare. This picture was taken in 1973 capturing the biggest flare ever documented. The sun is mainly made up of hydrogen and helium, and sometimes this nuclear fusion collide and release energy.

The First Human Footprint.

Credit: Kennedy Space centre and of course Neil Armstrong

This is a picture taken on 20th July 1969, of the first human footprint on the Moon. It belonged to Neil Armstrong. It is estimated that the live transmission of this first step was watched by one billion people worldwide, making it the highest rated television show ever. Armstrong then said, “That's one small step for a man, one giant leap for mankind.”

Hope you enjoyed this second installment as much as the first (click on "first" to view it) . I shall be along presently, for another collection of our photogenic universe's amazing pictures.

Other Works in This Series of Space Pictures

• 10 Most Awsome Pictures Taken From Outer Space
• Welcome to Makind s New Home in Space
• Pictures of Earth and Outer Space at Night
• A Handpicked Collection of Ultimate Space Pictures

Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

We normally see Saturn's rings the side from which the sun shines on them. This picture was taken from the other side by the robot Cassini spacecraft. I think it's still spectacular.

An Antarctic Total Solar Eclipse

Credit and Copyright:Fred Bruenjes (moonglow.net)

From the location of Antarctica, this mind boggling picture was taken of the Sun's total eclipse behind the Moon. This picture shows the Sun's corona around the Moon. A photographer and his deck chair are also caught up in the middle.

The Fox Fur Nebula

Credit & Copyright: Jean-Charles Cuillandre (CFHT) & Giovanni Anselmi (Coelum Astronomia), Hawaiian Starlight

Simply put, this is a load of dust and gas. Named Fox Fur Nebula, this particular interstellar event is a mixture of that dust and gas, together with lights and winds from stars. They can be found about 2,500 light years away.

If you lean your head towards the right, the left of this picture looks like the head and neck of a grizzly bear and not a fox (from my interpretation anyway).

Phobos: Doomed Moon of Mars

Credit: HiRISE, MRO, LPL (U. Arizona), NASA

Mars, the red planet in our magnificent solar system, has two moons - Phobos and Deimos. These names are derived from Greek, meaning Fear and Panic.

The one in this picture, Phobos, orbits so close to Mars that gravity is pulling it down. Scientists believe that gradually, the stress would shatter it. Poor thing!

Cat's Eye Hubble Remix

Credit & Copyright: Vicent Peris (OAUV / PTeam), MAST, STScI, AURA, NASA

The Cat's Eye Nebula is 3,000 light years away from Earth. Even people who're not really interested in Astronomy know of this well-known sky dweller.

This is actually a sad picture of a dying sun-like star. The picture has been reprocessed to sharpen the visibility of the details.

Hole in the Sun

Credit: SOHO - EIT Consortium, ESA, NASA

Welcome to our Sun, and welcome to its coronal hole. Sometimes high-speed solar winds, atoms and electrons flow out from this hole causing colourful displays of auroral lights visible from Earth.

Lunation

Credit & Copyright: António Cidadão

This is actually a slide show, so if it doesn't work properly from this page, go here (press control and click) because you simply must see it. This shows what our Moon looks like during all the phases of its lunar cycle. This full cycle takes about 29 and a half days, not unlike the menstrual cycle of a woman.

The surface of Mars

Credit: Viking Project, NASA

The Viking Lander 2 captured a fine image of Mars' surface which is covered by a thin layer of ice. Either that, or this is a close-up of a ham and cheese pizza.

The Eclipsed Earth

Credit: Mir 27 Crew; Copyright: CNES

This is a picture of Earth during a solar eclipse. The relatively tiny shadow which can be seen darkening the surface is that of the Moon. This shadow moved across the Earth at about 2,000 km per hour. Only people at the very middle of the dark circle can see a total solar eclipse, people further away are able to see a partial one. If you look carefully, you'll see two bright spots at the top left, which are thought to be Jupiter and Saturn.

I'm always impressed by these space pictures. I could see them again and again and still find something new to look at every time. Time after time, I shall be getting some more of these together. These are my favourite ones at the minute, what's yours?

The second installment is now available here.

Other Works in This Series of Space Pictures

• 10 Most Awsome Pictures Taken From Outer Space
• Welcome to Makind s New Home in Space
• Pictures of Earth and Outer Space at Night
• A Handpicked Collection of Ultimate Space Pictures 2

NASA has a Near-Earth Object Program Office in Pasadena, California. Their prime duties are to track objects, discover knew objects, and calculate statistics of an impact.

They are more commonly known as Space watch. You may be shocked to know that as of today, 5508 Near-Earth objects have been discovered. 742 of these monsters are asteroids with a diameter of approximately 1 kilometer or larger. Also, 945 of these possible hazards have been classifies as Potentially Hazardous Asteroids.

The definition of a Potentially Hazardous Asteroids, is currently defined based on parameters that measure the asteroid's potential to make threatening close approaches to the Earth. Scientists are studying fallen objects that already hit the earth. By studying the chemicals and matter near Earth-objects are made of, they can predict who their parents

may be. This is vital information on how to best stop an Asteroid or Meteor from impacting our planet. If the impact is inevitable, they may at least know the best approach to minimize the damage.

The damage to Earth is unpredictable, as they depend on the velocity, speed of impact, gasses, radiation, how many pieces, and does it strike land or water? We could have orbit changes, earthquakes, tsunamis, clouded atmosphere, fires, on a global scale epidemic? If a Potentially Hazardous object hit's a nearby planet with such destructive forces, we also risk a change in orbit as well. It is a fact that it will destroy all humanity, if the asteroid is at least 1 km (0.6 miles) in diameter.

Most people feel that up to date, the government is not doing enough to fund researches in this area. We are not as prepared as we should be. There are more life threatening acts to humanity from outer space then there are here on earth. Some of these other threats are

solar flares, supernovae, black hole explosions or mergers, gamma-ray bursts, galactic center outbursts, and super volcanoes.

Dextre (shown in Fig.1) which is part of Canada's contibution to the International Space Station (ISS) is the 3RD & final stage of the Mobile Servicing System. Dextre works in conjunction with the Canadarm2 which was installed on the ISS in 2001 & the mobile base which was installed in 2002. It is sometimes referred to as the Canada hand by analogy with the Canadarm and Canadarm2.

Figure 1: Dextre the Canadian Space Agency's Special Purpose Dexterous Manipulator

Installation

The Canadian Space Agency's Special Purpose Dexterous Manipulator, aka "Dextre," was successfully launched into orbit on March 11, 2008 aboard the space shuttle Endeavour (mission STS-123). Figure 2 shows Dextre being prepared for launch while Figure 3 shows Dextre all packed up and ready to head off into space aboard the space shuttle Endeavour.

Figure 2: Dextre is being folded up in preparation for launch

Figure 3: Dextre is loaded and ready to go.

Installing Dextre to the ISS required Endeavour astronauts Rick Linnehan and Robert L. Behnken to make three lengthy space walks. Firstly, the astronauts deployed the body section of Dextre on March 14, 2008. Then they connected Dextre to the space station's Canadarm2 (see Fig 4), which supplied the necessary power for Dextre to be “woken up”.

Figure 4: Dextre fully assembled and attached to Canadarm2

Dextre immediately activated the heaters so vital for keeping its joints and electronics warm in the cold environment of space.

One end of Dextre's torso has a special grapple feature that the International Space Station's (ISS) larger Canadarm2 can grasp in order to position Dextre at various work sites around the ISS.

The other end of Dextre's torso has an end effector like that of Canadarm2, which allows Dextre to be stored on the Space Station's special external grapple fixtures or for attachment to the Canadarm2 (Fig.5) to act as a high precision extension to the larger arm.

Figure 5: Graphical depiction of Dextre attached to Canadarm2

This combination of the Canadarm2 and Dextre allows these two robotic systems to reach virtually any site of the ISS desired. It also gives the ISS the ability to perform work upon other vehicles at a greater and safer distance from itself than before.

Bearing in mind that objects in orbit are travelling in excess of 25,000 miles/hour and will cause a lot of damage should they accidentally collide. The additional features, capabilities and added safety that Dextre delivers is essential if we humans are to successfully conquer space.

It was during the second space walk of the mission on March 16, 2008 that astronauts Rick Linnehan and Robert L. Behnken attached Dextre's two 3.35 meters (11 ft) long arms. Then they reattached Dextre to Canadarm2 in order for it to keep warm and allow NASA to conduct a series of thoroughly rigorous tests to ensure that all of Dextre's electronics and moving parts.

After NASA was satisfied, the crew of the Endeavour then conducted further in situ testing of all of Dextre's joints and braking systems. Final outfitting of Dextre the space maintenance robot took place during a third space walk on St Patrick's Day, March 17, 2008.

Design and Delivery

MDA Space Missions designed and built Dextre under contract from the Canadian Space Agency. The Canadian Space Agency bears the ongoing responsibility for its future operations and any training that may be necessary for future space station and ground crews alike. Do not forget that Dextre has the capacity for remote control from earthbound facilities.

With all testing complete Dextre arrived at the Kennedy Space Center in Florida mid-June 2007. There it underwent final flight verification testing and space shuttle integration (packaging and loading) in preparation for launch (Fig.2 and Fig. 3).

Features

Dextre's design plan (see Figure 6) incorporates the following features:

Two identical detachable highly dexterous 3.25 meters (11 ft) arms each of which has 7 joints allowing the following range of movements: Shoulder Roll, Shoulder Yaw, Shoulder Pitch, Elbow Pitch, Wrist Pitch, Wrist Yaw & Wrist Roll

Pivoting Body and Body Roll Joint - The nimble Dextre can pivot at the waist.

Torso mounted lights & video equipment. Dextre's five cameras allow its operators to view its work from practically every angle.

Remote Control via a Power Data Grapple Fixture - Dextre is controllable from a workstation aboard the ISS or by flight controllers on the ground. This is one of its most promoted safety features. In the event of a calamity, earthbound operators are able to conduct procedures via Dextre thereby freeing the ISS crew to attend to more pressing matters.

Ground based operators can also benefit from specialised high quality optics aboard the ISS, other space vehicles and even ground-based ones in conjunction with the pictures from Dextre's own video system. If Dextre's onboard systems fail these remote viewing and remote control features could be the difference between life and death in space aboard the ISS.

This also allows them to use Dextre in the event of onboard video becoming unavailable for whatever reason; a luxury the ISS crew does not have.

Other proposals suggest that Dextre might be of use in making running repairs on the space shuttle (e.g. fixing the ceramic thermal tiles) but whether or not this eventuates is something that only time will tell.

Orbital Replacement Unit (ORU)/Tool Changeout Mechanism (OTCM). At the end of each of Dextre's arms is a system called the Orbital Replacement Unit/Tool Changeout Mechanism (OTCM). It has built-in grasping jaws, a retractable socket drive, a monochrome TV camera, lights, and an umbilical connector that can provide power, data, and video to/from a payload.

Figure 6: Dextre; the Special Purpose Dexterous Manipulator, design plan

Dextre's lower body has a Camera Light & Pan/Tilt Unit (CLPA) consisting of pair of operator orientable colour TV cameras with lights, as well as a platform for stowing Orbital Replacement Units (ORU), and a tool holster. The tool holster is equipped with three different tools used to perform various tasks around the Space Station.

The jaws at the end of each arm will allow Dextre to grasp and hold objects while the retractable motorised socket wrench allows Dextre to connect or detach objects. The tool change mechanism and tool holder are critical components since everything in orbit is travelling very fast.

Any objects that are “free” to move will tend to do so since this is the normal behaviour for all objects in free fall inlcuding those in orbit. If accidently nudged, free to move objects, will cause incredibly large impacts resulting in considerable damage.

The latching end effector is as already mentioned a vital component of Dextre's attachment systems. Another system that helps place Dextre on a pedastal of greater precision than the two Canadarms are an assortment of sensors such as force moment sensors that give Dextre the capacity to be “gentle” when required.

Preventing Accidental Collisions

Dextre can only move one arm at a time. This is a very deliberately designed safety feature as it helps prevent the likelihood of Dextre's operator(s) from unwittingly causing both of Dextre's arms to collide. Note that I did say operator/operators as Dextre will at most times be under the control of a team of operators. Although when a crew member of the ISS is in charge they will perform the majority of commands.

Bearing in mind that Dextre's arms are 3.25 meters (11 ft) long and that we humans are unused to operating appendages of this length with any dexterity the in built safety guard of Dextre only being able to move one arm at a time assumes greater importance than would seem to be the case at first sight.

Another reason for building this feature into Dextre is that it helps to maintain stability and stability is critical whenever one is attempting a delicate procedure.

Dextre can also be attached to the space station Canadarm's railway which is shown in the graphic of Figure 5.

Figure 7: Dextre at work

Until next time, enjoy.

However, not all black holes are alike. We are going to look at the various types of black holes, their origins and their distinguishing characteristics.

Size and Origins

Black holes vary in size in terms of both their mass and the amount of spacetime that they occupy. These two attributes constitute the foundations upon which we distinguish one “type” of black hole from another. In addition, we will also use the mechanism and manner of their formation as a means of “typing” black holes.

Figure 1: Simulated view of a black hole in front of the Milky Way. The hole has 10 solar masses and is viewed from a distance of 600 km. An acceleration of about 400 million g-force is necessary to sustain this distance constantly.

In order to better facillitate a wider understanding of black holes scientists have subdivided the black holes into five categories using the mass of our sun as a relative metric as follows:

Supermassive Black Holes

The current scientific consensus is that supermassive black holes containing hundreds of thousands to billions of solar masses exist in the center of most galaxies, including our own Milky Way (Fig.2).

Current evidence points to the existence of a supermassive black hole in a region of our galaxy, the Milky Way known as Sagittarius A*. These massively dense objects can be up to 1.5 billion kilometers in radius.

Figure 2: Sagittarius A* (centre) and two light reflections from a recent explosion (circled)

There is much circumstantial evidence supporting this hypothesis. Astronomers have identified and observed regions at the center of numerous galaxies where the telltale orbital patterns of stars (see Fig.2) associated with these central objects are such that they must be orbiting incredibly massive dense objects.

These objects are so massive and dense that we know of no object other than the presence of a black hole that can satisfactorily explain the orbits and velocities of these stars.

Supermassive black holes are thought to be responsible for active galactic nuclei, and presumably form either from the coalescence of smaller black holes, or by the accretion of stars and gas onto them.

Intermediate-Mass Black Holes

Intermediate-mass black holes have sizes measuring thousands of solar masses. This group of black holes probably exists. However, we are yet to discover any. Therefore, the existence of intermediate-mass category of black holes is essentially theoretical at least for now.

In addition, we do not know of any mechanism by which they might form directly. It is widely considered that intermediate-mass category of black holes are most probably formed by the collisions of lower mass black holes. This type of event is most likely to occur either in the dense stellar cores of globular clusters or galaxies. It is also likely to occur when galaxies collide (Fig.3).

Figure 3: Colliding/Merging Galaxies-1 -The Mice NGC 4676

Concerning the lower mass size limit of this category of black holes the consensus is that it must be slightly larger than the maximum mass for a black hole created from the collapse of a massive star which is poorly understood at the moment.

Many scientists believe that the intermediate-mass black hole may be the source of ultra-luminous X ray sources.

Stellar-Mass Black Holes

Stellar-mass black holes have masses ranging from a minimum of 1.5 to 3.0 solar masses up to 20 solar masses. It is widely accepted that this group of black holes originate from the collapse of individual large stars or possibly from the coalescence of binary neutron stars.

Figure 4 is an artist's impression of a binary system consisting of a black hole and a main sequence star. The black hole is drawing matter from the main sequence star via an accretion disk around it, and some of this matter forms a gas jet.

Figure 4: Binary System of a main sequence star and partner vampire black hole

The stars from which they originate would originally have had masses up to 100 solar masses. These parent stars will have either shed their outer massive layers during various stages of their life cycle or expelled them in a supernova explosion.

Primordial Black Holes

Small black holes with a mass less than a star that were created as a result of the extreme density of matter present during the universe's early expansion and not by gravitational collapse as the other types of black holes were. This means that primordial black holes can be of any size including the very small.

One possible, although unlikely explanation for gamma ray bursts is the so-called “run-away” evaporation (slow leakage of Hawking radiation) of primordial black holes. Other cosmological conundrums for which primordial black holes may provide a solution include the dark matter issue, the monopole problem and the cosmological domain wall issue.

General relativity predicts that the smallest primordial black holes would have evaporated by now.

String theory predicts the existence of a fourth spatial dimension that would affect the behavior of gravity on small scales and slow down the evaporation effect considerably. The implication is that there could be thousands of black holes in a galaxy such as the Milky Way.

NASA will put the Gamma-ray Large Area Space Telescope (GLAST) into orbit to answer this very question. The first indirect evidence for the existence of primordial black holes and string theory will lie in the detection of specific small interference patterns within gamma-ray bursts.

Micro Black Holes

It may be possible for high-energy particle accelerators such as the Large Hadron Collider (LHC) to create micro black holes by smashing particles traveling at near light-speed into each other.

Figure 5 shows the ultra-high-energy collisions of particles in a particle accelerator can create microscopic black holes. All types of particles will be emitted by black hole evaporation, providing key evidence for any grand unified theory.

Figure 5: High energy particles produced in a gold ion collision

Quantum Gravity

The overall view from cosmologists and astrophysicists is that a quantum gravity theory needs developing before we will be able to explain all aspects of black holes fully.

Until next time, enjoy!

More solar images can be viewed from here. Other scientific solar resources can be obtained from here too.

Brief Introduction of the Sun

The core of the sun is said to have a density of up to 15000kg/m3. This density is 150 times higher than the density of the Earth. The thermonuclear reaction (nuclear fusion process)converts about 700,000,000 tones of hydrogen to about 695,000,000 tones of helium into the form of gamma rays every second and later the released energy of about 5,000,000 tones or equivalents to 3.86e33 ergs from the sun maintains it in a stable state. Every second, approximately 8.9 X 1037 Proton, which is a conversion of 426 tones hydrogen nuclei into helium nuclei. About 383 X 1024 joules of released energy within every second is equivalents to 9.15 X 1010 million tons of explosive energy of TNT.
From its core to its solar radii distance of 0.2, this is regarded as the only place for the sun to release its nuclear fusion energy. The remaining part of the sun is heated by such releasing energy that will later be transmitted and extended outwards to parts of the sun. This heating energy passes through many linked layers before reaching to its outer surface, and subsequently entering the space.

High-energy photons (γ and X-ray) are released from the core through the nuclear fusion process. Later, this energy has to take longer times to reach the outer surface of the sun. The slow pace and its changing path of its direction involve absorption and re-radiation of energy and thus causing relatively lower external photon energy. It is estimated that the time taken for each of the photon energy to reach its surface is 5000 million years, and the fastest was reported as 17,000 years. After venturing through the troposphere and finally reaching the end of its transparent ball-layer looking surface, the visible light photon escapes to the space.

Before entering the space, each γ-ray photon has already been converted into millions of visible light photons. Neutrino is another result of nuclear reactions that take place in the sun. It is different from the photon energy as it does not react with other substances and therefore it escapes immediately from the surface of the sun to the space. Over years, the number of measured neutrinos from the sun is always found lower than the theoretical value and thus creating the issue of neutrino for the scientists to venture into the depth study in this field. This mystery was then solved when scientists came to understand the theory of the neutrino's oscillation.

Very close to the core of the sun, its temperature is about 15 million K and its density is approximately 1.5g/cc or equivalents to about 10 times of the density of lead. Nevertheless, its temperature becomes less when moving from the core to the sun's surface, and its density too, reduces simultaneously. Its edge temperature is half of the core's temperature, that is approximately 7 million K, and at the same time its density is about 20g /cc as equivalent as the density of gold.

According to NASA, lunar eclipses are considered total when the moon passes completely into Earth's umbral shadow. This phenomenon happens when the Sun, Earth, and Moon are arranged in a line with the Earth in the middle. It was reported in May 2003 that the moon passed close to the middle of the umbra. The eclipse was long (52 minutes of totality) and dark. Another lunar eclipse was reported in November 2003 that produced lunar eclipse that was shorter (25 minutes of totality) and brighter.

This photo was shot in the early morning of February 21, 2008 in Buenos Aires, the capital of Argentina. It shows the phase of the total lunar eclipse that was believed as the last total lunar eclipse ever emerged before the year of 2010 in the Western Hemisphere.

This is an enhanced photo that shows a whole phase of the total lunar eclipse captured in the early morning in Buenos Aires.

This image of the lunar eclipse was photographed in Riyadh, Saudi Arabia at its local time on February 21, 2008.

This is a photo of the total lunar eclipse captured in Mexico on February 21, 2008.

The observation of the total lunar eclipse was held as long as 30 seconds by the astronomers, astronomy enthusiasts who used their telescopes and cameras aiming at the sky. They paid great interests looking at the space, while enjoying the splendid scene of the universe. This picture was taken at the University of Tennessee of the United States. The lower right of the photo shows a group of teachers and students who were attracted by the splendor look of the total lunar eclipse.

This photo shows the total lunar eclipse gradually climbing up the roof top of Miami Science Museum in the United States.

This total lunar eclipse was observed in the Western Port City of Washington, Tacoma. The eclipse seemed to erode itself into orange color.

The people in the capital of Uruguay (Montevideo) observed this lunar eclipse at their local time on February 21, 2008.

This photo was captured near the monument of astronomer in Los Angeles of United States.

This similar view of the total lunar eclipse was captured in Toronto, Canada.

The total lunar eclipse appeared over the sky of Seattle, United States.

A reddish-looking lunar eclipse climbed up the top of the Empire State Building in New York, United States.