SMART-1’s First Image of the Moon

Image credit: ESA
ESA’s SMART-1 captured its first close-range images of the Moon this January, during a sequence of test lunar observations from an altitude between 1000 and 5000 kilometres above the lunar surface.

SMART-1 entered its first orbit around the Moon on 15 November 2004. It has spent the two months following spiralling down to the Moon and testing its array of instruments.

The first four days after being captured by the lunar gravity were very critical. There had been the risk, being in an ‘unstable’ trajectory, of escaping the Moon’s orbit or crashing onto the surface. Because of this, the electric propulsion system (or ‘ion engine’) started a thrust to stabilise the capture.

The ion engine was switched on until 29 December, allowing SMART-1 to make ever-decreasing loops around the Moon. The engine was switched off between 29 December and 3 January 2005 to allow scientists to start observations. At this point, the AMIE camera took the close-up lunar images. The engine was switched off again to optimise fuel consumption on 12 January, and SMART-1 will spend until 9 February making a medium resolution survey of the Moon, taking advantage of the favourable illumination conditions.

ESA’s SMART-1 Project Scientist Bernard Foing said “A sequence of test lunar observations was done in January at distances between 1000 and 5000 kilometres altitude, when the electric propulsion was paused. We are conducting more survey test observations until the electric propulsion resumes from 9 February to spiral down further towards the Moon. SMART-1 will arrive on 28 February at the initial orbit with altitudes between 300 and 3000 kilometres to perform the first phase of nominal science observations for five months.”

The first close-up image shows an area at lunar latitude 75? North with impact craters of different sizes. The largest crater shown here, in the middle left of the image, is Brianchon. The second largest, at the bottom of the image, is called Pascal.

At low illumination angles, the crater shadows allow scientists to derive the height of crater rims.

“This image was the first proof that the AMIE camera is still working well in lunar orbit,” says AMIE Principal Investigator Jean-Luc Josset of Space-X.

The composite images shown here were created to show larger-scale features. The first mosaic shows the complex impact crater Pythagoras and the strip of images (bottom) was produced from images taken consecutively along one orbit.

Starting with this mosaic, SMART-1 scientists expect to build up a global medium-resolution context map, where high-resolution images later observed from lower altitude can be integrated.

Original Source: ESA News Release

Milky Way’s Black Hole Was Active Recently

The centre of our galaxy has been known for years to host a black hole, a ‘super-massive’ yet very quiet one. New observations with Integral, ESA’s gamma-ray observatory, have now revealed that 350 years ago the black hole was much more active, releasing a million times more energy than at present. Scientists expect that it will become active again in the future.

Most galaxies harbour a super-massive black hole in their centre, weighing a million or even a thousand million times more than our Sun.

Our galaxy too, the Milky Way, hosts a super-massive black hole at its centre. Astronomers call it Sgr A* (pronounced ‘Sagittarius A star’) from its position in the southern constellation Sagittarius, ‘the archer’.

In spite of its enormous mass of more than a million suns, Sgr A* appears today as a quiet and harmless black hole. However, a new investigation with ESA’s gamma-ray observatory Integral has revealed that in the past Sgr A* has been much more active. Data clearly show that it interacted violently with its surroundings, releasing almost a million times as much energy than it does today.

This result has been obtained by a international team of scientists led by Dr Mikhail Revnivtsev (Space Research Institute, Moscow, Russia, and Max Planck Institute for Astrophysics, Garching, Germany). As Revnivtsev explains, “About 350 years ago, the region around Sgr A* was literally swamped in a tide of gamma rays.”

This gamma-ray radiation is a direct consequence of Sgr A*’s past activity, in which gas and matter trapped by the hole’s gravity are crushed and heated until they radiate X-rays and gamma rays, just before disappearing below the ‘event horizon’ – the point of no return from which even light cannot escape.

The team were able to unveil the history of Sgr A* thanks to a cloud of molecular hydrogen gas, called Sgr B2 and located about 350 light-years away from it, which acts as a living record of the hectic black hole’s past.

Because of its distance from the black hole, Sgr B2 is only now being exposed to the gamma rays emitted by Sgr A* 350 years ago, during one of its ‘high’ states. This powerful radiation is absorbed and then re-emitted by the gas in Sgr B2, but this process leaves behind an unmistakable signature.

“We are now seeing an echo from a sort of natural mirror near the galactic centre – the giant cloud Sgr B2 simply reflects gamma rays emitted by Sgr A* in the past,” says Revnivtsev. The flash was so powerful that the cloud became fluorescent in the X-rays and was even seen with X-ray telescopes before Integral. However, by showing how high-energy radiation is reflected and reprocessed by the cloud, Integral allowed scientists to reconstruct for the first time the hectic past of Sgr A*.

The high state or ‘activity’ of black holes is closely linked to the way in which they grow in size. Super-massive black holes are not born so big but, thanks to their tremendous gravitational pull, they grow over time by sucking up the gas and matter around them. When the matter is finally swallowed, a burst of X-rays and gamma rays results. The more voracious a black hole, the stronger the radiation that erupts from it.

The new Integral discovery solves the mystery of the emission from super-massive but weak black holes, such as Sgr A*. Scientists already suspected that such weak black holes should be numerous in the Universe, but they were unable to tell how much energy and of which type they emit. “Just a few years ago we could only imagine a result like this,” Revnivtsev says. “But thanks to Integral, we now know it!”

As for the duration of the latest high state of Sgr A*, 350 years ago, Revnivtsev and his team have evidence that it must have lasted at least ten years and probably much longer. The team also expect that Sgr A* will become bright again in the foreseeable future. Detecting the next burst would provide much needed information about the duty cycle of super-massive black holes.

Original Source: ESA News Release

1,000 Issues of Universe Today

For those of you who get Universe Today by email, you’ll notice this is the 1000th issue of the newsletter. 1000 issues. Wow. That’s several hours a day of my life for nearly 6 years. Here’s a link to the first edition of Universe Today, which went out to about 10 of my closest friends (aka “Test Subjects”). And here’s a link to what the website looked like early on.

There have been a few design changes and technology upgrades over the last 6 years, but I’ve really tried to keep Universe Today faithful to its original goal: encapsulating the major events in space and astronomy in a consistent, easily digestible format. And as long as I’m around, that will always be the case.

For the longest time, it was a one-man effort, but that’s changing now. I’ve got lots of help these days. From the moderators and community support team in the forum, to the freelance writers contributing stories.

A big thanks to all 27,000 subscribers. Your feedback, friendship and emails make it all worth while.

Here’s to another 1,000!

Fraser Cain
Universe Today

P.S. Yes, that’s another shameless picture of Chloe and Logan. Here’s a bigger version.

Where Does Visible Light Come From?

It wasn’t too long ago (13.7 billion years by some accounts) that a rather significant cosmological event occured. We speak of course, of the Big Bang. Cosmologists tell us that at one time there was no universe as we know it. Whatever existed before that time was null and void – beyond all conception. Why? Well there are a couple answers to that question – the philosophic answer for instance: Because before the universe took form there was nothing to conceive of, with, or even about. But there’s also a scientific answer and that answer comes down to this: Before the Big Bang there was no space-time continuum – the immaterial medium through which all things energy and matter move.

Once the space-time continuum popped into existence, one of the most moving of things to take form were the units of light physicists call “photons”. The scientific notion of photons begins with the fact that these elementary particles of energy display two seemingly contradictory behaviors: One behavior has to do with how they act as members of a group (in a wavefront) and the other relates to how they behave in isolation (as discrete particles). An individual photon may be thought of as a packet of waves cork-screwing rapidly through space. Each packet is an oscillation along two perpendicular axes of force – the electrical and the magnetic. Because light is an oscillation, wave-particles interact with each other. One way of understanding the dual-nature of light is to realize that wave after wave of photons affect our telescopes – but individual photons are absorbed by the neurons in our eyes.

The very first photons travelling through the space-time continuum were extremely powerful. As a group, they were incredibly intense. As individuals, each vibrated at an extraordinary rate. The light of these primordial photons quickly illuminated the rapidly expanding limits of the youthful universe. Light was everywhere – but matter was yet to be seen.

As the universe expanded, primordial light lost in both frequency and intensity. This occured as the original photons spread themselves thinner and thinner across an ever-expanding space. Today, the first light of creation still echos around the cosmos. This is seen as cosmic background radiation. And that particular type radiation is no more visible to the eye as the waves within a microwave oven.

Primordial light is NOT the radiation we see today. Primordial radiation has red-shifted to the very low end of the electromagnetic spectrum. This occured as the universe expanded from what may have originally been no larger than a single atom to the point where our grandest instruments have yet to find any limit whatsoever. Knowing that primordial light is now so ternuous makes it necessary to look elsewhere to account for the kind of light visible to our eyes and optical telescopes.

Stars (such as our Sun) exist because space-time does more than simply transmit light as waves. Somehow – still unexplained-1 – space-time causes matter too. And one thing distinguishing light from matter is that matter has “mass” while light has none.

Because of mass, matter displays two main properties: Inertia and gravity. Inertia may be thought of as resistence to change. Basically matter is “lazy” and just keeps doing whatever it’s been doing – unless acted upon something outside itself. Early in the formation of the universe, the main thing overcoming matter’s lazyness was light. Under the influence of radiation pressure, primordial matter (mostly hydrogen gas) got “organized”.

Following light’s prodding, something inside matter took over – that subtle behavior we call “gravity”. Gravitation has been described as a “distortion of the space-time continuum”. Such distortions occur wherever mass is found. Because matter has mass, space curves. It is this curve that causes matter and light to move in ways elucidated early on in the twentieth century by Albert Einstein. Each and every little atom of matter causes a tiny “micro-distortion” in space-time-2. And when enough micro-distortions come together things can happen in a big way.

And what happened was the formation of the first stars. No ordinary stars these – but super-massive giants living very fast lives and coming to very, very spectacular ends. At those ends, these stars collapsed in on themselves (under the weight of all that mass) generating tremendous shock waves of such intensity as to fuse entirely new elements out of older ones. As a result, space-time became suffused with all the many types of matter (atoms) making up the universe today.

Today, two types of atomic matter now exists: Primordial and something we might call “star-stuff”. Whether primordial or stellar in origin, atomic matter makes up all things touched and seen. Atoms have properties and behaviors: Inertia, gravity, extension in space, and density. They can also have electrical charge (if ionized) and participate in chemical reactions (to form molecules of tremendous sophistication and complexity). All matter we do see is based on a fundamental pattern established long-ago by those primordial atoms mysteriously created after the Big Bang. This pattern is founded on two fundamental units of electrical charge: The proton and the electron – each having mass and capable of doing those things mass is liable to.

But not all matter follows the hydrogen prototype exactly. One difference is that newer generation atoms have electrically-balanced neutrons as well as positively-charged protons in their nuclei. But even stranger is a type of matter (dark matter) that doesn’t interact with light at all. And furthermore (just to keep things symmetric), there may be a type of energy (vacuum energy) that doesn’t take the form of photons – acting more like a “gentle pressure” causing the universe to expand with a momentum not orignally supplied by the Big-Bang.

But let’s get back to the stuff we can see…

In relationship to light, matter can be opaque or transparent – it can absorb or refract light. Light can pass into matter, through matter, reflect off matter, or be absorbed by matter. When light passes into matter, light slows – while its frequency increases. When light reflects, the path it takes changes. When light is absorbed, electrons are stimulated potentially leading to new molecular combinations. But even more significantly, when light passes through matter – even without absorption – atoms and molecules vibrate the space-time continuum and because of this, light can be stepped down in frequency. We see, because something called “light” interacts with something called “matter” in something called “the space-time continuum”.

In addition to describing the gravitational effects of matter on space-time, Einstein performed an extremely elegant investigation into the influence of light associated with the photo-electric effect. Before Einstein, physicists believed lights’ capacity to affect matter was based primarily on “intensity”. But the photo-electric effect showed that light effected electrons on the basis of frequency as well. Thus red light – regardless of intensity – fails to dislodge electrons in metals, while even very low levels of violet light stimulate measurable electrical currents. Clearly the rate at which light vibrates has a power all its own.

Einstein’s investigation into the photo-electric effect contributed mightily to what later became known as quantum mechanics. For physicists soon learned that atoms are selective about what frequencies of light they will absorb. Meanwhile it was also discovered that electrons were the key to all quantum absorption – a key related to properties such as one electrons relationships to others and with the nucleus of the atom.

So now we come to our second point: Selective absorption and emission of photons by electrons does not explain the continuous spread of frequencies seen when examining light through our instruments-3.

What can explain it then?

One answer: The “stepping-down” principle associated with the refraction and absorption of light.

Common glass – such as in the windows of our homes – is transparent to visible light. Glass however reflects most infrared light and absorbs ultraviolet. When visible light enters a room, it is absorbed by furniture, rugs etc. These items convert part of the light to heat – or infrared radiation. This infrared radiation is trapped by the glass and the room heats up. Meanwhile glass itself is opaque to ultraviolet. Light emitted by the Sun in the ultraviolet is mostly absorbed by the atmosphere – but some non-ionizing ultraviolet manages to get through. Ultraviolet light is converted to heat by glass in the same way furnishings absorb and re-radiate visible light.

How does all this relate to the presence of visible light in the Universe?

Within the Sun, high energy photons (invisible light from the perimeter of the solar core) irradiate the solar mantle beneath the photosphere. The mantle converts these rays to “heat” by absorption – but this particular “heat” is of a frequency well beyond our capacity to see. The mantle then sets up convective currents carrying heat outward toward the photosphere while also emitting lesser-energized – but still invisible – photons. The resulting “heat” and “light” passes to the solar photosphere. In the photosphere (“the sphere of visible light”) atoms are “heated” by convection and stimulated through refraction to vibrate at a rate slow enough to give off visible light. And it is this principle that accounts for the visible light emitted by stars which are – by far – the most significant source of light seen throughout the cosmos.

So – from a certain perspective, we can say that the “refractive index” of the Sun’s photosphere is the means by which invisible light is converted into visible light. In this case however, we invoke the idea that the refractive index of the photosphere is so high that high energy rays are bent to the point of absorption. When this occurs lower frequency waves are spawned radiating as a form of heat peceptible to the eye and not simply warm to the touch…

And with all this understanding beneath our intellectual feet, we can now answer our question: The light we see today is the primordial light of creation. But it is light that materialized some few hundreds of thousands of years after the Big Bang. Later that materialized light came together under the influence of gravity as great condensed orbs. These orbs then developed powerful alchemical furnaces de-materializing matter into light invisible. Later – through refraction and absorption – light invisible was rendered visible to the eye by rite of passage through those great “lenses of luminosity” we call the stars…

-1 How all things cosmological transpired in detail is probably the major area of astronomical research today and will take physicists – with their “atom-smashers”, astronomers – with their telescopes, mathematicians – with their number-crunching super-computers (and pencils!) and cosmologists – with their subtle understanding of the early years of the universe – to puzzle the whole thing through.
In a sense matter may simply be a distortion of the space-time continuum – but we are a long way from understanding that continuum in all its properties and behaviors.

-3 The Sun and all luminous sources of light do display dark absorption and bright emission bands of very narrow frequencies. These of course, are the various Fraunhofer lines related to quantum mechanical properties associated with transition states of electrons associated with specific atoms and molecules.

About The Author:Inspired by the early 1900’s masterpiece: “The Sky Through Three, Four, and Five Inch Telescopes”, Jeff Barbour got a start in astronomy and space science at the age of seven. Currently Jeff devotes much of his time observing the heavens and maintaining the website Astro.Geekjoy.

Book Review: Virtual LM

The book starts with a very brief summary of the lunar module, its conception by John Houbolt, the design and production trials of Grumman and then the astronauts’ concerns. Brief, yet complete, this introduction flows directly into the main feature of the book, the images of the lunar module. These images do a fantastic job of depicting the complete lunar module and then allowing the focus to narrow to examine many of the individual components.

The lunar module came in two versions, first the H series, and a later version, the J series. Though similar, the later J series had a greater capability evidenced mostly by the addition of the lunar rover. First the H and then J type lunar modules have plates showing their totality from a top, bottom and each of the four distinct side perspectives. These provide a ready comprehension of the surface planes, shapes and material. Purposefully simplified for comprehension (e.g. no grommets or weld lines), adjacent archival photographs easily bring reality alongside to compare to the view.

With this overview complete, the book drops into detail mode as the focus shifts to the two stages; the descent stage and the ascent stage. The descent stage first gets the same treatment as the overall module, then it gets ‘blown apart’ so that its internal constituents appear, something like a virtual biology dissection of a frog. The descent module’s shape is cruciform; each of the four quadrants clearly highlight the framework for internal and external supports, fuel tanks and electrical lines. Vivid colours differentiate the control lines and the ‘plumbing’ lines. Often a brief in-line paragraph describes the operational procedures or the design elements.

The ascent stage comes next and it is certainly more fun to go through. This stage housed the two astronauts and allowed them to control the craft, gave them access to the moon’s surface and got them returned to the command module. The windows, keypad computer, many control panels and helmet storage all have detailed closeups. Some of these have their own blow-apart diagrams to show construction. Should the readers get perplexed on the purpose of all these switches, levers and wires, then they can easily resolve this by perusing the attached CD-ROM which has over 2000 pages of operation manuals, checklists and cue cards.

When growing up, I was overly fond of building plastic models. I was amazed at the accuracy and detail of these small plastic miniatures and in my mind they all grew to real size and were valid working copies of the actual subject. This book gives me the exact same feeling. Without ever having seen a lunar module, I have become very acquainted with this craft. I understand its major parts, their placement and, with the documents on the CD ROM, their usage. Careful with this CD ROM though as the book is soft cover. Do not bend.

The missing element for this book would be the operation procedures. Sure they are in the CD ROM, but more could have been in the text. For example, why did the book include detailed views of the circuit interrupt connectors and one of the four hardpoint connections? Are they critical for some procedure? Why is there a close up of the docking light and flood light? Also, having the author’s name on every second page gets distracting. A preferable replacement would have been a length scale to facilitate gauging the size of the subject of the view. Yet, these changes would only have made an already good book that much better.

Today’s ready access to computer aided design (CAD) stations makes the design and development of complex machinery relatively simple. The lunar module came long before these tools, even well before the personal computer. Scott Sullivan in “Virtual LM” uses these amazing present day tools to dissect the lunar module, re-build it and display it for everyone to readily see and understand. This book, together with the enclosed CD-ROM, will bring this amazing spacecraft right up close in front of you, even if it is only virtual.

To get your own copy, visit Countdown Creations.

Review by Mark Mortimer

Microbes Use Hydrogen for Fuel in Yellowstone

Microbes living in the brilliantly colored hot springs of Yellowstone National Park use primarily hydrogen for fuel, a discovery University of Colorado at Boulder researchers say bodes well for life in extreme environments on other planets and could add to understanding of bacteria inside the human body.

A team of CU-Boulder biologists led by Professor Norman Pace, one of the world’s leading experts on molecular evolution and microbiology, published their report “Hydrogen and bioenergetics in the Yellowstone geothermal system” this week in the online edition of the Proceedings of the National Academy of Sciences.

The team’s findings, based on several years of research at the park, refute the popular idea that sulfur is the main source of energy for tiny organisms living in thermal features.

“It was a surprise to find hydrogen was the main energy source for microbes in the hot springs,” Pace said. “This project is also interesting in the context of microbiology because it’s one of the few times we’ve been able to study microbes to get information on an entire ecosystem. That’s never before been possible.”

The study was specifically designed to determine the main source of metabolic energy that drives microbial communities in park features with temperatures above 158 degrees Fahrenheit. Photosynthesis is not known to occur above that temperature.

A combination of three different clues led researchers to conclude that hydrogen was the main source of energy. Genetic analysis of the varieties of microbes living in the hot springs communities revealed that they all prefer hydrogen as an energy source. They also observed ubiquitous H2 in all the hot springs at concentrations sufficient for microbial bioenergetics. Thermodynamic models based on field data confirmed that hydrogen metabolism was the most likely fuel source in these environments.

“This work presents some interesting associated questions,” said John Spear, lead author of the report. “Hydrogen is the most abundant element in the universe. If there is life elsewhere, it could be that hydrogen is its fuel,” Spear said. “We’ve seen evidence of water on Mars, and we know that on Earth, hydrogen can be produced biogenetically by photosynthesis and fermentation or non-biogenetically by water reacting with iron-bearing rock. It’s possible that non-biogenic processes produce hydrogen on Mars and that some microbial life form could be using that,” he said.

There are many examples of bacteria living in extreme environments — including the human body — using hydrogen as fuel, according to Spear. “Recent studies have shown that Helicobacter pylori bacteria, which cause ulcers, live on hydrogen inside the stomach,” said Spear. “Salmonella metabolizes hydrogen in the gut. It makes me wonder how many different kinds of microbes out there are metabolizing hydrogen in extreme environments.”

Instead of relying on traditional techniques of microbiology that utilize cultures grown in the lab, the CU-Boulder team used methodology developed by Pace to genetically analyze the composition of the microbial community as it appeared in the field. “We didn’t look at what grows in a culture dish, we looked at the RNA of samples directly from the field,” Spear said.

“We’ve never before known what microbes were living in Yellowstone hot springs, and now we do,” Pace said.

A novel suite of instruments was used to gather data, some of which had never before been collected. “No one had measured the concentration of hydrogen in the hot springs before because the technology didn’t exist until about seven years ago. Now we can detect very low-level concentrations of hydrogen in water,” Spear explained.

“We found lots of hydrogen in the hot springs — an endless supply for bacteria,” he said. Measurements of the amount of H2 in water were recorded in Yellowstone hot springs, streams and geothermal vents in different parts of the park and during different seasons. All of the environments had concentrations appropriate for energy metabolism.

The team used computer-generated thermodynamic models to find out if hydrogen was indeed the principle source of energy. “You can smell sulfide in the air at Yellowstone, and the accepted idea was that sulfur was the energy source for life in the hot springs,” Spear said. Not so, according to the team’s computer models built on field measurements of hydrogen, sulfide, dissolved oxygen concentration and other factors.

Spear said it was difficult to explore a microbial ecosystem. “We have a hard enough time explaining what’s going on in a forest, for example, with all the interlacing systems. We can’t even see a microbial system.”

Sample extraction was a dangerous and delicate operation. In order to accurately analyze a hot spring’s entire microbial community, Spear needed to collect only about as much material as a pencil eraser. Sediment samples were scooped into special sample vials and immediately frozen in liquid nitrogen canisters to preserve the microbial community.

In springs where there was no sediment, Spear collected samples of planktonic organisms by hanging a glass slide in the water and allowing the microbes to accumulate. “Bacteria are just like us. They like to be together, they like to be attached to a surface and they like to have their food – dissolved hydrogen, in this case — brought to them.”

Spear explained that the hot springs’ colors are the result of interactions between minerals and the microbes living in the pools. Hotter water usually shows colors from minerals, and cooler water plays host to photosynthetic pigments.

“Based on what I’ve seen in this analysis, I think hydrogen probably drives a lot of life in a lot of environments,” Spear said. “It’s part speculation, but given the number and kinds of bacteria that are metabolizing hydrogen, it’s probably a very old form of metabolism.

That’s important because it tells us about the history of life on Earth,” he said. “And if it works this way on Earth, it’s likely to happen elsewhere. When you look up at the stars, there is a lot of hydrogen in the universe.”

Original Source: UCB News Release

What’s Up This Week – Jan 24 – Jan 30, 2005

Monday, January 24 – Up early? Great! Then let’s start the week off on authoritative note as Mars will be officially declared to have reached magnitude 1. As we’ve watched its return, the gain in brightness has us ready to once again begin viewing and looking forward to opposition at the beginning of November.

The Moon will dominate the evening skies tonight, but there are myriad delights to be explored on the lunar surface despite its brightness. It’s a fantastic opportunity to discover the bright rays of Tycho and explore “splashy” areas like Copernicus, Aristarchus and Keplar. How far can you trace the rays? Can you see the long ray that cuts across Mare Serentatis? Notice the crater rim of Plato to the north, how does it compare to Grimaldi in the west? For those with filters, enjoy looking for the bright rings of craters Dionysius and Pytheas. No filter? No problem! Although this might sound a bit strange, try wearing a pair of polarized sunglasses while viewing – you’d be surprised!

Only five degrees south of our “phat” Moon tonight, you will find the “Lord of the Rings” – Saturn. With the whole world buzzing about the excitement of the successful Huygens landing, why not invite family or friends to view with you? Titan is easily visible in even small scopes and it’s a wonderful opportunity to spark a child’s imagination!

Tuesday, January 25 – The Moon reaches Full this morning at 5:32 a.m. EST. Tonight it will rise within minutes of sunset and its majestic form at this time of year has long been captured in folklore. Known by many names, such as the Cold Moon, Winter Moon, Quiet Moon or Snow Moon, it is certainly an inspiring sight against the backdrop of the diamond bright stars of winter. Tonight let us visit the most brilliant star of all – Sirius.

Also known as the “Scorching One”, Alpha Canis Majoris is the brightest of the fixed stars at an amazing -1.42. With the exception of Alpha Centauri, Sirius is the closest of all the stars that we can see unaided at only 8.7 light years away – but it’s not standing still. As part of the Ursa Major Stream of moving stars, it has changed its position by one and half times the apparent width of the Moon in just 2000 years!

In the telescope, this main sequence star is a dazzling white tinged with blue. But thanks to our atmosphere, Sirius’ light will produce all the colors of the rainbow as it sparkles in our eyes. For many of us this beautiful iridescence is all we will ever see of Sirius, but for those with 10″ and larger telescopes a perfectly steady sky will reveal Alpha Canis Majoris’ secret – a white dwarf companion! Although this 8.5 magnitude star is well within the range of even small scopes, the blinding glare of the primary makes it a very elusive target. In another 20 years it will have reached its maximum separation of 11.5″, but keep a watch to the southeast as you view the “Scorching One” tonight – perhaps you’ll spot Sirius B!

Wednesday, January 26 – With just a small margin of time tonight to explore before the Moon rises, why not try your hand at a less popular Messier object? The M79 is located in the southern constellation of Lepus and it’s quite easy to find! Beta and Epsilon are the two southernmost stars, below them and forming a shallow “triangle” is a slightly dimmer star. Holding your hand at arms length, the M79 is two finger-widths away to the northeast.

Originally discovered by Mechain in October of 1780, Charles himself didn’t get around to looking at one of the very few globular clusters of winter until December of that year. On a good night, this small “round fuzzy” can be spotted with binoculars, but truly takes a telescope to appreciate. Moving away from us at 188 miles per second, the 8th magnitude M79 will show as a concentrated ball of unresolvable stars to small aperture and begin resolution with larger scopes. At around 42 light years away, this often over-looked Messier object is one of the very few globular cluster that resides further out in Milky Way galaxy than our own solar system!

If you need a winter smile, then wait about 3 hours after sunset tonight to check out the constellation of Leo – the “Lion” is taking a bite out of the Moon! Note the faint crown of stars about a hand span to the upper left of Luna. This is the “head” – while bright Regulus to the lower left is the “heart”. The figure becomes complete as the triangle of stars to the east represents the great “Lion’s” haunches.

Thursday, January 27 – Although the Moon will rise quite early tonight, open clusters make a fine target, so let’s head out toward Gemini and discover yet another Messier object that contains “more than meets the eye” – M35!

Cataloged by Messier in 1764, the M35 is easily found by locating Eta Geminorium and moving just slightly more than two finger-widths to the northwest. Best appreciated at lowest power, this very “open” cluster contains many different spectral types and magnitudes that are visible even in binoculars. At around 2200 light years away, large aperture telescopes at minimal magnification will pick up on an additional bonus on the cluster’s southwest edge. The NGC 2158 is about six times more distant than the M35. This very concentrated galactic cluster is roughly 8 million years old, making the trip to the M35 a dual delight!

If you’d like proof that the “Lion” had the Moon in its mouth yesterday, have look at the lunar surface tonight with a telescope or binoculars. Just north of the terminator’s mid-point you will see the very last remnants of the west wall of Mare Crisium – looking very much like a “bite” taken out of the lunar edge!

Friday, January 28 – And speaking of lunar geography, today Johannes Hevelius was born in 1611. So what, you say? Then think on this… Hevelius was using a telescope to view the Moon’s surface and produced the very first detailed maps which were published as “Selenographia” in 1647. That’s 358 years ago! The Polish astronomer then went on to name a constellation that still remains in use today – Lynx. When asked to explain how he came up with the name, he said that an observer needed to have eyes like a lynx just to see it!

Tonight let us celebrate Hevelius’ achievements by putting on our “cat’s eyes” as we go in search of one of the most distant objects in our galaxy – the NGC 2419. As a telescopic object only, this magnitude 11.5 study requires clear dark skies and at least 150mm of aperture. Since Lynx is a difficult constellation, you will find this easier by going 7 degrees north of Castor. You will know if you have the correct field if two stars appear to the western edge of a hazy patch. There is a very good reason “why” this elusive globular cluster is so special!

Most commonly known as “the Intergalactic Wanderer”, the NGC 2419 is so distant that it was at one time believed to actually be outside our own galaxy. Almost all globular clusters are found within our galactic “halo” – a region which exists about 65,000 light years around the galactic center. Our faint friend here is at least 210,000 light years from where it should be! When I tell you it’s out there… I’m not kidding. The NGC 2419 is as distant as our galactic “neighbors”, the Magellanic Clouds! But don’t worry, our galaxy has sufficient gravitation to keep “the Intergalactic Wanderer” around long enough for you to capture it for yourself!

Saturday, January 29 – While the Moon is absent from our early evening sky, take the time to simply go out and look up! The Winter Milky Way is a very glorious sight, with the Perseus and Orion spiral arms stretched overhead from the northwest to southeast. How could you not want to explore?! Tonight let’s aim binoculars and telescopes at one of the finest areas in our galaxy – the “Great Orion Nebula”.

One could devote years to studying just this region of the sky, as I could devote thousands upon thousands of words to tell you of its structure and beauty. Around 1600 light years away from us, this huge glowing cloud of “star stuff” is mainly florescence fueled by the extreme temperatures and ultra-violet radiation coming from its heart – Theta Orionis. Even small binoculars can see this “furnace” of four stars, but we will explore their intricacies at a later time. Tonight I would rather you just relax and note all delicate structure embedded in this grand nebula. For telescopes to truly grasp the vastness of this region, turn off your drives and allow it to flow gently past your gaze as you watch filaments, ribbons and encased stars sail past. For large telescopes, there is no more glorious sight than the fine streamers and slender threads which extend well beyond the bright parameters. There are loops, curls and swirls to be examined and the more aperture you have – the grander it becomes. If you sense this is an area of great turbulence, like frozen smoke, you would be correct. There are widely varied radial velocities throughout the structure!

Just relax and enjoy… It’s the finest in the night sky.

Sunday, January 30 – In the very early morning hours, the Moon will occult bright star Eta Viriginis for the biggest majority of Canada and the United States. See IOTA for times and locations. (I caution you this is right on the dividing line of time and date, so please make suitable adjustments for your specific locale.)

With a considerable amount of time before the Moon rises tonight, let’s bundle up in parkas and snow boots as we head for a namesake planetary nebula so fitting for this time of year – “The Eskimo”!

Fairly easily found by locating Wasat – Delta Geminorum – at the “waist” of Gemini, use the finderscope to locate wide double, 63 Geminorum to the east. You will find the NGC 2392 is only 2/3 of a degree southeast. Easily distinguished in even small telescopes as a blue/green “disc”, this colorful planetary nebula is around 3000 light years from us and requires large aperture to truly appreciate. At high power the 10th magnitude central star is very apparent and some of the “features” seen in photographs can be caught. While our eyes can never resolve the “Eskimo” in the same fashion that CCD imaging can, it is still possible to see the faint halo that surrounds the inner nebulosity, appearing much as a “parka-like hood” around a human face. Who knows? If we stay out in the cold long enough, we might even see “polar” bears rising in the northeast! Welcome back, Ursa Major…

And if you are out late enough to see the Moon rise in the northern hemisphere, have a look for Jupiter about 2 degrees to Luna’s lower left. If you were to watch all night, you would see the Moon cruise along just below the “Mighty Jove’s” position. By the time that dawn begins to stain the eastern sky, you will see the two ecliptic “dance partners” have now switched positions as the Moon is now 2 degrees to the lower left of Jupiter!

Until next week? Stay warm while you’re observing. We might be looking at the Moon, but we’re still reaching for those far away stars! Light speed… ~Tammy Plotner

NASA Will End the Search to Save Hubble

The US government has asked NASA to stop trying rescue Hubble, and instead focus on a way to safely deorbit the space-based observatory. This is based on the White House’s 2006 budget request, which doesn’t include any funds to save Hubble, but a small amount to attach a propulsion module to Hubble that would safely deorbit it into the Pacific Ocean. Outgoing NASA Administrator, Sean O’Keefe, is expected to announce this final decision during his February 7 public presentation of NASA’s 2006 budget request. Hubble supporters are rallying to defend the great observatory, so the final chapter has yet to be written.

Second Chinese Mission Announced

Chinese space officials have confirmed that their next mission, Shenzhou VI, could launch as early as September 2005. This next mission will carry a two astronauts, who will orbit the Earth for five days and perform a series of experiments in space. This will be the first flight for China since Yang Liwei was sent into orbit in October 2003. If this next flight is successful, China will follow this mission with spacewalks by 2007, and then orbital docking. China has also said that it’s looking to recruit women as astronauts for future missions.

Did Volcanoes Cause the Great Dying?

For the last three years evidence has been building that the impact of a comet or asteroid triggered the biggest mass extinction in Earth history, but new research from a team headed by a University of Washington scientist disputes that notion.

In a paper published Jan. 20 by Science Express, the online version of the journal Science, the researchers say they have found no evidence for an impact at the time of “the Great Dying” 250 million years ago. Instead, their research indicates the culprit might have been atmospheric warming because of greenhouse gases triggered by erupting volcanoes.

The extinction occurred at the boundary between the Permian and Triassic periods at a time when all land was concentrated in a supercontinent called Pangea. The Great Dying is considered the biggest catastrophe in the history of life on Earth, with 90 percent of all marine life and nearly three-quarters of land-based plant and animal life going extinct.

“The marine extinction and the land extinction appear to be simultaneous, based on the geochemical evidence we found,” said UW paleontologist Peter Ward, lead author of the paper. “Animals and plants both on land and in the sea were dying at the same time, and apparently from the same causes — too much heat and too little oxygen.”

The paper is to be published in the print edition of Science in a few weeks. Co-authors are Roger Buick and Geoffrey Garrison of the UW; Jennifer Botha and Roger Smith of the South African Museum; Joseph Kirschvink of the California Institute of Technology; Michael De Kock of Rand Afrikaans University in South Africa; and Douglas Erwin of the Smithsonian Institution.

The Karoo Basin of South Africa has provided the most intensively studied record of Permian-Triassic vertebrate fossils. In their work, the researchers were able to use chemical, biological and magnetic evidence to correlate sedimentary layers in the Karoo to similar layers in China that previous research has tied to the marine extinction at the end of the Permian period.

Evidence from the marine extinction is “eerily similar” to what the researchers found in the Karoo Basin, Ward said. Over seven years, they collected 126 reptile or amphibian skulls from a nearly 1,000-foot thick section of exposed Karoo sediment deposits from the time of the extinction. They found two patterns, one showing gradual extinction over about 10 million years leading up to the boundary between the Permian and Triassic periods, and the other for a sharp increase in extinction rate at the boundary that then lasted another 5 million years.

The scientists said they found nothing in the Karoo that would indicate a body such as an asteroid hit around the time of the extinction, though they looked specifically for impact clays or material ejected from a crater left by such an impact.

They contend that if there was a comet or asteroid impact, it was a minor element of the Permian extinction. Evidence from the Karoo, they said, is consistent with a mass extinction resulting from catastrophic ecosystem changes over a long time scale, not sudden changes associated with an impact.

The work, funded by the National Aeronautics and Space Administration’s Astrobiology Institute, the National Science Foundation and the National Research Foundation of South Africa, provides a glimpse of what can happen with long-term climate warming, Ward said.

In this case, there is ample evidence that the world got much warmer over a long period because of continuous volcanic eruptions in an area known as the Siberian Traps. As volcanism warmed the planet, large stores of methane gas frozen on the ocean floor might have been released to trigger runaway greenhouse warming, Ward said. But evidence suggests that species began dying out gradually as the planet warmed until conditions reached a critical threshold beyond which most species could not survive.

“It appears that atmospheric oxygen levels were dropping at this point also,” he said. “If that’s true, then high and intermediate elevations would have become uninhabitable. More than half the world would have been unlivable, life could only exist at the lowest elevations.”

He noted that the normal atmospheric oxygen level is around 21 percent, but evidence indicates that at the time of the Great Dying it dropped to about 16 percent — the equivalent of trying to breathe at the top of a 14,000-foot mountain.

“I think temperatures rose to a critical point. It got hotter and hotter until it reached a critical point and everything died,” Ward said. “It was a double-whammy of warmer temperatures and low oxygen, and most life couldn’t deal with it.”

Original Source: UW News Release