Posted on by Fraser Cain

Best Views of Titan and Tethys

Image credit: NASA/JPL/SSI
New views of two of Saturn’s moons, Titan and Tethys, represent the most detailed look at these moons to date and show a sharp contrast between them — one is foggy and one is cratered.

The Cassini spacecraft captured the puzzle pieces for the full-disc view of the mysterious Titan during its first close encounter on Oct. 26, 2004. The mosaic comprises nine images taken at distances ranging from 650,000 kilometers (400,000 miles) to 300,000 kilometers (200,000 miles).

The pictures are available at http://saturn.jpl.nasa.gov, http://www.nasa.gov/cassini and http://ciclops.org.

The images that make up the mosaic were processed to reduce effects of the atmosphere and to sharpen surface features. The mosaic of images has been trimmed to show only the illuminated surface and not the atmosphere around the edge of the moon. The Sun was behind Cassini, so nearly the full disc was illuminated. South polar clouds are seen at the bottom.

Surface features are best seen near the center of the moon. The surface features become fuzzier toward the outside of the image, where the spacecraft is peering through more haze. The brighter region on the right side near the equator is named Xanadu Regio. Scientists are debating what processes may have created the bizarre surface brightness patterns seen there. Titan’s lack of obvious craters is a hint of a young surface. However, the exact nature of that activity, whether tectonic, wind-blown, river-related, marine or volcanic, is still unknown.

Two days after the close encounter with icy Titan, Cassini captured the images used in the mosaic of the battered and cratered moon Tethys. The result is the best-ever natural color view of Titan.

As seen here, the surface of Tethys has a neutral hue. Three images form this natural color composite. The mosaic reveals a world nearly saturated with craters — many small craters lie on top of older, larger ones, suggesting an ancient surface. Grooves can be seen at the top and along the boundary between day and night.

Tethys is known to have a density very close to that of water, indicating that it is likely composed mainly of water ice. Its frozen mysteries await Cassini’s planned close flyby in September 2005.

The images to create this mosaic were taken on Oct. 28, 2004, at a distance of about 256,000 kilometers (159,000 miles) from Tethys. This view shows the trailing hemisphere of Tethys, which is the side opposite the moon’s direction of motion in its orbit.

Both images were taken with the narrow angle camera onboard the Cassini spacecraft. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Tethys Hangs Under Saturn

This dazzling view looks beyond gigantic storms near Saturn’s south pole to the small but clear disc of Tethys (1,060 kilometers, or 659 miles, across). Clouds and ribbons of gas swirl about in the planet’s atmosphere in the foreground, while a tremendous chasm is visible on the icy moon.

The image was taken with the Cassini spacecraft narrow angle camera on Oct. 18, 2004, at a distance of 3.9 million kilometers (2.4 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 61 degrees. The view is in wavelengths of visible red light centered at 619 nanometers. The image scale is 23 kilometers (14 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org .

Original Source: NASA/JPL News Release

Posted on by Mark Mortimer

Book Review: Earth from Space

This book is somewhere between a coffee table art book and a grade school science book. It has over three hundred stunning images of the Earth and, in particular, man-made structures divided up into eight chapters. The break down isn’t immediately obvious, but the overall result is. These views from remote sensing satellites help us understand the forces at work and in particular man’s influence. Seeing the drastic changes due to mankind causes some deep retrospection.

A typical chapter starts with a couple of pages detailing the importance of a particular topic. Often side bars therein contain small pictures of the earth (on the typical lat/lon perspective) that focus on one measurable parameter, such as surface temperature or ozone level. The main text discusses these and other related subjects all within the broad topic. Mineral content, for example, includes surface geology, presence of craters and shapes of desert plumes.

The pages after the text contain many large format (25cm by 25cm) images that highlight the topic. A view’s extent ranges from continental to citywide. The colour format can be real, infrared, or false coloured for highlighting. Also, a caption adjoining each image clearly describes the feature of interest, a bit of background of its significance (e.g. longest river in the world), the originating satellite and the acquisition date.

Man-made marvels take up a good portion. Toronto’s Skydome stabs upwards. Robert Smithson’s artwork ‘Spiral Jetty’ is just that, an impressive 450m long sculpture of placed rocks curling into Great Salt Lake of Utah. One awe inspiring view shows the al Haram mosque in Mecca with 400,000 worshipers surrounding the Ka’bah.

Though man-made features predominate, nature gets to show off as well. North America’s spring and fall foliage have gorgeous comparative views. Volcanoes and lava flows strut their fire and aftereffects. Hurricanes and glaciers meander in pleasant streams of vortices and funnels. The sand dunes from Yemen look like a beach shore at your toes until you read that the camera is at 800km and the average dune’s height is tens of metres. The Lena River in Siberia appears refreshingly green except for the vivid slashes of red scars throughout, the result of natural forest fires. Nature apparently makes great art without really trying.

Yet in a very unassuming way, the author highlights the main purpose of the remote sensing satellites; to identify the processes at work on the Earth’s surface. Though no preaching occurs, the images of the quickly disappearing Aral sea, the removal of the rain forests in the Amazon or the irrigation of crops in deserts serve this purpose well. Interestingly enough, the natural views tend to have smooth shapes and colours that gently flow from one type to another. However, the influence of humankind takes this smooth melody and introduces sharp discordant chords, breaking the rhythm. Mind you, nature can make its own sour music; just see the lava flow that slices right through the city of Goma. Nevertheless, humankind’s influence on the Earth is usually front row centre throughout.

The clarity of the images, whether of humankind or natural subjects, are outstanding. Resolutions at about 2m by 2m per pixel enable you to see individual cars. Many shots from the space shuttle give more of an oblique angle that puts the viewer closer to the action. Play an out of this world game of ‘eye-spy’ by guessing the area before reading the caption. Missing from the book are discussions on the accomplishments of remote sensing; in particular views showing changes over time and ensuing reactions by people. The many artistic shots, though bright and sharp, tend to quickly drift out of memory from this lack of mandate for inclusion.

Having grown up in fairly flat surroundings I really appreciate views from height. Images from 800km up are definitely out of the ordinary. Andrew Johnston in his book, Earth from Space, provides a wonderful trip about Earth, seeing some of the best images available from this height. Their source, mostly remote sensing satellites, provide these great artistic pictures that also provide important insight into how humans change this world.

To read more reviews online, or to get your own copy, visit Amazon.com.

Review by Mark Mortimer

Posted on by Fraser Cain

Interview with Colin Pillinger

Image credit: Beagle 2
Colin Pillinger is married and has two children. He lives on a small farm in Cambridgeshire, where his livestock keep him busy out of working hours. He first became interested in ‘space science’ by reading Dan Dare comics and listening to ‘Journey Into Space’ on the radio.

“The loss of Beagle-2 I would say was very frustrating to everyone who worked on the project including myself, because the craft carried the first instruments down onto the Martian surface that would actually look for Carbon based organisms, as apposed to carrying out a chemical analysis of the Martian soil by adding liquid nutrients, which is what the Label Release Experiment did on the Vikings landers back in 1976,” explained Professor Pillinger.

2004 has truly been ‘The year of Mars’ with the European Space Agency’s Mars Express doing remarkable science in Martian orbit, while sending back highly detailed images of the planet, and with the successful landing of the two NASA/JPL rovers Spirit and Opportunity in January which have done good geological science leading to the discovery that a huge quantity of water once flowed on the red planet.

“Finding out that a large amount of water existed on Mars in the past was good news because it brings the possibility of some form of life on the planet that bit closer,” explained Colin. “Meteorites from Mars that have landed on Earth show clear evidence that conditions appropriate to life did exist on the red planet, including in the recent past.

“However, features in the meteorites which have been described as nanofossils are highly controversial. Unfortunately, we cannot be sure that organic matter found in the meteorites is the remnant of organisms that lived on Mars and not due to contamination on Earth. We need to repeat the experiments on rocks that never left Mars,” he continued.

A short time ago I talked to Sir Patrick Moore about the best chance of finding life in the solar system, and I posed this question to Professor Pillinger as well. In our interview, Sir Patrick had said, “I believe our best chance of finding life is on the planet Mars. We now know that a lot of water once existed on this planet sometime in the past, and the latest surface rovers (Spirit and Opportunity), along side orbiting space probes like Mars Express, have shown that the Martian conditions are more favorable for life to evolve their today than at any time in the past. If the conditions are right, life will always find a way to exist.”

Prof. Pillinger replied “The fact that Mars Express has also confirmed the existence of methane in the thin Martian atmosphere, is interesting too.

“There have been two independent astronomical observations that first detected the presence of methane while Mars Express just confirmed it, and we now know that the amount of this gas is more than can be accounted for by volcanic activity.”

On Earth, there are many creatures, large and small, that produce methane. The simplest biological sources, including peat bogs, rice fields and ruminant animals (cows, sheep, etc.), continuously supply fresh gas to replace that destroyed by oxidation.

Methane also has a very short lifetime on Mars because of the oxidizing nature of the atmosphere, so its presence would indicate a replenishing source, which may be life, even if it is buried beneath the surface. If this methane exists, the Mars Express Orbiter has an instrument which should be able to detect it in the atmosphere.

“The Beagle-2 lander would have looked for signatures of life on Mars, whether long-dead or still-living, by measuring the ratio of two different types of carbon in the rock,” explained Prof. Pillinger. “Biological processes on Earth favor the lighter isotope of carbon, carbon-12, over the heavier carbon-13. Hence, a high carbon-12 to carbon-13 ratio is taken as evidence of life and has been found in rocks up to 4000 million years old, even where geological processing has occurred.”

Dr. Gilbert V. Levin, an experimenter with the original 1976 Viking Mission to Mars has been following this methane discovery with great interest. He has been advocating for years that Viking did find evidence of life on Mars with the Labeled Release life detection experiment, but other scientists are still skeptical.

I asked Colin if the discoveries by Spirit and Opportunity in 2004, or the recent discovery of methane supported Dr. Levin’s findings.

“I have heard of Dr. Levin. I think it is a firm understanding among planetary scientists that the Viking life investigation experiment only detected a chemical reaction rather than finding life on Mars itself. There is no point in harking on about the past, it’s time to move on and look for the real evidence of the carbon-based organisms that may exist on Mars today. That is where the Beagle 2 experiment differed from that of the Viking landers.”

Is there any other evidence that life may exist on the red planet, I asked? “Yes, meteorites from Mars that have landed on Earth show clear evidence that conditions appropriate to life did exist on the planet, including in the recent past, unfortunately, we cannot be sure that organic matter found in the meteorites is the remnant of organisms that lived on Mars and not due to contamination on Earth. We need to repeat the experiments on rocks that never left the Red Planet.

“At the moment there is no new Beagle Mars Lander project; however, I think this is an exciting time to look for life on Mars, and Beagle was well equipped to try and find it, which is why it has been very frustrating for my team and myself. I think that a new British Beagle lander should be built at this time to go to Mars and look for signs of life on the planet’s surface.”

By Science Correspondent Richard Pearson

Posted on by Fraser Cain

What’s Up This Week – Nov 22 – 28, 2004

Monday, November 22 – How about taking time to study a bit of astronomy this morning before a busy work week begins? Before dawn, ultra-bright Venus commands the ecliptic plane. Just above it, blue star Spica and mighty Jupiter capture attention and dim, red Mars is below Venus. This is a wonderful sight for just the unaided eye, but why not try a challenge this morning? All it will require is binoculars and clear sky! For viewers in both hemispheres, (40 degrees and below) the time is perfect to locate Comet C/2003 K4 LINEAR as it slides just slightly south of visible star Beta Hydra. At an estimated magnitude of 5, it will be a beauty for the Southern Hemisphere and a challenge for the North!

Tonight’s lunar feature can be spotted in binoculars, but needs a telescope to be studied. The Riphaeus Mountains will appear to the southwest of Copernicus. Highlighted by the bright ring of Euler, the Riphaeus Mountains under high power show a variety of isolated hills and sharp peaks which may have been the original crater walls of Mare Cognitum before having been filled with lava flow. Northeast of this range is an area with a smooth floor on the border of Oceanus Procellarum. It is here that Surveyor 3 landed on April 19, 1967. After having bounced three times, the lunar probe came to rest on a smooth slope in a sub-telescopic crater. As its on-board television monitors watched, Surveyor 3 deployed the “first of its kind” miniature power shovel and dug to a depth of 18 inches. The revelation of sub-soil material and clean-cut lines allowed scientists to come to the conclusion that the loose lunar soil was capable of compaction. Watching as Surveyor 3 pounded its shovel against the surface, the tiny “dents” it produced answered the crucial question – the surface of a mare would support the landing of a spacecraft and subsequent exploration by astronauts.

In the mood to stay up late tonight? Then wait until well past midnight until Orion has risen well in the sky and let’s try for another comet despite the Moon. Comet C/2004 Q2 (Machholz) is visible to larger binoculars, but better achieved in telescopes for northern viewers 40 degrees and below. At around magnitude 8, it will appear on the Columba/Caelum border. Viewers in both hemispheres should enjoy this one!

Tuesday, November 23 – The first photograph of a meteor shower was taken on this day in 1885 in Prague, Czechoslovakia but no picture can rival the beauty of the predawn skies as Venus once again dominates the scene. While lovely Spica and Jupiter try to steal the show, try to ignore them as it’s time to start observing Mars (right below Venus) and watch in the coming days as they appear closer and closer together.

Weather satellite Tiros II was launched on this day in 1960. Carried to orbit by a three-stage Delta rocket, the “Television Infrared Observation Satellite” was about the size of a barrel, testing experimental television techniques and infrared equipment. Operating for 376 days, Tiros II sent back thousands of pictures of Earth’s cloud cover and was successful in its experiments to control orientation of satellite spin and infrared sensors. Oddly enough, a similar mission – Meteosat1- also became the first satellite put into orbit in 1977 on this day by the European Space Agency. Where is all this leading? Why not try observing satellites on your own! Thanks to a wonderful tool from NASA you can be alerted by email whenever a bright satellite makes a pass for your specific area. It’s fun!

Tonight’s lunar feature will be bright, medium-sized class one crater, Artistarchus. On the terminator tonight north of Keplar, this dazzling feature can sometimes be seen by the naked eye and with no problem in binoculars. For telescopic viewers, Aristarchus will offer up a splendid challenge as you are encouraged to look for a thin, bright thread that curls away from it. Named Schroter’s Valley, it is a sinous rille and the largest of its kind. It may have once been a lava drainage channel, for it bears similarities with our own terrestrial volcanic features.

Wednesday, November 24 –
Heads up! There will an occulation of a bright star tonight by an asteroid. Visible from the NE to SW United States, Asteroid 860 Ursina will occult HIP 11395 (magnitude 7). For more details, click here for an IOTA locater chart and prediction times.

Comet C/2001 T4 (NEAT) will make its closest approach to Earth at a distance of 8.190 AU. Dry fact or an observable reality? Comet T4 is indeed very visible to the northern hemisphere, but it is not for the faint of heart. Right now it is holding around a magnitude 11 and is cutting its way across the Draco/Bootes border, making it a prime target for early morning viewers when the Moon is as low as it can possibly be. Requiring at least 12.5 inches of aperture, T4 will closely resemble a small, out-of-focus globular cluster since the Moon will toast any indication of coma. Are you up to that kind of challenge? I dare ya…

Tonight’s highlighted lunar feature can be seen in binoculars but best viewed with a telescope. Located in the southwest quadrant and on the terminator just south of Shickard, crater Wargentin is most unique. Once upon a time, it was a very normal crater and had been that way for hundreds of millions of years – then it happened. Either a fissure opened in its interior, or the meteoric impact that formed it caused molten lava to begin to rise. Oddly enough, Wargentin’s walls were without large enough breaks to allow the lava to escape and it continued to fill the crater to the rim. Often referred to as “the Cheese”, enjoy Wargentin tonight for its unusual appearance!

Thursday, November 25 – Ready to aim for a bullseye? Then tonight as darkness completely falls, go have a look at the Moon. To the right of it will be the M45, or the Pleiades star cluster. Just below it you will note bright, reddish star, Aldeberan. Set your eyes, scopes or binoculars there and let’s look into the “eye” of the Bull.

Known early on as “Al Dabaran”, or “the Follower”, Alpha Tauri it took its name for the fact that it appears to follow the Pleiades across the sky. In Latin it was “Stella Dominatrix”, yet the old English knew it as “Oculus Tauri”, or very literally the “eye of Taurus”. No matter which ancient astronomy lore we explore, there is reference to Aldeberan. As the 13th brightest star in the sky, it almost appears from Earth to be a member of the V-shaped Hyades star cluster, but its association is merely coincidental since it is about twice as close to us as the cluster. In reality, Aldeberan is really on the small end as far as K5 stars go and like many other orange giants, could possibly be a variable. Aldeberan is also known to have five close companions, but they are faint and highly difficult to observe with backyard equipment. At a distance of approximately 68 light years away, Alpha is only about 40 times larger than our own Sun and approximately 125 times brighter. To get a grasp on that size, think of it as being about the same size as the Earth’s orbit! Because of its position along the ecliptic, Aldeberan is one of the very few stars of first magnitude that can be occulted by the Moon.

And speaking of Moon, let’s explore tonight’s lunar feature – Galileo. It is a challenge for binoculars to spot this feature, but telescopes of any size capable of higher power will find it easily on the terminator to the west, northwest section of the Moon. Set in the smooth sands of Oceanus Procellarum, Galileo is a very tiny, eye-shaped crater and has a soft rille that accompanies it. It was named for the very man who first viewed and contemplated the Moon through a telescope. No matter what lunar resource you chose to follow, all agree that giving such an insignificant crater a great name like Galileo is unthinkable! For those of you familiar with some of the outstanding lunar features, read this account of Galileo’s life and just look at how many spectacular craters were named for people he supported! We cannot change the names of lunar cartography, but we can remember Galileo’s many accomplishments each time we view this crater.

Friday, November 26 – Today is the fifth anniversary of the discovery of SAU 005 & 008 labeled “Mars Meteorites”. These meteorites are known to be of Mars origin because of gases preserved in the glassy material of their interior. They were hurled into space some 600,000 years ago when a probable asteroid impact on Mars tossed them high enough to escape the planet’s gravity and were captured by our gravity thousands of years later. These are just 2 of the 32 meteorites found on Earth positively classed from their chemical compositions to be of Martian origin.

Comet 32P Comas Sola will make its closest approach to the Earth at a distance of 1.237 AU, but is it visible? The answer is yes. At around magnitude 13, Comas Sola is within the range of large aperture telescopes, but viewing will be difficult tonight thanks to the full Moon. Now cruising the border of Cetus and Aries, 32P can be found very near Mu Cetus. If you cannot spot it tonight, try in just a few days when the later rise of the Moon will provide darker skies.

Since it will be bright tonight, why don’t we try doing something a little different with an astronomical twist? Earlier in the week we discussed watching satellites, so how about if we learn how and when to locate the International Space Station! It’s easy to discover visible passes of the ISS using tools like this link provides, and even more fun to watch them. There may be a pass that will occur tonight in your area, and you might have to wait a few days, but the tool is now in your hands to predict the sightings. If you are new to the astronomy game, it may take a few times before the numbers that determine the height of the pass make sense from where you view, but don’t be discouraged if you don’t spot it right away. A rule of thumb is an altitude value of 10 means it will be very low on the horizon, while one of 90 means it will pass directly overhead. It’s very exciting to follow with binoculars because you can make out a certain amount of detail and those talented enough to “track” with a telescope will see even more. Even if you just watch with your eyes, it’s still a wonderful event that folks of all ages enjoy. Happy Hunting!

Tonight’s full Moon is also known as the “Frost Moon” and there is little doubt about how its name came to be! For those of you interested in viewing lunar features tonight, libration will be favourable to study a collection of shallow, dark craters known as Mare Australe. Located on the southeastern limb, this large binocular and telescopic object is well-worth locating because it isn’t always visible to the degree it will be tonight.

Saturday, November 27 – Tonight Uranus is at opposition. No, this doesn’t mean the planet is causing an altercation in the heavens or joining a political party. It just means that Uranus has now reached the point in its orbit where its celestial longitude is precisely 180 degrees from that of the Sun. Here’s a tip: planets that have reached opposition are visible all night long!

Tonight, rather than adventure on the lunar surface, let’s turn our eyes to the far north and explore the constellation of Cassiopeia. Almost everyone is familiar with the legend of Cassiopeia and how the Queen came to be bound in her chair, destined for an eternity to turn over and over in the sky, but did you know that Cassiopeia holds a wealth of double stars and galactic clusters? Seasoned sky watchers have long been familiar with this constellation’s many delights, but let’s pretend that not everyone knows where they are all at and tonight let’s begin our exploration of this Cassiopeia with a two of its primary stars.

Looking much like a flattened “W” the southern-most bright star is Alpha. Also known as Schedar, this magnitude 2.2 spectral type K star, was once suspected of being a variable, but no changes have been detected in modern astronomy. Binoculars will reveal its orange/yellow coloring, but a telescope is needed to bring out its unique features. In 1781, Sir William Herschel discovered a 9th magnitude companion star and our modern optics easily separate the blue/white component’s distance of 63″. A second, even fainter companion at 38″ is mentioned in the list of double stars and even a third at 14th magnitude was spotted by S.W. Burnham in 1889. All three stars are optical companions only, but make 150 to 200 light year distant Schedar a delight to view!

Just north of Alpha is the next destination for tonight… Eta Cassiopeiae. Discovered by Sir William Herschel in August of 1779, Eta is quite possibly one of the most well-known of binary stars. The 3.5 magnitude primary star is a spectral type G, meaning it has a yellowish color much like our own Sun. It is about 10% larger than Sol and about 25% brighter. The 7.5 magnitude secondary (or B star) is very definitely a K-type, metal poor, and distinctively red. In comparison, it is half the mass of our Sun, crammed into about a quarter of its volume and around 25 times dimmer. In the eyepiece, the B star will angle off to the northwest, providing a wonderful and colorful look at one of the season’s finest!

Sunday, November 28 – Why not step outside this morning before dawn and have a look at Mars just below Venus on the horizon? This would be a fitting way to celebrate the 40th anniversary of the Mariner 4 launch. Mariner 4 gave us our first “up close and personal” looks of the planet’s surface as it beamed back 22 television pictures of Mars’ barren, dusty red surface. As we look at Mars this morning, think of all the changes that have occurred in its exploration in just 40 years!

Heads up for this evening! In a line from Greenland, through Canada, to the northwest United States, Asteroid 80 Sappho will occult HIP 19229 (7.9 magnitude). For the northeast to southwest United States, 64 Angelina will occult SAO093069(b) (magnitude 11.3) and then a bit later take out SAO093069(a) (magnitude 10) for the southeast/southwest United States. Be sure to click on the links for appropriate times and finder charts supplied by IOTA.

Thanks to just a slightly later rise of the Moon, let’s return again to Cassiopeia and start first by exploring the central most bright star, Gamma. At approximately 100 light years away, Gamma is a very unusual star. Once thought to be a variable, this particular star has been known to go through some very radical changes with its temperature, spectrum, magnitude, color and even diameter! Gamma is also a visual double star, but the 11 magnitude companion is highly difficult to perceive so close (2.3″) from the primary.

Four degrees southeast of Gamma is our marker for this starhop, Phi Cassiopeiae. By aiming binoculars or telescopes at this star, it is very easy to locate an interesting open cluster, NGC457, because they will be in the same field of view. This bright and splendid galactic cluster has received a variety of names over the years because of its uncanny resemblance to a figure. Some call it an “Angel”, others see it as the “Zuni Thunderbird”, I’ve heard it called the “Owl” and the “Dragonfly”, but perhaps my most favourite is the “E.T. Cluster”, As you view it, you can see why! Bright Phi and HD 7902 appear like “eyes” in the dark and the dozens of stars that make up the “body” appear like outstretched “arms” or “wings”. (For E.T. fans? Check out the red “heart” in the center.)

All this is very fanciful, but what is the NGC457, really? Both Phi and HD 7902 may not be true members of the cluster. If magnitude 5 Phi were actually part of this grouping, it would have to have a distance of approximately 9300 light years, making it the most luminous star in the sky, far outshining even Rigel! To get a rough of idea of what that means, if we were to view our own Sun from this far away, it would be no more than magnitude 17.5. The fainter members of the NGC457 comprise a relatively “young” star cluster that spans about 30 light years across. Most of the stars are only about 10 million years old, yet there is 8.6 magnitude red supergiant in the center.

No matter what you call it, the NGC457 is an entertaining bright cluster that you will find yourself returning to again and again. Enjoy!

Until next week? Keep looking up and enjoying the wonders of the night sky! Wishing you clear skies and light speed…

~Tammy Plotner

Posted on by Fraser Cain

Private Spaceflight Legislation Passes

The US House of Representatives approved legislation on Saturday that would make regulations easier for companies looking to provide rides on private spacecraft. The vote for HR 5382 passed 269-120, which allows it to now go on for Senate approval, and finally to be signed by the President. This bill would streamline space tourism, allowing passengers to fly at their own risk, instead of forcing operators to take on excessive risk and insurance.

Posted on by Fraser Cain

Swift Launches to Search for Cosmic Explosions

NASA’s Swift satellite successfully launched today aboard a Boeing Delta 2 rocket at 12:16 p.m. EST from Launch Complex 17A at the Cape Canaveral Air Force Station, Fla. The satellite will pinpoint the location of distant yet fleeting explosions that appear to signal the births of black holes.

About 80 minutes after launch, the spacecraft was successfully separated from the Delta second stage. It has also been confirmed that the solar arrays are properly deployed.

“It’s a thrill that Swift is in orbit. We expect to detect and analyze more than 100 gamma-ray bursts a year. These are the most powerful explosions in the universe, and I can’t wait to learn more about them,” said Swift Principal Investigator Dr. Neil Gehrels, at NASA’s Goddard Space Flight Center, Greenbelt, Md.

Each gamma-ray burst is a short-lived event, lasting only a few milliseconds to a few minutes, never to appear again. They occur several times daily somewhere in the universe, and Swift should detect several weekly.

Swift, a mission with international participation, was designed to solve the 35-year-old mystery of the origin of gamma-ray bursts. Scientists believe the bursts are related to the formation of black holes throughout the universe – the birth cries of black holes.

To track these mysterious bursts, Swift carries a suite of three main instruments. The Burst Alert Telescope (BAT) instrument, built by Goddard, will detect and locate about two gamma-ray bursts weekly, relaying a rough position to the ground within 20 seconds. The satellite will swiftly re-point itself to bring the burst area into the narrower fields of view of the on-board X-ray Telescope (XRT) and the UltraViolet/Optical Telescope (UVOT). These telescopes study the afterglow of the burst produced by the cooling ashes that remain from the original explosion.

The XRT and UVOT instruments will determine a precise arc-second position of the burst and measure the spectrum of its afterglow from visible to X-ray wavelengths. For most of the bursts detected, Swift data, combined with complementary observations conducted with ground-based telescopes, will enable measurements of the distances to the burst sources.

The afterglow phenomenon can linger in X-ray light, optical light, and radio waves for hours to weeks, providing detailed information about the burst. Swift will check in on bursts regularly to study the fading afterglow, as will ground-based optical and radio telescopes. The crucial link is having a precise location to direct other telescopes. Swift will provide extremely precise positions for bursts in a matter of minutes.

Swift notifies the astronomical community via the Goddard-maintained Gamma-ray Burst Coordinates Network. The Swift Mission Operations Center, operated from Penn State’s University Park, Pa., campus, controls the Swift observatory and provides continuous burst information.

“Swift can respond almost instantly to any astrophysical phenomenon, and I suspect that we’re going to be making many discoveries which are currently unpredicted,” said Swift Mission Director John Nousek, Penn State professor of astronomy and astrophysics.

Goddard manages Swift. Swift is a NASA mission with the participation of the Italian Space Agency (ASI) and the Particle Physics and Astronomy Research Council in the United Kingdom.

Swift was built through collaboration with national laboratories, universities and international partners, including General Dynamics, Gilbert, Arizona; Penn State University; Los Alamos National Laboratory, New Mexico; Sonoma State University, Rohnert Park, Calif.; Mullard Space Science Laboratory in Dorking, Surrey, England; the University of Leicester, England; ASI-Malindi ground station in Africa; the ASI Science Data Center in Italy; and the Brera Observatory in Milan, Italy.

For more information about Swift on the Internet, visit:

http://www.nasa.gov/swift and http://swift.gsfc.nasa.gov

Original Source: NASA News Release

Posted on by Fraser Cain

Supermassive Black Holes Early On

NASA’s Chandra X-ray Observatory has obtained definitive evidence that a distant quasar formed less than a billion years after the Big Bang contains a fully-grown supermassive black hole generating energy at the rate of twenty trillion Suns. The existence of such massive black holes at this early epoch of the Universe challenges theories of the formation of galaxies and supermassive black holes.

Astronomers Daniel Schwartz and Shanil Virani of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA observed the quasar, known as SDSSp J1306, which is 12.7 billion light years away. Since the Universe is estimated to be 13.7 billion years old, we see the quasar as it was a billion years after the Big Bang. They found that the distribution of X-rays with energy, or X-ray spectrum, is indistinguishable from that of nearby, older quasars. Likewise, the relative brightness at optical and X-ray wavelengths of SDSSp J1306 was similar to that of the nearby group of quasars. Optical observations suggest that the mass of the black hole is about a billion solar masses.

Evidence of another early-epoch supermassive black hole was published previously by a team of scientists from the California Institute of Technology and the United Kingdom using the XMM-Newton X-ray satellite. They observed the quasar SDSSp J1030 at a distance of 12.8 billion light years and found essentially the same result for the X-ray spectrum as the Smithsonian scientists found for SDSSp J1306. Chandra’s precise location and spectrum for SDSSp J1306 with nearly the same properties eliminate any lingering uncertainty that precocious supermassive black holes exist.

“These two results seem to indicate that the way supermassive black holes produce X-rays has remained essentially the same from a very early date in the Universe,” said Schwartz. “This implies that the central black hole engine in a massive galaxy was formed very soon after the Big Bang.”

There is general agreement among astronomers that X-radiation from the vicinity of supermassive black holes is produced as gas is pulled toward a black hole, and heated to temperatures ranging from millions to billions of degrees. Most of the infalling gas is concentrated in a rapidly rotating disk, the inner part of which has a hot atmosphere or corona where temperatures can climb to billions of degrees.

Although the precise geometry and details of the X-ray production are not known, observations of numerous quasars, or supermassive black holes, have shown that many of them have very similar X-ray spectra, especially at high X-ray energies. This suggests that the basic geometry and mechanism are the same for these objects.

The remarkable similarity of the X-ray spectra of the young supermassive black holes to those of much older ones means that the supermassive black holes and their accretion disks, were already in place less than a billion years after the Big Bang. One possibility is that millions of 100 solar mass black holes formed from the collapse of massive stars in the young galaxy, and subsequently built up a billion-solar mass black hole in the center of the galaxy through mergers and accretion of gas.

To answer the question of how and when supermassive black holes were formed, astronomers plan to use the very deep Chandra exposures and other surveys to identify and study quasars at even earlier ages.

The paper by Schwartz and Virani on SDSSp J1306 was published in the November 1, 2004 issue of The Astrophysical Journal. The paper by Duncan Farrah and colleagues on SDSS J1030 was published in the August 10, 2004 issue of The Astrophysical Journal.

Chandra observed J1306 with its Advanced CCD Imaging Spectrometer (ACIS) instrument for approximately 33 hours in November 2003. NASA’s Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA’s Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Additional information and images are available at:
http://chandra.harvard.edu and http://chandra.nasa.gov

Original Source: Chandra News Release

Posted on by Fraser Cain

Rhea Shows Off a Big Impact

Saturn’s moon Rhea shows off the moon equivalent of a black eye — a bright, rayed crater near its eastern limb.

Rhea is about half the size of Earth’s moon. At 1,528 kilometers (949 miles) across, it is the second-largest moon orbiting Saturn.

The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 24, 2004, at a distance of about 1.7 million kilometers (1 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 40 degrees. The image scale is approximately 10 kilometers (6 miles) per pixel. Cassini will image this hemisphere of Rhea again in mid-January 2005, just after the Huygens probe landing on Titan – with approximately 1-kilometer (0.6-mile) resolution.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org .

Original Source: NASA/JPL/SSI News Release

Posted on by Fraser Cain

Atacama Desert From Space

This Envisat image was acquired over northern Chile’s Atacama Desert, the driest place on Earth outside of the Antarctic dry valleys.

Bounded on the west by the Pacific and on the east by the Andes, the Atacama Desert only knows rainfall between two and four times a century. The first sight of green in this Medium Resolution Imaging Spectrometer (MERIS) image occurs some 200 kilometres west of the coast, at the foothills of the Western Cordillera, where wispy white clouds start to make an appearance.

There are some parts of the desert where rainfall has never been recorded. The only moisture available comes from a dense fog known as camanchaca, formed when cold air associated with ocean currents originating in the Antarctic hits warmer air. This fog is literally harvested by plants and animals alike, including Atacama’s human inhabitants who use ‘fog nets’ to capture it for drinking water.

The landscape of the Atacama Desert is no less stark than its meteorology: a plateau covered with lava flows and salt basins. The conspicuous white area below the image centre is the Atacama Salt Flat, just to the south of the small village San Pedro de Atacama, regarded as the centre of the desert.

The Atacama is rich in copper and nitrates ? it has been the subject of border disputes between Chile and Bolivia for this reason – and so is strewn with abandoned mines. Today the European Southern Observatory (ESO) has located in high zones of the Atacama, astronomers treasuring the region’s remoteness and dry air. The Pan-American Highway runs north-south through the desert.

Along the Pacific coast, the characteristic tuft-shape of the Mejillones peninsula is visible, where the town of Antofagasta lies just south of Moreno Bay on the southern side of the formation.

This MERIS full resolution image was acquired on 10 January 2003 and has a spatial resolution of 200 metres.

Original Source: ESA News Release