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Articles for February2001
Buzz Aldrin Speaks
Buzz Aldrin describes his moon walk on Hardtalk (a BBC World programme).
A Sharper View of the Stars
A new generation of optical interferometers is letting astronomers study stars in 100 times finer detail than is possible with the Hubble Space Telescope.
A Mars Never Dreamed of
As the Mars Global Surveyor beams home unprecedented images, our assumptions about the red planet explode.

Making Sense of Modern Cosmology
This is an exciting time for cosmologists: findings are pouring in, ideas are bubbling up, and research to test those ideas is simmering away. But it is also a confusing time. All the ideas under discussion cannot possibly be right; they are not even consistent with one another. How is one to judge the progress? Here is how P. James E. Peebles goes about it.
Monsters in Galactic Nuclei
Thirty million light years away, a monster rules the heart of a galaxy. With the gravity of a billion suns, it controls the movements of millions of stars in its domain. Long ago, it blazed with a light that eclipsed the galaxy it lives in. Today, it is dark and quiet. Looking at NGC 3115 in a telescope, we would not guess that it is present.
Such monsters lurk in the centers of many galaxies, including our own. They are almost surely black holes, an extremely dense form of matter predicted by the general theory of relativity. Soon after quasars were discovered in 1963, astronomers proposed that their tremendous luminosities come from matter falling into giant black holes. The confirmation of this idea has been one of the exciting sagas of modern astrophysics.
Star Struck
A billion light years away, thereís a kind of stellar war going on. Stars, grouped together in dense clusters, are colliding. You could call it, well, star wars. But to astrophysicist Michael Shara, it's a "cosmic billiard game." Hereís your chance to learn what happens when stars, moving in excess of 50,000 mph, crash and burn. Some will survive, others will perish. Learn how massive black holes disrupt the pattern of star collisions. And learn the fate of that most famous star of all - our sun.
Life's Far-Flung Raw Materials
Life may owe its start to complex organic molecules manufactured in the icy heart of an interstellar cloud
Mapping the Universe
Using techniques drawn from the analysis of music, astronomers have been studying how galaxies form into progressively larger groupings.
When astronomer Edwin Hubble began to study the large-scale structure of the Universe in the early part of the century, he noticed something very interesting. Distant galaxies in space appeared to be flying away from the Milky Way, some with very large velocities. Not only were the galaxies receding, but the farther away they were, the faster they appeared to be moving away. Thus the Hubble Constant, Ho, a number which describes the speed of apparent recession as a function of distance, was born...
Is Space Finite?
The universe may look infinitely large, but that could be an illusion. If space folds back on itself like the braids of a pretzel, it might be boundless, and light could spool around the cosmos endlessly. Astronomers are looking for patterns in the star field that could signal a finite volume for space.
Hubble Goes Deep
Hubble recently complemented an earlier "deep field" observation of the northern hemisphere by peering down a 12-billion-light-year-long corridor in the southern sky. It revealed a dazzling array of far-flung, previously unseen galaxies. Cosmological theory predicts that the sky should look the same in all directions. What do these observations reveal? World-renowned astronomers discuss that question during this Web simulcast. Marc Steiner's guests include Dr. Carol Christian, STScI; Dr. Mark Dickinson, STScI; and Jim O'Leary, Baltimore Science Museum.
The Mysterious Middle of the Milky Way
Astronomers used to dismiss our own galaxy as boring--until they found that its center is a storm of exploding stars and roiling gas, all circling a hungry black hole and adorned by a fountain of antimatter.
Galaxies behind the Milky Way
Our galaxy covers more than 20 percent of the sky, frustrating astronomers trying to see the cosmos beyond it. Behind that veil of stars is the elusive Great Attractor, which pulls much of the nearby universe in the direction of Hydra, and a dwarf galaxy inside the spiral arms of our own
Hubble Witnesses The Final Blaze Of Glory Of Sun-Like Stars
In another five billion years, our Sun will cease to exist. Like other main-sequence stars, its internal heat-producing engine will exhaust its supply of hydrogen, creating a fatal imbalance between the Sun's internal gas pressure and the intense weight of its external layers. As gravity takes over, the Sun's core will contract, which in turn will heat its outer layers, causing them to expand to 200 times the Sun's normal diameter. It's happened to other stars...
Einstein's Drag
In 1918 Austrian physicists Joseph Lense and Hans Thirring derived from Einstein's equations of general relativity that an object that spins also twists the fabric of space-time around it. The Lense-Thirring effect is so small, however, that it has been hard to measure. In an elegant approach scientists measured how the rotation of Earth distorted space-time and thereby altered the paths of two orbiting satellites.
Why neutron stars and white dwarfs rotate: kicks at birth, not inheritance
Henk Spruit at the Max Planck Institute for Astrophysics and Sterl Phinney at Caltech explain an observation that has usually been considered a non-problem: the fact that pulsars rotate. Rather than being just an uninteresting leftover inherited from their progenitors, they interpret this rotation as a clue to the very process that forms the pulsar.
To Infinity and Beyond
The good news is that the Universe will not end in a cataclysmic crunch, says Robert Matthews. The bad news is that an even worse fate lies in store
Our Expanding Universe
Is our universe expanding faster than it used to? What does that mean for us?
Circles in the Sky
Detecting the shape of the universe. Scientists face difficulties in discerning the overall shape, or topology, of the universe - the shape of three-dimensional space itself rather than that of a two-dimensional surface.
Everything you ever wanted to know about galaxies, but were afraid to ask.
Virtual Trips to Black Holes and Neutron Stars
Ever wonder what it would look like to travel to a black hole? A neutron star? If so, you might find this page interesting. Here you will find descriptions and MPEG movies that take you on such exciting trips.
Black Holes
Beyond an event horizon lies a black hole - nature's ultimate abyss, a gravitational trap in space.

A Designer Universe?
Steven Weinberg was asked to comment on whether the universe shows signs of having been designed: "I don't see how it's possible to talk about this without having at least some vague idea of what a designer would be like. Any possible universe could be explained as the work of some sort of designer. Even a universe that is completely chaotic, without any laws or regularities at all, could be supposed to have been designed by an idiot."
Why Go to Mars?
Today Mars looms as humanity's next great terra incognita. And with dubious prospects for a short-term financial return, with the cold war a rapidly receding memory and amid a growing emphasis on international cooperation in large space ventures, it is clear that imperatives other than profits or nationalism will have to compel human beings to leave their tracks on the planet's ruddy surface. Could it be that science, which has long been a bit player in exploration, is at last destined to take a leading role? The question naturally invites a couple of others: Are there experiments that only humans could do on Mars? Could those experiments provide insights profound enough to justify the expense of sending people across interplanetary space?
Fossilized Bacteria in Murcheson and Efremovka
At a conference in Denver, July 20-22, 1999, a pair scientists from the Russian Academy of Sciences presented sharp images that look very much like fossilized microorganisms taken from fragments of several carbonaceous meteorites. Here are some of those images with comments from one of the scientists.
Migrating Planets
Did the solar system always look the way it does now? New evidence indicates that the outer planets may have migrated to their present orbits.
Not All Habitable Zones Are Created Equal
In this series of reports, author Bruce Moomaw examines the current tendency of some astronomers to believe that planets habitable to life -- such as Earth -- may be relative rarities.
Star Travelers: Craft Powered by Antimatter, Fusion and Solar-Driven Sails Could Take Us to Interstellar Space
Robert Frisbee is huffing cheerily as he ambles downhill toward a nondescript building on NASA's Jet Propulsion Laboratory campus in Pasadena, California. The San Gabriel mountains form a stunning backdrop, and the sun has warmed the January air to spring-like temperatures, but Frisbee doesn't seem to notice any of it. Indeed, his mind is far away. In interstellar space, to be exact. Frisbee is talking about how we'll someday visit the stars with spacecraft.
Close Approaches of Asteroid 1999 AN10
The Earth passes very close to the orbit of the asteroid 1999 AN10 twice per year, but whether or not this asteroid can have a close approach depends upon the timing of its passage across the ecliptic plane. Among the possible orbits there are some with a close approach in 2027. The period of the asteroid may be perturbed in such a way that it returns to an approach to the Earth at either of the possible encounter points. The authors have developed a theory which successfully predicts the 25 possible such returns up to 2040. They have also identified 6 more close approaches resulting from the cascade of successive returns. Because of this extremely chaotic behaviour there is no way to predict all possible approaches for more than a few decades after any close encounter, but the orbit will remain dangerously close to the orbit of the Earth for about 600 years.
The Way to Go in Space
Engineers have no shortage of inventive plans for new propulsion systems that might someday expand human presence, literally or figuratively, beyond this planet. Some are radical refinements of current rocket or jet technologies. Others harness nuclear energies or would ride on powerful laser beams. Even the equivalents of 'space elevators' for hoisting cargoes into orbit are on the drawing board.
Light Sails
Engineers have no shortage of inventive plans for new propulsion systems that might someday expand human presence, literally or figuratively, beyond this planet. Some are radical refinements of current rocket or jet technologies. Others harness nuclear energies or would ride on powerful laser beams. Even the equivalents of 'space elevators' for hoisting cargoes into orbit are on the drawing board.
Spaceships of the future
The Discovery channel takes a look at the future of spaceships.
Next Generation of Spacecraft
What would you do with four minutes of weightlessness? Conduct a science experiment to test out a pet project? Make love? Meditate? Whatever your heart desires, says world-renowned aviation designer Burt Rutan. Rutan is one of the competitors in the X Prize Competition, an international spacecraft contest that will award $10 million U.S. to the first person or company that designs a private spaceship which successfully launches three humans to a suborbital altitude of 100 km - where many consider space to begin - on two consecutive flights within as many weeks.
EQ Peg: A Detection?
An anonymous amateur astronomer in Great Britain claimed to have found an extraterrestrial signal in the direction of the star system EQ Pegasi. While some attention has been paid to this claim by the media, there is every indication that the claim is either an unrecognized detection of terrestrial interference or, as now seems overwhelming likely, a deliberate prank.
The Scientific Case for Human Spaceflight
Many scientists are sceptical about the scientific value of sending people into space. Here I.A. Crawford argues that this scepticism is seriously misplaced, and that science has been, and will continue to be, a major beneficiary of human space flight.
Life's Cosmic Origins
Are we alone? Astronomical observations over the last few years indicate that environments suitable for life are probably plentiful in the universe. World-renowned astronomers tackle this compelling question during the "Tour the Cosmos" Web simulcast. On this show, Marc Steiner's guests include Dr. Chris Burrows, Space Telescope Science Institute; Jim O'Leary, Baltimore Science Center; Dr. Steven Squyres, Cornell University; and Dr. Mark Voit, Space Telescope Science Institute.
Why did the supernova "morph"?
Most objects in the sky can be pigeonholed into a few of the hundreds of categories that classify stars, galaxies, and other bodies. Every now and then, you get one that changes its colors - literally - and seems to beg for closer examination.
Exploring New Worlds
Astronomers are puzzling over the formation and evolution of a slew of recently discovered massive planets that closely orbit stars near the solar system.
The Search for Extraterrestrial Intelligence
There can be little doubt that civilizations more advanced than the earth's exist elsewhere in the universe. The probabilities involved in locating one of them call for a substantial effort. (by Carl Sagan and Frank Drake)
Liquid water and life on Mars
Many objections have been raised to challenge a biological interpretation of the 1976 Viking Mission Labeled Release (LR) life detection experiment on Mars. Over the years, they have dwindled in the face of the failure of experiments and theories to demonstrate a nonbiological alternative. Recently, NASA's chief scientist, responding to the rapidly accumulating knowledge about life in extreme environments, reduced the remaining obstacles to a single one: the lack of liquid water. Now, a model for the presence of precipitable micron amounts of liquid water over large areas of Mars is presented. The model is consistent with the thermodynamics of the triple point of water.
The Significance of the Martian Frontier
The creation of a new frontier presents itself as America's and humanity's greatest social need. Nothing is more important. Robert Zubrin believes that humanity's new frontier can only be on Mars.
Reach for the Sky
Soon we are about to see the 21st century version of the Oklahoma Land Rush, only this time the race will be to see who can stake the best claims to the unfathomable potential of space. With NASA's blessing, a new wave of space exploration is soon to begin, one driven by a sense of adventure but also by something less quixotic -- the profit motive.
Space Burial: An Analysis
Considering the primordial star dust of which the solar system originated, it seems appropriate that people are returning to their origins aboard various spacecraft. The concept of burial in space, or burial of ashes and dust among the primordial star dust, has finally come of age. A new commercial market in space has begun to develop.
SETI and Radio Astronomy
A fabulous Question and Answer session on modern SETI efforts with Radio Astronomy.
Evading quantum barrier to time travel
Ruling out the possibility of traveling back in time has turned out to be trickier than many physicists had supposed. Mathematicians have demonstrated that a particular kind of vacuum state permits the occurrence of time loops.
Scooping Up a Chunk of Mars
In Michael Crichton's 1969 novel The Andromeda Strain, an unmanned government spacecraft returns to Earth, contaminated by an alien organism that destroys an entire town. NASA is striving to ensure that fact won't collide with fiction a decade from now, when a small capsule containing a canister the size of a soda can, packed with soil and rock fragments from Mars, is scheduled to parachute onto Earth.
Perturbing the Oort Cloud
Far beyond the orbit of Neptune, nearly halfway to the nearest stars, our solar system is surrounded by a vast spherical reservoir of comets known as the Oort cloud. In the classical view, these comets remain in the distant reservoir until a passing star perturbs the cloud, diverting some of the comets toward the inner solar system. Now, some recent developments suggest other explanations.
Imagination and Change: Science in the Next Millennium
A 50-minute lecture presented by Stephen Hawking at the Whitehouse on March 6th. The lecture looks at the ways science may go in the next few decades. The lecture for 14.4k connections.
First Sunrise of the New Millennium
When and where does the Sun first rise at the beginning of the next millennium?
Should We Return to the Moon? - A World Wide Web Public Policy Forum
A Unique Opportunity To Speak Out on an Important Issue touching upon our past, our present, and our future.
Geophysicists Ponder Hints of Otherworldly Water
More than 7000 geophysicists gathered here from 8 to 12 December for the annual fall meeting of the American Geophysical Union (AGU). All eyes were on a session addressing the claim that tiny comets pummel Earth every minute, but more distant wonders--oceans within Jupiter's moons--were one topic in a little-noticed Friday afternoon session.
The Case for Relic Life on Mars
A meteorite found in Antarctica offers strong evidence that Mars has had -- and may still have -- microbial life.
The Face on Mars
Here's an engaging discussion of the rock outcropping that some people think is evidence of Martian civilization. Find out why it's probably an optical illusion. From the Astronomical Society of the Pacific.
Did comets stir Earth's brew?
Did comet power spark life on Earth? Researchers in California are suggesting that comets might not only have provided the starting material, but could also have supplied the energetic push that got biological chemistry rolling.
Did Earth's Life Originate on Mars?
This is a speculative argument, based on a preliminary NASA finding of possible ancient cellular life on Mars. It is not intended to represent proven scientific fact, but is a speculation based on ongoing scientific work that is incomplete at the time of writing.
The Bimillenary of Christ's Birth: The Astronomical Evidence
Everyone knows that we are approaching the two-thousandth anniversary of the birth of Christ, but exactly when should it be celebrated?
The 'Stars' of Bethlehem
A look at astronomical and historical records leads to a few intriguing possibilities as to what the Star of Bethlehem may have been.
Yet Another Eclipse for Herod
The date of the reported lunar eclipse shortly before the death of King Herod has long been recognised to be important for delimiting possible dates for the birth of Christ.

A Sharper View of the Stars
A new generation of optical interferometers is letting astronomers study stars in 100 times finer detail than is possible with the Hubble Space Telescope.
A Mars Never Dreamed of
As the Mars Global Surveyor beams home unprecedented images, our assumptions about the red planet explode.
Interview with Ray Bradbury
A fifteen minute interview with author and poet, Ray Bradbury, featuring his thoughts, reminiscences and hopes for the future.
A Mars Never Dreamed of
As the Mars Global Surveyor beams home unprecedented images, our assumptions about the red planet explode.
Buying a Star FAQ
Many people wonder if it's possible to buy a star or have one named in someone's honour. There are organizations that will take your money and send you a certificate for such, but those documents have no validity and are not recognized by anyone else. There are at least a half-dozen companies or individuals who claim the ability to name stars. However, no private company has ever been granted the authority to name stars by any government, professional astronomical organization, or international treaty.
The Bottom line: The International Astronomical Union is the only organization with the right to name anything in the sky. They get this right from international treaty. No private company has ever been given such authority. The IAU does not name stars after people. Click here for the IAU's statement on the buying and selling of star names.
This Frequently Asked Questions page should answer any questions you may have regarding "buying" a star.
Where Are They?
How common are other civilizations in the universe? This question has fascinated humanity for centuries, and although we still have no definitive answer, a number of recent developments have brought it once again to the fore. Chief among these is the confirmation, after a long wait and several false starts, that planets exist outside our solar system.
The Discovery of Brown Dwarfs
Less massive than stars but more massive than planets, brown dwarfs were long assumed to be rare. New sky surveys, however, show that the objects may be as common as stars.
Giant Rocks and Snowballs
A new comet is speeding in from the dark. If it comes as a surprise to you, well, join the crowd. The comet has probably changed little since it clumped together some 4.5 billion years ago. Ten miles wide, it is an uneven mass of the same ice, rock and dust that swirled around our early sun during the solar system's formation.
Floating in Space
Balloons offer scientists a low-cost, quick-response way to study the upper reaches of Earth's atmosphere and those of other planets. Rejecting the idea that an old dog can't be taught new tricks, scientists and engineers at the NASA are revolutionizing the size, shape, durability and stamina - indeed, just about everything - of the balloon, humankind's oldest flight vehicle.
Migrating Planets
Did the solar system always look the way it does now? New evidence indicates that the outer planets may have migrated to their present orbits.
Basic Celestial Phenomena
These pages provide explanations and learning activities in an accessible format to students, teachers, families, and visitors to planetariums. Altogether, they represent an introductory course in observational astronomy.
Folklore of the "Blue Moon"
A most interesting bit of modern folklore is the sudden popularity of the term "blue moon." Names of moons at certain times of the year have been around a long time, and almanacs are especially wont to list twelve of them. Blue Moon is different from the monthly or seasonal moon names as it isn't restricted to a time of year. It is a movable feast.
What's a Blue Moon?
A 53-year-old mistake in Sky & Telescope changed pop culture and the English language in unexpected ways.
Introduction to Amateur SETI
Today, the search for evidence of other inhabited worlds is in full swing, thanks in part to the interest and expertise of the world's amateur radio operators, radio astronomers, and microwave experimenters. This Introduction tells you how you can join the search.
The Leonids are Coming! The Leonids are Coming!
Every year in mid-November, Earth encounters the Leonid storm, so named because it was thought to come from the constellation Leo. In fact, this storm originates from a tenuous stream of dusty debris expelled by Comet 55P/ Tempel-Tuttle during centuries of passes near the sun. These particles, known as meteoroids, spread out along the cometís orbit.
The Mars Underground Emerges: The Founding Convention of the Mars Society
Boulder, Colorado has been the temporary base camp for Earthbound Martians for more than a decade. Every few summers, they roll into town for one in a series of "Case for Mars" conferences wherein a diverse mixture of scientists, engineers, and space enthusiasts (the so-called "Mars Underground") have gathered to keep the dialog going -- even if NASA had apparently lost interest. This summer, the Mars Underground finally came out of hiding -- with a vengeance.
Climbed a Mountain, Saw a Comet, Defined the Far Parameters of the Visible Universe
Just another day of the extreme science at Mauna Kea, the most breathtaking observatory in the world. Rising 13,796 feet above sea level, the mountain offers astronomers heavenly visions.
A Field of Martian Dreams
Baseball would be a whole different game on Mars. McGwire would have bagged the home run record several times this season, and the scores for every game would be in multiple digits. A bunch of outfielders would be in the hospital, nursing broken arms, too.
How hot is the Crab?
In early summer of 1054, the people of Japan and China witnessed an amazing display of fireworks in the summer sky. NASA's next Great Observatory takes aim at the result of that explosion: the Crab Nebula pulsar.
The Discovery of the Perseid Meteors
Edward Claudius Herrick, bookworm and failed businessman who suffered chronic eyelid inflammation discovered the history of the Perseids.
First Light!
On the cold, cloudless night of May 25 in a remote desert in Chile, a huge protective enclosure slid open, exposing a giant telescope to the dim light of distant stars and galaxies. As the faint illumination reflected onto its gleaming, newly-coated mirror, 8.2 meters in diameter, the instrument began collecting its first scientific data--a once-in-a-telescope event that astronomers call "First Light."
Chat: Astronomer David Levy
David Levy took part in an hour-long CNN "Author's Chat" on May 12, 1998. This is a transcript of the chat.
The Magnificent Cosmos
Exploration of space has sprinted forward over the past two decades, even though no human has ventured outside the lunar orbit. Scientific American summarizes the most extraordinary discoveries and still open mysteries of modern astronomy in a series of excellent online feature articles.
Visions from Kennedy Space Center, Part 2
Herb Malsman returns to Kennedy Space Center to pay an exclusive peek, but no-touch visit to Columbia's "white-room"...and "blast-off" with Discovery.
Visions from Kennedy Space Center, Part 1
Head for the moon with Neil Armstrong and friends, visit an astronaut's home-away-from-home...and take a probing look at a Martian probe.
Out of the Cosmodrome
Former space shuttle engineer, James Oberg, author of Red Star in Orbit explores the continuing odyssey of space station Mir.
Reviews of space missions which took place in 1997 - Pathfinder, Mir, Pioneer 10, Cassini and Timothy Leary's ashes.
Reviews of astronomical discoveries and events which occurred in 1997 - Hubble's New Prism, the Pistol Star, comet Hale-Bopp, weird object 1996TL66, gamma-ray bursts and whether there's water on the Moon.
Astro-2 Archives
Astro-2 was a high-tech observatory which flew for 16 days in the payload bay of the Space Shuttle Endeavour during the STS-67 mission. The Astro-2 instruments allowed astronomers to view stars, galaxies, planets and quasars in ultraviolet light. The most exciting discovery to date has been the first definitive detection of primordial helium.
Comet or Asteroid?
When is a minor object in the solar system a comet? And when is it an asteroid?
Mars Pathfinder Foldout
Presents images and analysis from the Mars Pathfinder Mission that are discussed in seven subsequent linked Reports.
Repairing MIR - CNN Special Section
Tons of information, past and present, on the trials and tribulations of the Russian space station.
Signatures From Earth
Signatures from thousands of people around the world are voyaging out to Saturn on the Cassini probe.

Carl Sagan, 1934-1996
The death of Carl Sagan on December 20, 1996, robbed the science world of one of its most creative researchers and articulate spokesmen.
Eugene M. Shoemaker: A Timeless Tribute
A tribute to the man who contributed to the moon programme and who co-discovered the Shoemaker-Levy 9 comet which slammed into Jupiter in 1994.
Clyde Tombaugh, 1906-1997
On January 17, 1997, Clyde Tombaugh, the discoverer of the planet Pluto, passed away. In his nearly 91 years Tombaugh made tremendous contributions to the field of astronomy and inspired generations of future astronomers to follow in his footsteps.

Calendars & Time
A Walk Through Time
Does anybody really know what time it is? If anyone does, it's the researchers at NIST, the modern successor to the old National Bureau of Standards. Here you can find out all about the history of time measurement and learn how modern clocks stay accurate to within millionths of a second. And of course there are links to tell you, very very exactly, what time it is right now.
The Calendar FAQ
A comprehensive 'frequently asked questions' list dealing with just about everything to do with calendars. Well worth a read.
Astronomical Time Keeping
Time keeping and the construction of calendars are among the oldest branches of astronomy. Up until very recently, no earth-bound method of time keeping could match the accuracy of time determinations derived from observations of the sun and the planets.
Time and the Amateur Astronomer
Knowing time is simple in everyday life. You look at a clock. You assume that everyone else's clock in your time zone reads the same. And that's that. For astronomers, however, time can become quite complex.

Meteor Showers and their Observation
This guide is intended for the amateur just starting out with meteor observing and forms the basis of the training provided by the North American Meteor Network (NAMN).
The Leonids
A roundup of information about the Leonid meteor shower which includes current and historical information on the subject.
A New View Of Mizar
Last year saw two interesting events in the world of double stars, both of them connected with an astronomer's old friend in the Big Dipper. While the early history of double star astronomy had to be completely rewritten after an examination of 17th century Italian manuscripts, its future at the beginning of the next millennium was briefly unveiled by the amazing precision of a new astrometric instrument, which will soon eliminate the difference between spectroscopic and visual binaries.
The Universe en Rose
On a clear night, most astronomers would consider themselves lucky to be on Hawaii's Mauna Kea, in the control room of the world's biggest optical telescope. What could be more exhilarating than to know that 3.6 kilometers away, on the summit of this extinct volcano, the giant mirror of the Keck I Telescope is at your command? By all rights, astrophysicist Richard G. McMahon should have been sitting pretty. But on this night, he was frustrated.
So You Think You've Discovered A Comet...
"Discovering" a comet means different things depending on whether one is a very experienced observer or is a beginning observer. For every real new comet discovery, the Central Bureau for Astronomical Telegrams (CBAT) gets perhaps five reports of "discoveries" that do not pan out. If you think that you might have come across a new comet, here is a check-list that you should go through before proceeding further.
Astronomical League Observing Clubs
The Observing Clubs offer encouragement and certificates of accomplishment for demonstrating observing skills with a variety of instruments and objects. These include the Messier Club; Binocular Messier Club and the Herschel 400 Club, the Deep Sky Binocular Club, the Southern Skies Binocular Club, the Meteor Club, the Double Star Club, and the newly formed Lunar Club. Each Club offers a certificate based upon acheiving certain observing goals. These are usually in the form of a specific number of objects of a specific group with a given type of instrument. Ocassionally there are multiple levels of accomplishment within the club. There is no time limit for completing the required observing, but good record keeping is required.
Meteor Observing
With the imminent advent of the beginning of the Perseid meteor shower, this article takes a look at what's involved in observing meteors and recording your observations.
Touring the Moon with Binoculars
The moon lies only a quarter million miles away exhibiting a wealth of detail in a small telescopes and binoculars. Both will reveal the Moon's desolate landscape punctuated by bright highlands, dark plains, and rayed craters.
Backyard Astronomy: Tips on Observing the Universe
Sky & Telescope's selection of popular how-to articles from the Backyard Astronomy series, along with an assortment of other useful tips. Ideal for beginners.
Eclipse Home Page
No one knows more about eclipses than Fred Espenak at NASA. Here you can find out about all the solar and lunar eclipses for the next 50 years. Tips of viewing and photographing them, too.
Moon Watching
Our Moon is too often overlooked, but there is much to see on Earth's satellite that will delight both beginners and experienced astronomers.
The Constellations See also: The Constellations
These two sites contain information on the 88 constellations; the first includes the Greek myths and data on individual stars; the second provides better maps and more detailed object information.
Fred Schaaf's Light-Pollution Notes
Stargazers today face a problem that barely existed only a generation ago. Light pollution has spread so much in the last few decades that it compromises our view of the stars. For about half of us, the stars no longer really come out at all.

Vixen SkySensor 2000 Product Review
The idea of being able to select a deep sky object from a data base, press a key and have the telescope automatically point at that object appeals to many amateurs. This appeal has made the LX200 a very popular product especially to the new generation of technology oriented amateur astronomers with spare cash in their wallets. The Vixen SkySensor 2000 is the first of the third generation of add-ons for Computerizing Telescopes. After a decade of development, the promise of the Computerized Telescope has been fully realized.
Telescopes with Al Nagler
For years, Tele Vue Optics has been a source for new designs in telescopes and eyepieces for amateur astronomers. Founder Al Nagler is a former Gemini engineer who built his first telescope in a high school shop class. It's been over 20 years since Al introduced the telescope line that bears his name. Now he's teamed with his son, David Nagler; both join Andy and Michael this week for a peek at what's new in the world of optics!
X-Ray Space Vision
To see deep into space and look at its oddball collection of cosmic inhabitants takes a lot more than human eyes alone. It requires eyes that can see different kinds of light. That's the thinking behind NASA's 'Great Observatories' -- the next generation of high-tech devices that are proving invaluable to astronomers mapping the universe. Black holes, supernovae and star nurseries are just the beginning of a long list of what's out there that astronomers want to explore more deeply. The new mechanical space observers make it possible because they detect light that's otherwise invisible to us. The latest of the bunch is the Chandra X-ray Observatory.
The New Scope Owner
Nice scope! Bet you can't wait to get out and use it. Oh, you say you have tried to use it already? Frustrated? Can't figure out what to point it at? Don't know what all the accessories are for? Step into the Astro Lair, and the owner of this page will try to help you out!
Weasner's Mighty ETX Site
Created by a dedicated user of the most popular amateur telescope in history, this site has lots of general astronomy resources as well as a wealth of practical info for ETX users and prospective buyers.
It takes more than one kind of telescope to see the light
By studying the electromagnetic emissions of objects such as stars, galaxies, and black holes, astronomers hope to come to a better understanding of the universe. Although many astronomical puzzles can only be solved by comparing images of different wavelengths, telescopes are only designed to detect a particular portion of the electromagnetic spectrum. Astronomers therefore often use images from several different telescopes to study celestial phenomena.
Polar Alignment of a Telescope on Equatorial Mount
A method of polar alignment for clock-driven Fork or German mounts which might not be of much use for Poncet or so-called barn-door types. The method is designed for telescopes fitted with fairly large and accurate setting circles and will be useless on small, badly-functional types.
The Heretic's Guide to Purchasing a Telescope
There are a lot of people who are dying to own a telescope to view the heavens above, but who need direction on how to spend the money they've been saving.
A Quartz Controlled Scotch Mount
The Scotch mount, also called the Haig or barn door mount, has been around for many years, and has allowed amateurs to produce photographs of the night sky simply and cheaply. The addition of a quartz controlled stepper motor increases the utility at a modest cost. The circuit described can also be used for driving a telescope.
Motorize Your Dobsonian Telescope
Dobsonian telescopes offer big thin mirrors with stable, inexpensive altazimuth mounts. Motorizing a dobsonian adds automatic tracking and finding capabilities. In addition, you can use higher magnifications to bring out detail. Finally, you can greatly extend your reach into the universe by attaching a CCD or electronic camera to your large mirror dobsonian telescope.
Good Neighbor Outdoor Lighting
Learn some simple ways to fight the scourge of light pollution!
What Telescope Should I Buy?
This set of questions and answers about purchasing amateur telescopes was originally posted as an FAQ article on the Internet newsgroup sci.astro.amateur. Since it was originally aimed at an American audience, the addresses, models, prices etc. pertain to the USA; equivalent information for a UK audience is planned in the future. Note that prices may have changed a little since the article was written.
Buying Your First Telescope
Taking the time to research your purchase is a good idea. It's even a lot of fun. But don't agonize over the decision. With the exception of certain department-store 60mm refractors, there are few lemons on the telescope market.
History of Astronomical Spectroscopy
Astronomical spectroscopy played a crucial role in the elucidation of the physics of stellar atmospheres. This site goes into a detailed historical review of various objects and elements discovered spectroscopically in outer space, such as the supposedly 'new' elements nebulium and coronium.
Maunder-Pickering Experiments
A common discussion among amateur astronomers concerns the resolution limits of telescopes, and the sizes of details which can be seen on planets.

Guiding Techniques for Astrophotography
This is a description the techniques that the author (Philip Perkins) uses to guide his LX200 10" f/10 for long exposure astrophotography.
Meteor Observation with Video Equipment
The idea of using a video camera for observing the night sky and searching for meteors was born at the International Meteor Conference in 1992. There two Canadian astronomers presented a poster about their video equipment and how they managed to find and analyse meteors on their video tapes. One of the most significant facts was that they reach dreamlike limiting magnitudes with their system. On the other hand they could observe only a small area of the sky. So, a team of young meteor observers at Archenhold Observatory Berlin, decided to reproduce a similar system for wide angle sky observations with the already existing equipment at their observatory.
QuickCam Astrophotograhy
Using the Connectix QuickCam is a cheap way to get into CCD astrophotography. The camera has a CCD that can capture a 6-bit greyscale image which is transmitted through a parallel port to a computer. Software can then be used to manipulate the images. This page describes the use of such a camera.
Adjusting Your Astrophotos with Photoshop Levels
In the course of his travels to numerous astrophoto sites Chuck Vaughn has noticed that the majority of images are not adjusted properly. He's not talking about whether images are over/under saturated or even if the colors of nebulas are what are expected, but the most basic of image processing adjustments - Levels.
Adventures in Astrophotography with a Small Telescope
This article is mainly for those who have only a small telescope, and is intended to show you just what can be done with such an instrument. This article covers the full spectrum of available subjects, from terrestrial and lunar to planets and deep-sky objects. As will be seen, small telescopes are capable of producing good photos of deep-sky objects, even at relatively large image scales, with today's fast color films. All photos were taken with a 4" aperture or smaller instrument.
A Quartz Controlled Scotch Mount
The Scotch mount, also called the Haig or barn door mount, has been around for many years, and has allowed amateurs to produce photographs of the night sky simply and cheaply. The addition of a quartz controlled stepper motor increases the utility at a modest cost. The circuit described can also be used for driving a telescope.
Starting Out Right in CCD Imaging
A CCD system can provide a personal grand tour of the universe or total frustration! You won't get good results by just buying a camera and slapping it on any telescope. Achieving top performance requires you to carefully match the CCD detector to the optical system or vice versa. It's also important to pay attention to details like the telescope's focuser, finder, and mounting.
Lunar Eclipse Photography
The ins and outs of photographing various stages fo a lunar eclipse.
Photographing the Moon
Site dedicated to photographing the various phases of the moon using a standard camera.

Astronomical Events
The Galileo Mission to Jupiter and Its Moons
Few scientists thought that the Galileo spacecraft, beset by technical troubles, could conduct such a comprehensive study of the Jovian system. And few predicted that the innards of these worlds would prove so varied.
HD 209458 Planetary Transit
The first transit of an extrasolar planet across the disk of its star has been detected with the T8 0.80 meter Automatic Photoelectric Telescope (APT) operated by Tennessee State University in Nashville.
Report about the Solar Eclipse on August 11, 1999
This webpage provides information about the total eclipse on Wednesday, August 11, 1999, as it was seen by ESO staff, mostly at or near the ESO Headquarters in Garching (Bavaria, Germany). The zone of totality was about 108 km wide and the ESO HQ were located only 8 km south of the line of maximum totality. The duration of the phase of totality was about 2 min 17 sec.
The Millennium's Last Total Solar Eclipse
Nearly four decades have passed since a total eclipse of the Sun was visible from Europe. The long drought finally ends with the last total eclipse of the Second Millennium on Wednesday, August 11, 1999.
Spinning Stardust into Planets
Astronomers are getting a fresh look at what may be the early stages of planetary system formation. Recent pictures by NASA's Hubble Space Telescope don't show actual planets, but rather edge-on disks that provide some of the clearest views to date of potential planetary construction zones. The photos may hold clues to what happened some 4.5 billion years ago when the Earth and the other planets in the Solar System condensed out of a similar pancake-shaped disk around our young Sun.
The Status of Pluto
The IAU has issued a Press Release describing the limited decisions that have been made and reaffirming that Pluto is considered a planet. Extensive media reporting on this issue, both print and electronic over the last several days, has varied from excellent to abysmal. Errors in the media include a) errors of fact about what has been decided, b) misidentification of people making proposals, c) inverted chronology of events. This article describes the issues.
The Struggle to Find the Ninth Planet
Many papers have been written and published on the triumphal detection and discovery of Pluto. As the sole survivor of the Lowell Observatory staff in that frustrating year of 1929, Clyde Tombaugh tels the story about his trials in the search.
The Day the Sands Caught Fire
Not so long ago a garage-size meteorite slammed into the uninhabited heart of Arabia and flash-cooked the sand into glass. Exploration of the site is a sober reminder of the destructive power of rocks from space.
Hubble Goes To The Limit In Search Of Farthest Galaxies
Stretching the vision of NASA's Hubble Space Telescope farther across space and further back into time than ever before, astronomers have peered into a previously unseen realm of the universe. (50 minute RealVideo).
Crusty young star makes its presence felt
A powerful flash of gamma rays, strong enough to be detected through a satellite's own shielding and to turn night into day in the Earth's outer atmosphere, has led to confirmation of the existence of super-magnetized stars.
Mooning over the dust rings of Jupiter
The deep impacts that killed the dinosaurs or excavated our moon's vast craters count among the most spectacular examples of collisions in the solar system. Even little crashes, however, can make a big difference. Images taken by the Galileo spacecraft reveal that the dust kicked up by scraps of interplanetary debris plowing into four of Jupiter's tiniest moons are the source of the giant planet's dust rings. Mars' moon Phobos also has been pummeled and its surface pulverized into powder perhaps a meter deep.
The Ring Cycle
The video news conference at Cornell University on September 15, 1998, held in conjunction with NASA and the Jet Propulsion Laboratory (JPL), announcing the discovery of the origin of Jupiter's rings as determined through analysis of data from NASA's Galileo spacecraft.
Craft Finds New Evidence of Magnetars
Late last month, astronomers witnessed a star going berserk. Ever since they saw it hiccuping X rays during the last week of May, researchers had been taking daily observations of this Milky Way resident. On Aug. 27, the star sent a spectacular flood of gamma rays coursing through the solar system.
The Mars "Face" and Lowell's "Canals"
"I find it unfortunate that for the last two decades, some people have expended a large amount of time, energy, and effort on a surface feature that looked like a face based on a couple of distant images taken by the Viking orbiter," says Larry Klaes.
Target Earth
In one of the most awesome sights of prehistory, the earliest dinosaurs may have looked up from their evening meals to witness a mountain hurtling through the sky. Blazing white-hot and moving at 61,000 kilometers per hour, the giant comet or asteroid screamed through Earth's atmosphere-possibly close enough to snap the tops off any high peaks in its path. Then the object disappeared back into space, missing the planet by the thinnest of margins.
Asteroid Impact
It terrorized us for one day in the news awhile back, and it promises to do the same in two upcoming big-budget movies. But what happened when an asteroid DID strike Earth 65 million years ago? This and other questions.
Dust Disks Hint at Baby Solar System
Radio and infrared images unveiled in April suggest that three nearby stars have recently spawned planets and may still be in the throes of forming complete planetary systems. These portraits, showing dust surrounding youthful stars from 10 million to about 350 million years old, may offer snapshots of what the Milky Way looked like shortly after the birth of the sun 4.5 billion years ago.
Shock Wave Sheds New Light on Fading Supernova
Recent Hubble telescope observations show a brightening knot on the upper right side of Supernova 1987A's Ring. This is the site of a powerful collision between an outward moving blast wave and the innermost parts of the circumstellar ring. The collision heats the gas and has caused it to brighten in recent months. This is likely to be the first sign of a dramatic and violent collision that will take place over the next few years, rejuvenating SN1987A as a powerful source of X-ray and radio emissions.
Asteroid Threat Downgraded
Astronomers at NASA's Jet Propulsion Lab have reversed a prediction that an asteroid would pass perilously close to earth in the year 2028.
Asteroid on Earth Course
Astronomers have discovered an asteroid they say is headed for a close encounter with Earth. The mile-wide space rock appears to be on a trajectory that will bring it uncomfortably close to our planet three decades from now.
Total eclipse
A total solar eclipse, when the Moon passes directly in front of the Sun, is an awe-inspiring sight. Wherever one happens, it attracts legions of sightseers from across the world, many of whom become hopelessly addicted and dedicate the rest of their lives to chasing the "high" of an eclipse.
Feb. 26th's Total Solar Eclipse
Coverage of the solar eclipse which was visible in the Carribean in February. Includes a realvideo video of the eclipse.
Near-Earth asteroid 3753 (1986 TO) -- Earth's curious companion
The near-Earth asteroid 3753 (1986 TO) is now known to be a companion, and an unusual one, of the Earth. This asteroid shares the Earth's orbit, its motion "choreographed" in such a way as to remain stable and avoid colliding with our planet.
Meteorite Impact on Greenland ???
It seems very likely that a large meteor impacted on Greenland in December 1997. This article gathers the disparate reports and commentaries on the impact into a comprehensive article.
The Day the Earth Was Hit
At 7.16am on 30 June 1908 in the skies above Tunguska in remotest Siberia, a gigantic fireball exploded, setting fire to 2000 square kilometres of forest, toppling the trees like matchsticks and sending a pressure-wave twice around the world.

Space Events
Water Found on Mars
Archived webcast of NASA's report on the latest findings that water may have been detected on Mars. The webcast is alnost two hours long.
Moonwalk: Earthlings' Finest Hour
The Discovery Channel's tribute to the Apollo 11 mission which took place 30 years ago.
Mission to Mars '99
About every 25 months, when Earth and Mars are favorably aligned, NASA launches a pair of robotic probes to chisel away at the Martian mystery. This year, the field agents are a polar-orbiting weather watcher and an on-site chemist that will give scientists an initial look at the Martian underground.
Charting the Future of Planetary Science Missions
As planetary scientists from around the world gathered in Madison, Wisconsin in October for the annual conference of the Division for Planetary Sciences of the American Astronomical Society, NASA officials and scientists laid out some newly revised and updated plans for solar system exploration into the next decade and beyond that shows that NASA has completed the transition from a few high-cost science missions to many more low-cost missions.
Cosmic Power
A cosmic-ray particle coming from the direction of the constellation Auriga, detected by an instrument in Utah in 1991, had an energy of 3 x 10^20 electron volts - more than 100 million times beyond the range of present accelerators. Such natural largesse achieves what purpose-built machines have long sought: a probe of physics underlying the current Standard Model.
Mission to Mars '99
Sometime in its distant past, Mars was another world. The climate was warmer, the air moist, with great pools of water and running rivers lacing the planet's surface like blood vessels. But something happened. Somehow the water vanished, leaving a dry, dusty, wind-swept orb that makes our deserts seem lush. Where did the water go?
The Search for E.T. Begins at Home
Every day, every hour, the world's most sensitive ear is listening for ET's call. This particular search for extraterrestrial intelligence -- using Arecibo's radio observatory in Puerto Rico -- is serendipitous, skirting from star to star like a hitchhiker with no destination.
The Next Logical Step
On November 20 the science of engineering will take a giant step into the 21st century. After 15 years of delays and controversy, the first module of the International Space Station known as "Zarya" -- Russian for "Sunrise" -- will blast off a launch pad in Kazakstan. During the next five years, if all goes as planned, an international group of astronauts will take turns assembling the 43 pieces built by engineers and technicians in 16 countries. So begins the first global collaboration to build a way station to the stars.
Man on a Mission: John Glenn Goes Back Into Orbit
The story of the astronauts, as recounted in Tom Wolfe's The Right Stuff, the book that came to define the breed, properly begins with the story of the nation's military test pilots.
The Soviets Reach for the Moon
The launching of the first Sputniks caused such a stir in the West that Soviet Premier Nikita Krushchev could not help but exploit the propaganda value of Soviet space missions. But with the successful launching of the first three Sputnik satellites, all the "easy" space spectaculars had already been achieved. By the beginning of 1958 the Soviet Union's infant space program had set its sights on the Moon.
The International Space Station
The United States and Russia are finalizing plans for the first "world space program." This audio article comes from Discovery Online.
Space stations: past, present, future
A special report on space stations of the past present and future, from MSNBC.
Six Months on Mir
As the Shuttle-Mir program draws to a close, a veteran NASA astronaut reflects on her mission on board the Russian spacecraft and the implications for the International Space Station.
From Mir to Mars
On March 23, 1998, with about half of his stay aboard Mir behind him, U.S. astronaut Andy Thomas was interviewed by Scientific American Frontiers host Alan Alda in a live webcast which gave viewers an opportunity to hear Andy Thomas's thoughts on a human trip to Mars.
Water Detected on the Moon
Using the Lunar Prospector spacecraft in a 60-mile-high orbit around the moon, NASA detected small amounts of water in the form of ice at the moon's polar regions. If significant amounts are found, it could mean any future moon voyagers might not have to carry their own, could make oxygen for breathing, and would have the material to make fuel for their rockets.
NASA announcement about finding water on the moon
Streaming video of the NASA press conference about the Lunar Prospector finding water on the moon. Requires the VXtreme plugin.
X-38 Escape Pod
The X-38, a smaller version of an emergency "lifeboat" for the planned international space station, underwent a test flight on Mar.12 in the skies over Edwards Air Force Base in California.
NEAR Again
Since the Near Earth Asteroid Rendezvous spacecraft set out in Feb. 1996 for a Jan. 1999 date with asteroid 433 Eros, its circuitous path has taken it far beyond the orbit of Mars, where it flirted briefly with another chunk of space rock named Mathilde. But on Jan. 23, NEAR swooped by Earth for one last look at home.