Observing Project 7D The Tricks of Venus Atmosphere

The ashen light is one of the great mysteries of the inner solar system. Giovanni Riccioli first reported it in 1643. Looking through his telescope at the crescent Venus he reported seeing a strange and unexplainable luminescence on Venus night side similar to Earthshine on a crescent Moon. Sir William Herschel also reportedly viewed the ashen light. The sharp-eyed E.E. Barnard never saw it but much more recent contemporary accounts made by prominent scientists reveal simultaneous viewing of...

Interlopers in the Inner Solar System

The inner solar system is at first glance a pretty clean place, having long since been swept clean of most interplanetary debris by the gravity of the Sun or that of the planets in the area. Every now and then there will be an interloper that will drop down into the inner solar system after a gravitational interaction with Jupiter or Saturn or out beyond the planets in the Kuiper Belt or Oort Cloud. It has been the secret fear of astronomers for many years that a large asteroid or comet will...

Observing Project 13D The Detail in the Great Nebula of Orion

It sprawls over more than one full square degree of the sky, equal to four full moons. It is the crucible and nursery where new stars are born. In open clusters, we have viewed the beginning of the journey of infant stars. In the cluster M16 and the adjacent Eagle Nebula, we have viewed newborns leaving the womb. Now in Orion, we can see the star creation engine in progress. The nebula is so huge and so relatively close to Earth that we can see an amazing wealth of detail in its structure....

Diffuse Nebulae

Diffuse nebulae are thin conglomerations of dust and gas that if they acquire sufficient mass may begin to form stars within them. Some may form a handful of stars while others may form stars by the hundreds, creating large open clusters. Diffuse nebulae therefore are not stellar tombstones, but nurseries, where stellar lives begin. As stars begin to shine from within the dust cloud, if they are sufficiently hot and massive, their high-energy radiation will excite the gas to shine just as they...

Observing Asteroids

The asteroids orbit mainly outside the orbit of Earth and so they behave much the same way as Mars does. The best time to view an asteroid then is when it is at opposition to the Sun. For each of the big four, this occurs each sixteen to twenty months. Since the asteroids are very faint, you will always need optical aid to find them, except for Vesta, which can reach naked-eye visibility at very favorable oppositions. Each of the Big Four can be seen with binoculars. Ceres is not only the...

Mountings

The most optically perfect telescope money can buy will not do you the slightest bit of good if it sits on a mounting that is poor or poorly maintained. It is important to ensure that all the connections are tight and the telescopes axes and locks are properly maintained. Clock driven telescopes may have internal batteries that must be properly cared for if they are to deliver maximum performance. It is as important to take care of your telescope's mounting as it is to take care of the...

Hypoxia and the Physical Organism

As crucial as the condition of the sky is the physical condition of the observer. The observer may have the perfect combination of sky conditions and observing technique yet is unable to see the faintest details of objects or see at all if he is betrayed by his own physical condition. Two key contributors to the physical health and efficiency of the eyes are adequate supplies of vitamin A and the ability to respi-rate and metabolize oxygen. In any modern industrial society, vitamin A...

Observing Projects 10E Saturns Inner Moons

Saturn has nine major moons that are brighter than magnitude +16, which is the photographic limit of an 8-inch telescope under a dark sky. Realistically under any level of light pollution a telescope in the 8-10 inch class will be able to pick out as many as five of Saturn's moons. One of these moons, Titan is within easy reach of any telescope. Three moons inside of Titan Rhea, Dione and Tethys are about magnitude +10 and can be viewed with some effort in moderate light pollution with a medium...

Variable Stars Now You See Me Now You Dont

Our lives on Earth are dominated by the presence of a star that shines with a light that never changes. The Sun is today what it was yesterday and will be precisely the same tomorrow. Not all stars are so consistent though. Many will vary considerably in luminosity from year to year or month to month or even day to day. Some will do so on a very precise schedule and others will do so on no schedule at all. And they will do so for a wide variety of reasons. Variables can be categorized into two...

Observing Project 6C The Analemma and the Equation of Time

Have you ever looked at a globe of Earth and noticed the odd figure eight shape that is placed usually somewhere over the Pacific Ocean and wondered what it was The figure eight pattern is called the analemma. The analemma is a representation of where the Sun appears in the sky at exactly the same day on each day of the year. Two important motions that are fundamental to astronomy and to our lives on Earth are responsible for the motion. These motions are Earth's axial tilt and Earth's...

Observing Project 11A Uranus and Neptune at the Eyepiece

At first glance it would seem that the triumph is in simply finding the two icy giants at the edge of the solar system. But with sufficiently large instruments and a little patience and skill, you can coax some of the secrets of the ice giants out of those pale blue-green dots. Uranus shines at a feeble magnitude +5.7 and through a telescope its disk spans not quite four arc seconds. Even if Uranus had some details to see, you could not see them through amateur telescopes anyway. What may...

The Asteroid Belt

On New Year's night in 1801, the Italian astronomer Giuseppe Piazzi found a small object wandering across the sky. Piazzi at first thought that he had discovered a new comet. After study however it was found that the object was moving in a nearly circular orbit around the Sun. Piazzi named the little body Ceres for the Sicilian goddess of grain25. Ceres turned out to be way too small to be a planet, measuring 933 kilometers in size. Even at that size, Ceres contains about 25 of all the mass in...

Our Own Galaxy Galactic Structures and Types

Our knowledge of galaxies and their structures has grown by leaps and bounds through the twentieth century including knowledge of our own galaxy. Our knowledge of the Milky Way continues to grow and evolve in fits and starts because in visible wavelengths we just cannot see a great deal of it. The core of the galaxy is completely hidden from our view in visible light because of thick interstellar dust clouds. We know that our galaxy is spiral in shape with several arcing structures or arms that...

Elliptical and Lenticular Galaxies

Elliptical galaxies are very different from spirals in that they have very little in the way of internal structure. Even to the largest telescopes, they only appear to be uniform patches of light that form an elongated shape. These galaxies have very little in the way of interstellar matter such as dust and gas traveling between stars. This gives the suggestion that the elliptical galaxies are extremely old. Elliptical galaxies vary tremendously in size from the tiny companion galaxy M32 to the...

Telescope Maintenance

Cleaning precision optics is not the same as cleaning household windows or mirrors. Remember that the lenses and mirrors of your telescope are tasked with collecting miniscule amounts of light, then amplifying, magnifying and focusing that light into a viewable image. The slightest damage to the glass surface of your objective lens or mirror can ruin it as a viable scientific instrument. It is simply not acceptable to pick up a bottle of Windex and a paper towel and try to wipe the lens mirror...

Observing Projects 8D Surveying the Martian Geography Quadrant 1 Centered on 45 Degrees

Mars is a world much like the Moon in geological diversity and though we can't see nearly the detail in Mars that we can in the Moon, it offers us a lot of interesting things to see in what is there. To begin working this project, the first thing you will need is a global topographic map of Mars. You can find this on several Internet sites or if your astronomy software has a sufficiently detailed Mars model, it will suffice. The first thing you always notice right away about Mars is the...

Observing Project 8C Looking for Deimos and Phobos

Mars' two tiny moons, Deimos and Phobos, circle the planet with blistering speed and never stay very far from it. When Phobos is at its greatest elongation from Mars, it is never more than three planetary radii from the planet. Since the moon circles Mars in just over seven hours, the window of opportunity to see it while it is away from the planet is only about an hour long. It is critically important therefore to know when the moon is at that point of greatest elongation and have a plan. Use...