After weeks cruising through Perseus and into Pisces, Comet Linear is an easy binocular target and is approaching naked eye visibility. Tonight, the comet will be at mag5.3 -- certainly visible from a dark sky location. Since its discovery in December of 2000, the comet has brightened from mag18 to almost mag 5. Projections are that it'll brighten further to around mag 4.9 in mid January. Not too shabby.

The image to the left was obtained by Michael Jäger on 2001 November 16. It is an 8-minute exposure obtained using a Celestron Schmidt camera and special film. Notice how the image seems to reveal two tails... one extending nearly straight downward, and the other towards the upper right. 

On Friday night 11/30 the full moon will again drift in front of Saturn. Referred to as an occultation, this event will be best viewed in the eastern portion of the country. The further west (and north) you get, the more likely you are to see Saturn graze the edge of the moon -- or miss it entirely. For instance, Denver will only see Saturn disappear for a very short time. Seattle will miss it all together. Unfortunately for us in northern Utah we'll also miss out. We will however see the two come really, really close. How close? Good question :) Get out there and take a look and let me know.

If you're unable to view this event, don't worry. We'll get the a full fledged occultation again in late December when the nearly full moon glides in front of Saturn for all of the US :)

 I took the accompanying image in September just prior to the previous occultation. Since Saturn appears considerably larger now, the event will take quite a bit longer to complete. Don't get too excited here, we're talking seconds.

THE GLOWING EYE OF NGC 6751

Astronomers using NASA's Hubble Space Telescope have obtained images of the strikingly unusual planetary nebula, NGC 6751. Glowing in the constellation Aquila like a giant eye, the nebula is a cloud of gas ejected several thousand years ago from the hot star visible in its center.  
"Planetary nebulae" are named after their round shapes as seen visually in small telescopes, and have nothing else to do with planets. They are shells of gas thrown off by stars of masses similar to that of our own Sun, when the stars are nearing the ends of their lives. The loss of the outer layers of the star into space exposes the hot stellar core, whose strong ultraviolet radiation then causes the ejected gas to fluoresce as the planetary nebula. Our own Sun is predicted to eject its planetary nebula some 6 billion years from now.  
The Hubble observations were obtained in 1998 with the Wide Field Planetary Camera 2 (WFPC2) by a team of astronomers led by Arsen Hajian of the U.S. Naval Observatory in Washington, DC. The Hubble Heritage team, working at the Space Telescope Science Institute in Baltimore, has prepared this color rendition by combining the Hajian team's WFPC2 images taken through three different color filters that isolate nebular gases of different temperatures.  
The nebula shows several remarkable and poorly understood features. Blue regions mark the hottest glowing gas, which forms a roughly circular ring around the central stellar remnant. Orange and red show the locations of cooler gas. The cool gas tends to lie in long streamers pointing away from the central star, and in a surrounding, tattered-looking ring at the outer edge of the nebula. The origin of these cooler clouds within the nebula is still uncertain, but the streamers are clear evidence that their shapes are affected by radiation and stellar winds from the hot star at the center. The star's surface temperature is estimated at a scorching 140,000 degrees Celsius (250,000 degrees Fahrenheit).  
Hajian and his team are scheduled to re-observe NGC 6751 with Hubble's WFPC2 in 2001. Due to the expansion of the nebula, at a speed of about 40 kilometers per second (25 miles per second), the high resolution of Hubble's camera will reveal the slight increase in the size of the nebula since 1998. This measurement will allow the astronomers to calculate an accurate distance to NGC 6751. In the meantime, current estimates are that NGC 6751 is roughly 6,500 light-years from Earth. The nebula's diameter is 0.8 light-years, some 600 times the diameter of our own solar system. 

As always, if there is a CME, you can expect Utah Skies to get the word out. So, make sure you're signed up to receive our astro-alerts. This  will guarantee that you have the information that you need... when you need it :)

Viewing Aurora - To view aurora, simply scan the horizon to the north. In the event of a large display, you won't have to look too hard at all. I've seen more than half of the sky turn wild reds and greens. You couldn't miss it if you tried. 
To enhance your views, make sure that all exterior lights are turned off. Or... better yet, head to your favorite dark sky location. 

Imaging Aurora - Capturing images of aurora is a fairly simple process which involves a minimum of equipment. First off you'll need a camera which allows you to take a long exposure. Many cameras have a bulb setting labeled B. Next, you'll need a tripod to support the camera. And, finally you'll need a cable to activate the shutter. All this will provide you with a solid platform to take extended exposures from. 
I'd recommend a faster speed film than you might typically have around. Films rated at ASA400 or higher are great for low light situations. Keep your exposures in the 5-30 second range. This will allow you to capture lots of color with a minimal amount of star trail. More specifically, a 50mm lens will begin to show star trails after about 12 seconds. A 28mm lens will allow you to expose for about 25 seconds. Also, set your aperture to at or near its widest... in the f/2 to f/4 range.
At this point, you are ready to capture stunning images :) And... don't forget. If you do capture a really good image, make sure to send us a copy to post on the Utah Skies website.

If you have a telescope and clear skies :( get it out and point it at the moon. You will see an incredible amount of surface detail. I'd recommend using a moon filter though. The full moon can be a bit overpowering in a telescope. I use what is called a variable polarizer. This is a moon filter that allows you to decide how much filtering you want to do. Perhaps just a little at first and last quarter and a lot approaching full. The moon is an especially easy target to view. It's big. It's bright. You just can't miss it. You just might discover (or rediscover) a love for astronomy. 

I took the accompanying image last year using an old (1970's) Minolta shooting through my 10" f/4.5 reflector.

Mercury is rising at about 7:30 am. It has reached its maximum brightness now, shining at mag -1.05. Unfortunately, at this point, we've all but lost Mercury to the glare of the sun. Don't worry if you missed it though, it'll start rising in the evening sky by the beginning of December. How can this be you might ask?

Well, it's simple. Since Mercury is the inner most planet, it never gets far from the sun. It reached it's farthest point from the sun in the eastern sky a few weeks ago. Since then, it's been moving rapidly back towards the sun. It'll drop behind the sun and the re-emerge on the other side... in the evening (western) sky.

The accompanying image was taken by the Mariner 10 spacecraft which imaged the planet during 3 flybys. Mariner 10 is the only spacecraft to visit Mercury. While it was there it imaged about 45% of the planets surface. Details visible on the planets surface are as small as 1 mile across. Notice how cratered the planet is. It almost looks like our moon. This is caused by meteor bombardment. Since Mercury has no atmosphere, every crater that comes its way is able to score a direct hit. Also, without the active weather like we have here on Earth, once a mark is made, it stays there for ever. On Earth, it would eventually be eroded away and/or grown over by vegitation.

Pluto, the 9th planet, is rising at about 7:35 am. Pluto is a tiny, faint little spec in a telescope... any telescope. It is currently almost 3 billion miles from Earth. It's size varies between 0.11" and 0.065" and it's brightness between mag 13.6 and mag 16. Mag 13.6 is pushing the limits of a 6" just to detect it, while mag 16 is doing the same to a 16".  But... pushing the limits and beyond the limit are two different things. Utah Skies readers are pretty hard core. I'm sure that there'll be a few out there who just have to go out and see what you and your telescope are made of. Let me know how you do. Here's my claim: "Photons from Pluto have struck my retina". Now.. with that said, I could not tell for sure which of those tiny specs was Pluto. Hey... at least I'm honest :) 

Pluto was discovered by Clyde Tombaugh in January 1930. The discovery was not simply that of a man with a telescope under dark skies. Nope. As early as 1905, Percival Lowell had been lecturing and writing on his belief that there must be another planet beyond the orbit of Neptune. His studies of the outer planets and the orbits of comets convinced him that there was another body out there that was affecting their orbits. Tombaugh combined Lowell's predictions with his own tenacity to make this amazing discovery.

The accompanying image by the Nordic Optical Telescope shows you what a LARGE land based telescope is capable of. You can imaging what Tombaugh went through during his search. Anyway...don't expect much... just finding Pluto is an impressive accomplishment. If you're planning on searching for Pluto, your best bet will be in the spring -- as it is currently in the constellation Ophiuchus.

Neptune, the 8th planet, is rising around 11:35. Shining at mag7.95, Neptune is a relatively easy target. However, at only 2", it displays absolutely no surface detail. Almost star-like in binoculars, it shows it's beautiful blue color in telescopes. Neptune gets this beautiful blue coloring from a layer of Methane in its upper atmosphere.

Located almost 3 billion miles from Earth, Neptune has a huge circular orbit -- taking just over 164 years to orbit the Sun. In fact, Neptune's orbit varies by less than 1% from circular. Neptune has a couple of other claims to fame... It has the fastest wind speeds in the solar system with gust at almost 1500 mph.

Similar to Jupiter, it is categorized as a gas giant. Neptune is roughly 17 times more massive than the Earth. In another similarity to Jupiter, Neptune has a  Great Dark Spot.

William Herschel is credited with the discovery of Neptune in 1781. However, it had been recorded in several catalogs as a star as far back as 1690.

The accompanying Voyager 2 image shows the blue color of Neptune along with it's "Great Dark Spot". 

Uranus, the 7th planet, is rising at 12:20. Shining at mag5.85, Uranus is a relatively easy target. However, at only 3", it displays absolutely no surface detail. It does however show it's beautiful aquamarine color. Uranus gets this beautiful coloring from a layer of Methane in its upper atmosphere.

Located almost 2 billion miles from Earth, Uranus has a huge orbit -- taking just over 84 years to orbit the Sun. It is categorized as a gas giant as is Jupiter, Saturn and Neptune. Uranus is roughly 14 times more massive than the Earth. 

Discovered by William Herschel in March of 1781, Uranus was the first planet to be "discovered". All the others are plainly visible, and hence have been known since antiquity. The name Uranus was suggested for mythological reasons. Since Jupiter was the father of Saturn, it made sense to name the next planet out Uranus -- the father of Saturn.

The accompanying Voyager 2 image shows the aquamarine color of Uranus along with a surprise... it's ring system. Yup... Uranus has rings similar to Saturn's'. They're nowhere near as bright, but... they're there. Also visible in this image are a handful of Uranus' many moons.

Mars is rising in the southeast around  12:30 pm. The Earth continues to pull away from Mars in it's orbit. In fact, the distance between the two planets has grown from about 40 million miles this summer to almost 118 million miles. This has cause Mars' apparent diameter to shrink. It is currently down to a measly 7" as compared to its 21" in June. It has dimmed significantly as well - currently shining at magnitude 0.42 down from -2.4 in June. 

The accompanying image by Ed Grafton shows an amazing amount of detail on the planets surface.  We'll have to wait until its next approach in the spring/summer of 2003 before we get views like this again. 

Saturn reaches what is called opposition on December 2nd. Opposition is when the planet is opposite the sun as viewed from Earth. Getting back to Aldebaran (above). Saturn will begin moving westward relative to the stars. Keep an eye on the distance between Saturn and Aldebaran. The gap will shrink rapidly over the next several weeks until on December 17th, Saturn is actually north of the star.

Saturn is, as mentioned above, a gas giant. This means that it is large and composed mainly of gas. How large? Well, Saturn is over 95 times more massive than the Earth and has a diameter that is more than 9 times that of the Earth. If you throw in the diameter of the rings, that number jumps to over 20 times that of the Earth. Wow!

And... speaking of the rings... they are now tipped 26* towards us. This is very close to the maximum in this category as well. So...what are you waiting for. This is probably the best time to view Saturn. Dust off your telescope and put it to work. Saturn looks awesome in virtually any telescope.

The accompanying image shows Saturn with two of its many moons. Pretty cool, huh? 

Next, look for Jupiter rising around  7:30pm. Jupiter is the king of the Planets. It is more massive than all the other planets combined. In fact, Jupiter is over 300 times more massive than the Earth. Not surprisingly, Jupiter also has the largest moon in the solar system, Ganymede. Jupiter is currently shining at mag -2.63 and has grown to a whopping 46". Jupiter will grow to over 47" -- just shy of it's maximum possible size of 50".. 

Jupiter is the second most reflective (a quality know as albedo) planet in the solar system. Only Venus reflects more of the sun's light. Add this fact with Jupiter's immense size, and it's no wonder that Jupiter shines so brightly.

This accompanying image captures Jupiter and it's moon Europa. Notice the tiny black spot on Jupiter's surface. This is the shadow cast by Europa.

Many of the features visible in this image are within the reach of modest amateur telescopes. Depending on the size of the telescope and the quality of your skies, you might even do better! In fact, on an amazingly steady night last fall, I did significantly better.

I'll remind you again. You have to check out the tools section of the Utah Skies website for a cool java applet which depicts the relative position of the four major Jovian moons and their shadows. It's called JavaJup. I regularly refer to JavaJup to help plan my viewing sessions.

This weekend we move on to the constellation Camelopardalis the Giraffe. This constellation is extremely faint and hard to identify... it's brightest star is only mag 4. In fact, this is the first time that my software package actually refused to draw lines for the figure!

The focus of our efforts this week will be the deep sky objects of Camelopardalis . Camelopardalis is high overhead and to the north, northeast. Camelopardalis is due north of Perseus and northeast of Cassiopeia. There are some really nice objects in this constellation. Ok... so they're a bit on the dim side. But... that's only half your battle. Since there are barely any guide stars in the constellation itself, you'll have to use stars in other constellations. This, of course, will require you to span large chunks of the sky in your search. Oh, well... Utah Skies readers are often pretty hard core. 

The Affects of Light Pollution on Health
We often discuss the problems associated with Light Pollution in weekly The Utah Skies Report. This week we're going to discuss the health risks associated with improper lighting. " Health risks from improper lighting?", you may ask....

Yes. Serious health risks. Consider the following  findings from some of the world's preeminent medical researchers.

Did you know that sleeping in a room that is not totally dark suppresses melatonin production and disturbs your natural circadian rhythm? A recent article in the Journal of Neuroscience (August 15, 2001) discusses this very connection.

Even more disturbing, sleeping in a room that is not totally dark has been linked to breast cancer. In an article published in the Journal of the National Cancer Institute (October 17, 2001). Researchers found that "Exposure to light at night may increase the risk of breast  cancer by suppressing the normal nocturnal production of melatonin...." They went on to state that "There was an indication of increased risk among subjects with the brightest bedrooms." And then concluded that "The results of this study provide evidence that indicators of exposure to light at night may be associated with the risk of developing breast cancer."

So.... why wouldn't a bedroom be totally dark at night? Very often street lights or a neighbors porch or security lights shine into peoples homes from dusk to dawn. This is the case in my neighborhood, how about yours?. Do you have lights shining into your home? Are you concerned that this could have a negative impact on your health?

Remember,

Light Pollution provides no benefit to the light polluter

Light Pollution wastes huge amounts of money.

Light Pollution causes the needless waste of our valuable natural resources.

Light Pollution causes the needless generation of electric power and the associated release of toxins into our environment

Light Pollution has been linked to a variety of serious health problems

Light Pollution and it's partner glare, actually reduce our visibility by blinding us with light

Light Pollution turns neighbors into adversaries when one persons lights are turned on another

Light Pollution destroys the beautiful views of the heavens which mankind has pondered for all our existence

Light Pollution is a serious problem

But, don't lose hope; Light Pollution is easily cleaned up. All we need to do is act intelligently.

Here are a few, simple principles to keep in mind:

1. Use only as much light as you need
   

2. Use only when you need it
   

3. Use it only where you need it