Carpe Noctem - Seize the Night!

Hevelius at his telescope

Hello!

Hello to Trustin in Newfoundland and James in Christchurch

Eclipse

Visit the show notes from my Eclipse Special and follow the link to "Live from Turkey" from the Exploritorium. It was a great program and this time they lucked out and didn't have to fight the clouds. If you missed their equinox webcast (2005?) from Mexico and Chichen Itza go take a look.

Glossary of Telescope Terms

concave lens or convex mirror - causes light to spread out. convex lens or concave mirror - causes light to come together to a focal point.
field of view - area of the sky that can be seen through a given eyepiece. focal length - distance required to bring the light to a focus. focal point - point at which light comes together. objective - lens or mirror is the primary light directing source magnification - telescope's focal length divided by the eyepiece's focal length. resolution - how close two objects can be and yet still be detected as separate objects, usually measured in arc-seconds (this is important for revealing fine details of an object, and is related to the telescope's aperture) secondary - the mirror that reflects the light from the primary mirror to the eyepiece

Telescopes

Rice University's Galileo project
Refractors
Hans Lippershey gets credit for inventing the refractor in 1608, and the military used the instrument first. Galileo was the first to use it in astronomy. Both Lippershey's and Galileo's designs used a combination of convex and concave lenses. Kepler improved the design to have two convex lenses.

Reflectors

Isaac Newton developed the reflector about 1680, in response to the chromatic aberration (rainbow halo) problem that plagued refractors during his time. Instead of using a lens to gather light, Newton used a curved, metal mirror (primary mirror) to collect the light and reflect it to a focus. Mirrors do not have the chromatic aberration problems that lenses do. Newton placed the primary mirror in the back of the tube.

In 1722, John Hadley developed a design that used parabolic mirrors, and there were various improvements in mirror-making. The Newtonian reflector was a highly successful design, and remains one of the most popular telescope designs in use today.

Hybrids

The first compound telescope was made by German astronomer Bernhard Schmidt in 1930. Catadioptric telescopes are hybrid telescopes that have a mix of refractor and reflector elements in their design. Schmidt-Cassegrain design, which was invented in the 1960s, is the most popular type of telescope; it uses a secondary mirror that bounces light through a hole in the primary mirror to an eyepiece.

Telecope mounts

Alt-Azmuth mounts move left-right and up-down. Dobsonians are the most popular Alt-Az mounts
Equitorial mounts are polar aligned so their "left-rights" will track along the ecliptic keeping objects in the scope as the Earth turns (if motorized)

Finders (Finder scopes)

peep sights reflex sights finder scopes or telecope sights

The Moon

This weekend the moon is a waxing gibbous moon which will make things tough for our starparty on Saturday, tough but not impossible!

Images created with Lunar Phase Pro

Triple Marshes(pa'les) Palus Epidemiarum (latin for Marsh of Epidemics) -pink circle p Palus Somni (Latin for "Marsh of Sleep") -yellow circle p Palus Putredinus (latin for "Marsh of Decay")-blue circle p

Triple craters Three craters that tell a story - in a red elipse Theophilus, Cyrillus, and Catharine. Starting with Theophilus note how each crater progressively older.

Triple ranges Montes (Monteez) Alpenninus(ap a nay us)-yellow line Montes Heamus(He ma us) - blue line Montes Caucasus (Caucasias)-pink line

Planets

• Venus - The brightest planet visible this month. Venus is outstanding in the Eastern morning sky and you will want to grab a pair of binoculars or even just a finder scope to check out her phase. Just over half full she is intensely bright in her gibbous phase.
• Jupiter - In Libra and Any telescope can reveal its two widest cloud bands to you, along with its four Galilean satellites. There are some great new Cassini composit images on the Planetary Society Webpage
• Saturn - Is in Cancer and tonight stop in it's apparent backsliding to the West and will begin moving in it's direct motion to the East. It appears as a yellowish star that rivals Capella in brightness, A small telescope will always show Titan, Saturn's largest and most extraordinary moon. A 6-inch telescope will begin to show the orange color of its atmospheric haze.
• Mars has swung past Aldeberon and is almost between the tips of the bulls horns.
• Mercury - Just south of east about 25 degrees from Venus (towards the horizon and easterly) if you remember how to measure 25 degrees, it is the spread between your pinky and thumb when fully extended. Show #10 has our primmer for measuring distances in the sky

News

There are so many great space and astronomy news sites out there I won't try and duplicate them all, I'll just report things that really strike my fancy or that I think you might be interested in. Here is a list of some of the sites I visit daily:

• NASA's Eclipse Page -
• How Prometheus Pulls on Saturn's F Ring Wed, 05 Apr 2006 - One of the most amazing images sent back by the Cassini spacecraft shows one of Saturn's shepherd moons, Prometheus, tugging a stream of particles away from the F ring. Scientists from Queen Mary, University of London have developed a model that explains the forces at work in this dramatic interaction. It was originally believed that Prometheus steals ring particles, but it now appears that it just borrows them as it comes past, and they drift back into the ring system after the moon sweeps by.
  
  Prometheus acting on Saturn's F ring. Image credit: NASA/JPL/SSI
• Don Quijote to impact an asteroid -ESA 3 April 206 Asteroids: treasures of the past and a threat to the future If a large asteroid such as the recently identified 2004 VD17 â�� about 500 m in diameter with a mass of nearly 1000 million tonnes - collides with the Earth it could spell disaster for much of our planet. As part of ESAâ��s Near-Earth Object deflecting mission Don Quijote, three teams of European industries are now carrying out studies on how to prevent this. The impactor, Hildalgo will be monitored by an orbitor, Sancho.
• Dead Stars Producing Planets - NASA's Spitzer Space Telescope has uncovered new evidence that planets might rise up out of a dead star's ashes. The infrared telescope surveyed the scene around a pulsar, the remnant of an exploded star, and found a surrounding disk made up of debris shot out during the star's death throes. The dusty rubble in this disk might ultimately stick together to form planets. This is the first time scientists have detected planet-building materials around a star that died in a fiery blast.
• Spirit continues to have problem - Two years and three months after landing on Mars, Spirit can't help but dig trenches in the martian sand. The right front wheel of NASAâ��s Mars Exploration Rover is no longer working.

  Essentially, it's a race against time. The period of minimum sunshine in the martian winter is more than 100 days away, but Spirit currently gets only enough power for about one hour of driving on flat ground. And, Spirit literally has an up-hill battle.

• Great Moon Buggy Race - Fifty high school and college student teams are putting the finishing touches on designs of their very own lunar vehicles. Teams from the United States and Puerto Rico are competing in NASA's 13th annual Great Moonbuggy Race. The event, which is open to the media and public, runs Friday and Saturday at the U.S. Space & Rocket Center in Huntsville, Ala.

 

Listener Question

There was a question in my inbox that was worth sharing with everyone. The current status of Voyager 1 and Voyager 2
There is a pdf file from the main Voyager site that has their estimated distances plotted through the fall of 2015. This week V1 should be 98.73 AU away and V2 79.28 and better yet, if you go to Heavens Above you can find it plotted VOYAGER 1 received by AMSAT-DL group

Space probe VOYAGER 1 successfully received On March 31st, 2006 an AMSAT-DL / IUZ team received the American space probe VOYAGER 1 with the 20m antenna in Bochum.

The distance was 14.7 billion km. This is a new record for AMSAT-DL and IUZ Bochum. The received signal was clearly identified through means of doppler shift and position in the sky. The receive frequency was exactly measured and compared with the information provided by NASA.

This distance equals approximately 98 times the distance between Earth and Sun. VOYAGER 1 is the most distant object ever built by mankind. This again proves the superior performance of the Bochum antenna. Most probably this is the first time Voyager 1 has been received by radio amateurs.

Comets visible with binoculars/telescopes in the northern hemisphere.

Pojmanski
and 73P/ Schwassmann-Wachmann 3
and C/2005 E2 ( McNaught )

 

"One touch of nature makes the whole world kin"
-- Shakespeare

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Music

Josh Woodward -"Bonjour, Mon Amie"
Mario Ajero -"Piano Sonata in E-flat Major, mvt. 3 by Joseph Haydn"

Talking about the different types of telescopes available and the critical parts of a telescope, visit some unique features on the Moon, check in on the planets and get an update on astronomy related news!