WHERE: AT EXPLORIT Science Center, 3141 5th Street, Davis.
Hosts: Vinita & Calvin Domier 756-7443

Phases & Transit of Venus!
Sunday, March 28, 2004
at 7:00 p.m. at Explorit

Join us Sunday evening, March 28th at 7:00 p.m. when we will discuss and view the third brightest object in the sky (after the sun and the moon) and Earth's closest neighbor, beautiful Venus. We will also highlight one of the rarest planetary events, the transit of Venus occurring on June 8, 2004.

Venus is one of three planets (besides Uranus and Pluto) that have retrograde or backward rotations (western sunrises and eastern sunsets). It rotates very slowly: its day (243 Earth days) is nearly as long as its year (225 Earth days).

The greatest angular distance between Venus and the Sun is 46o. Thus for about 10 months it rises up to 3 hours before sunrise and is known as the Morning Star, and for the next 10 months it sets up to 3 hours after sunset and is known as the Evening Star. It is not visible for about 3 weeks during the transitions.
At its brightest, Venus reaches an apparent magnitude of -4.4. Its brightness is due to its closeness to the Sun and the Earth, and its high albedo of 0.76 (76% of the sunlight reaching Venus is reflected back into space by the dense carbon dioxide clouds shrouding it).

Venus exhibits phases like the Moon, as it is an inferior planet with its orbit inside the Earth's. At superior conjunction (when the Sun is between Earth and Venus), Venus appears as round like a full Moon. When it is at inferior conjunction (when Venus is between Earth and the Sun), it is lost in the sun's glare like a new Moon.

Three weeks before and after inferior conjunction,. binoculars and telescopes reveal dazzling bright Venus's crescent phases. Venus is at its brightest even though only part of it is illuminated as its angular size is 6 times that of its full phase (it is 6 times closer at inferior conjunction than at superior conjunction).

At rare intervals, when the orbit of Venus is tilted just right, Venus passes in front of the Sun's disk during inferior conjunctions. It can be observed (with proper sun filters) as a small black dot moving across the Sun from celestial east to west. Transits occur in pairs every 121 years, with the next one on June 8, 2004, (previous transit was in 1882 and next one is in 2012). Transits are solar eclipses caused by the very narrow shadow cone of Venus, which only obscures a tiny portion of the Sun. It does not happen at every inferior conjunction due to the 3.4o inclination of its orbit to the plane of the ecliptic.

On Mar. 28, we will look at the big and bright crescent phase of Venus. There will also be activities and demonstrations for the young astronomers. We will also look at Saturn, and Jupiter. Please bring your telescope if you own one.
ASTRO NEWS
Astronomers discovered Sedna, an icy, red planetoid between 800-1100 miles in diameter orbiting the Sun. At a distance of 8 million miles from Earth, it is three times as far as Pluto, and is the furthest object discovered thus far in our solar system. Sedna is red and bright, and extremely cold (-400o F) as it takes 10,500 Earth years to go around the Sun.
MARCH/ APRIL SKY
All five planets are visible in the night sky. Mercury (mag. -1.0) is hard to spot, as it is close to the sun. Venus (mag. -4.2 in Aries/Taurus) is the brightest in the western sky. Mars (mag. 1.3 in Taurus), is at its upper left. Saturn (mag. 0.0 in Gemini) is above Orion. Jupiter (mag. -2.3 in Leo), passed opposition on Mar. 3, and rises at sunset and sets at sunrise. Moon's phases are as follows: New Moon: Mar. 20/Apr. 19, First Quarter: Mar. 28/Apr. 27, Full Moon: Apr. 5, and, Last Quarter: Apr. 11.

To Receive These Bulletins via E-mail Contact Explorit at: Explorit Science Center

The Astronomy Club is for everyone - adults, children, knowledgeable or ignorant. Come to listen, look and learn, or to share your expertise or experience.