Venus Has Phases ...
Like the Moon

 

Venus is coming around from behind the Sun and getting closer to the Earth with each month. As it does this, the illumination angle changes and earthlings can witness the telescopic phases of this planet.

On January 31 Venus is in its gibbous phase (more than half lit on left side of image below). In this phase Venus appears 75% illuminated and is nearly 105 million miles (169 million kilometers) from Earth. By March 29 Venus is in its first quarter phase, half lit or 50% illuminated and about 64 million miles (103 million kilometers) from earth. Also, on March 29, Venus is at its greatest elongation, angular distance to the east of the Sun. (half lit Venus on the left of the image below)

Phases of Venus
Why Is Venus So Bright?

Image: Society for Popular Astronomy/Adobe Photoshop

Venus is presently moving from a full phase toward a thin crescent phase.

Even though less and less of it is illuminated Venus looks brighter and brighter! This occurs because it is moving closer to the Earth and appears bigger and bigger. As the distance between Earth and Venus shrinks the apparent diameter of Venus grows. A thin crescent Venus closer to the Earth looks bigger and, therefore, brighter than a small full Venus farther away from Earth.

Animated Phases of Venus
Watch Venus diminish in size as it moves from a thin crescent
phase toward a full phase. Understand why its thin crescent
phase would look more brilliant from Earth than its full phase.

Venus, because it is the closest planet to the Earth, is the brightest of all planets. This planet is brighter than all the stars. In the night sky, Venus is second in brightness only to our Moon. Another reason for its blazing brightness is that it is completely enshrouded in layers of bright clouds, which make it reflect light from the Sun almost like a mirror.

In 2004 Venus is at its brightest in mid spring, reaching its greatest brilliancy for this apparition on May 2 at magnitude –4.5. At this time Venus is only 42 million miles away (68 million kilometers) Note: On May 2 Venus is 28% illuminated and still moving toward the Earth (the phase just before the sliver crescent Venus on the left side of the image above.)

BTW, when Venus is closest to us, it lies between the Earth and Sun at inferior conjunction and its illuminated surface faces the Sun. We can't see Venus at this time because no light is reflected toward us! However, when Venus is closest to the Earth and its orbit passes directly in front of the Sun, it can be seen as a black dot crossing the Sun! This rare event occurs on June 8, 2004, is called a Venus transit and has esoteric significance. On this day Venus will be a mere 27 million miles (43 million kilometers) away from the Earth.

For Northern Hemisphere observers, Venus is embarking on its best evening apparition in a decade. Look Up and marvel at this breathtaking planet. Tune to its rare daylight dance across the Sun on June 8, 2004. Be amazed and delighted!

Venus' Phases
See the phases from November, 2003–June 2004.
Includes an overhead view of the orbits of
Earth and Venus that force the changes. Full Story

Compute the apparent disk size of Venus
and other solar system objects. See the telescopic
phase of Venus for any given date and time.

Transit Observer
Locate the position of the Sun and Venus
or the Sun and Mercury for any location, date and time.