08 April 2012

Venus in Motion

The brilliant planet Venus shines each evening in the west, leaving most who see it saying "that's not a planet, that's an airplane, isn't it?" For the next two months, its orbit around the Sun is bringing it closer to Earth each day, en route for a rare and exciting Transit on June 5th (for Western Hemisphere viewers).

Because Venus is located nearer to the Sun than Earth, as it moves in its orbit around the Sun it only is visible in the evening sky after sunset, or in the morning sky before sunrise. Right now, as we observe Venus in the evening sky, we can watch it speed around the Solar System by comparing its position to the backdrop of stars in the distance. Last week, Venus passed near the Pleiades star cluster, and for the next few weeks it will glide away from the Pleiades, as the star cluster moves quickly into the glare of the sunset sky while Venus hangs high in the west. At the end of April, Venus is at its greatest brilliance (brightest) for the year. Nakedeyeplanets.com has excellent charts showing the changing position of Venus in the heavens.

Soon after greatest brilliance, Venus will reverse its course into retrograde motion and begin a slow fade into the glare of the sunset sky as it rapidly closes the gap for its nearest approach to Earth and the June 5th Transit. I'll have more on the Transit of Venus in another article. For now, enjoy the bright shiny object in the west as it holds 'center stage' for all of us.

Image courtesy of Sky & Telescope Magazine.

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