March 14, 2012

Venus, Jupiter Give Dazzling Nighttime Show

Skywatchers are in for a real treat this week as Jupiter, Venus and other objects in the solar system put on a spectacular nighttime show.

Venus and Jupiter, which have been dancing toward each other in the night sky for weeks, were at their closest point on Monday and Tuesday evenings, appearing to be just three degrees apart shortly after Sunset in the western sky, astronomers said.

The two planets are actually separated by inconceivable distances, but appeared to be almost rubbing shoulders Monday evening as their orbits aligned.  Their intense brightness made the planets easily distinguishable from stars.

After Tuesday night, the planets will begin to drift apart again, with Jupiter moving lower in the sky as Venus rises towards the end of the month.  However, the dazzling sky-show goes on, peaking on Thursday when the full moon of March takes over the night sky and Venus and Jupiter line up in something known as planetary conjunction — an event that occurs roughly once every 13 months.

Astronomers say this year´s conjunction should be one of the best in recent years for stargazers in the mid-northern latitudes of the Northern Hemisphere.  This is because the two planets will be visible for such a long time — about four hours -- in the western horizon.

Although Jupiter is about 11 times larger, Venus will shine 8 times as bright from our perspective here on Earth due to its closer proximity.
On average, the Earth orbits the Sun at about 93 million miles, a distance defined as 1 astronomical unit (AU).  By comparison, Venus orbits around the Sun at about 0.72 AU, while Jupiter is found roughly 5.2 AU from the Sun.

Venus will put on a show once again this year on June 5, when it will cross the face of the Sun from Earth's perspective, appearing as a tiny black dot against the backdrop of our star.   The best views of this rare event — which occurs less than two times per century -- can be seen from eastern Asia, eastern Australia or Alaska, where Venus will appear to pass directly in front of the face of the Sun.

After June 5, the next time Venus will transit across the Sun is in 2117.


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