Last week, Mars drew close to Earth. This week, Jupiter and Venus are putting on a show of their own.
When you look to the western sky tonight, you'll see two bright points of light among the stars. They are hard to miss and a great opportunity to take the family out for some brief observing, even from your front yard.
The one on the left is Jupiter. On the right, several times brighter, is Venus. Unlike the stars behind them, the planets give off no light of their own, only reflecting that of the sun, but they are hard to miss. If your vision is really, really good or if you have a small telescope or pair of binoculars you can even make out that Venus is a crescent shape with only the side pointed towards the sun illuminated. Mercury and Venus have phases not unlike our moon.
Jupiter and Venus will appear side by side to us here on Earth but in reality, they are about 450 million miles apart.
If you continue to look in that same location over the remaining evenings this week, you'll see Jupiter pass Venus as it continues its journey behind the sun from our perspective. Jupiter will continue to widen the gap with the next interesting alignment happening on the 26th of this month when the moon, Jupiter and Venus will form a triangle in the western sky shortly after sunset and continue to be visible until the moon and Jupiter set around 9:30 p.m.
Intensely bright Venus has been the source of many UFO sightings over the years. Frightened observers have phoned police reporting a "strange light hanging in the sky" and an unnamed air traffic controller in Detroit commented, "Do you know how many times we have cleared Venus to land?"
Jumpy citizens on the West Coast reported Venus as an "enemy plane" during WWII. First Sergeant Jeff Gordon was happy to confirm that there have been no reports of UFOs coming into the North Carolina State Highway Patrol communications center from concerned North Carolinians though.
Why is Venus so bright? It's a cloudy planet slightly smaller than Earth. Those clouds reflect nearly all the sunlight that hits them.
Additionally, this conjunction brings Venus close to Earth making it appear bigger and brighter in the sky.
Conjunctions are more than trivia on the celestial calendar. They are unique opportunities to view these sights with the naked eye. Planets and stars seem to look better when they are bunched together. More than just this observer's opinion, there is a physiological explanation. Your eye is made up of millions of light-sensing rods and cones. Near the center of your retina, the cones are extra-densely packed in a region called the fovea centralis. The fovea provides a higher definition image to your brain in a field of vision about 5 degrees wide. That's just enough for Venus and Jupiter to fit into this week. So get out there and enjoy some HD viewing.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.