The Backyard Stargazer

Moon-1.31.10, originally uploaded by david parmet.

You might have noticed that the Moon looks awfully large this week. In fact you are correct. The Moon is at perigee – at the point in its orbit that it is closest to the Earth.

At this point, the Moon is a couple ten thousand miles closer than it is at apogee, the furthest from Earth. And its roughly 14% larger than normal.

So if you felt a bit loony this week, blame the Moon.

More information at Moon Connection.

Jupiter

Tonite, right after sunset, look directly south, about 1/3 of the way up from the horizon. That bright star you’ll see is Jupiter, the King of Planets.

For the next few weeks, Jupiter is dominating the night sky. It’s currently in the constellation Sagittarius, coincidentally one of the most deep-sky rich constellations visible in the Northern Hemisphere.

In 1609, Galileo first viewed Jupiter through a telescope and saw right away the four Galilean Moons: Io, Calisto, Ganymede and Europa.

Over the course of several nights, the moons can be viewed orbiting around Jupiter – it was this discovery by Galileo that led to the downfall of the geocentric world view – that everything revolved around the Earth. This was the birth of the modern world-view, in short – the birth of modernity.

With binoculars, you can clearly make out Jupiter as a disk and see the moons. With a small telescope you can see the Jovian system. In my telescope I can see at least two equitorial bands and on a very clear night I can make out even greater details on the surface of Jupiter.

Saturn is one of the easiest and most rewarding views for a small telescope.

A good pair of binoculars can show the rings. Moving up to a small telescope and you can see some cloud details, a moon or two and maybe even the elusive Cassini Division between the A and B rings.

The secret to viewing planets is having good seeing. Seeing is a losely defined term refering to the quality of the air between you, the viewer, and what you are looking at. It might be clear as a bell from where you stand but 60,000 feet above you there might be enough turbulance in the upper atmosphere to ruin a good night’s viewing.

The best way to deal with this is to stick with what you are viewing for at least a half hour. You’ll get enough breaks in that time for the skies above you to clear and the views to sharpen. So be patient. And enjoy the view.