Full Moon and Jupiter on a clear night

After days (months?) of rainy weather we're having a cold, dry spell. With this comes clear skies at night and a fabulous view of tonight's full Moon.

As we drove home eastwards along the M62, we noticed the amazingly bright 'star' directly in front of us. So bright, in fact, that it was even visible shining through the patchy, high level cloud which was also being beautifully lit by the moonlight. It was the planet Jupiter, the brightest object in the night sky after the Moon.

Jupiter and its Great Red Spot
From the Earth, Jupiter is a bright white dot. Closer, it's an intriguing mix of gases (mostly hydrogen and helium) and on its surface can clearly be seen the Great Red Spot, a huge gas storm in the southern hemisphere which has been known to exist for at least 300 years. Which makes our bad summer seem a bit trivial.

Jupiter is the largest planet and is truly massive. To give an idea of scale, the white oval area just below the Great Red Spot is roughly the same size as the Earth. So it's hardly surprising that we can see it from the Earth despite it being about 380 million miles from us. In fact Jupiter rarely passes closer to the Earth than it is now and this is why it is especially bright and noticeable in the night sky.

Jupiter is 34 'light minutes' from the Earth. When we look at Jupiter we are seeing light which left the planet 34 minutes ago. Travelling at over 186,000 miles per second, light still takes a measurable time to travel the great disance from one planet to another.

The full Moon setting in the west with Jupiter clearly visible (above and to the left)
Once you get outside our local solar system and start talking about other stars the distances get far greater. The closest star is over 4 light years away and beyond that the numbers just grow. The farthest star that we know about is over 10 million light years away, a distance that's impossible for a normal person to think about.