Plenty of Planets!

Now is a great time to feel that you are part of the solar system. Venus, Mars, Saturn and the Moon are all visible in the evening sky. As you can see in the photograph I took a few nights ago (below), all the planets lie along a line called the ecliptic, which goes to show just how flat our solar system is. (Just hover your mouse over the image for labels)

Our solar system is like a big flat pancake! Imagine the Earth sitting on that pancake, along with the rest of the planets. The grid marks where that pancake (the flat plane of our solar system) goes out into space, and so where all the planets can be found. The constellations of Leo (top left) and Gemini (bottom right) are also shown.

The following animation shows just how it looks from the ground and from above the solar system.

New Years' Eve 2009: Lunar eclipse and a Blue Moon

One thing is for sure - the Full Moon will past through the shadow of the Earth on New Years' Eve. For about 30 minutes either side of 19:24GMT, the bottom right of the Moon will be dark-red in colour (looking similar to the photo below taken in 2006). The bottom-right of the moon will appear red due to sunlight passing through the Earth's atmosphere and hitting the Moon, and our atmosphere only allows red light to go straight through, which is also why sunsets are red.
Do take a look while you are preparing your New Year celebrations!

One thing that is not so sure - will the full Moon on the 31^st also be a "Blue Moon"?

For sure, the Moon will not be the colour blue. But as with the expressions "Turned the air blue" or "Feeling blue", blue does not always refer to colour. And there is more confusion, since there are several definitions of "Blue Moon" in the English language.

The modern definition (thought to originate from an article in a 1946 article in the Sky & Telescope magazine) states that if a month has two full moon's, the second one is called a "Blue Moon". This definition is popular today probably due to its simplicity.

The older (pre-war) definition is that a "Blue Moon" is the third full Moon in a season with four. This is because each full moon has a name. For example, the full Moon in April in English Medieval times was known as the Seed Moon. If there was a second full moon in March, the Seed Moon would come too early for seeding crops, and so a "Blue Moon" was inserted and the following full-moon was called the "Seed Moon". So a "Blue Moon" was inserted to keep the names of all the other full moons synchronised.

Do enjoy the Full Moon of New Year's Eve - and why not go for a Blue Moon Walk to see in the New Year?

Water, water, everywhere...?

We believe that water is one of the key ingredients for life, and this is often discussed in schools, and so it have been interesting to hear the reports of water on the Moon and Mars over the last few days.

Last week, the Indian Chandrayaan-1 lunar orbiter discovered that areas of the lunar surface are slightly damp... slightly meaning that the Moon is still dryer than the driest of Earth's deserts! But there is water present. Full details of that can be found on the Astronomy Picture of the Day site.

Orbiting Mars, NASA's Mars Reconnaissance Orbiter has discovered 100 fresh meteor impact craters. On Earth, most meteors burn up in our atmosphere, and do not reach the ground. But the atmosphere of Mars is much thinner than ours, allowing far more meteors to hit the surface. And when a crater is formed, you can see what is just beneath the martian surface... and it appears to be ice. More details of this story at the NASA-Science website, and on the BBC News.

This also implies that had the robotic arm on NASA's Viking 2 (which landed on Mars back in 1976) been just 10 cm longer, it might have struck ice!