The Sun with giant sunspot group AR11944 (lower left) on 6 January 2014. Courtesy SDO/HMI Solar astronomy delivers! Without warning new and strange examples of your subject appear – a gift ‘for those who would scan the face of Nature’ (as C.P Gaposchkin put it).
On this day in 1610 the Italian scientist Galileo Galilei turned his very basic telescope towards the planet Jupiter. He saw three faint “stars” arranged in a straight line adjacent to the planet.
To the west or left of Orion, almost due north in the early evening we find the Hyades, a group of stars in the form of an inverted "v". Apart from the bright reddish star Aldebaran, they are all part of a cluster of stars about 150 light years away.
This evening at 10:59 pm eastern summer time the Earth is at perihelion, its closest point to the Sun for the year. At this point we are 147.1 million km from the Sun. Though this distance is 5 million km less than the distance at our furthest point in July, it has little effect on the temperature.
The closest star to Earth is the Sun at a distance of 150 million km. Travelling in a straight line at the speed of a modern jet aircraft it would take us about 19 years to reach it. The nearest star system to the Sun is that of Alpha Centauri, which is at a distance of about 40 million million km.
On this date in 1959 the old Soviet Union launched the Luna 1 spacecraft, also known as Mechta, towards the Moon. It passed within 6000 km of the lunar surface and went into orbit around the Sun. It made significant observations regarding the belt of charged particles around the Earth and discovered that the Moon has no magnetic field.
To help you learn about the southern night sky, Sydney Observatory provides an audio guide/podcast, transcript of that audio, and a sky map or chart each month. This month's guide is presented by Dr Nick Lomb (pictured at right), Sydney Observatory's Curator of Astronomy.
This year 2014 will be an interesting one with two total eclipses of the Moon and a partial eclipse of the Sun. With the first Moon eclipse in April people around most of Australia will have the pleasing sight of a red, fully eclipsed Moon rising in the eastern sky.