A sketch of crater Humboldt. Sketch and copyright Harry Roberts ©, all rights reserved The Moon is a fine example of a rocky planet – and one that is not being changed by on-going geological forces.
Pollux is the second of the two bright stars of Gemini the Twins. It is above and to the right or east of its twin Castor. The name Pollux means the Boxer. It is a giant reddish star that is ten times the width of our Sun and is 34 light years from us.
Astronaut Buzz Aldrin, who was born in New Jersey, USA on this day in 1930, took part in the first manned landing on the Moon. He had been an US Air Force pilot flying combat missions in Korea. After the Korean War he obtained a doctorate from MIT on how spacecraft can rendezvous while in orbit.
Sunday is the anniversary of the launch of the New Horizons spacecraft (American time) in 2006 towards the then major planet Pluto. To the disappointment of some of the scientists involved with the mission, later that year the International Astronomical Union demoted the planet to dwarf status.
Pollux and Castor are the two bright stars of Gemini the Twins. In the early evening they are low in the north-east, directly below Orion. Being a constellation named in the northern hemisphere the twins are upside down with the two bright stars representing the heads of the twins at the bottom.
These are the constellations the Sun passes in front of during the year. Looking from west to east in the early evening the following zodiac constellations are visible: Aquarius, Pisces, Aries, Taurus, Gemini and Cancer.
The giant planet Jupiter is visible low in the north-east after dusk in the early evening. It is in the constellation of Gemini the Twins, which is recognisable through its two bright stars, Pollux and Castor.
Visitors with Sydney Observatory’s main telescope, the 29-cm Schroeder lens telescope. From The Sydney Mail Saturday 12 January 1895. Courtesy Sydney Observatory Sometime in early to mid 1885 the young journalist Thomas Heney received a ‘card of admission’ to Sydney Observatory “to view the moon and planets” and went on an evening visit.
A space rock or asteroid named after Australia’s first and largest city is today at its closest to Earth for the year. Discovered by John Broughton at Reedy Creek Observatory on Queensland’s Gold Coast, 15550 Sydney circles the Sun every five years or so between the paths of Mars and Jupiter.
If we extend a line through Orion’s belt westwards we reach a faint group of stars called the Pleiades or the Seven Sisters. Although without a telescope most people can only see six stars in the group, the Ancient Greeks called them the Seven Sisters.
The astronomer William Herschel discovered Titania and Oberon, the two largest moons of the planet Uranus, on this date in 1787. The next two moons, Ariel and Umbriel, were only found in the middle of the next century.
Nobel Prize winner Robert Woodrow Wilson was born on this day in 1936. In the mid 1960s Wilson, together with his colleague Arno Penzias, discovered the uniform microwave radiation that permeates the Universe.
This month after dusk we have a good view of favourite constellation of the Australian summer sky, Orion, high in the northern sky. Above and to the right or east of Orion is Sirius, the brightest star in the sky, while closer to the horizon are the twin bright stars Pollux and Castor.
An animated diagram showing the daily motion of the Sun at the turning points of the year, the summer and winter solstices and the spring and autumn equinoxes, as seen from southern latitudes at places such as Sydney, Melbourne or Perth.
The great theoretical physicist Stephen Hawking was born on this day in 1942 in Oxford, England. Hawking obtained a first class honours degree from Oxford and then moved on to Cambridge to study cosmology.