Scientists studying the microwaves left over from the Big Bang have worked out the makeup of the Universe. Only five per cent is ordinary matter like the matter in people, bricks and air. The rest of the Universe is mysterious dark matter or even more mysterious dark energy.
The ingredients of the Universe after Planck. Courtesy ESA and the Planck Collaboration
We cannot see the origin of the Universe at the Big Bang, but scientists can study its afterglow dating from only a few hundred thousand years after the event. To do so they are using the European Space Agency’s Planck spacecraft that circles the Sun at a distance of 1.5 million km from Earth.
Planck’s map of the Universe. Courtesy ESA and the Planck Collaboration
Over the last few evenings the elusive planet Mercury has become visible low in the west after dusk. Tonight a very thin crescent Moon can be seen above and to the left or south of the planet. This is the first opportunity to see the crescent after the instant of new Moon that occurred just after midnight on Tuesday morning.
Mercury and a thin crescent Moon on the evening of 27 August 2014. Chart Nick Lomb
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 Geoffrey Wyatt, Sydney Observatory’s Senior Astronomy Educator.
Geoff fascinates us with his guide to the stars and constellations to look out for in September and also with insight into how astronomy was important to the ancient people of Mesopotamia, Greece and Rome.
Geoff tells us where and when to look out at night for the planets Mercury, Mars, Saturn in September. And he points out his highlight for the month, on 1st September when, shortly after sunset, Saturn, the Moon and Mars will all be in the constellation of Libra, with the Moon and Saturn just five degrees (or five pinkie widths) apart.
Listen to the September 2014 night sky guide audio, or read the transcript below.
HEAR THE AUDIO
You can subscribe with iTunes or upload the (34 mins) audio to your iPod or mp3 player, or listen to it on your computer.
SEE THE SKY CHART
We provide an embedded sky map (below) and a September 2014 night sky chart (PDF) which shows the stars, constellations and planets visible in the night sky from anywhere in Australia. To view PDF star charts you will need to download and install Adobe Acrobat Reader if it’s not on your computer already.
September 2014 night sky chart
BUY THE BOOK
Our annual book, ‘The 2014 Australasian sky guide’, by Dr Nick Lomb has more information and star maps for months from December 2013 until December 2015 inclusive (or wait till November when you can purchase the 2015 book), plus information about the Sun, twilight, the Moon and tides, and a host of other fascinating astronomical information. You can purchase it ($16.95) at Sydney Observatory and Powerhouse Museum shops or other good bookshops, or online through Powerhouse Publishing (additional packing/postage costs apply).
READ THE TRANSCRIPT (after the jump)
The constellation of Centaurus the Centaur contains the two pointer stars to the Southern Cross as well as Omega Centauri, a famous cluster of a million or so stars. From a dark sky the cluster is easily visible to the naked eye, while through binoculars it looks like a fuzzy blob.
Hubble Space Telescope image of the central parts of Omega Centauri. Photo courtesy NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
The red planet Mars and the ringed planet Saturn are both in the north-west sky each evening after dusk. Over the last few evenings Mars has been approaching Saturn which has remained sedately still near the star Zubenelgenubi. Tonight and tomorrow night the two planets are at their closest with seven moon-widths between them.
Mars and Saturn on the evening of 25 August 2014. Chart Nick Lomb
Tomorrow Sunday morning early risers can enjoy the sight low in the eastern sky of a thin crescent Moon above and to the right or south of the planet Jupiter. As the sky starts to brighten with the approaching sunrise the bright planet Venus rises above the horizon and forms an equilateral triangle with Jupiter and the Moon.
Jupiter, Venus and the Moon on the morning of 24 August 2014. Chart Nick Lomb
The two bright stars marking the location of the Southern Cross are called the Pointers. Alpha Centauri, the one that appears furthest from the cross, is the closest star to the Sun at a distance of 4.3 light years from Earth. On the other hand Beta Centauri, the other Pointer star, is 392 light years from us.
The pointer stars. Photo Nick Lomb
The Southern Cross gives us an easy means of finding south on any clear night. Extend its long axis by four and a half times its length to reach a point known as the South Celestial Pole. South is the point on the horizon directly below the pole.
How to find south using the Southern Cross. Chart Nick Lomb
The stars of the Cross all appear to be at the same distance but that is not the case. Like the stars of all constellations, they are physically far apart: the closest star to us in the Cross is Gamma at a distance of 88 light years, while the furthest star Delta is at 364 light years distance.
The Southern Cross. Photo Nick Lomb