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What’s up? Night sky for February 2014

WHEN STARTING OUT IN STARGAZING, most people are particularly keen to spot the planets. The problem is, that, to the novice, planets and stars look pretty much alike. The best way to identify planets is to determine their locations in relation to nearby bright stars or the Moon, and then see how watch as they change their positions slightly as each night passes. The information below will help you spot planets using this method.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. Dates and times are for the Australian Eastern Summer Time zone, and sky directions are from the point of view of an observer at mid latitudes in the Southern Hemisphere.

7 Feb

It is First Quarter Moon today at 6:22am Sydney time. First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains are throwing nice shadows, making it easier to get that 3D effect.

8 Feb

The just-past-half Moon is the north-western sky this evening, and just above it is a group of stars called the Hyades. See if you can spot them – they’re in a triangular formation. The Hyades is an ‘open star cluster’ about 153 light years from Earth, making it the closest such cluster to our Solar System. Although you’ll probably only be able to see a handful of stars with the naked eye (assuming, of course, that you’re not standing under a streetlight), a pair of binoculars will show many more – and long-exposure photographs reveal hundreds.

Just above and to the right of the Moon is a bright orange-coloured star called Aldebaran, although astronomers classify it as a red giant. It is roughly 44 times as big as the Sun and located about 65 light-years from Earth. Think about that – if Aldebaran were at the same distance from us as the Sun, it would appear 44 times as big in the sky. Just as well it’s a long way away!

View showing where the Moon is on the night of 8 February 2014

The Moon (shown bigger than it really is) will be near the star Aldebaran and the star cluster the Hyades on the evening of 8 February. Another star cluster, the Pleiades, is lower in the sky.

11 Feb

By tonight, you’ll see that Moon has moved a fair distance to the right (or east) of the Hyades, as a result of its slow orbit around the Earth. You won’t be able to miss what looks to be a bright star just below the Moon – this is the planet Jupiter. Grab a pair of binoculars and see if you can make out some tiny pinpricks of light on either side of the planet – these are the moons discovered by Galileo; Ganymede, Europa, Io and Callisto. Try to see all four – you might find there are two on each side of Jupiter, or one and three, or all four on one side – depending on where they are in their orbits around the planet. You might find that one or more are missing – this’ll be because that moon or moons is currently hidden behind Jupiter, or in the glare in front of the planet.

View showing the position of the Moon on 11 Feb

On the evening of 10 February, the Moon (not shown to scale) will be just above the planet Jupiter.

12 Feb

Today the Moon will reach the farthest point in its orbit around Earth, apogee, at a distance of 406,231 kilometres.

15 Feb

Full Moon occurs today at 10:53am Sydney time. If you’re out stargazing tonight and look just above (or north of) the Moon, you’ll see a bright blue star. This is Regulus, the brightest star in the constellation Leo. Located about 77.5 light years from Earth, Regulus is not one star but four, grouped into two pairs – with the naked eye we see only the brightest of the four. Multiple star systems are very common throughout the Milky Way galaxy.

20 Feb

Take a look around midnight tonight and you’ll see the Moon just below what appears to be a brightish red star. This is not actually a star but the planet Mars. A small planet, it doesn’t give away much detail even when viewed through a telescope.

Just below the Moon is Spica, the brightest star in the constellation Virgo. Like Regulus, Spica is a member of a multiple star system, in this case a binary (or two) star system. The two stars orbit each other so close together that not even a telescope can show them separated. In fact, so close are they that their mutual gravitational pull distorts each of them from a round shape into an egg shape. The Spica system is about 260 light years from Earth.

View showing the position of the Moon on 20 February

If you’re up after midnight on 20 February, you’ll be greeted by the sight of the Moon with the star Spica above and the planet Mars below.

22 Feb

Tonight it’s Saturn‘s turn, with the ringed planet appearing just below and to the right of the Moon. If you have access to even a small telescope, take a look at Saturn’s amazing rings.

23 Feb

It is Last Quarter Moon today at 4:15am Sydney time. In the early hours of this morning you’ll find the star Antares above and to the right of the Moon. Antares is the brightest star in the constellation Scorpius. Like Mars, it is a red colour too – in fact, the name Antares means ‘rival of Mars’. Because they’re both in the same part of the sky, this is a good time to compare the two.

26 Feb

If you’re up before dawn, take a look out to the east and you’ll see the thin crescent Moon just above a bright ‘star’ – this is actually the planet Venus, which, aside from the Sun and the Moon, is the brightest object in the sky. Because it is in our morning sky at present, it is called the ‘morning star’. Later in the year it will be visible to west in the evening sky, and will be known as the ‘evening star’.

View showing the position of the Moon on 26 February

This shows the view out to the east less than an hour before sunrise on 26 February. The thin crescent Moon is just above the planet Venus. Very low down on the horizon, and difficult to see, is the planet Mercury. The Moon will be just to the left of Mercury on 28 February.

28 Feb

Today the Moon will be at the closest point in its orbit, called perigee, which is the opposite of apogee. The distance between the two bodies today will be 360,438 kilometres. If you’re up and about before dawn, and you have an unobstructed (by buildings, trees, hills etc) view of the eastern horizon, see if you can spot the planet Mercury just to right of the very thin crescent Moon. It won’t be easy to see either Mercury or the Moon, but give it a try.

Here are some more great sources of southern stargazing information:

Melbourne Planetarium

Royal Astronomical Society of New Zealand

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

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What’s up? The night sky for January 2014

WHEN STARTING OUT IN STARGAZING, most people are particularly keen to spot the planets, five of which are visible to the naked eye – Mercury, Venus, Mars, Jupiter and Saturn. The problem is that, to the novice, planets and stars look pretty much alike. An easy way to identify planets is to find them in relation to nearby bright stars or the Moon, and then watch as they change their positions slightly as each night passes. The information below will help you spot planets using this method.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. Dates and times are for the Australian Eastern Summer Time zone, and sky directions are from the point of view of an observer at mid latitudes in the Southern Hemisphere.

People stargazing using a telescope

There’s plenty to see in the night sky during January 2014.

Jan 1

The Moon is in its ‘new’ phase (the opposite of ‘full’) tonight at 10:14pm. This means that, seen from Earth, it is in the same direction as the Sun, and therefore won’t be seen all night – which is good for stargazing, as the absence of its light will make fainter objects easier to see.

Jan 2

Today at 8:01am, the Moon will be at the closest point – called perigee – in its elliptical orbit around the Earth. The distance between the centres of the two bodies will be 356,921 kilometres.

Jan 4

Today the Earth reaches perihelion, which is the point at which our planet is closest to the Sun during its orbit. The distance separating the two bodies is 147,089,638 kilometres. Note the similarity between the words perigee and perihelion – perigee is used for anything orbiting the Earth (‘peri’ coming from the Greek for ‘around’, while the ‘gee’ part derives from gaia, the Greek word for Earth), while perihelion is used for anything orbiting the Sun (the ‘helion’ part coming from ‘Helios’, the ancient Greek god of the Sun).

There’s a common misconception that the Earth’s changing distance from the Sun (it varies from about 147 million to roughly 152 million kilometres over the course of the year) is responsible for giving us our summers and winters. This is wrong, and a few moments thought shows why. Taking perihelion as an example, the misconception says that with the Earth being at its closest point to the Sun, our planet should experience summer. Well, it’s certainly true that perihelion occurs when it is summertime in the Southern Hemisphere… but what season is it in the Northern Hemisphere? It’s winter. And why is it winter and not summer? Because perihelion has nothing to do with our seasons. The seasons are caused by the tilt of the Earth’s axis of rotation, which sees the Southern Hemisphere tilted toward the Sun at the end of the calendar year, and the Northern Hemisphere tilted away. Six months later it’s the other way around – the north is tilted toward the Sun (and thus the northern summer and southern winter are in the middle of the calendar year) and the south is tilted away.

Jan 8

It is first quarter Moon today at 2:39pm. A few days either side of first quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains throw nice shadows, making it easier to get that 3D effect.

Jan 12

Tonight, the almost-full Moon will be just below the star Aldebaran, the brightest star in the constellation Taurus. Aldebaran is a red giant star roughly 44 times as big as the Sun, located about 65 light-years from Earth. Have a look to the left of Aldebaran and you’ll see a beautiful, broad group of stars in a V-shape. These are the Hyades. If you have a pair of binoculars, take a look; you’ll be amazed by the beautiful sight of these sparkling stars! (A little further to the left, or west, is an even more beautiful cluster of stars – the Pleiades. See the diagram for its location.)

Diagram of the night sky for January 12

The Moon will be near the star Aldebaran on the evening of January 12. Just above and to the left of Aldebaran is a group of stars called the Hyades – take a look with a pair of binoculars; it’s a beautiful sight. An even better cluster of stars, the Pleiades, is a little further to the left (or west). Below and to the right in this view is the planet Jupiter – the Moon will be close to it on January 15.

Jan 15

Tonight the almost-full Moon will be just above and to the right of what looks like a very bright star, but is in fact the planet Jupiter – the largest planet in our Solar System. If you have a decent pair of binoculars (ie. anything bigger than opera glasses), train them on Jupiter and you should be able to see its shape and perhaps even some of the ‘banding’ of the atmosphere (the planet’s different weather zones). You should also be able to see up to four tiny, bright pinpricks of light – these are the famous moons discovered by Galileo. You might see one or two on one side of Jupiter, and the others on the other side. (If you take a look in the late evening on January 18, you’ll see them all on the same side.)

Jan 16

Full Moon occurs today at 3:52pm. When the Moon is full, it rises in the east around the same time as the Sun is setting in the west, which means it will be visible all night long. This is great for finding your way around in the dark, but the Moon’s glare is generally not welcomed by stargazers as it makes fainter objects harder or impossible to see.

Still on the subject of the Moon, today at 12:54pm it will reach apogee (the opposite of perigee), which is the farthest point in its orbit around the Earth. The distance separating the centres of the two bodies will be 406,536 kilometres.

Jan 23

If you’re awake around midnight, look out to the east and you’ll see the Moon with a reddish star just below it. That ‘star’ is actually the planet Mars. Mars is a small planet, so you need at least a medium-sized backyard telescope to get any decent sort of view of it. But even as you gaze at it with the naked eye, stop and think for a moment – right now there are two missions on their way to Mars (NASA’s MAVEN and India’s Mars Orbiter), plus there are three orbiters and two operational rovers already working at or on the Red Planet. When the two new spacecraft reach their destination in September 2014, Mars is going to become a busy place!

Diagram of the evening sky for January 23

The Moon and Mars will be near each other in the sky in the early hours of January 23.

Jan 24

It is last quarter Moon today at 4:19pm. When you take a look tonight, you’ll notice that Moon has moved a bit since last night (as a result of its slow crawl around its orbit), and Mars is now above and to its left. But directly above the Moon is a bright star called Spica, which is the brightest star in the constellation Virgo. Spica is a blue giant star located about 260 light-years from Earth.

Jan 26

If you’re awake in the early hours after midnight, you’ll be rewarded with the view of the just-less-than-half Moon down near the eastern horizon, with a brightish ‘star’ just above it. That’s not a star, it’s the planet Saturn. If you have access to a small telescope, train it on Saturn and you’ll its magnificent system of rings.

Jan 29

If you’re up before the sunrise today, look out to the east and you’ll see a very thin crescent Moon. Just below it is what looks to be a very bright star, but is in fact the planet Venus. After the Sun and the Moon, Venus is the brightest object in the sky.

Diagram of the morning sky for January 29

The thin crescent Moon will be near Venus in the morning sky on January 29. (Venus is not shown to scale in this diagram.)

Jan 30

The Moon reaches perigee today, with the distance between the centres of the Earth and Moon being 357,079 kilometres.

Jan 31

New Moon occurs for the second time this month, at 8:39am

Here are some more great sources of southern stargazing information:

Melbourne Planetarium

Royal Astronomical Society of New Zealand

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

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What’s up? Night sky for February 2013

Night sky on February 3, 2013

Saturn and the Moon will appear near each other on February 3, 2013.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Standard Time zone, and sky directions are from the point of view of an observer in the Southern Hemisphere.

Feb 3

If you’re a night owl, look out to the east after midnight and you’ll see the Moon near the horizon. Below and to its right is what seems to be a bright star. It’s actually the planet Saturn. If you have access to even a small telescope, take a look. Its rings never fail to entrance. The gas giant planet has 62 confirmed natural satellites (ie. moons), and one artificial satellite – the NASA/ESA Cassini spacecraft, which has been exploring the Saturnian system since 2004. Saturn is presently about 1,455 million kilometres from Earth.

Feb 4

It is Last Quarter Moon today at 12:56am Australian Eastern Daylight Time (Feb 3, 13:56 Universal Time).

Feb 5

This evening, the Moon will appear close to the star Antares, the brightest star in the constellation Scorpius. Antares is a red supergiant star, about 880 times bigger and 10,000 times brighter than our Sun! It is about 550 light-years from Earth.

Feb 7

Today the Moon will be at the closest point in its orbit around Earth, called perigee. The distance between the two bodies will be 365,318 kilometres.

Feb 10

New Moon occurs today at 6:20pm Australian Eastern Daylight Time (07:20 Universal Time).

Feb 12

Just after sunset this evening, you might be able to see a very thin crescent Moon low on the horizon due west. To its left will be a brightish-looking ‘star’; it’s actually the planet Mercury. And just to Mercury’s left will be the ruddy-coloured planet Mars. Today Mercury is about 161 million kilometres from Earth, while Mars is about 348 million kilometres away.

Diagram showing the Moon and Jupiter

For stargazers in southern Australia, the Moon will pass in front of Jupiter on February 18, 2013.

Feb 18

There will be a major sky event this evening for those in the southern half of Australia! – the Moon will appear to move in front of the planet Jupiter. This is called an occultation (where ‘to occult’ means to ‘make go dark’). You’ll see the Moon slowly approaching Jupiter (which, to the naked eye, just looks like a bright star). Then, all of a sudden, as the Moon’s edge ‘reaches’ the planet, Jupiter will wink out. A short while later, after the Moon has moved on a bit (you’re actually watching it trundle along in its orbit), Jupiter will reappear on the other side.

Timings for the beginning of the event, in Standard (that is, non-Daylight Saving time – please adjust for your location if necessary) for capital cities are:

Adelaide: 10:00pm

Hobart: 10:22pm

Melbourne 10:33pm

Perth: 7:39pm

Unfortunately, the other capital cities will miss out.

Incidentally, it is First Quarter Moon this morning at 7:31am Australian Eastern Daylight Time (Feb 27, 20:31 Universal Time). First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains are throwing nice shadows, making it easier to get that 3D effect.

Feb 19

In tonight’s evening sky, to the northwest you’ll see the Moon, and to it’s left will be a bright star. And it really is a star this time, not a planet. It’s Aldebaran, the brightest star in the constellation Taurus. Just to Aldebaran’s left, you might be able to see a wide grouping of stars (binoculars will help). This is called the Hyades star cluster.

And today the Moon is at the farthest point in its orbit around the Earth, called apogee, at a distance of 404,472 kilometres.

Feb 25

Just near the Moon in this evening’s sky, will be the star Regulus, the brightest star in the constellation Leo.

Feb 26

Full Moon occurs today at 7:26am Australian Eastern Daylight Time (Feb 25, 20:26 Universal Time).

There’s more great night sky viewing information at Melbourne Planetarium’s Skynotes site.

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

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What’s up? Night sky for January 2013

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Daylight Time (AEDT) zone, and sky directions are from the point of view of an observer in the Southern Hemisphere.

January 2

If you’re an early riser, take a look out to the north-west and high up you’ll see a bright star near the Moon. This is Regulus, the brightest star in the constellation Leo. Actually, Regulus is not one star but four, grouped into two pairs. Multiple star systems are very common throughout the Milky Way galaxy.

The Moon will appear near the bright star Regulus on January 2.

The Moon will appear near the bright star Regulus on January 2.

And today the Earth reaches perihelion in its orbit around the Sun. Perihelion is the point in a solar orbit when the body in question (eg. Earth) is at its closest to the Sun. Perihelion occurs today at midday AEDT, at a distance between Earth and Sun of about 147,098,089 kilometres. (The opposite of perihelion is aphelion, which for Earth will occur on July 5, 2012 at a distance of about 152,097,351 kilometres.)

January 5

It is Last Quarter Moon today at 2:58pm Sydney time (03:58 Universal Time).

January 6

If you’re up very early this morning (from 2:00am onwards), you’ll see a bright star appearing to almost touch the Moon. This Spica, the brightest star in the constellation Virgo; it is a blue giant star about 260 light-years from Earth. And don’t miss tomorrow’s morning sight…

January 7

This morning, the Moon has moved along a bit in its orbit, and no longer appears to be near Spica. Instead, it appears to hover just above what appears to be another bright star, but which is instead the planet Saturn. If you have a small telescope, or can borrow someone else’s, take a look at Saturn – you’ll see the huge rings tilted nicely to our line of sight, and – depending on the power of your telescope – you might also be able to make out a couple of the planet’s moons, although they’ll only look like bright pinpricks of light.

January 7: If you're an early riser, take a look at the Moon and you'll see what appears to be bright star just below it. Well, that's actually not a star but the ringed planet Saturn.

January 7: If you’re an early riser, take a look at the Moon and you’ll see what appears to be bright star just below it. Well, that’s actually not a star but the ringed planet Saturn.

January 9

Again, the Moon has moved along in its orbit, and is now quite distant from both Spica and Saturn. This morning it appears near the red star Antares, the brightest star in the constellation Scorpius. Antares is a red supergiant star about 883 times bigger than our Sun, located about 470 light-years from us.

January 10

This morning the Moon, now a thin crescent, can be seen above what looks like a very bright star. Actually, it’s the planet Venus, low on the horizon. Venus will remain low in the east before dawn until the middle of February, when it will have moved too close to the Sun to be visible.

The Moon today will be at the closest point to Earth in its orbit, called perigee. The distance between the two bodies today will be 360,046 kilometres.

January 12

New Moon occurs today at 6:44am Sydney time (19:44 Universal Time on January 11).

January 14-27

If you have dark skies and are a little bit lucky, you might spot a few meteors between these dates, emanating from the southern sky. The Eta Carinid meteor shower occurs at this same time every year, but it’s not a very good one compared with others – you might be lucky to see a few meteors per hour, between midnight and dawn.

January 19

It is First Quarter Moon today at 10:45am Sydney time (23:45 Universal Time on January 18). First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains are throwing nice shadows, making it easier to get that 3D effect.

January 21: The Moon, Jupiter and the Pleiades star cluster will all be close together in the evening sky.

January 21: The Moon, Jupiter and the Pleiades star cluster will all be close together in the evening sky.

January 21

In tonight’s evening sky, the Moon will be situated quite near a famous cluster of stars, called the Pleiades or Seven sisters. When the Moon is not around and the sky is dark, most people can make out 6 to 7 of the Pleiades stars, although eagle-eyed stargazers can see a few more. With the Moon tonight being more than half full, it might be a little harder to see them. But if you have a pair of binoculars or a small telescope, take a look and you’ll be rewarded with a lovely sight – there are actually hundreds of stars (only some of them are visible through small optical instruments) in this beautiful “open star cluster“, and it is also filled with beautiful whispy gas clouds, although the stars and the gas are not actually related to each other—we just happen to be seeing them at a time when the stars are drifting through the gas.

And what’s that bright object just to the right (east) of both the Moon and the Pleiades? That’s actually the planet Jupiter.

January 22

Today the Moon will reach the farthest point from Earth in its orbit, apogee, at a distance of 405,312 kilometres. Take a look at it, and you’ll see what looks like a bright star just above it – it’s actually the planet Jupiter, the largest planet in our Solar System. Even a pair of binoculars will begin to show its size and shape, as well as up to four of its moons. A small telescope will reveal the different cloud bands that colour its upper atmosphere.

January 27

Full Moon occurs today at 3:38pm Sydney time (04:38 Universal Time).

There’s more great night sky viewing information at Melbourne Planetarium’s Skynotes site.

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

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Resources and web links

HELLO FOLKS. My apologies for the lack of updates on SpaceInfo.com.au in recent weeks, but your editor has been away conducting astronomy lectures aboard a cruise ship (the wonderful m/s Oosterdam, of the Holland America Line) on a journey to various tropical paradises scattered throughout the Pacific Ocean. Having now reluctantly returned to reality, it’ll be back to normal with SpaceInfo.

Lots of people aboard the Oosterdam asked me where I got all the incredible images of space that I showed during my lectures, and I promised to post some links. So here we go.

NASA has plenty of great web sites, for adults and children, including these favourites of mine:

NASA home page

NASA Planetary Photojournal

NASA Human Space Flight Gallery

NASA Quest

NASA Kids’ Club

There are lots of amazing images from the Hubble Space Telescope at these sites:

Hubble Space Telescope

European Space Agency Hubble site

There are other telescopes up in space too – here are a few:

Spitzer Space Telescope

Kepler Observatory

Herschel Space Telescope

And then there are all the wonderful ground-based observatories — here’s a small selection:

Australian Astronomical Observatory

Australia Telescope

Square Kilometre Array

Keck Observatory

Gemini Observatory

For keeping an eye on the Sun and solar activity, try these sites:

SOHO spacecraft

Solar Dynamics Observatory spacecraft

Here are links to some of the spacecraft missions that are exploring the planets of our Solar System:

MESSENGER (Mercury)

LRO (the Moon)

Cassini (Saturn)

Juno (Jupiter)

New Horizons (Pluto)

Curiosity rover (Mars)

Mars Express (Mars)

Mars Odyssey (Mars)

Mars Reconnaissance Orbiter (Mars)

Opportunity rover (Mars)

My thanks to everyone aboard the m/s Oosterdam, both crew and passengers, for making the journey so enjoyable and fulfilling.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

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What’s up? Night sky for April 2012

Star trails over an observatory

The southern sky is full of wonderful treats for the stargazer. (This star trail photo by Iztok Boncina was made by keeping the camera shutter open.)

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Standard Time zone, and sky directions are from the point of view of an observer in the Southern Hemisphere. (If you’re in the Northern Hemisphere, please see the video at the bottom of the page for What’s Up in your night sky.)

April 3

The Moon, now just over three-quarters full, will be about 11 Moon widths above and to the left of the bright blue star, Regulus, the brightest star of the constellation Leo. A little further below is what looks like a red star, but is actually the planet Mars. The colours of Regulus and Mars make a nice contrast. About 77.5 light years from Earth, Regulus is not one star but four, grouped into two pairs. Multiple star systems are very common throughout the Milky Way galaxy.

April 4

The Moon is still in the vicinity of Mars tonight, being above and to the right of the planet. Incidentally, when I use a term such as “vicinity”, it is not to be taken as suggesting the two bodies are physically near each other out there in space. Rather, they are simply within similar lines-of-sight from our vantage point on Earth.

April 4 sky view

April 4, 8:00pm. The Moon, Mars and the star Regulus will make an attractive triangle in the northern part of the sky. Note the colour difference between blue Regulus and ruddy Mars.

April 7

Full Moon occurs today at 5:19am Sydney time (19:19 Universal Time on April 6). In a similar fashion to its “encounters” with Regulus and Mars a few days earlier, tonight the Moon will be about six Moon widths to the right of another bright star, Spica, and about 10 Moon widths above the planet Saturn. Spica is the brightest star of the constellation Virgo; it is a blue giant star about 260 light years from Earth. This is a great time to see Saturn (see April 16), so it’s a good idea to use the nearby Moon to identify it.

April 8

Today the Moon will be at the closest point in its orbit, called perigee. The distance between the two bodies today will be 358,311 kilometres.

April 10

This evening, take a look about 12 Moon widths below the Moon and you’ll see a reddish looking star that looks a bit like Mars. It’s the star Antares, and its name actually “rival of Mars”. Antares is the brightest star of the constellation Scorpius, and is a red supergiant star about 883 times bigger than our Sun!

Saturn

Saturn, as it appears through a backyard telescope. Image by Steve Massey.

April 13

It is Last Quarter Moon tonight at 8:50pm Sydney time (10:10 Universal Time).

April 16

Today the planet Saturn reaches what astronomers call “opposition”. This means that, from an Earthly perspective, it is the opposite direction to the Sun—so if you could look down on the Solar System from above you’d see the Sun, Earth and Saturn (in that order) in a straight line … although Saturn, of course, is much further from us than the Sun. The period around opposition is a considered a great time to view a planet, as it rises in the east around the same time as the Sun sets in the west, and is therefore nice and high in the sky by late evening.

April 19

If you’re an early riser, out to east this morning before sunrise you’ll see the very thin crescent Moon. Above and to its right is a bright looking star. Well that’s not a star; it’s the planet Mercury, the closest planet to the Sun.

April 19 sky view

April 19, 6:30am. The thin crescent Moon and the planet Mercury will be visible together in the eastern sky before sunrise.

April 21

New Moon occurs today at 5:18pm Sydney time (07:18 Universal Time).

April 23

Today the Moon will again reach the farthest point in its orbit, apogee, at a distance from Earth of 406,421 kilometres.

April 24

Today the Moon makes another apparent close approach to a star, this time Aldebaran, the brightest star of the constellation Taurus. The pair will be low in the western sky after sunset. Like Antares, Aldebaran too is a red star, but not a supergiant—it is only about 44 times the size of our Sun. It’s about 65 light years from Earth.

April 25

There’ll be a lovely astronomical pairing in this evening’s sky, with the Moon very close to Venus. The Moon is the second-brightest object in our night sky, and Venus is the third-brightest.

April 25 sky view

April 25, about 7:15pm. The thin crescent Moon and Venus will be close together in the western sky.

April 29

It is First Quarter Moon today at 7:58pm Sydney time (09:58 Universal Time). First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains are throwing nice shadows, making it easier to get that 3D effect.

There’s more great night sky viewing information at Melbourne Planetarium’s Skynotes site.

If you’re in the Northern Hemisphere, here’s a Jet Propulsion Laboratory video that details what you can see this month:

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU and Iztok Boncina / ESO.

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What’s up? Night sky for January 2012

Stargazers with telescopes at night

Summer nights are perfect for stargazing.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Daylight Time (AEDT) zone, and sky directions are from the point of view of an observer in the Southern Hemisphere.

January 1

It is First Quarter Moon today at 5:15pm AEDT. First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains  throw nice shadows, making it easier to get that 3D effect.

January 3

Today the Moon will reach the farthest point in its orbit from the Earth, which is called apogee. It’s distance from our planet will be 404,578 kilometres.

While you’re out looking at the Moon, you’ll notice a bright looking star above and to the left. Well, that’s not a star; it’s actually the planet Jupiter. If you have access to a telescope, or even a pair of 7×50 (or better) binoculars, train them on Jupiter and you should see up to four tiny pinpoints of light on either or both sides of the planet—these are the moons Galileo discovered, Io, Europa, Ganymede and Callisto. If you take a look again tomorrow night, you’ll see that their positions will have changed as they whiz around the planet.

And in fact, we’re only a few days away from the anniversary of their discovery. On the 7th of this month, it will be 402 years since Galileo spotted them!

January 5

Today the Earth reaches perihelion in its orbit around the Sun. Perihelion is the point in a solar orbit when the body in question (eg. Earth) is at its closest to the Sun. Perihelion occurs today at midday AEDT, at a distance between Earth and Sun of about 147,098,000 kilometres. (The opposite of perihelion is aphelion, which for Earth will occur on July 5, 2012 at a distance of about 152,098,000 kilometres.)

If you have a pair of binoculars, you’ll see a pretty sight tonight, with the soon-to-be-full Moon appearing to sit above a beautiful star cluster called the Pleiades, or Seven Sisters. When the Moon is not around and the sky is dark, most people can make out 6 to 7 of the Pleiades stars, although eagle-eyed stargazers can see a few more. There are actually hundreds of stars in this beautiful open star cluster, and it is also filled with beautiful whispy gas clouds, although the stars and the gas are not actually related to each other—we just happen to be seeing them at a time when the stars are drifting through the gas.

Diagram of Moon near Pleiades in January 5's night sky

This is the view in the evening of January 5, with the Moon sitting above the beautiful star cluster known as the Pleiades. A pair of binoculars will show the scene well. Tomorrow night the Moon will have shifted east, and will be near to Albebaran, the brightest star in the constellation Taurus.

January 6

Tonight you might notice a fairly bright, reddish-looking star just above the Moon. This is Aldebaran, the brightest star in the constellation Taurus.

January 9

Full Moon occurs today at 6:30pm AEDT.

January 12

Tonight, the Moon will appear above and to the right of a bright blue star. This is Regulus, the brightest star in the constellation Leo.

January 14

In this morning’s pre-dawn sky out to the east, the Moon will appear above and to the left of the planet Mars, which looks like a ruddy-coloured star. As you gaze at it, spare a thought for the Mars Science Laboratory, which was launched a little under two months ago and which is due to reach the Red Planet on August the 6th this year.

January 16

It is Last Quarter Moon today at 8:08pm AEDT.

January 17

In this morning’s sky, the Moon will be just above and to the right of the planet Saturn, which looks like a bright star. Nearby is Spica, the brightest star in the constellation Virgo.

Diagram showing the Moon near Spica and Saturn in January 17's night sky

The Moon will be near to both the star Spica and the planet Saturn (the bright yellowish "star" below the Moon) on January 17. If you have access to a small telescope, take a look at both the craters and mountains on the Moon and Saturn and its glorious rings.

January 18

Today the Moon will be at the closest point in its orbit, called perigee. The distance between the two bodies today will be 369,887 kilometres.

January 20

In the early dawn sky, take a look for the Moon and you should see a reddish-looking star just above it. This is Antares, the brightest star in the constellation Scorpius. Compare Antares with Mars—do you think they look similar? The ancients thought so, and in fact the name Antares means “rival of Mars”.

January 23

New Moon occurs today at 8:39pm AEDT.

January 27

Tonight, there’ll be a lovely sight in the evening sky out to the west, with the crescent Moon paired with the bright planet Venus (about 20 Moon widths to its left).

January 30

This evening, the Moon meets up with Jupiter again, appearing below the planet in the northwestern part of the sky.

Also today, the Moon will again reach apogee again, at a distance from Earth of 404,323 kilometres.

Diagram showing the Moon near Jupiter in January 30's night sky

The Moon will sit just below the planet Jupiter in the evening sky of January 30.

January 31

And finally for January, we have a second First Quarter Moon, which occurs today at 3:10pm AEDT.

There’s more great night sky viewing information at Melbourne Planetarium’s Skynotes site.

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Main image courtesy IAU.

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Australia’s newest telescopes – bird’s eye view

Artist's impression of ASKAP dishes

The Australian Square Kilometre Array Pathfinder (artist's impression) is under construction in a remote part of Western Australia.

A NEW WEB FEATURE makes it possible to take a ‘bird’s eye view’ over the Murchison Radio-astronomy Observatory (MRO) and see the construction progress of CSIRO’s ASKAP radio telescope.

ASKAP Live is an interactive map of the 36 antennae that will make up the Australian Square Kilometre Array Pathfinder (ASKAP). In addition to showing the location of each antenna, ASKAP Live gives pictures and status reports on the construction of each antenna.

Colour coding provides, at a glance, the construction status of each antenna: antennae indicated by green icons have already been completed, those currently being constructed are in blue, and the six antennae that will make up the Boolardy Engineering Test Array, or BETA, are marked with yellow or purple icons.

A screenshot from the ASKAP Live web site.

A screenshot from the ASKAP Live web site.

All 36 ASKAP antennae are being constructed at the MRO by their manufacturer, the 54th Research Institute of China Electronics Technology Group Corporation (known as CETC54), with the assistance of CSIRO’s ASKAP team and local contractors.

The antennae are first built and tested in China by CETC54, with the antenna sections then disassembled and shipped to Australia. The antennae are then reassembled on site at the MRO, approximately 315 kilometres north east of Geraldton in the Mid West region of Western Australia.

Once built, ASKAP will operate as part of CSIRO’s radio astronomy facility for use by Australian and international scientists.

As well as being a world-leading telescope in its own right, ASKAP will be an important test-bed for the Square Kilometre Array (SKA), a future international radio telescope that will be the world’s largest and most sensitive.

Take a look at ASKAP Live.

You can also view the ASKAP Webcam.

Adapted from information issued by CSIRO.

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Kepler finds planet in the habitable zone

Artist's conception illustrates Kepler-22b

This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a Sun-like star. It is the first planet that NASA's Kepler mission has confirmed to orbit in a star's habitable zone—the region around a star where liquid water, a requirement for life on Earth, could persist. The planet is 2.4 times the size of Earth.

  • “Super Earth” found in its star’s “habitable zone”
  • Located 600 light-years away from our planet
  • Scientists studying 2,326 planet candidates

NASA’S KEPLER MISSION has confirmed its first planet in the “habitable zone,” the region around a star where liquid water could exist on a planet’s surface.

Kepler also has discovered more than 1,000 new planet candidates, nearly doubling its previously known count.

Ten of these candidates are near-Earth-size and orbit in the habitable zone of their host star. Candidates require follow-up observations to verify they are actual planets.

The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our Sun. The planet is about 2.4 times the radius of Earth.

Scientists don’t yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.

Clear confirmation

Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive.

Two other small planets orbiting stars smaller and cooler than our Sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.

“This is a major milestone on the road to finding Earth’s twin,” said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington.

Artist's impression of the Kepler space telescope

Artist's impression of the Kepler space telescope

“Kepler’s results continue to demonstrate the importance of NASA’s science missions, which aim to answer some of the biggest questions about our place in the universe.”

Kepler discovers planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets that cross in front, or “transit,” the stars. Kepler requires at least three transits to verify a signal as a planet.

Follow-up with ground-based telescopes

“Fortune smiled upon us with the detection of this planet,” said William Borucki, Kepler principal investigator at NASA Ames Research Centre, who led the team that discovered Kepler-22b.

“The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season.”

The Kepler science team uses ground-based telescopes and NASA’s Spitzer Space Telescope to review observations on planet candidates the spacecraft finds.

The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in the Northern Hemisphere’s spring through early autumn.

The data from these other observations help determine which candidates can be validated as planets.

Over 1,000 new planet candidates

Kepler-22b is located 600 light-years away. While the planet is larger than Earth, its orbit of 290 days around a Sun-like star resembles that of our world. The planet’s host star belongs to the same class as our Sun, called G-type, although it is slightly smaller and cooler.

Of the 54 habitable zone planet candidates reported in February 2011, Kepler-22b is the first to be confirmed.

The Kepler team is hosting its inaugural science conference at Ames this week, announcing 1,094 new planet candidate discoveries.

Diagram comparing our Solar System to Kepler-22

This diagram compares our own Solar System to Kepler-22, a star system containing the first "habitable zone" planet discovered by NASA's Kepler mission. The habitable zone is the sweet spot around a star where temperatures are right for water to exist in its liquid form. Liquid water is essential for life on Earth.

Since the last catalogue was released in February, the number of planet candidates identified by Kepler has increased by 89 percent and now totals 2,326.

Of these, 207 are approximately Earth-size, 680 are super Earth-size, 1,181 are Neptune-size, 203 are Jupiter-size and 55 are larger than Jupiter.

The findings, based on observations conducted May 2009 to September 2010, show a dramatic increase in the numbers of smaller-size planet candidates.

Abundant Earths out there?

Kepler observed many large planets in small orbits early in its mission, which were reflected in the February data release.

Having had more time to observe three transits of planets with longer orbital periods, the new data suggest that planets one to four times the size of Earth may be abundant in the galaxy.

The number of Earth-size, and super Earth-size candidates, has increased by more than 200 and 140 percent since February, respectively.

There are 48 planet candidates in their star’s habitable zone.

While this is a decrease from the 54 reported in February, the Kepler team has applied a stricter definition of what constitutes a habitable zone in the new catalogue, to account for the warming effect of atmospheres, which would move the zone away from the star, out to longer orbital periods.

“The tremendous growth in the number of Earth-size candidates tells us that we’re honing in on the planets Kepler was designed to detect: those that are not only Earth-size, but also are potentially habitable,” said Natalie Batalha, Kepler deputy science team lead at San Jose State University.

“The more data we collect, the keener our eye for finding the smallest planets out at longer orbital periods.”

Adapted from information issued by NASA/Ames/JPL-Caltech.

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Australian dish charts where stars are born

The Large Magellanic Cloud

The Large Magellanic Cloud (LMC) is the nearest sizeable galaxy to our Milky Way, and is therefore a popular target for astronomers studying the evolution of stars.

ASTRONOMERS HAVE MAPPED in detail the star-forming regions of the nearest star-forming galaxy to our own, a step toward understanding the conditions surrounding star creation.

The researchers, led by University of Illinois astronomy professor Tony Wong—and including Associate Professor Sarah Maddison and PhD student Annie Hughes, both of the Swinburne University of Technology in Melbourne, Australia—have published their findings in the December issue of the Astrophysical Journal Supplement Series.

The Large Magellanic Cloud (LMC) is a popular galaxy among astronomers both for its nearness to our Milky Way and for the spectacular view it provides, a big-picture vista impossible to capture of our own galaxy.

“If you imagine a galaxy being a disc, the LMC is tilted almost face-on so we can look down on it, which gives us a very clear view of what’s going on inside,” Wong said.

Mopra dish

CSIRO's 22-metre-diameter Mopra radio telescope, located near Coonabarabran in NSW.

As the LMC is in the far southern sky, it is an ideal target for Australian telescopes. And indeed, the team used the CSIRO’s 22-metre-diameter radio telescope at Mopra, near Coonabarabran in north-central New South Wales.

Where are stars born?

Although astronomers have a working theory of how individual stars form, they know very little about what triggers the process or the conditions in space that are optimal for star birth.

Wong’s team focused on areas called molecular clouds, which are dense patches of gas—primarily molecular hydrogen—where stars are born. By studying these clouds and their relationship to new stars in the galaxy, the team hoped to learn more about how gas clouds turn into stars.

Using the Mopra dish, the astronomers mapped more than 100 molecular clouds in the LMC and estimated their sizes and masses, identifying regions with ample material for making stars. This seemingly simple task engendered a surprising find.

Conventional wisdom states that most of the molecular gas in a galaxy is apportioned to a few large clouds. However, Wong’s team found many more low-mass clouds than they expected—so many, in fact, that a majority of the dense gas may be sprinkled across the galaxy in these small molecular clouds, rather than clumped together in a few large blobs.

MAGMA image of the LMC

False-colour image of the Large Magellanic Cloud galaxy combining maps of neutral atomic hydrogen gas (red), hydrogen energised by nearby young stars (blue), and new data from Wong’s team which roughly show the locations of dense clouds of molecular hydrogen (green). It's thought that stars form within molecular hydrogen clouds.

Star formation widespread in the LMC galaxy

The large numbers of these relatively low-mass clouds means that star-forming conditions in the LMC may be relatively widespread and easy to achieve.

To better understand the connection between molecular clouds and star formation, the team compared their molecular cloud maps to maps of infrared radiation, which reveal where young stars are heating cosmic dust.

“It turns out that there’s actually very nice correspondence between these young massive stars and molecular clouds,” Wong said.

“We can say with great confidence that these clouds are where the stars form, but we are still trying to figure out why they have the properties they do,” he added.

Adapted from information issued by University of Illinois at Urbana-Champaign. Mopra photo courtesy CSIRO. MAGMA image of LMC courtesy Tony Wong, University of Illinois.

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