Tag Archives: Jupiter

Planetary Alignments in the Evening Sky

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Over the next 4 weeks, the solar system’s brightest planets will be putting on a spectacular evening show as they start to move into formation over the nights to come.

If you go out just after sunset and look towards the west, you will see Venus and Jupiter popping out of the twilight even before the sky has gone completely dark. After you have found them once or twice you will be able to find them earlier.   Seeing these two brilliant planets surrounded by darkening blue of the evening sky is a lovely sight.

If you go out at the next night, the view improves, because Venus and Jupiter are converging.  In mid-February they were about 20 degrees apart but by the end of the month, the angle narrows to only 10 degrees—so close that you can hide them together behind your outstretched palm.  Their combined beauty grows each night as the distance between them shrinks.

 A special night to look is Saturday, February 25th, when the crescent Moon moves in to form a slender heavenly triangle with Venus, Jupiter and the Moon as its vertices.  One night later, on Sunday, February 26th, it happens again.  This arrangement will be visible all around the world, from city and countryside alike.  The Moon, Venus and Jupiter are the brightest objects in the night sky; together they can shine through city lights, fog, and even some clouds.

 After hopping from Venus to Jupiter in late February, the Moon exits stage left, but the show is far from over.

 In March, Venus and Jupiter continue their relentless convergence until, on March 12th and 13th, the duo lie only three degrees apart—a spectacular double beacon in the sunset sky. Now you’ll be able to hide them together behind a pair of outstretched fingertips.

 There’s something mesmerizing about stars and planets bunched together in this way. This strange phenomenon is due to the fact that your eye works in much the same way as a digital camera does. In front, there is a lens which focuses the light and the retina acts like a photo-array behind the lens to capture the image of what you see. The retina is made up of rods and cones which are the organic equivalent of electronic pixels.

 There’s a tiny patch of tissue near the centre of the retina where cones are extra-densely packed. This is called “the fovea.” This enables you to see objects in high definition – it is critical to everyday tasks such as reading, driving and watching television. The fovea has the brain’s attention.

 The field of view of the fovea is only about five degrees wide. Most nights in March, Venus and Jupiter will fit within that narrow cone.  And when they do—presto!  It’s spellbinding astronomy.

January Evening Skies for Southern Hemisphere Readers

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Venus and Jupiter are the ‘evening stars’ which appear soon after sunset with the brilliance of  Venus is lowest in the west setting about 9.30pm by the end of the Month. In a telescope, now, it looks like a gibbous moon. Venus is still on the far side of the sun from us around 180 million km away but gradually catching up to us again.

Jupiter is above and to the North of Venus as the Sun goes down and it will be setting around 11.30 pm by the end of the month. Its four big moons are easily seen in a small telescope or good binoculars, looking like four little stars lined up on either side of the planet. It is now about 720 million km away as we move to the far side of the sun away from it.

Sirius is the brightest real star that is visible in our evening sky at present. It appears at around 60 degrees above the Eastern horizon just after dusk. Known as ‘the Dog Star’, it marks the head of Canis Major the big dog. A group of stars to the right of it makes the dog’s hindquarters and tail, upside down just now. Sirius is the brightest star in the sky both because it is relatively close, being only nine light years away, and the fact that it is 23 times brighter than the sun. Procyon, in the northeast and below Sirius, marks the smaller of the two dogs that follow Orion.

To the left of Sirius, as the sky darkens, Rigel and Betelgeuse the brightest stars in Orion the hunter will appear. Between them, but fainter, is a line of three stars making Orion’s belt. Rigel is a bluish supergiant star, which is much hotter than the Sun and some 70,000 times brighter. It is located around 800 light years away. Orange Betelgeuse, below Orion’s belt, is a red-giant star, cooler than the sun but hundreds of times bigger. It is actually a ball of extremely thin hot gas. To us in the South we tend to remember Orion as the Saucepan as this appears to be the bottom of  the Saucepan. A faint line of stars above and right of the belt is the pot’s handle or Orion’s sword. It has a glowing cloud at its centre: the Orion Nebula, a place where stars are being born. This is visible in good binoculars as a cloudy fuzzy area.

Left of Orion is the V-shaped pattern of stars makes up the face of Taurus the Bull. The V-shaped group is also known as the Hyades cluster. It is 150 light years away. Orange looking Aldebaran, Arabic for ‘the eye of the bull’, is not a member of he cluster but on the line of sight, is about half the cluster’s distance away from us.

Left again, toward the north and lower, is the Pleiades/ /Seven Sisters or Subaru star cluster depending on where you hail from. It is a pretty cluster with a bit of fuzziness (nebulosity surrounding it) even to the naked eye and is even more impressive in binoculars. The cluster is around 70 million years old and located about 400 light years away from us. There is a very colourful looking star Capella which is not too high above the horizon in the North – in the thicker lower atmosphere,  it often looks like a disco star as it twinkles very prettily due to the effects of the atmosphere.

Low in the south is the Southern Cross, and Beta and Alpha Centauri, often called ‘The Pointers’. Alpha Centauri is the closest naked-eye star, 4.3 light years away. A telescope shows it is a binary star: two stars orbiting each other in 80 years. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away. Canopus is also another very bright star, very luminous and distant: 13,000 times brighter than the sun and 300 light years away.

The Large and Small Magellanic Clouds, (LMC and SMC) are high in the southern sky and easily seen by eye on a dark moonless night. They are two small companion galaxies about 160,000 and 200,000 light years away who over time are orbiting our own Milky Way. They look like fuzzy light clouds in the southern skies above and even further to the South than the Southern Cross.

All of these objects mentioned above can be seen without a telescope or binoculars between sunset and around 9.30pm and makes for a great after dinner exercise for the family to see how many you can find.

The Milky Way is in the eastern sky, brightest in the southeast toward Crux. It can be traced towards the north but becomes faint below Orion. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. Binoculars show many star clusters and a few glowing gas clouds in the Milky Way, particularly in the Carina region.

Mars, is rising by the end of the month before 10:30pm and looks like a bright orange-red star. It is brightening as the Earth moves closer to it. It is around 140 million km away so appears quite small in a telescope.

Saturn will rise in the east around 1:00 am by the end of the month, making a pretty sight as a pair with the bright white star, Spica, which is the brightest star in Virgo, above and to the left of Saturn. Saturn is around 1,460 million km from us.

Click on Images Above to see sky charts from North South East and West horizons around 9.30pm as seen from NSW Australia