WHAT’S IN THE NIGHT SKY

Stargazing For This Week

(As seen from Eastern Australia)

If you have binoculars, aim them toward the planet Jupiter. It’s that bright ‘star’ looking westward after sunset. Binoculars will enhance the view. Jupiter enjoys an entourage of over 60 moons but only four of these moons are large and bright enough to see with a backyard telescope (or good binoculars).

They’re called the Galilean moons because Galileo first observed them through a telescope in 1610. In order outward from Jupiter the Galilean moons are Io, Europa, Ganymede and Callisto.  Jupiter’s moons are always in motion, so their positions change from night to night, or even from hour to hour.

A great exercise and fun way for kids to understand how moons move in relation to planets is to get them to look at Jupiter with a small telescope and record these movements on paper. Draw a disc and make the moons little dots.  It won’t take long to see a change in their positions. Give ‘em a Mars bar as a reward!

Jupiter, the fifth planet outward from the sun, is truly the giant world of our solar system. It’ll hold our Earth over 1300 times! In fact, all of the planets in the solar system would fit neatly into Jupiter – with enough room to also park your car.

Jupiter is about 40 light minutes away meaning when you look at the planet the light has taken all that time to reach your eye. Mars is 12 light minutes from the Sun and Saturn about 70 light minutes away. When we talk about planets we talk in light hours or light minutes. When we talk about stars we’re dealing with light years.

Let’s have a look at some light travel time distances to a few well known places. These are measured from the Sun which is about 8 light minutes away. Think about this for a minute. If the Sun’s light takes 8 light minutes to reach Earth, then something catastrophic could happen on the Sun and we wouldn’t know for 8 minutes.

The nearest star to the Sun, Alpha Centauri, is more than 4 light years away. Look to that star in the sky tonight, the lower star in the pointers to the Southern Cross, and you’re seeing it as it was 4 years ago. The centre of our Galaxy is 26,000 light years away. The light we see from there left when our ancestors were painting primitive scenes in caves.

One of the most distant objects we can see with our eyes, in a dark sky without the aid of a telescope, is the Andromeda Galaxy, more than 2 million light years away. What was happening on Earth 2 million years ago?

The moon will appear almost full phase this weekend, rising late in the afternoon and visible all night long.  The moon is always partly lit by the sun, but, as it orbits Earth, we see different parts of the moon’s ‘day’ side. That’s why we see the phases of the moon.

So what causes these phases? Well contrary to popular belief, it isn’t caused by the earth’s shadow hitting the Moon. Its sunlight hitting different parts of the Moon as it orbits the Earth.

If this is confusing, you can always try what I do, make a simple model. Use a stationary light source, like a lamp, for the sun. Then find a ball for the moon and you will be Earth. Turn around with the ball held at arm’s length and notice how the view of the lit side changes.

More tips on sky watching and how to get the most out of your telescope can be found at my website www.davidreneke.com. There are free e-books, an astro quiz to pick up an Australian Astronomy 2012 Yearbook, great new stories and astro videos to watch on rainy nights.  Enjoy your skies.

 Targets For Your telescope

Orion is one of the most easily recognizable and beloved constellations. By far, the most popular celestial gem in the constellation of Orion is M42, The Great Orion Nebula. Although it is 1500 light-years away, M42 is a great target to view in small telescopes. This is due not only to its brightness, but also to its wonderful cloud structure, which in telescopes takes on a clearly three-dimensional shape. Observers new and old come back to M42 time and time again because of the wealth of detail visible: pinpoint stars hang among uncanny, ghostly tendrils of glowing hydrogen that stream across space for trillions of miles. Astronomers call M42 a stellar nursery; when you look at this giant gas cloud you are seeing what our own solar system might have looked like billions of years ago.

The nebula’s reddish coloration (visible only in photographs) betrays the ionized hydrogen that predominates the composition of the cloud, but carbon monoxide and other complex molecules have also been detected. When viewed through a large telescope, the cloud takes on a wonderful greenish hue. The energy that keeps the nebula glowing so bright comes from the very hot, young stars in the brightest part of the cloud. Known as the Trapezium, this formation of four stars (from west to east: A, B, C, and D) is visible in most backyard telescopes. A fun challenge for amateur astronomers is to “bag” the two 11th magnitude E and F stars, shown here in green. Their proximity to far brighter stars makes them difficult to separate on nights of so-so seeing. On great nights, discerning the E and F stars is a good test of your telescope’s optics.

More Targets The Horsehead Nebula was made famous from its beautiful photographs – it really does resemble what its name implies! The Horsehead can be found just below Alnitak (the leftmost/easternmost star in Orion’s belt). The Horsehead is an extremely difficult target for medium aperture telescopes, and requires steady and dark skies to be seen even in a larger telescope. A far easier nebular target in the same area can be found above Alnitak: Located above Orion’s belt, M78 belongs to the same large cloud of gas and dust as the main Orion nebula (M42). It has 2 companion nebulae (NGC 2067 & 2071). All 3 are reflection nebulae, and M78 is in fact the brightest reflection nebula. It is visible in binoculars but best seen through a telescope.

NGC 2022 is a bright planetary nebula: a dying sun peeling off its outer shell. Because planetary nebulae are best viewed at high magnification, you should start out low (40x) to find the object, and then try 100x and 200x. The name “planetary” is misleading, as these objects are not planets at all but stars at the end of their life cycle. However, they do look something like cloudy planets, and this fact confused earlier observers whose incorrect naming convention has stayed with us to this day. NCG 2174 is a bright but diffuse emission nebula, a cloud of hydrogen gas very close to a young hot star (or multiple stars). In such clouds, energy from the stars heats up the hydrogen to 10,000°K until it glows with the distinctive red color one can see in long-exposure photographs.

Betelgeuse is the only red star in Orion. Not only does this make it easy to identify, it also tells us we are looking at a giant star.   Betelgeuse (pronounced beetle juice by most astronomers) derives its name from an Arabic phrase meaning “the armpit of the central one.” The star marks the eastern shoulder of mighty Orion, the Hunter. Another name for Betelgeuse is Alpha Orionis, indicating it is the brightest star in the summer constellation of Orion. However, Rigel (Beta Orionis) is actually brighter. The misclassification happened because Betelgeuse is a variable star (a star that changes brightness over time) and it might have been brighter than Rigel when Johannes Bayer originally categorized it.

Betelgeuse is an M1 red supergiant, 650 times the diameter and about 15 times the mass of the Sun. If Betelgeuse were to replace the Sun, planets out to the orbit of Mars would be engulfed!  Betelgeuse is an ancient star approaching the end of its life cycle. Because of its mass it might fuse elements all the way to iron and blow up as a supernova that would be as bright as the crescent Moon, as seen from Earth. A dense neutron star would be left behind. The other alternative is that it might evolve into a rare neon-oxygen dwarf. Betelgeuse was the first star to have its surface directly imaged, a feat accomplished in 1996 with the Hubble Space Telescope.  On the western heel of Orion, the Hunter, rests brilliant Rigel.

In classical mythology, Rigel marks the spot where Scorpio, the Scorpion stung Orion after a brief and fierce battle. Its Arabic name means the Foot.Rigel is a multiple star system. The brighter component, Rigel A, is a blue super giant that shines a remarkable 40,000 times stronger than the Sun! Although 775 light-years distant, its light shines bright in our evening skies, at magnitude 0.12. Telescope observers should be able to resolve Rigel’s companion, a fairly bright 7th magnitude star. A heavy star of 17 solar masses, Rigel is likely to go out with a bang some day, or it might become a rare oxygen-neon white dwarf. Don’t forget to compare the colors of Betelgeuse and Rigel on your next outing under the stars!

              Ten Ways To Appreciate The Night Sky        

Anything you may find of interest in life takes on greater meaning and may keep your attention longer if you take steps to appreciate it more. This is easily said of interest in the night sky – whether you want to call it amateur astronomy or simply loving the stars above. Here are 10 suggestions to go from a casual interest to calling yourself a dedicated observer.

1. Learn the constellations Evening star charts for each month of the year are readily found in astronomy magazines available at the news-stand, as well as in books we sell on this webpage. Becoming familiar with the patterns among the stars helps you to organize the heavens. Also become acquainted with the phases and motions of the moon and planets.

2. Read Learn about the universe. There are many good books available, as well as magazine articles and websites. Find out what astronomers have found out there, and the theories that have developed and are continually tested as mankind finds out more. There seem to be more questions than answers, which helps keep us going. Be inspired and learn how you can have a look for yourself – for free, and hopefully as close as your backyard.

3. Keep a journal A “stargazing log” of some kind helps you keep track of what you observed, and when. Depending on how far you’d like to go with it, you can keep the dates, hours, descriptions, sketches and impressions of the celestial phenomena that you discovered. Enrich your time by looking up more information about what you just chronicled.

4. Keep warm! You’ll last longer out there if you are dressed for the cold night air; it doesn’t take long to feel cold standing outside! If you use a telescope, find a way to look through it with as little strain as possible.

5. Adapt eyes Have your eyes adapted for the dark. It takes about 10 minutes or so to see the stars well after coming out from a bright house. It can help to let your eyes adjust for a few minutes in a partially lit room. Hint: If you plan to look at the moon in a telescope and also some stars, look at the stars first. Once you train your telescope at the bright moon, you will lose any dark adaptation that you had. A lunar filter fitted to the eyepiece helps.

6. Clubs Get to know others of similar interest. Visit an astaronomy club or planetarium. They sometimes have public observing sessions scheduled.

7. Equipment Before buying a telescope, try binoculars. You will always find them useful, and for some uses, they are better to use than a telescope. When buying a telescope, it may be wise to start small, and get advice from others who have experience. A poor-quality telescope might discourage some, or spur you on to greater. Remember: You don’t have to take a second job to afford astronomy. You can enjoy the sky FREE OF CHARGE – with eyes alone. Sooner or later, however, you’ll likely want a closer look!

8. Picking site Find a suitable location. Observe from an area that is safe, with a wide-open sky and shielded from neighboring lights. Do the best you can with what you have. Even from a city, you have good views of the moon and bright planets.

9. See it all Take it all in – look for meteors, the moon, planets, star clusters, galaxies and satellites, and more.

10. Patience Lastly, have a humble spirit, a patient heart and a good imagination. Rember, little in the sky will appear to happen quickly, and you will frequently be “clouded out.” Let yourself be inspired and filled with awe!

Moon Facts

There are many interesting facts about the moon and trivia that may or may not be important to you. Some interesting facts include:

• We all know there was a man on the moon, but did you know that there is one who stayed there? Dr. Eugene Shoemaker, a Geological Surveyor, who educated the Apollo mission astronauts about craters, never made it into space himself, but it had always been one of his dreams. He was rejected as an astronaut because of medical problems. After he died, his ashes were placed on board the Lunar Prospector spacecraft on January 6, 1999, which was crashed into a crater on the moon on July 31, 1999. The mission was to discover if there was water on the moon at the time, but it also served to fulfill Dr Shoemaker’s last wish.
• When Neil Armstrong took that first historical step and said “That’s one small step for man, one giant leap for mankind” it would not have occurred to anyone that the step he took in the dust of the moon was there to stay. It will be there for millions of years because there is no wind on the moon. That is, assuming the downdraft from the Command Module upon takeoff back into space didn’t destroy the print. Buzz Aldrin reportedly saw the American flag, much further away, blow over during launch. Nevertheless, any footprints made by the famous astronauts undisturbed by takeoff are, in fact, there to stay.
• When Alan Sheppard was on the moon, he hit a golf ball and drove it 2,400 feet, nearly one half a mile.
• In a survey conducted in 1988, 13% of those surveyed believed that the moon is made of cheese.
• The multi layer space suits worn by the astronauts to the moon weighed 180 pounds on earth, but thirty pounds on the moon due to the lower gravity.
• How close can you get without completely running out of gas? Apollo 11 had only 20 seconds of fuel left when they landed on the moon.
• Apollo 15 was the first mission to use a lunar rover. The top speed that was ever recorded in this 4-wheeled land vehicle was 10.56 miles per hour.
• It is possible to have a month without a full moon. This occurs in February, but either January or March will have two moons.
• In China, the dark shadows that are on the moon are called “the toad in the moon”.
• The Apollo missions brought back 2196 rock samples weighing 382 kg in total

Facts About the Moon

• The moon is not a planet, but a satellite of the Earth.
• The surface area of the moon is 14,658,000 square miles or 9.4 billion acres
• Only 59% of the moon’s surface is visible from earth.
• The moon rotates at 10 miles per hour compared to the earth’s rotation of 1000 miles per hour.
• When a month has two full moons, the second full moon is called a blue moon. Another definition of a blue moon is the third full moon in any season (quarter of year) containing 4 total full moons.
• From Earth, we always see the same side of the moon; the other side is always hidden.
• The dark spots we see on the moon that create the image of the man in the moon are actually craters filled with basalt, which is a very dense material.
• The moon is the only extraterrestrial body that has ever been visited by humans. It is also the only body that has had samples taken from it.
• The first space craft to send back pictures from the moon was Luna 3 (built by the Soviet Union) in October 1959.
• The moon has no global magnetic field.
• The moon is about 1/4 the size of the Earth.

This Month’s Highlights

The Moon will be at apogee (furthest from Earth) on Tuesday 3rd and Tuesday 31st at distances of 404 588 km and 404 325 km respectively. The Moon will be at perigee (closest to Earth) on Wednesday 18th at a distance of 369 899 km. Source: Melbourne Planetarium.

Let the Moon be Your Guide

The Moon can be used as a pointer to find other objects in the sky:

• The waxing gibbous Moon sits below Jupiter on the evenings of the 2nd and 3rd.
• On the 5th the Moon is just above the star cluster Pleiades in the northern sky.
• The waning gibbous Moon, just past full, sits in a line with the twin stars of Gemini, Castor and Pollux, but a bit further away in the sky, on the night of the 10th.
• On the night of the 12th the Moon is near the bright star Regulus (Leo).
• The Moon sits close to the planet Mars late on the 13th and into the morning of the 14th.
• During the early hours of the 17th, the last quarter Moon makes a neat grouping with the planet Saturn and above them the bright star Spica (Virgo).
• Before dawn on the 20th the thin crescent Moon is below the red supergiant star Antares (Scorpius).
• On the evening of the 26th the waxing crescent Moon will sit below brilliant Venus above the western horizon making a beautiful sight in the evening sky.
• On the 30th the Moon will again sit near Jupiter in the evening sky.

Planets

Mercury can be seen low to the eastern horizon before sunrise at the beginning of January. The best time to look for Mercury is in the first two weeks – by the end of January Mercury is getting lost in the glare from the Sun.

Venus is the brilliant evening star and grows slowly brighter throughout the month. On the 26th the Moon, just a few days past new, sits below the bright planet in the evening.

Earth will be at perihelion (closest approach to the Sun) on Thursday 5th, at a distance of 147 million km from the Sun.  However, this is not the reason behind our summer warmth. The seasons are caused by the Earth’s axial tilt. During summer, Australia is tilted towards the Sun, causing the Sun to appear high in the sky and lengthening our days. The Sun’s light also increases in intensity because it hits our part of the Earth more directly.

Mars is rising just after midnight at the beginning of the month and can be seen in the sky throughout the morning hours. It rises earlier through the month and by the end of January is rising before midnight.

Jupiter is high in the northern sky after sunset. On the nights of the 2nd and 3rd, and then again on the 30th the Moon is near Jupiter.

Saturn is rising around two hours after Mars and is also seen in the morning sky throughout the month. Saturn is sitting close to Spica, the brightest star in Virgo throughout January. Before dawn on the 17th, the Moon makes a neat triangle with Spica and Saturn.

Meteors

The year starts slowly for meteor showers. The month’s most active shower, the Quadrantids, is a strong Northern Hemisphere shower. Sometimes it is possible to spot some long-pathed meteors around the peak of the shower on the 4th.

The shower best suited for viewing in the Southern Hemisphere is the Eta Carinids which is active from 14th to 27th. The meteors are typically faint, with hourly rates of only 2 or 3 at the shower’s peak around the 21st. The shower is centred near the faint star Eta Carina, which is one of the most massive stars in our Galaxy. Eta Carina is found near the Southern Cross and is high in the south from midnight to dawn, the ideal time for meteor observing.

Stars and Constellations

Orion, the hunter, is now high in the north-eastern sky and easily located by the three bright stars that form his belt. In Australia, we recognise the belt as the base of the Saucepan. The handle of the Saucepan (also known as the sword of Orion) contains a spectacular nebula that is a birthplace of new stars. This cloud of glowing gas is 1,500 light-years away but is still easily visible through binoculars. Above the Saucepan is the blue-white supergiant star Rigel and below is the red supergiant star Betelgeuse.

On the western side of Orion is the hunter’s prey Taurus, the bull. A small triangle depicts the face of the bull with the brightest star in the group being the red giant, Aldebaran. Aldebaran sits in front of a widely spread cluster of about 200 stars called the Hyades. Taurus also contains a second cluster, the Pleiades (or Seven Sisters), which is the brightest and most famous star cluster in the sky. Approximately seven stars can be seen with the naked eye but binoculars reveal many more.

The Southern Cross and the Two Pointers are low in the south-east, which means that the Magellanic Clouds, two of our nearest galaxies, are high in the sky. They sit opposite the Southern Cross and away from city lights, they appear as two fuzzy patches or ‘clouds’.

International Space Station

The ISS orbits the Earth every 90 minutes at an average distance of 400 km. The ISS appears as a bright star that steadily moves across the sky. Predictions of when to see the ISS can be obtained from the website: www.heavens-above.com

On this Day

1st 1801, the first asteroid, Ceres, was discovered by Giuseppi Piazzi (Italy).

2nd 1839, Louis Daguerre (France) takes the first photograph of the Moon.

2nd 1959, Luna 1 (USSR) was launched and became the first spacecraft to fly by the Moon and orbit the Sun.

4th 1958, the first satellite, Sputnik (USSR), fell back into the atmosphere and disintegrated.

5th 1972, the Space Shuttle (USA) program was launched.

6th 1892, an aurora was first photographed.

7th 1610, Galileo Galilei discovered the Jupiter’s four largest moons: Io, Europa, Callisto and Ganymede.

9th 1839, Thomas Henderson (South Africa) is the first person to measure the distance to a star other than the Sun, Alpha Centauri.

9th 1998, an international team including Australians announces the discovery that the expansion of the Universe is accelerating.

10th 1946, the US Army Corps bounce a radar signal off the Moon, showing that radio waves could penetrate the atmosphere.

11th 1787, Sir William Herschel discovered the first moon of Uranus.

22nd 1997, Lottie Williams (USA) becomes the only person known to have been hit by space junk when she is struck in the shoulder by a piece of metal, believed to have been part of a Delta II rocket.

24th 1986, Voyager 2 (USA) made the first flyby of Uranus and sent back close-up pictures of the planet.

27th 1967, the Apollo 1 (USA) fire kills crew of 3.

28th 1986, the space shuttle Challenger (USA) explodes after lift-off killing all seven crew members.

31st 1958, Explorer 1, was the first USA satellite launched.

 Major Meteor Showers 2012

Quadrantids
Comet of Origin: 2003 EH1
Radiant: constellation Bootes
Active: Dec. 28, 2011-Jan. 12, 2012
Peak Activity: Jan. 4, 2012
Peak Activity Meteor Count: 120 meteors per hour
Meteor Velocity: 25.5 miles (41 kilometers) per second
Notes: A waxing gibbous moon will set at about 3 a.m. local time, allowing for several dark-sky hours of observing before dawn. This shower has a very sharp peak, usually only lasting a few hours, and is often obscured by winter weather. The alternate name for the Quadrantids is the Bootids. Constellation Quadrant Murales is now defunct, and the meteors appear to radiate from the modern constellation Bootes.

Lyrids
Comet of Origin: C/1861 G1 Thatcher
Radiant: constellation Lyra
Active: April 16-25, 2012
Peak Activity: April 21-22, 2012
Peak Activity Meteor Count: 10-20 meteors per hour
Meteor Velocity: 30 miles (49 kilometers) per second
Notes: A new moon on April 21 guarantees a dark sky in the late night and early morning hours, making this year ideal for observing from 10 p.m. to dawn. Lyrid meteors often produce luminous dust trains observable for several seconds.

Eta Aquarids
Comet of Origin: 1P Halley
Radiant: constellation Aquarius
Active: April 19-May 28, 2012
Peak Activity: May 5-6, 2012
Peak Activity Meteor Count: 10 meteors per hour
Meteor Velocity: 44 miles (66 kilometers) per second
Note: While the shower peaks an hour or two before dawn, the year’s closest and largest full moon will be out all night, resulting in a moonlit sky that will wash out all but the brightest meteors. Meteor watchers in the Southern Hemisphere stand the best chance of seeing any meteors.

Delta Aquarids
Comet of Origin: unknown, 96P Machholz suspected
Radiant: constellation Aquarius
Active: July 12-Aug. 23, 2012
Peak Activity: July 28-29, 2012
Peak Activity Meteor Count: Approximately 20 meteors per hour
Meteor Velocity: 25 miles (41 kilometers) per second
Notes: It’s not a good year for the Delta Aquarids — light from the August full moon make them nearly impossible to see.

Perseids
Comet of Origin: 109P/Swift-Tuttle
Radiant: constellation Perseus
Active: July 17-Aug. 24, 2012
Peak Activity: Aug. 12, 2012
Peak Activity Meteor Count: Approximately 100 meteors per hour
Meteor Velocity: 37 miles (59 kilometers) per second
Notes: Moonlight won’t be as big a problem as last year, as its waning crescent won’t rise until after midnight, and the shower peaks from about 10-11 p.m. local on the night of Aug. 12.

Orionids
Comet of Origin: 1P/Halley
Radiant: Just to the north of constellation Orion’s bright star Betelgeuse
Active: Oct. 2-Nov. 7, 2012
Peak Activity: Oct. 21, 2012
Peak Activity Meteor Count: Approximately 25 meteors per hour
Meteor Velocity: 41 miles (66 kilometers) per second
Note: With the second-fastest entry velocity of the annual meteor showers, meteors from the Orionids produce yellow and green colors and have been known to produce an odd fireball from time to time.

Leonids
Comet of Origin: 55P/Tempel-Tuttle
Radiant: constellation Leo
Active: Nov. 6-30, 2012
Peak Activity: Night of Nov. 17, 2012
Peak Activity Meteor Count: Approximately 15 per hour
Meteor Velocity: 44 miles (71 kilometers) per second
Note: The Leonids have not only produced some of the best meteor showers in history, but they have sometimes achieved the status of meteor storm. During a Leonid meteor storm, many thousands of meteors per hour can shoot across the sky. Scientists believe these storms recur in cycles of about 33 years, though the reason is unknown. The last documented Leonid meteor storm occurred in 2002.

Geminids
Comet of Origin: 3200 Phaethon
Radiant: constellation Gemini
Active: Dec. 4-17, 2012
Peak Activity: Dec. 13-14, 2012
Peak Activity Meteor Count: Approximately 120 meteors per hour
Meteor Velocity: 22 miles (35 kilometers) per second
Note: The Geminids are typically one of the best, and most reliable, of the annual meteor showers. This year’s peak falls perfectly with a new moon, guaranteeing a dark sky for the show in the nights on either side of the peak date. This shower is considered one of the best opportunities for younger viewers because the show gets going around 9 or 10 p.m.