Observing the flyby of asteroid 2012 DA14 can be done with binoculars or a low-powered telescope.
I am often contacted by people for advice on buying telescopes, particularly as gifts around Christmas. So if you are one of those lucky people with a shiny new telescope (or just want to have a fun night observing) then your eyes are about to be opened to a wonderful Universe. But what can you point your 'scope at? Deciding what to look for can be tricky, so here are my top ten objects for beginners.
Obvious perhaps, but choosing the right time to look at the moon is crucial to what you will see. The worst time to study the Moon is when it is full because very few shadows are being cast except around the very edge or limb. Shadows are great at enhancing surface detail so avoid a full moon. Concentrate study along the line between the dark and light -- this is called the "terminator" and its here where surface detail is enhanced well. Experiment between low and high magnification.
The largest planet in the solar system is very well placed this time of year for observations. Not only will you be able to pick out detail in the cloud belts of this gas giant but at certain times you will be able to see the Great Red Spot, a hurricane larger than Earth that has been raging for centuries. Look for the four Galilean moons either side of the planet to and notice how they change their position night after night. Medium to high magnification.
This beauty is a morning object but well worth getting up early for. With a magnification from around 25x and above you will be able to detect the stunning ring system the planet is famous for. If the atmosphere is steady and you use a high enough magnification you can even see gaps in the rings such as the Cassini Division. Just like Jupiter, Saturn has a family of moons but fewer are visible with smaller telescopes. Medium to high magnification.
One of the most underrated stunners of the night sky is this multiple star system. It's found in the constellation Andromeda to the East of the famous Andromeda Galaxy. Through small telescopes the widest components can be seen as beautiful golden yellow and blue stars. Larger telescopes and good viewing conditions will reveal the blue star is actually another binary star. Medium to high magnification required and a large aperture telescope to reveal third star.
Perhaps the best of all the nearest major galaxies is the Andromeda Galaxy which lies a staggering 2.3 million light-years away. As its name suggests it is found in the constellation Andromeda on its western side, just off the north east corner of the Square of Pegasus. Keep magnification low for this object and larger aperture telescopes will reveal more detail. See if you can spot the satellite galaxies M32 and M110. Low magnification.
One of the real jewels of the sky is the Orion Nebula. Found just below the famous three star belt in Orion, the nebula is a vast stellar nursery. It can just be seen with the naked eye but binoculars or small telescope reveal it in its fully glory. Medium sized telescopes and modest magnifications will show the stars inside the nebula called the Trapezium. Don't expect to see it in all its colourful glory like the pictures. Cameras are more sensitive to color in low light levels than the human eye so it will only appear as grey/green. Low to medium magnifications.
Perseus Double Cluster
This is a great target for smaller telescopes, which will often give a nice wide field of view on the sky. The Perseus Double Cluster is, as its name suggests, a couple of star clusters around 7,000 light-years away. A wide field of view is the best way to see the two clusters so low power eyepieces are essential. There are around 200 stars in each of the clusters that are separated by just a few hundred light years. Low magnification.
Found in Pegasus over in the western sky in winter evenings, this is amongst the best of the globular clusters in the sky. Its quite easy to spot. Just off to the north west of the orange star Enif. Small telescopes will show it only as a fuzzy blob but telescopes of at least 15cm aperture are needed to reveal individual stars. Medium to high magnification.
Probably the finest open cluster in the sky, the Pleiades or Seven Sisters can be seen with the naked eye to the north west of Taurus the bull. This is a great example of how high magnification isn't always necessary in fact low magnification is essential to see this cluster at its best.
Credit: Ian O'Neill
Take a break from night time observing and have a peek at the sun. Do not use your telescope to look directly at the sun! It's far too bright and will result in blindness. Instead, cut a disk out of thick card no larger than about 75cm and place the card with a small hole cut out over the sunward end of the telescope. You can now use this slightly modified telescope to point at the sun and project an image through the eyepiece and onto another piece of card held about a foot away. Don't leave the telescope pointed at the sun for long periods as I have seen the glue inside eyepieces start to melt, so use great caution when studying the sun. Make sure have also put lens caps on your finder telescopes so you don't accidentally get a glimpse of the magnified sun. Experiment with magnifications from low to high.
Feb. 23, 2012, started out as a fairly normal Thursday for astronomers at the La Sangra Sky Survey in Spain.
That soon changed when they made the discovery of asteroid 2012 DA14. It was quickly classified as one of those objects that strikes fear into the heart of any astronomer -- a near-Earth asteroid!
Further studies over many weeks revealed its orbit would bring it very close to Earth. An asteroid of DA14's size -- around 45 meters (150 feet) in diameter -- would pack quite a punch if it was on target.
Fortunately, this time we have avoided an impact event -- 2012 DA14 will pass about 27,700 kilometers (17,000 miles) from the surface. That's close in astronomical terms and using my own personal scale of "asteroid closeness," it's a bit of a butt-clencher.
At this distance, it will come closer than geosynchronous satellites, but thanks to a high degree of scrutiny, we know it will sail harmlessly past without denting anything.
If we were less lucky on this occasion, we can look to a couple of events in recent geological history that are thought to have been caused by impacts from asteroids of comparable size.
The first took place in 1908 over Tunguska, Siberia, when an asteroid is believed to have exploded near the surface, flattening millions of trees over a remote area of at least 2,000 square kilometers. The other was an impact in the Arizona desert around 50,000 years ago, the so-called Meteor Crater that measures a staggering mile in diameter.
Clearly, if 2012 DA14 were to hit us, and if it slammed into a metropolitan area, it would be an impact of catastrophic proportions with the potential to cause millions of deaths (assuming no evacuation plan was put in place).
This time round, however, and during future predicted orbits of 2012 DA14, no impacts will occur.
What this flyby will do, however, is give sky watchers a great opportunity to watch one of these rare and historic close passes of an interplanetary visitor. Its closest approach will bring it over Indonesia at 19:25 UT (2:25 p.m. ET) on Friday, Feb. 15, but amateur astronomers from many parts of the world -- principally Eastern Europe, Asia and Australia -- will get a chance to glimpse it on its way past.
The tiny dot of sunlight reflecting off the asteroid will shine at magnitude 7.2, meaning it will be just beyond naked eye visibility. But binoculars will show it nicely.
It is difficult to explain exactly where and when to look, since its exact whereabouts in the sky will depend on where you are on Earth. Check out Heavens-above.com to find out exactly where to look in your sky. When you get out there and look into the sky with binoculars or telescope trained in the right direction, look for a "star" slowly moving against the background stars.
If you aren't lucky enough to be in the right part of the world, or your skies aren't clear, there are several observatories online that will be streaming the event live:
NASA is planning a
Slooh will be covering the event live
Bareket Observatory in Israel will also be streaming a live feed
Happy asteroid hunting!