Archive for the ‘Learning Astronomy’ Category

Mars – Siding Springs Comet – A Close Call

Oh… to be on Mars this weekend (October 19th 18:30 UT) Thats about 4 am in the morning on Monday the 20th for us in Australia (Mars not Visible at closest to the comet in Australia) 

This is being billed as a once in a million years event and this is probably true.

While Comet  Siding springs is faint from our perspective, as it approaches Mars. It will be a spectacular sight from the fleet of Mars probes and rovers. It will not only give us delightful pictures, but will give a once off opportunity to study a first time Oort cloud comet up close. From our perspective in Australia we are about 10hrs ahead of the point of closest approach, when Mars is still visible in our western Sky. Remember, the comet is very faint (Mag11) and Mars very bright, so you will not see it with the naked eye. You may like to give it a go if you have a  medium to large Aperture (6″ and above) telescope though with the comet approaching Mars.

Check out NASA’s Mars-Comet page on this comet for all the info & I expect the follow up photos.

As we wait for this historic Comet to make its very close approach to Mars, we get an idea of what is to come on Mars with this fantastic Photo .

I eagerly await the pictures from NASA, ESA & others on this never before seen close approach of a comet to almost everyone’s favourite planet Mars.

On approach to Mars  Photo by CometCatcher (Kevin)

On approach to Mars
Photo by CometCatcher (Kevin)

 

Venus & The Moon

Venus, The Moon, Mt Whitfield Range and The Cairns Airport.

Venus, The Moon, Mt Whitfield Range and The Cairns Airport.

As I am always letting Night Sky Secrets subscribers know about the happenings in the night (and early morning) sky, I thought it only right to get up early myself this morning to check out the conjunction between Venus and the moon. While not as close as the previous morning, I was able to photograph this event . You can see the earth shine on the crescent moon & through the Telescope, Venus also showed a thin crescent phase. I was fortunate enough to catch a look at Mercury too, just before the gathering dawn washed out the morning sky.

The morning sky also featured Sagittarius & Scorpius in the east, So I was able to get a look at the Lagoon nebula and the Sagittarius star cloud before first light, always a magnificent sight.

With the new moon upon us this weekend & if the rain stays away in FNQ it will be prime time for an observing night.

 

 

August observing report – What’s Up ?

Much like in this photo from 2004,  Members of Gove astronomers gathered at our Dhupma Rd site for an observing night on Sat 18th Aug 2012. Using a refracting telescope that is similar (but shorter focal length) than the one pictured, we took in some classic deep sky targets.

  • The first constellation visible on the night was, as is usual this time of the year, the bright stars of Alpha & Beta Centaurus. They point the way to the southern cross & this was our first target .
  • The sparkling stars of the aptly named Jewel Box adjacent to the blue/white star Beta Crux and its dim red companion Ruby Crux made a fine trio in the wide angle low power view offered with the combination of a 600mm Refractor and a 32mm pan-optic eyepiece. Giving a magnification of just 18.75x allowing all 3 targets to be easily seen.
  • With the obvious pairing of Mars, Saturn & Spica this was clearly our next target. The rings of Saturn being just visible at this low magnification.
  • The fully dark sky now beckoned us to look at the dim fuzzy ball that is Omega Centuri, the faintest object to the naked eye in Centaurus. However with the scope a  ball of 1000’s of stars is revealed as a fuzzy cotton ball. Just a hint of what through a larger aperture telescope, is a sparkling bowl of diamonds.
  • Pointing the little scope almost straight up to the Zenith revealed the dual star cluster’s & Nebulas of the Trifid & Lagoon nebulae in Sagittarius, again easily fitting in the field of view.
  • Some searching along the rich star field of the Milky Way revealed many star clusters and some interesting “asterisms” of stars making chain like patterns against the myriad of stars of the spiral arms of our grand galaxy.
  • Stretching the little scope to its limits I sought out the dim smoke ring of the well named Ring Nebula, a stellar remnant in the constellation of Lyra ‘The Harp”

Much of the night was spent relaxing in camp chairs looking at the glorious vista of the Milky Way stretched out before us. This time spent patiently looking at the clear night sky was rewarded several times with some spectacular Meteors. One of which was orange in colour and lasted for several seconds.

Its was great to see so many members of Gove Astronomers out under the night sky (about 20) several of whom are new members in the club. 

The next observing night for GAA will be on Saturday the 15th of September, with I hope by then our large aperture (18″) scope “Big Blue” back in action for an observing session up at the Gun Club, where we plan to establish a more permanent observatory for Gove Amateur Astronomers.

Mars Science and Climate Change

Techniques pioneered by the European Space Agency (ESA) for use on Mars are set to have a very down to earth use here on planet Earth and beyond to the Icy moon Europa, circling the Gas Giant Jupiter as well as another Ice moon Titan, the biggest of Saturns Moons.

ESA’s Mars Express has aboard some pioneering radar experiment currently investigating the Red Planet and searching for any evidence of sub-surface reservoirs of water and ice.

The technology used by Mars express cannot be used directly here on earth, as the frequency of 5 Mhz used for Mars would quickly interfere with radio communications.

Experiments are currently underway to adapt the technology for use at 435 Mhz where the radar will not cause disruption to earth based communications.

So what are these experiments all about ?

In a boost for earth science research, funded by ESA’s General Studies Program, the new study has been dubbed the Advanced Concept for RAdar Sounder (ACRAS)

This technique has been proposed once before by ESA in the late 90’s, however at that time the technology was not available to filter out false signals. These false signals come firstly from the earths Ionosphere and then secondly from terrain outside the radar’s target area.

ACRAS appears to have found a way around this problem by the use of multiple radar beams, in this case 3 beams, each with slightly different properties, using the principles of the Doppler effect .

The Doppler effect is best demonstrated by the changing pitch of siren on a fast moving vehicle, as it first moves towards you then away from you.

This new study is meeting with success and opens the doors for even more precise instruments that could work around Earth. A satellite fitted with this type of radar could accurately estimate the ice sheet thickness of the Antarctic and other ice covered regions. The data coming back would reveal the three-dimensional internal structure of the ice sheets, the contours of the underlying terrain and give information right down to the bedrock. Watching how this changes over time will give climate scientists invaluable data.

Currently work such as this is largely done by expensive and difficult drilling programs.

As we all hear in the news day after day, melting ice from the polar regions is set to have a huge impact on climate change

The most recent example of this is the large scale break up of the Ross ice shelf in Antarctica.

The ACRAS study is set to conclude in October this year. Although a fully-fledged satellite mission is a long way off yet. Florence Hélière, the ESA study officer, says, “We hope to conduct an airborne test of the technique.” Source: ESA.

As you go out to gaze up at the night sky, looking at the prominent planets Mars and Saturn in the early evening and Jupiter late in the evening. Spare a thought for the hardworking scientists who have made it possible for this pioneering work to be done.

Not only could this make a real difference to our understanding of the effects of climate change here on the lovely blue green planet we call home, it could unlock the doors to the search for life in our own solar system.

The Best Telescopes for Kids

Discovering astronomy with your first look through your first telescope at one of our major planets such as Saturn or Jupiter and even our very familiar moon is the beginning of a lifetime of pleasure, in discovering the wonders of the night sky. However if the first telescope you get is a standard tripod mounted refracting telescope (one using lenses not mirrors) as found in most department stores, the experience is usually one of frustration and disappointment instead.

It is very tempting I know, when you see the telescope for maybe $90 to $150 with claims of “Magnifies 600 times” or “See galaxies and nebulas” to think that this will delight your children. The reality is one of these telescopes will have a wobbly tripod that will not allow you to see anything at 60 times, much less 600. The aperture (that’s the diameter) of the lens will typically be 70 to 90 mm and this will never gather enough light to see faint and distant galaxies, most of which are millions of light years away.

So what can you do? Well, in my experience of almost 10 years of showing 1000’s of children and my own 3 kids around the night sky, the best way to start is in fact with a Star Disc, a red light and a pair of low powered binoculars. The reason is that for starters you will need to find something worthwhile to look at. A Star Disc will show you a few bright deep sky objects that are easily seem with binoculars on any given night. The red light will allow you to see the Star Disc without ruining you night vision. Your night vision takes at least 20 minutes away from white light to adapt to the darkness. A low powered pair of binoculars (EG: 8×50 – 8 times magnification and a 50mm lens) will show you many faint galaxies, nebulas and star clusters. A picnic blanket is a good idea to lay on as well. What a great way to get the family together!

Perhaps you have already done this and are ready to make the next step, and really want to get that telescope. What should you do? My experience and that of my astronomy peers from around Australia and across the world have shown me that the telescope that is (a) Quick to set up and pack up (b) Easy to use and (c) has preferably at least 200mm (8″) of aperture will get the most use and provide many years of observing pleasure. Not just for the kids but the whole family and many friends.

What does one of these telescopes look like? Well, it is not a refractor and it is not on a tripod. It is a Dobsonian mounted reflector. A reflector is much like the telescopes used in professional observatories (only much smaller!) Put in simple terms the telescope is mounted on a horizontal (azimuth) turntable close to ground level allowing you to move the telescope to all points of the compass and a vertical pivot point allowing you to move the telescope from the horizon to directly overhead (the zenith) through 90 degrees. The eyepiece (this does the magnifying) is in the side of the telescope tube at about 1.3 meters above the ground, an ideal height for kids. A 200mm (8″) Dobsonian is lightweight enough that a child of perhaps 10 years old can easily move and set it up in the park or backyard. Confused about what it looks like? Just imagine a cannon that spins around and can point straight up.

How much is one of these going to cost you? You may be thinking thousands of dollars. In fact, a 200mm Dobsonian can cost as little as $550 in Australia and a similar amount in the USA. So start into astronomy the fun and easy way and your Christmas present will live on for many years to come.