The Scruffy Astronomer

Geostationary orbit What if you could park a satellite in a permanent position so it moves along with the Earth? How useful would that be? Most satellites are in a dynamic orbit around the Earth. You can see then after sunset and before sunrise, moving like a silent aeroplane through the sky. This photo shows one. My daughter and I were trying to get a photo and a satellite photobombed the Pleiades. This happens a lot. Because these satellites move in relation to the Earth, they can look down and see large parts (in some cases the whole) of the Earth slip by underneath them. It's useful for spy satellites, weather satellites, and GPS satellites. Communication satellites are like mobile phone towers, in that you can swap from one to another without breaking the call. But having satellites that don't move in relation to the Earth, that just hang in one place, is terribly useful. You've seen all those TV dishes on people's houses - they don't track at all, b...

I’ve done a few posts lately about winter birds in Melbourne. The other day I was walking the dog in our local park when I heard the instantly recognisable call of the Yellow-tailed Black-cockatoo (YTBC). Looking about, I spotted a group of about ten. They were busy tearing bark off some trees. By the way, the Yellow-tailed Black-cockatoo does seem to be well named. It is a Cockatoo, which is predominantly black.  It does, however, have a tail which is mainly yellow. I quickly nicked home and grabbed my camera, and returned to get this shot. It was a bit difficult, and I got a bit dirty crawling underneath some thickets around the back of some houses. I always half expect to be approached by suspicious residents asking why I’m creeping about with a large lens, but it’s never happened yet. The scientific (or Latin) name for the YTBC is Calyptorhynchus funereus . I’m given to the understanding that the name funereus was chosen due to a tradition of wearing yellow with black clo...

People normally associate astronomy with telescopes. But a bright pair of binoculars is probably just as good a way of exploring the sky. I’ve spent ages just staring through mine. For beginners in particular, the freedom that a pair of binoculars gives you is way more than what you’d get with a scope. For a start, it’s a whole lot easier just to wander about the sky, looking at whatever catches your eye, than it is to move a telescope around. As well, the magnification is much lower, which gives you a more intuitive feel for what you’re looking at. The other thing that people like about binoculars for astronomy is that you don’t have to close one eye while peering through a telescope. Having both eyes open is more comfortable, particularly if you’re going to be out all night. It also gives a nice illusion of three-dimensionality. A good pair of binoculars for astronomy needs a big wide lens for sucking in as much light as possible. This photo shows the Celestron Skymaster 25x100...

We're now well past the winter solstice and the days are starting to get longer. What that means is the birds are starting to wake up a bit and think about nesting. They're becoming more vocal and more obvious. Males whose feathers go dull after breeding are starting to colour up again. So it's time to grab those binoculars and go for a wander to your local birding site. I'm pretty lucky, living where I do. The Yarra is nearby and there are a number of billabongs that I can poke around in search for the little birds, like this Red-browed Finch. The larger birds, of course, like Ravens, Wattlebirds, Butcherbirds and Kookaburras are much more obvious. The other day I had to take my daughter to the airport, so I dropped in at Woodlands Historic Reserve. This is a great place for a pile of different birds - although I think the resident Little Eagle has gone. It was quite windy, so the birding was a bit of hard work. Willie Wagtails, Grey Fantails and Superb Fairy-wrens...

A few weeks ago, Ivan picked up his new Sky-Watcher Esprit 100 and a Sky-Watcher EQ6-R go-to mount. The Esprit is an awesome scope – a triplet refractor, especially designed for imaging. The EQ6-R is a heavy-duty belt-driven computerised equatorial mount. Together they make an instrument capable of very high precision astrophotography. After a few weeks of testing and getting to know the equipment, he started producing images. This one is the Lagoon Nebula, and was his first image with the new equipment. The photo was taken with his Canon 5D MKII DSLR. The camera attaches to the scope with the field flattener and a Canon adapter. The flattener ensures that the focus is sharp across the whole of the field. Without one, the stars at the edges get a bit fuzzy. To get this image, Ivan took 20 two-minute photos at ISO 3200. He gave the images to a free program called Deep Sky Stacker, which combined these into one high quality image. This quality means he can process it further in Photo...

We're happy to report (to those who haven't already heard) that Clint Conn (@clintconnphotograghy) has won the Australian Amateur Astrophotography competition. This was run during July on the Australian Amateur Astrophotography Facebook group. The theme of the competition was "people in astronomy", and entrants were required to include a human in their images, which restricted the competition to astroterrestrial photographs. Clint's image was taken at Big Rock in the You Yangs, south west of Melbourne. It's a relatively dark area if you don't count Melbourne's light pollution in the north east. This photo was taken pointing a bit south of west, so that wasn't an issue. The photo itself is of the galactic core, with Scorpio above Clint. That's Antares under his left armpit. If you look closely, you can see a lot of the currently visible nebulas in the photo - from the Cat's Paw and the War and Peace nebulas above Clint to the Lagoon, the...

Detection of aliens is fine, but is it a good idea to communicate? We've got a new way of detecting what may be alien communications - light pulses. Humans have been listening to radio frequencies for about 100 years now. This really isn't a great length of time when you're talking about interstellar communications. The Milky Way galaxy is about 100,000 light years across, so those first signals broadcast by Marconi have travelled only about 0.1 percent of the width of our own galaxy! Of course, listening is a different matter. Alien civilizations, if they're out there, may have been broadcasting for thousands, or hundreds of thousands of years, so we could detect them from much further away, even from the far side of the galaxy. But have we been wrong to look only at radio transmissions? Breakthrough Listen, a group founded in 2015 to search for signs of alien life, has begun watching for short flashes of light - something they call "pulsed optical beaco...