partial solar eclipse, november 2012

There was a solar eclipse in Australia today; in a few lucky places, such as Cairns in far-north Queensland, it was a total eclipse, but down here in Melbourne it was just a partial eclipse. I wasn’t sure if the sun would be up high enough to get much of a view of it from my backyard, so at first I just caught a quick glimpse of it using my eclipse glasses. As it turned out, I had a great view, so I cobbled together the same observing setup I used for the transit of Venus earlier this year: binoculars strapped to a tripod, projecting the sun’s image on to a sheet of paper.

My simple solar observing setup — this took all of about five minutes to put together

This setup produced some sharper pictures than I managed with the transit of Venus — I think sitting the paper further away from the binoculars helped. I’ve processed these shots a little, converting them to grayscale using just the green channel (it was sharper than the red or blue channels, and much sharper alone than combining all three channels) and boosting the contrast to bring out some surface detail. The “grain” in the images is just from the paper, but those dark spots on the images are definitely sunspots.

This was within a few minutes of the eclipse’s greatest coverage. It’s super-obvious here, but it was still very bright outside — if you didn’t know there was an eclipse I’m sure you wouldn’t have noticed

We’re towards the end of the eclipse now; I think this shot has the best surface detail out of any of the shots I took today

One final shot, from just before the end of the eclipse

Seeing this has given me an even greater desire to see a total solar eclipse — I’m sure I’ll get the opportunity eventually! They do happen fairly often, but you need to be in the right place in the right time, so unless one happens to occur right here I might have to plan a trip to see one.

transit of venus 2012

I haven’t written about any astronomical stuff for a while, but today was a special day — the 2012 Transit of Venus. A transit is just like an eclipse, but with a visibly smaller object moving in front of a large one; in this case, Venus moved across the face of the Sun, as viewed from Earth. These transits are rare — the next isn’t until 2117 — so I spent the morning at a special viewing event at the Melbourne Planetarium.

There were some clouds around early in the morning, but by the start of the transit at about 8:16, all was clear. The Planetarium had a great setup: a couple of small solar telescopes, which gave a great view of the whole Sun with some surface detail, and a couple of larger telescopes with heavy solar filters on them, which had more zoomed-in views. There was also a telescope set up to project the Sun’s light on to a projection screen.

After the actual viewing, there was a planetarium show explaining the mechanics of the transit, and discussing its historical importance; there’s some more detail on Wikipedia, but suffice it to say that observations of the transit were a big deal, and the 1769 transit in particular saw expeditions to all corners of the globe to get measurements. By the time the show was done, clouds had rolled over, and it looked like they were there to stay, but I hoped there’d be some breaks later in the day so I could make some observations from home.

Home observations

I hadn’t intended to try observing the transit at home, but after seeing it at the Planetarium, I was ready to give it a go. I took a simple approach: I strapped my binoculars to a tripod, pointed the big end toward the Sun, and pointed the eyepiece toward a piece of paper set up as a makeshift projection screen. It was very rudimentary, but it worked! I attached some extra paper to the binoculars to act as a shade, making sure that the projection screen was in shadow to give the best possible image.

A simple projection setup for solar observation, using binoculars

I used my DSLR to get some photos of the projected image, too. The images aren’t super-sharp, but you can definitely see Venus, and even a couple of faint sunspots in one of the images:

A little bit before the end of the transit, with Venus still within the Sun's disc

Right near the end of the transit, Venus looks like a tiny indent in the side of the Sun

I had trouble with the clouds on-and-off at home, and they rolled over after that last shot and stayed for a while; by the time they cleared, Venus was long gone.

It was definitely worth the effort of setting up at home, and it was surprisingly easy to do. After observing this transit, I’m definitely keen to look at some other solar events — a solar eclipse would be great! I don’t know when the next solar eclipse is due, but whenever it is, I’ll be ready.

lunar eclipse, june 2011

In the wee hours of this morning, the Moon moved in to the Earth’s shadow and fell in to near-complete darkness — a lunar eclipse. This eclipse was especially long and dark, as the Moon traveled right through the centre of the Earth’s shadow, giving it a very deep, eerie red glow before fading to near-invisibility as it neared the horizon.

I had the telescope and binoculars out for visual observation, but the Canon 550D provided the real fun, with the 75-300mm lens giving enough zoom to get a reasonably close look at the action. The timing didn’t allow me to see the whole thing (it started around 4:30AM, and was still heavily in shadow as it set around 7AM), but I still got some pretty good shots.

4:48AM: a chunk of the Moon goes missing

5:25AM: parts of the Moon fall in to deep shadow

I had to increase the exposure time as the Moon grew darker, which caused some slight blurring from the Moon’s motion across the sky. To limit the blurring, I also had to progressively increase the ISO setting, which made later images more noisy, but these shots still give you some idea of just how dark the Moon became in the sky.

5:44AM: the entire Moon glows red

You might expect the Moon to go completely dark during the eclipse, but even when it’s entirely within the Earth’s shadow, our atmosphere scatters a small amount of light toward it. Only the reddest parts of that light make it all the way through our atmosphere, though, which causes the Moon’s red colour.

6:15AM: the Moon all but fades from view during totality

I think this is the photo of the night, though:

6:05AM: a timely encounter with a morning jet

It’s not uncommon for jets to fly past our house, and after seeing one fly past, my wife was ready at the camera when a second appeared. The camera was still set on a two-second exposure to capture the (by this point very dim) Moon, but that just makes the jet look like something from a sci-fi movie.

Another eclipse will be visible from here in December — it may not be as spectacularly dark as this one, but it starts at a more reasonable hour (around midnight) and the whole thing will be visible. I’m sure I’ll have more photos then, at least as long as the weather co-operates.

mars at opposition

I should’ve blogged about this a bit earlier, but what can I say? I blame a combination of general slackness, and being totally addicted to Mass Effect 2. Anyway, on with the show!

Last Friday night, an event occurred that I’ve been looking forward to ever since the day I bought my telescope — Mars came in to opposition. In simple terms, that’s the point at which Mars and Earth come closest to each other in their respective orbits, which means that Mars is far bigger and brighter to look at than at other times. Oppositions with Mars happen only every 26 months or so, but it was definitely worth waiting for!

Even though this was a fairly bad opposition (some oppositions bring Mars and Earth closer together than others), I got a far better view of Mars than I’ve ever had before. Usually it’s just a very small, fuzzy, red disc — clearly not a pin-point star, but too small to see any detail on. On Friday, though, I could clearly see one of the polar ice-caps, a small bit of dark red banding below the cap, and larger areas of dark banding across the rest of the otherwise bright red surface.

The next opposition, in 2012, won’t bring Mars any closer than this one did, but a few after that, in 2018, Mars will be almost twice as close as it was this time. I’ll have to make sure I’m ready for it!

iss success

Conditions were perfect for watching last night’s overhead pass of the ISS, and I got a great view of it through my telescope. I think it could’ve been better, though — I used my 13mm Nagler eyepiece, so the magnification was perhaps a little high, which made tracking the ISS as it (very quickly) moved through the field of view very difficult. Even when I did get it in view and keep it there for a bit, it was still moving so fast across the field that it was all a bit of a blur. Next time, I think I’ll stick with my less powerful 21mm Stratus eyepiece, which should make it easier to both track the ISS, and to hold it still long enough to make out some good detail.

Speaking of next time, there’s actually another really good pass tomorrow night (the 4th), starting about 9:08pm. Here’s hoping today’s clouds have disappeared by then!

iss overhead tonight!

It’s a beautifully clear day outside today, and if it stays that way, I’ll be watching the ISS pass overhead tonight. The ISS passes overhead fairly often, but tonight’s showing is going to be particularly good, since it’s at a nice, easy viewing time (around 10pm), and it’ll be riding very high up in the sky, so it’ll be a great sight.

If you’re in Melbourne, and you want to check it out, head outside at 9:58PM and look north-west — you should very soon see a bright dot, climbing steadily up in to the sky, and growing brighter as it does. It’ll reach its highest point in the sky at 10:01, in the south-west, and then head back down to set in the south-east at 10:04. If you have a small telescope, or even binoculars, you should be able to make out some structure. Tracking it in a telescope will require quick movements, though!

If you miss tonight’s pass, you can get a list of other upcoming passes at Heavens Above.

apollo fever

The world is going Apollo-mad with the 40th anniversary of Apollo 11, the first manned mission to land on the moon, and there’s no better way to celebrate than with some fresh images of those pioneering missions. Last month, NASA launched the Lunar Reconnassance Orbiter, or LRO, which will map the moon in greater detail than ever before. It’s the first lunar mapping mission with the resolution needed to photograph the equipment left behind by the Apollo missions, and just a few days ago, that’s exactly what it did.

This shot of the Apollo 14 landing site is definitely the best of the lot so far — you can see not just the base of the Lunar Module, but also the science payload set up a short distance away, and the path the astronauts walked to deliver it:

There are more images on the LRO website. The best news is that LRO still isn’t in its final mapping orbit, so it should be sending back even better photos of these historic sites in the future.

lulin success!

I didn’t believe the BOM on Wednesday when it said that the miserable morning we were having was going to give way to a clear night, but they were spot on, and after getting back from NIN around midnight it was the perfect time to track down Comet Lulin. It’s moving across the sky pretty quickly at the moment (a good few degrees per day), but I knew it’d still be fairly close to Saturn, so I found that in my binoculars and then just started panning around from there.

It took a little while, but eventually, I found Lulin in my binoculars. It wasn’t exactly a spectacular sight — little more than a faint, roundish smudge, really — but after studying it for a little while I thought I could just make out the bright central spot of the comet’s nucleus. After checking the star charts for any fixed objects in that location (just as Charles Messier would have nearly 250 years ago) and finding nothing, I’m sure that what I saw was indeed Comet Lulin.

chasing comet lulin

I was hoping to get a glimpse of Comet Lulin last night, but unfortunately, the weather didn’t co-operate. Lulin was closest to Earth on the 24th, but for at least the next week or so it should be quite bright, as comets go — visible to the naked eye, if only just, in a clear, dark sky, and relatively easy to spot in binoculars from suburbia. At about 9:30, things were looking good last night, with just a few clouds visible, so I thought I’d get the telescope out to try to track down M1. By the time I was set up and had found where to look, though, more clouds had rolled in, and I had to give up the hunt. By midnight, which was when Lulin should have been coming in to the field of view from my front yard, the sky was just a blanket of clouds.

Ah well, such is this hobby of mine! It looks like we’re heading in to a stormy weekend, so I’m hoping that either tonight (though it’s not looking good so far) or tomorrow night will deliver the goods.

galaxy hunting

Saturday was another clear night, so I took the telescope out in search of one of the brigtest galaxies in the southern skies, the Sculptor Galaxy. Unfortunately, like my earlier experience with Centaurus A, I didn’t end up spotting it; I got it lined up as far as I could tell, star-hopping along in the finderscope based on nearby stars, but I couldn’t actually see it in the end.

I know how to find it now at least, so when I do get out in to some nice dark skies, I should have no trouble tracking it down.