If you’ve been paying attention to the world of planetary exploration you’ll have noticed the excitement about the unexpected white spots on the dwarf planet Ceres. Here’s an image from May 29th that shows them well.
Having looked at a few images my theory is that impacts are exposing some much higher albedo material, which you can see here at the top of the rebound peak at the center of the crater, and that the impact has thrown some of this material up and that material has fallen back as Ceres has rotated slowly beneath it giving rise to the blobs to the side of the crater.
If my theory is right then if you know Ceres gravity and its rotational speed and the distance between the rebound peak and the other spots then you should be able to work out how far up the material was thrown up. That might tell you something about the size of the impact (depending on how much you know about the structure of Ceres itself).
As an analogy, here’s an impact on Mars captured by the HiRise camera on MRO that shows an area of ice exposed by an impact.
As some of you know I’m involved with the Mount Burnett Observatory, a community run astronomical observatory in the Dandenong Ranges of Victoria near Emerald to the south-east of Melbourne. Originally built by Monash University in the early 1970’s it’s 3 years since a small group of people formed a community association, took over the site and starting resurrecting it as an observatory by and for the people. It’s now three years on and by the end of last year we were the second largest astronomical association in Victoria!
At 6pm we have a barbecue and then at 7pm there will be a talk by Perry Vlahos on what there will be to see in the sky over the coming month. After that we’ll be socialising and, if the weather behaves itself, viewing the stars through the many observatory telescopes.
Tonight Melbourne got to experience the tail end of a lunar eclipse as the moon rose in eclipse at 17:48. We took a friend on a trip up to the (apparently now closed) Olinda Golf Course to view the moon rise. It was nice and clear and after roaming around a bit to find a place where we should have been able to see the eclipsed moon we found a suitable spot but couldn’t see the moon itself. Mars was visible in the right area but of course the salient point of a lunar eclipse is that the moon is in the earths shadow and so wasn’t findable until it started to exit at third contact. Got a few photos, of which this was the best.
We had to head back down the hill as Donna had an appointment at 7pm but later on our friend called up and said excitedly “Have you seen the moon? Go and look!”. I went out to see but the hills were still in the way then, so later on I headed out with the camera once the moon was visible and got some more photos as the moon headed towards fourth contact (when it exits the shadow of the Earth).
Just over a week ago it was the Mount Burnett Observatory’s second birthday, celebrating two years since being reopened as a community observatory. Originally it was built by Monash University and used as a research and teaching observatory until becoming surplus to requirements. A group of people made a community association to take up the lease after the Astronomical Society of Victoria passed it over and now it’s the third largest astronomical society in Victoria!
To celebrate being two years old MBO held an open day running from 10am until 6pm when there was an open barbecue followed by a talk by Prof. Sarah Maddison from Swinburne University. We really didn’t know what to expect in terms of turn out but were amazed to see our first visitors arrive before we opened at 10am! I helped out demonstrating the large 18″ telescope in the dome until 12:30pm when I had to head home, at that stage we’d had 30 people through. I was struck by the number of people who were amazed they had no idea that there was an observatory on their doorstep, let alone one they could join and participate in. One person asked how much it was to join and when told it was just $50 for the year said “I spend more than that on astronomy magazines every year!”. 😉
It was a very successful day with well over 100 non-members visiting the observatory during the day, plus of course many members. It was certainly a packed club house for the talk that night! I donated two bottles of sparkling wine for a door prize, one of which was one by a member (and volunteer for the day) and one was one by a visitor. The only disappointment of the day was that we had cloud that night, so there wasn’t really much to see in the sky.
It was very good to see that the following Friday we had over 30 people attend the regular Friday night members night and probably about half were new faces.
This morning was a partial solar eclipse in Melbourne. Back up where we saw the total solar eclipse last November they got an annular eclipse which would have been spectacular, but work is too frantic at the moment bringing up a new machine to even think about going up!
The first glimpse of it was from the train going into work with (of course) eclipse glasses (from Ice In Space) and by the time I got to Richmond I remembered I’d not taken a photo so had a go with my phone and the eclipse glasses and came up with this:
My plan though was to go to the playing fields at the University of Melbourne where I’d learnt before (via Twitter) that there would be some astro folks. There was a small group of people there with a telescope set up to project onto a screen at the rear who were having fun trying to keep it on target as it wouldn’t lock into place. The nice thing about projections like this is that you get a nice big image, like this:
I had a couple of left over eclipse glasses from the total eclipse so I passed them around and left them with them, they seemed to go down well!
Friday night I was at the Mount Burnett Observatory for the talk about the ASV’sNew Astronomers Group (NAG), but we took a break from the talk shortly after sunset to look for the two comets in the southern sky that night, C/2011 PANSTARRS and C/2012 F6 Lemmon. It was a lovely clear night, though very windy, and we managed to see both of them. I’d brought my camera and tripod along and got these photographs:
Comet C/2011 PANSTARRS as seen from Mount Burnett Observatory
Comet C/2012 F6 Lemmon as seen from Mount Burnett Observatory
…and this time with a passing aircraft…
Then on Saturday night I got this photo of PANSTARRS from Upper Ferntree Gully, visible as a naked eye object.
Sadly PANSTARRS is heading off to the northern hemisphere so we may not get much more of it here in Australia.
For almost a year now I’ve been a member of the Mount Burnett Observatory, a community project at the old Monash University astronomical observatory at Mount Burnett in the Dandenong Ranges. It’s great fun with both the original 18″ telescope and new 6″ and 8″ Dobsonian telescopes (some thoughtfully sponsored by the Bendigo Bank for education and outreach purposes).
It’s had a Facebook presence for a while, but nothing on Twitter, so after speaking to the webmaster and the president I’ve now set up a Twitter presence as @MBObservatory.
So if you’re into astronomy and around Melbourne (especially the south-eastern suburbs, though we do have people travelling in from quite a way) and use Twitter please do follow us!
Donna and I travelled up to Trinity Beach, about 20 minutes north of Cairns, for a holiday with a total solar eclipse in the middle of it.
We were really lucky as firstly we nearly didn’t make it up there at all as Jetstar cancelled our flight up and couldn’t get us another seat until Wednesday which would mean missing the eclipse and losing the accomodation we’d booked. Fortunately we were able to get a flight up with Virgin instead on the same day as our cancelled one, but it cost more than the refund from Jetstar. Then there was the weather; we arrived on a nice sunny Sunday and it looked quite promising, but Monday and Tuesday were both pretty cloudy and wet at times, so it wasn’t looking good.
Wednesday morning rolled around and we were up early (with three different alarms, just in case) and it was clearer than the previous days, but still plenty of broken cloud around.
There were probably a few thousand people around on Trinity Beach…
…who watched the partial phases nervously, but with growing excitement, through the cloud.
We were getting close to totality, but a large cloud was looming, and we wondered if we might miss the total eclipse phase!
Our luck held though, and we managed to see totality through broken cloud.
Of course, after third contact and the end of totality the cloud started to clear and we had a good view for once.
The folks down in Cairns (including my friend Ian Grant from the Bureau of Meterology who lent me a 1976 solar eclipse filter) were not so lucky, they saw the partial phases but missed totality due to cloud. An American in front of him told him that was the third time in a row it had happened to him!
This is my attempt to capture the view of the total solar eclipse as seen from Trinity Beach in Queensland, Australia with my D90 DSLR, uploaded to YouTube with a CC-BY license.
Our tripod wasn’t usable unfortunately so this was taken resting on my knee and, as you’ll see, I got distracted by totality so it wandered off target a couple of times. I stopped filming so I could try and take a still photo as it looked like we were about to get clouded out, hence stopping short. We did manage to see the diamond ring just after though!