Thoughts on the white spots of Ceres

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.

Ceres with white spots

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.

UniFi systemd unit file for Ubuntu 15.04

At work we’ve started using some UniFi wireless gear and the system I’ve managed to commandeer to do the control system for it is running Kubuntu 15.04 which uses systemd. Now the UniFi Debian packages don’t supply systemd unit files so I went hunting and found a blog post by Derek Horn about getting it running on CentOS7 so I nabbed his and adapted it for Ubuntu (which wasn’t that hard).

The file lives in /etc/systemd/system/unifi.service and was enabled with systemctl enable unifi.service (from memory, there might have been another step that involved getting systemd to rescan unit files to pick up the new one, but I don’t remember for sure).

Here is the unit file:

#
# Systemd unit file for unifi-rapid
#

[Unit]
Description=UniFi Wireless AP Control System
After=rsyslog.target network.target

[Service]
Type=simple
User=root
#ExecStart=/usr/bin/java -Xmx1024M -jar /usr/lib/unifi/lib/ace.jar start
ExecStart=/usr/bin/jsvc -nodetach -home /usr/lib/jvm/java-7-openjdk-amd64 -cp /usr/share/java/commons-daemon.jar:/usr/lib/unifi/lib/ace.jar -pidfile /var/run/unifi/unifi.pid -procname unifi -outfile SYSLOG -errfile SYSLOG -Djava.awt.headless=true -Dfile.encoding=UTF-8 -Xmx1024M com.ubnt.ace.Launcher start
#ExecStop=/usr/bin/java -jar /usr/lib/unifi/lib/ace.jar stop
ExecStop=/usr/bin/jsvc -home /usr/lib/jvm/java-7-openjdk-amd64 -cp /usr/share/java/commons-daemon.jar:/usr/lib/unifi/lib/ace.jar -pidfile /var/run/unifi/unifi.pid -procname unifi -outfile SYSLOG -errfile SYSLOG -Djava.awt.headless=true -Dfile.encoding=UTF-8 -Xmx1024M -stop com.ubnt.ace.Launcher stop
SuccessStartStatus=0
SuccessExitStatus=255

[Install]
WantedBy=multi-user.target

Mount Burnett Observatory Open Day and Third Birthday – Saturday 24th January 2015

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!

DSC_7143_v1

This Saturday (24th January) is our third birthday celebration so we’re having an open day running from 1pm through to 6pm with tours, activities, a solar telescope and components from the Murchison Widefield Array (MWA), one of the precursor telescopes to the massive Square Kilometer Array telescope project!

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.

MBO_open_day_2015_flyer

ARM v8 (64-bit) developer boxes

Looks like things are moving along in the world of 64-bit ARM, systems aimed at early adopting developers are now around. For instance APM have their X-C1 Development Kit Plus which has 8 x 2.4GHz ARMv8 cores, 16GB RAM, 500GB HDD, 1x10gigE, 3x1gigE for ~US$2,500 (or a steep discount if you qualify as a developer). Oh, and it ships with Linux by default of course.

Found via a blog post by Steve McIntyre about bringing up Debian Jessie on ARMv8 (it’ll be a release architecture for it) which has the interesting titbit that (before ARM had their Juno developer boxes):

Then Chen Baozi and the folks running the Tianhe-2 supercomputer project in Guangzhou, China contacted us to offer access to some arm64 hardware

So it looks like (I presume) NUDT are paying it some attention & building/acquiring their own ARMv8 systems.

IBM Pays GlobalFoundries to take Microprocessor Business

Interesting times for IBM, having already divested themselves of the x86 business by selling it on to Lenovo they’ve now announced that they’re paying GlobalFoundries $1.5bn to take pretty much that entire side of the business!

IBM (NYSE: IBM) and GLOBALFOUNDRIES today announced that they have signed a Definitive Agreement under which GLOBALFOUNDRIES plans to acquire IBM’s global commercial semiconductor technology business, including intellectual property, world-class technologists and technologies related to IBM Microelectronics, subject to completion of applicable regulatory reviews. GLOBALFOUNDRIES will also become IBM’s exclusive server processor semiconductor technology provider for 22 nanometer (nm), 14nm and 10nm semiconductors for the next 10 years.

It includes IBM’s IP and patents, though IBM will continue to do research for 5 years and GlobalFoundries will get access to that. Now what happens to those researchers (one of whom happens to be a friend of mine) after that isn’t clear.

When I heard the rumours yesterday I was wondering if IBM was aiming to do an ARM and become a fab-less CPU designer but this is much more like exiting the whole processor business altogether. The fact that they seem to be paying GlobalFoundries to take this off their hands also makes it sound pretty bad.

What this all means for their Power CPU is uncertain, and if I was nVidia and Mellanox in the OpenPOWER alliance I would be hoping I’d know about this before joining up!

Update: I’ve spoken to some IBM’ers about this and they assert they’re not leaving the chip business, they are offloading off the fabs and the manufacturing IP to GlobalFoundries but not the chip design side of things. In my opinion, though, it does mean that should they decide to exit the chip business at some point it’ll be easier for them to do so.

How Far We Have Come: Comets

In 1986 ESA’s Giotto mission visited Comet Halley and I watched Patrick Moore on the BBC as the first images of a comets nucleus were returned.

Composite image of Comet Halley's nucleus from Giotto

Now it’s 28 years later and the ESA mission Rosetta has just arrived at 67P/Churyumov-Gerasimenko, and the difference in imagery is just amazing – and this isn’t even the full resolution version!

Detail from image of Comet 67P/Churyumov-Gerasimenko from Rosetta

More images from Rosetta are on the ESA Space Images website.

Getting Political

I’ve not been blogging recently, though I’ve been tweeting a fair bit, and I’ve been getting more and more disconcerted by what the Australian government has been up to, especially with respect to refugees. We are seeing the emergence of a militaristic approach where the facts about rights to seek asylum are conveniently ignored and refugees are labelled as “illegal” (they’re not) and a threat to our borders (they’re not). Questions are met with silence (unless they happen to coincide with their agenda) to frankly absurd levels.

We keep them in concentration camps on foreign soil and deprive them of necessities even though they’ve committed no crime and we leave them to go mad from boredom, fear and neglect. We’ve had one person murdered in our care with the prime suspect being a Salvation Army worker, but somehow after 6 months nobody has been charged. Others were seriously injured, but their assailants haven’t been charged either.

Now we have the situation of refugees from Sri Lanka who have boarded boats in India being intercepted at sea and returned, not to Indias care, but to the Sri Lankan navy where on their return to Sri Lanka they are then handed over to the police for prosection (as it’s apparently illegal to leave Sri Lanka without permission, the sentence is “two years of rigorous imprisonment and a fine”).

This seems like a prima-facie case of refoulement and a clear breach of international law. I’m not the only person to think like that, 57 legal scholars from 17 Australian universities have written an open letter expressing the same feelings.

Such summary procedures do not comply with minimum standards on refugee status determination under international law. Holding asylum seekers on boats in this manner also amounts to incommunicado detention without judicial scrutiny.

I cannot stand by and be seen to acquiesce in this abuse of fundamental human rights and so I’ve decided that I must join The Greens as none of the major parties appear to understand international law and obligations.

This is not an easy decision for me, I spent 7 years working in the UK Civil Service and so that ethos of being independent of a political party is deeply ingrained, but the revulsion I have for the policies of this government and my fear of the dark places it is leading us has finally overcome it.

This is not in my name.

Lunar Eclipse 15th April 2014

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.

Lunar Eclipse 15th April 2014 taken from Olinda Golf Course

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).

Lunar Eclipse 15th April 2014 taken from Upper Ferntree Gully
Lunar Eclipse framed in gum leaves, 15th April 2014 taken from Upper Ferntree Gully
Lunar Eclipse through trees, poles and wires - 15th April 2014 taken from Upper Ferntree Gully
Lunar Eclipse shortly before fourth contact, 15th April 2014 taken from Upper Ferntree Gully