I couldn’t help myself. I ran home this morning and grabbed my small Cannon 12.1 mega pixel camera and sat down out the front of the museum to take some shots. Had to wait for the clouds to come over the sun slightly as to block out a lot of the brightness and it worked!! Shitty photo I know, but taken by yours truly! Might try again if I’m around in another 100+ years to see the next pair of transits.
Archive for the ‘Astronomy’ Category
So the Transit of Venus is occurring right now as I write this. It’ll be the last chance any of us have of seeing this in the flesh, or like me, watching it over the internet in the flesh, unless we live past about 150 until the next one occurs.
For those wanting to view it at home without having to stare straight up at the sun here’s a quick video on how to use some binoculars to project and image of it onto some cardboard.
You can also watch it live streamed online on this page.
Neil deGrasse Tyson is currently on Reddit answer any questions asked of him (there’re 1000s that have appeared in the past 30 minutes) in the r/AMA or Ask Me Anything sub forum. Go here if you’re interested in asking a questions or reading what others have asked him!
Thought I’d chuck up this interview of Neil with Stephen Colbert.
The SKA is a radio telescope currently in development which will have a collecting area of about a square kilometre, with receiving stations up to 3000kms away from the concentrated central core. It will use a vast range of radio frequencies and its going to be 50 times the size of the current most sensitive radio instrument. Due to the amount data being collected and transmitted throughout the array, more than the capacity of the current global Internet traffic, it will require a computer 100 times more powerful than anything in current existence.
It will be able to continuously survey the sky at 10 000 times faster than ever before, and penetrate something like 15 billion years into the history of the universe, a great deal further than ever before.
As it’s planned to be built in the southern-hemisphere where the view of the Milky Way and so Australia is also in competition with South Africa and New Zealand for the project, which is going to cost up approximately $2 billion to complete. It’s scheduled to begin construction in 2016. Fingers crossed!
A ‘Blue Marble’ image of the Earth taken from the VIIRS instrument aboard NASA’s most recently launched Earth-observing satellite – Suomi NPP. This composite image uses a number of swaths of the Earth’s surface taken on January 4, 2012. The NPP satellite was renamed ‘Suomi NPP’ on January 24, 2012 to honor the late Verner E. Suomi of the University of Wisconsin.
Suomi NPP is NASA’s next Earth-observing research satellite. It is the first of a new generation of satellites that will observe many facets of our changing Earth.
Suomi NPP is carrying five instruments on board. The biggest and most important instrument is The Visible/Infrared Imager Radiometer Suite or VIIRS.
Follow this link for larger resolution images.
Stargazers in northern Europe are being treated to a spectacular showing of northern lights after the most powerful solar storm in six years. This time-lapse footage shows the Aurora Borealis in the skies above Trondheim, Norway. (Jan. 24)
My girlfriend Hannah asked me the other day how the Earth’s magnetic field was generated. I knew a little about the rotation of the liquid core of the Earth having to do with producing its protective magnetic field. However, I couldn’t full satisfy her question to her nor to myself. So I thought I’d do a little investigating.
The Earth’s core drives the magnetic field of the Earth. The inner core is believed to be primarily a solid ball of iron, which is surrounded by a liquid outer core made up of effectively an ocean sphere of molten iron and nickel. These oceans of molten metal are in perpetual motion within the Earth.
When a celestial body, such as the Earth or the Sun, has a magnetic field being generated around it this is caused by a phenomenon named geodynamo.
In geophysics, dynamo theory proposes a mechanism by which a celestial body such as the Earth or a star generates a magnetic field. The theory describes the process through which a rotating, convecting, and electrically conducting fluid can maintain a magnetic field over astronomical time scales.
So three things are clearly required:
1. a rotating core
2. a liquid metal
3. the presence of convection
The inner core, outer core and mantle of the Earth were formed early on in the planet’s life when it was still incredibly hot. When you heat a mixture of solid material made up of rock and iron to very high temperatures the iron will begin to separate because it is heavy. And so it will start to sink under gravity to the centre of the earth, and thus the core will be formed.
So as a result of this separation of molten rock and metals we get these different layers of the Earth, and as the heat from the centre of the Earth started escaping it caused the liquid metal within the core to move. This perpetual motion within the depths of the Earth is what generates its magnetic field.
If you want to generate a magnetic field the way the earth does all you need is a metal, like iron in our case, it needs to be liquid, which means it has to be very hot, but you also need a temperature difference. Where the heat flows from the hot inner core to the cooler mantle of the planet it causes convection currents to form in the molten metal of the outer core. Those motions, through the process of electromagnetic induction, is the way in which the magnetic field of the Earth is produced.
Without the Earth’s magnetic field we’d have a lot more to worry about besides out compasses not working. Its most important role is protecting the biosphere on the surface of the planet from being hit by the infinite number of charged particles thrown at us by the Sun (solar wind). If you want to know what happens to a planet when its core ceases to rotate, and it loses its magnetic field, take a look at the Moon.
For more information I highly recommend watching this documentary on the core of the Earth.
Posted in Astronomy, Photography, Science, tagged astronomy, galaxy autumn lake, masahiro miyasaka, milky way, photo, sirakomanoike lake, the japanese alps, yatsugatake on 27/09/2011 | Leave a Comment »
Galaxy Autumn Lake, Japan. The Milky Way shining bright above Sirakomanoike lake, situated at 2,115m above the sea level, in the Yatsugatake, the Japanese Alps.
Photograph by Masahiro Miyasaka