Saturday, May 19, 2012

Solar eclipse tomorrow

Get your sun watching eyeglasses out. If you live in either East Asia (particularly southern Japan) or western North America you will get to see an annular solar eclipse.

The Moon's shadow will streak across the Pacific mostly, as our natural satellite will be positioned between the Earth and the Sun. People located in East Asia will see the phenomena the morning of the 21st of May, while those located in Western America will see it at the late hours of the 20th, right before sunset. Those in the penumbra will be able to see a partial eclipse.

However, the moon is currently close to it's apogee (when it's furthest to the earth), so its apparent size is not enough to cover the Sun's disk. The result is what looks like a bright ring on the sky, hence the name 'annular eclipse' (from the latin annulus, meaning little ring).

Although the Moon will cover some of the sun's brightness, it is not safe to look at it with naked eyes. It is advisable to get some purpose made glasses or filters, in case of observation with binoculars or a telescope.

This eclipse is a part of a series which has been going on since the year 984, every 18 years and 11 days, called Saros 128. Goes to show how much of a clockwork our solar system can be. The series has 73 events and will end in November of 2282.

Monday, May 14, 2012

Earth from Space in 121 megapixels

From Russia with love, we have this spectacular images of the earth taken from a geo-stationary satellite called Elektro-L No.1, orbiting above the Indian ocean.

With a camera that combines three visible and one infrared wavelengths in one shot, we get this 121 megapixel single shot of the planet, the best resolution yet for a single image. We also get some weird, warped colors because of this: the vegetation looks reddish instead of green. Don't worry, the trees are still there.

More high resolution images at Planet Earth

Friday, May 4, 2012

Recovering a failed hard drive. Part II, the solution

Getting SpinRite to start working is really easy. With the burnt CD inside the CD drive, all one has to do is turn the computer on, with the intended hard drive to recover connected, and wait some time. A welcome screen with clear options tells you what you need to press for which operations, and off you go.

SpinRite has different “levels” of operation, for different functions. The default and recommended level is level 2, which will scan the contents of the disk and attempt to recover whichever sectors are damaged or unreadable. I chose this option and let it go. At first, the scan seemed to go quite fast. Obviously the scanned parts were healthy and were duly being skipped. After about 12 hours of operation, the screen was telling me it was 2.89% done, trying to repair the first bad sector… at which point I understood it was going to take a while, lost interest, and turned the screen off. I let it work for around 12 hours before I checked on it again.