Wednesday, October 14, 2009

Vancouver Harbour

Derek's post of October 13, referring to the change in the Vancouver skyline over the last 50 years or so prompted me to dig out a couple of my own pictures of the Vancouver harbour view. I photographed the top image in 1956, the bottom one dates from 2008. Both pictures were taken from the same spot (within a couple of meters, or so). While the cameras and angle-of-view for the two source images are very different, I made an attempt to crop and resize the pictures in such a way as to make them appear similar. Click on the image for a larger view.
The change is astounding. The only edifice I can discern in both pictures is the spire of the Holy Rosary Cathedral on Dunsmuir Street in downtown Vancouver. The arrow in the top picture points to it. You can also spot it among the high rises in about the same relative position in the lower picture.
The two tallest structures in 1956 are the Vancouver Hotel on the right, and the Marine Building on the left. Both buildings are still in existence, but they are obscured by the newer high-rise buildings which have since sprung up.
Ah, progress!!

Friday, October 9, 2009

Crash Landing

After much hype in the media, the actual preplanned collision of the LCROSS (NASA's Lunar Crater Observation and Sensing Satellite)with the Moon was a visual disappointment for me. At first I was contemplating setting up my 200mm (8 inch) telescope, using my "new" eye, but advance information suggested that the telescope would have to perform at its very limit, and in excellent conditions - i.e no light pollution, absolutely clear and dark sky (an impossibility in this light-polluted city of Vancouver). I therefore decided to watch the NASA coverage instead, if I were to wake up around 4:15 in the morning. Well, I did watch it, but the images sent down from the Moon did not show me any impact. I've watched the replay several times, but to no avail.

Later today, NASA published more pictures, after analysis and using images from a "medium infrared imager" (MRI) camera. It showed the impact a little better, but I saw no sign of the calculated 10km debris plume, which was to expose any water ice possibly located in the permanently shadowed impact crater.

(both images from the NASA website - click on them to enlarge)

Here is the impact image the way I saw it. It shows the visible light image - the way you and I would see it if we were on board of the LCROSS satellite. I can't identify any crash.

This is the MIR image. Infrared shows hot spots a lot better, but the human eye cannot perceive infrared light.

Here is an excerpt from NASA's media advisory describing the mission:


NASA Spacecraft Impacts Lunar Crater in Search for Water Ice

MOFFETT FIELD, Calif. -- NASA's Lunar Crater Observation and Sensing Satellite, or LCROSS, created twin impacts on the moon's surface early Friday in a search for water ice. Scientists will analyze data from the spacecraft's instruments to assess whether water ice is present. The satellite traveled 5.6 million miles during an historic 113-day mission that ended in the Cabeus crater, a permanently shadowed region near the moon's south pole. The spacecraft was launched June 18 as a companion mission to the Lunar Reconnaissance Orbiter from NASA's Kennedy Space Center in Florida. "The LCROSS science instruments worked exceedingly well and returned a wealth of data that will greatly improve our understanding of our closest celestial neighbor," said Anthony Colaprete, LCROSS principal investigator and project scientist at NASA's Ames Research Center in Moffett Field, Calif. "The team is excited to dive into data." In preparation for impact, LCROSS and its spent Centaur upper stage rocket separated about 54,000 miles above the surface of the moon on Thursday at approximately 6:50 p.m. PDT. Moving at a speed of more than 1.5 miles per second, the Centaur hit the lunar surface shortly after 4:31 a.m. Oct. 9, creating an impact that instruments aboard LCROSS observed for approximately four minutes. LCROSS then impacted the surface at approximately 4:36 a.m.

Saturday, October 3, 2009

A new view

Well, as mentioned in my previous post, I had cataract surgery on my right eye on September 30. The procedure itself was painless, although I liken the level of comfort during the operation to the experience of having your teeth cleaned by a dental hygienist - i.e. slightly discomforting.

The result is absolutely astounding, though, and well worth a bit of uneasiness. My right eye can now discern fine detail I haven't seen in decades. Since I'm into astronomy, that result is exactly what I had hoped for.

At the moment, I have to take some care - no heavy lifting, and an interwoven schedule of taking medication in the form of eyedrops - but I'm looking at the world with a new eye (pun intended). Until now, I hadn't realized how much I was really losing, when looking around, and am now aware that my left eye, which was the better eye lately (using glasses) would also benefit from this kind of operation.

So, at the moment, I'm using eyeglasses in which the left part of the frame retains the bifocal lens formulated for my left eye; I have removed the right-eye lens altogether. The result, for distance viewing, is a reasonably close balance between my two eyes, with the right eye outperforming the left one by a noticable margin. It also makes it possible for me to read the newspaper and books (and typing this story on the computer) because, at my age, reading glasses are usually necessary. My reading is done with my left eye, through the "reading section" of the lens. This is no problem for me, because my right eye had deteriorated to the point at which I could not use it for reading anyway.

If and when I finally get my left eye "restored" in the fashion described above, I won't need glasses for distance view (that includes naked-eye astronomy, and watching TV, for instance). For reading, I can purchase some of those inexpensive, off-the-shelf reading glasses available anywhere. I'll then use both eyes for reading and close-up viewing.

In short, from my experience, if you are contemplating cataract surgery, go for it.