The Four Ages Of Sand

Question of the week: Why is the Moon orange?

I just got this message from Nick:  

Why is the Moon so orange right now?

I thought for a moment that his "orange Moon" experience was similiar to his recent "pink elephant experience" (s)  if you know  I'm saying... but I went outside and checked anyway, and the Moon is indeed orange!

Luckily I've got my 500mm Ultratelephoto lens to capture the magic. 

Apart from cropping, this is straight out of the camera:

 

What's going on? Well it's the same explanation as to why the Sun appears orange at sunrise and sunset, namely, when it's low on the horizon the light has to travel through more air, which scatters the short wavelength blue end of the spectrum leaving the long wavelength red end:

http://home.hiwaay.net/~krcool/Astro/moon/moonorange/

Supermoon update

I'm thinking of making Nick the official 4AoS Moon-Man.  He alerted me to the fact that the biggest Moon for 18 was showing well (yesterday's post) and now he's just texted to say that it's turned a funny colour, and By Golly he's right:

Also notice how the shadows are forming on the upper right side, compared to the upper left side last night: 

 

 

Biggest Moon for 18 years

I wasn't going to blog this on the assumption, based on bitter experience, that whenever 4AoS announces an upcoming astronomical phenomenon, the clouds roll in. Nick just texted me to say that the biggest Moon for 18 years IS showing itself, so I rushed out and snapped this with the Nikon and the 500mm lens.

What a whopper!

And close up: Notice that you can still see a little shadow at the top left. A truly full moon isn't possible because if the light from the sun was falling 100% perpendicular to the surface as we see it, that would mean that the Earth would be between the Sun and the Moon, which would give us a Lunar eclipse.

The bright "blob" at the lower right side it the crater Tycho, one of the few crater visible with the naked eye. Here's m'photo of it a couple of weeks age: (lower centre)

Full story on what's happening: 

http://uk.news.yahoo.com/38/20110318/tsc-world-to-see-biggest-full-moon-in-tw-98fda55.html

Ps. My sister-in-law asked me if there was any possible link between "Supermoon" phenomena and Earthquakes. At the time I said absolutely not. This is the view of most scientists but some disagree, especially Dr Victor Gostin:

http://www.dnewsglobal.com/supermoon-phenomenon-triggers-earthquake-tsunami-japan/3507.html

The Joy, actually, no, the ecstasy of Asteroid 37 Fides

Asteroids are chunks of rock and metal left over from the creation of the Solar System. There are millions of them and most are in the main asteroid belt between Mars and Jupiter:

http://en.wikipedia.org/wiki/Main_asteroid_belt

Most of them are very faint and I've never seen one before, which was why I was very annoyed to read in the January issue of Astronomy that a 67 mile wide asteroid called 37 Fides is at this moment flying through the Pleiades cluster (also know as M45 and The Seven Sisters cluster).  At magnitude 10.4 it's at least 100 times too dim to be seen with the naked eye, but my 10" scope shouldn't have any difficulty picking it up but the skies are cloudy and are predicted to stay the same for the coming week.

 But wait... I took some stacked images of The Paleiades the other week, using the piggybacking technique with the 500mm telephoto lens (see previous post)

Is it possible I photographed Asteroid 37 Fides by accident?

It was on the 8th January so according to the chart it should be above and to the right of a fairly bright star. I went back to the original stack and...

comparing it to the chart:

There is indeed a bright spot in exactly the right place!

 But as an aspiring boffin, I knew I couldn't publish my results without further investigation so I went to http://www.sky-map.org/ and zoomed in on the top area of M45. (It takes very long exposures to reveal the nebulosity like this.)

Closing in on the exact section and comparing it with a close up of my photo, you can see that the 3 stars (a) are clearly visible in both images but (b) is only visible in my image, even though it is roughly the same magnitude as the (a) stars. 

It would be nice to identify the even fainter star (c) which would then "pin down" (b) with even more certainty. It's not visible in the image but if the levels are boosted in Photoshop, it just makes an appearance. Along with similar magnitude stars at (d) this confirms beyond any doubt that (b) really is the asteroid.

Marvellous! 

And here's the colour-corrected version, rotated to match the postion of the sky through the scope, along with hints of the nebulosity showing:

Interesting to ponder that every point here is a star producing its own light, except for the asteroid which is only visible due to the refected light of our own star, the Sun. 

There are no images of 37 Fides showing it as anything other than a point of light, but it's too small to have pulled itself into a spherical shape so it probably looks something like this one, 253 Mathilde

http://en.wikipedia.org/wiki/File:(253)_mathilde.jpg

 

Now I'd like to try for other asteroids and minor planets.  

 

 

 

 

 

Return to the Seven Sisters (The Pleiades)

I have posted a photo of the Seven Sisters before:

 The Pleiades is the best star cluster in the sky and it's easily visible to the naked eye , rising in the East and staying high in the southern sky all night. It's 380 light years away, so the light you are seeing has been travelling through space at 186,000 miles a second since shakespearean times (if my maths and my history is right)

It looks like a large fuzzy blob, and you should be able to see 7 of the 200 stars, hence its more common name of Seven Sisters. If you have binoculars, take a look. It's stunning, and because it's so big, it's actually more impressive through binoculars than a telescope.

 

 What do you mean "Where is it?" Between the branches of the tree on the right, of course!

I'm happy to say, my skill set has expanded over the last year. Ta dah!  

  

 

This is a combination of 7 exposures at 800 ISO, totalling 2 minutes 55 seconds, using the 500mm telephoto lens on the Nikon, piggybacked on the telescope.

The stars are bathed in nebulosity, which is just beginning to show with the star at the bottom of the cluster. 

Earthshine!

We've looked at Earthshine before but now I have a decent camera to capture it properly. Unfortunately I didn't have a tripod when I saw this the other day so it's still a bit dodgy.

The thin crescent Moon:

If you look closely at the dark part, you can see the rest of the moon:

How come? Because when the Moon is "new" for us, the Earth is "full" on the Moon, so the Earth illuminates the night side of the Moon and this light is then reflected from the Moon. So what you are seeing is sunlight bounced off the Earth's surface, onto the Moon's and then back to us.

A longer exposure:

Star trails around the North Star

Point your camera at the North Star, open it up on Manual setting for half an hour or so. Hey Presto!

The Moon again

A major 4AoS announcement is due around 2.00pm today, in the meantime, here's the moon from last night:

  It's interesting to compare the features to the night before:

Question of the week 78: can a digital camera photograph galaxies?

Yes!

It's quite easy to image the Milky Way, which is our galaxy of course. This is towards the galactic centre and the dust lanes are clearly visible. Without the dust, this would be as bright as a full moon:

Now, how about another galaxy? Our nearest galactic neighbour is Andromeda. It's 2.2 million light years away but it's rushing towards us at great speed and will one day collide with us. If you have binoculars you can easily see it at this time of year, and it will look something like this. (15 second exposure)

 

 Amazing to think that the light that was recorded on the camera's sensor  had been travelling for 2.2 million years. It started its journey before our species even existed  (See here for human timeline)

Colourful star trails

If your camera has a Manual setting, stick it on a tripod or place it on the ground on its back, open up the aperture as far as it will go and take some long exposures. You'll be amazed at what you can see.

Stars are actually very colourful (young starts are blue, middle aged yellow - like the Sun - old are orange) but they are so faint that our eyes tend to see most of them in black and white. The longer exposures really bring out the colours. This was about 30 minutes:

This is the Milky Way. The darker areas in the middle are the dust lanes at the centre of our galaxy. Without these, the Milky Way would be as bright as the full Moon: