On May 5, 2012, while everyone else was waiting for the “Super Moon” astrophotographer Alan Friedman was out capturing this super image of a super Sun from his back yard in Buffalo, NY!
Taken with a specialized telescope that can image the Sun in hydrogen alpha light, Alan’s photo shows the intricate detail of our home star’s chromosphere — the layer just above its “surface”, or photosphere.
Prominences can be seen rising up from the Sun’s limb in several places, and long filaments — magnetically-suspended lines of plasma — arch across its face. The “fuzzy” texture is caused by smaller features called spicules and fibrils, which are short-lived spikes of magnetic fields that rapidly rise up from the surface of the Sun.
On the left side it appears that a prominence may have had just detached from the Sun’s limb, as there’s a faint cloud of material suspended there.
Alan masterfully captures the Sun’s finer details in his images on a fairly regular basis… see more of his solar (and lunar, and… vintage headwear) photography on his blog site here.
This weekend will provide the full Moon’s closest approach of the year to Earth. On Saturday, May 5, 2012 the Moon could appear as much as 14% bigger and 30% brighter than other full Moons of 2012, according to some calculations. Will you notice it? Not if you haven’t really been paying attention, or have a reference point to compare it to other full Moons. And it certainly won’t have any adverse effects on Earth, as this closest approach happens every year — just a fact of orbital mechanics. But perhaps a great way to celebrate Cinco de Mayo is to spend the evening gazing at the Moon!
Every month, as the Moon circles the Earth in its elongated orbit, its distance from the Earth varies. This weekend, the Moon is reaching what’s known as its perigee, the closest point to Earth in its orbit. It will be about 356,953 kilometers (221,802 miles) from Earth on Saturday. Apogee — when the Moon is farthest away — varies, but is around 405,000 km (252,000 miles) away.
What is most interesting is that the timing of the perigee and full Moon is really, really close: The full moon occurs at 03:34 UTC on May 6 (11:34 p.m. EDT on May 5 )eastern and perigee follows at 03:35 UTC (11:35 p.m. EDT)
David Morrison, from NASA says “supermoon” is not an astronomical term and he confirms a supermoon has no effect on Earth, and that the change in size is hardly noticeable to the average person. If you miss it, the Moon will be very nearly as close at the next full Moon, and very nearly as close as it was at the last full Moon.
But even better is that two weeks after the “supermoon” on May 5th, the Moon will be at apogee as it lines up in front of the Sun for an amazing annular eclipse on May 20th. An annular eclipse occurs when the Sun and Moon are exactly in line, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or annulus, surrounding the outline of the Moon.
If you’re a photographer, take a picture of the Moon and send it to us. If we get a some good images, we’ll share them. Join our Flickr group, or send us your images by email (this means you’re giving us permission to post them). Please explain a little about it such as when you took it, the equipment you used, etc.
How super was your full Moon on March 19, 2011? I was completely clouded out, but thankfully quite a few people have been kind enough to share their images. Here are a pictures sent in by readers, as well as via Twitter and Facebook. We’ve got images from all around the world, and even though the size of the Moon really wasn’t that much bigger than usual, (read here why not) it is great to see so many people getting out and looking up at the sky! Our lead image comes from Rasid Tugral in Ankara, Turkey.
This gorgeous shot, was sent in by Donna Oliver from western Australia, take a bit of creative license. She says: “The goal was not to shoot the moon as such but to take advantage of the additional light. Obviously on a long exposure, the moon would not look this good, so I shot the moon, then added it. You can see star movement if you look carefully. I made the moon extra large as my interpretation of the Super Moon.”
Check out these two from Tavi Greiner on her blog, A Sky Full of Stars: In this one, the Moon rises over a boat on the Shallotte River, just a few hundred yards from the Atlantic Ocean.
And in this one, the Moon appears captured by the rigging, and even almost appears to have lit the ropes on fire.
You’ve probably all seen it before, a huge Full Moon sitting on the horizon and you wonder why it looks much bigger than at other times? It isn’t, really; it’s an illusion.
And now, if you have heard about the close approach of the moon, or so called “Supermoon” on March 19th and are concerned about the disasters and mayem it may cause, there is no need to worry. And surely, when this so-called “Supermoon” occurs on March 19th — at its closest approach to Earth in two decades — people will indeed report that the Moon looks much bigger than normal. But it won’t really be much bigger in the sky at all. It’s all an illusion, a trick of the eye.
The moon does have an effect on the Earth with its gravity affecting ocean tides and even land to a lesser extent, but the moon on the 19th won’t interact with our planet any differently than any other time it’s been at its closest (also known as perigee).
If anything we may get slightly stronger tides, but nothing out of the ordinary.
The Moon orbits the Earth in an elliptical orbit, meaning that it is not always the same distance from the Earth. The closest the Moon ever gets to Earth (called perigee) is 364,000km, and the furthest is ever gets (Apogee) is around 406,000km (these figures vary, and in fact this Full Moon on March 19, 2011 will see a slightly closer approach of 357,000km).
So the percentage difference in distance between the average perigee and the average apogee is ~10%. That is, if the Full Moon occurs at perigee it can be up to 10% closer (and therefore larger) than if it occurred at apogee.
This is quite a significant difference, and so it is worth pointing out that the Moon does appear to be different sizes at different times throughout the year.
But that’s NOT what causes the Moon to look huge on the horizon. Such a measly 10% difference in size cannot account for the fact that people describe the Moon as “huge” when they see it low on the horizon.
What’s really causing the Moon to look huge on such occasions is the circuitry in your brain. It’s an optical illusion, so well known that it has its own name: the Moon Illusion.
If you measure the angular size of the Full Moon in the sky it varies between 36 arc minutes (0.6 degrees) at perigee, and 30 arc minutes (0.5 degrees) at apogee, but this difference will occur within a number of lunar orbits (months), not over the course of the night as the Moon rises. In fact if you measure the angular size of the Full Moon just after it rises, when it’s near the horizon, and then again hours later once it’s high in the sky, these two numbers are identical: it doesn’t change size at all.
So why does your brain think it has? There’s no clear consensus on this, but the two most reasonable explanations are as follows:
When the Moon is low on the horizon there are lots of objects (hills, houses, trees etc) against which you can compare its size. When it’s high in the sky it’s there in isolation. This might create something akin to the Ebbinghaus Illusion, where identically sized objects appear to be different sizes when placed in different surroundings.
Ebbinghaus Illusion – the two orange circles are exactly the same size
When seen against nearer foreground objects which we know to be far away from us, our brain thinks something like this: “wow, that Moon is even further than those trees, and they’re really far away. And despite how far away it is, it still looks pretty big. That must mean the Moon is huge!”.
These two factors combine to fool our brains into “seeing” a larger Moon when its near the horizon compared with when it’s overhead, even when our eyes – and our instruments – see it as exactly the same size.
Source: “Moon Illusion” on Dark Sky Diary Special thanks to Steve Owens