Tag: Astronomy

The full moon at daytime

One obviously has the night sky before one’s eyes when thinking of the full moon. In reality, however, the event »full moon« has nothing to do with the fact whether it is night or day for us. The full moon occurs when Sun – Earth – Moon form a line in space and exactly in this order. The Earth lies in fact between the Sun and the Moon. Depending on what time this happens, it is night on the hemisphere that is turned away from the Sun and you can see the Moon in the sky. But on the hemisphere that is turned towards the sun it is daytime at this point and the full moon cannot be seen, because when observed from this position it is actually behind the Earth. [read more] “The full moon at daytime”

The lunar maria

When observing the Moon, you can see dark spots on its surface. In the old days, these were thought to be the seas and oceans just like on Earth, so they were called »mare« (plural: »maria«). Giovanni Riccioli (1598–1671), an Italian priest and astronomer was leading in this area and was responsible for giving many lunar maria their Latin or partially poetic names. We would like to single out a few that we consider to be worthwhile mentioning. [read more] “The lunar maria”

Halo and corona

We would like to turn our attention to two interesting types of light apparitions around the Moon: halos and coronas. Both are optical phenomena in the atmosphere that, if looked at from a physical point of view, come about in different ways and also look dissimilar.

A halo (left picture) develops through refracting ice crystals and creates a clearly defined light ring around the Sun or the Moon, whereas the surface between the celestial body and the ring, almost appears to be empty. Light spots, light arches and pillars can also emerge. [read more] “Halo and corona”

The GRAIL twin moon probes

A probe is an unmanned flying object, which explores space. Different to a satellite, a probe does not circle the Earth but flies to other celestial bodies, which they circle, too, but are then called orbiters. Two of these probes have been on the way to the Moon since 10th September 2011, to take measurements with unprecedented accuracy. The GRAIL lunar probes have reached the orbit of the Moon as planned, at the turn of the year 2011/12 and are now currently at work, until they will shatter on the Moon’s surface. In the meantime, they will have transmitted lots of data back to Earth. [read more] “The GRAIL twin moon probes”

New moon – the opposite of full moon!

The new moon is the opposite pole to the full moon, being the time when the Moon is not visible in the sky to us people. Maybe this is why we pay less attention to it, because what you don’t see is less prevalent in our awareness.

However, there is one aspect, which continues to lend significance and fascination to the new moon. It is the word »new« and the described moment of renewal and of a new beginning. This word can be found in different languages:

[read more] “New moon – the opposite of full moon!”

Waxing or waning?

This is about how to differentiate the waxing moon from the waning moon in the sky. »Waxing« is known to be the lunar phase between the new moon and the full moon (meaning the time when the crescent increases in size), whereas »waning« is known to be the lunar phase between the full moon and the new moon (the time when the crescent decreases in size). In order to remember on which side the curve is, here are some neat mnemonics. [read more] “Waxing or waning?”

Is the moonlight white or blue?

As is generally known, the moonlight is actually sunlight reflecting from the surface of the Moon and reaching us here on Earth. You ask yourself the question, whether the moonlight may have a different colour than the sunlight, especially since a  nightly scenery usually appears to be bluish. Also movie scenes, are portrayed in blue and so are many pictures and photographs. We would like to forestall the answer: the moonlight is nearly white. The night appears blue due to other reasons. [read more] “Is the moonlight white or blue?”

The Moon and the tides

It is well known the tides are caused by the tidal forces that are formed through gravity between the Earth and the Moon (and also between the Earth and the Sun). To put it simply, you can say that the Moon moves masses of ocean waters. At the full moon and the new moon, the Sun, the Moon and the Earth are roughly in alignment, hence, the forces are greater and cause so called spring tides, thus a slightly higher tide. Now, many people conclude that the Moon – and in particular the full moon – ought to move and influence us people accordingly, because our bodies consist mostly of water. This claim contains several errors in reasoning, which we would like to explain in the following. [read more] “The Moon and the tides”

Surfing with full moon power

When natural forces are involved, people are mostly torn between fear and fascination. They are looking for the challenge to come into contact with these forces. At the same time, everyone has to respectfully recognize these elemental forces, sooner or later. This becomes impressively apparent in surfing, when a person is gliding on a metre high wave on a surf board. If he manages to stay in front of the crest, and not to be rolled over by the breaking of the wave, he is the winner and in the belief to control the element. If he is not able to do so, it mostly turns dangerous or at least uncomfortable. It is a risky game. [read more] “Surfing with full moon power”

The Nebra sky disk

This disk, made of bronze and gold, with an age of around 3,600 years, belongs to the oldest find representing astronomical phenomena and thereby depicting planets and stars in the sky. It is thus of great value, because it is evidenced that people of the Bronze Age (2200-800 BC) did not only possess manual skills to create such a refined metal disk, but above all, had the knowledge about astronomical processes. They observed the celestial events with the naked eye and portrayed this in an artistic form. [read more] “The Nebra sky disk”

The lunar calendar of Islam

As a general rule, we live our secular life by a so-called solar calendar, the Gregorian calendar, which determines our calculation of time since the end of the 16th century. The biggest advantage of a solar calendar is its connection to the seasons: it is warm in summer, cold in winter, at least this is how it should be … at times however, as we all know, the weather goes crazy and sunshine is long-awaited in summer and snow stays away in winter. The seasons are connected to the (solar) calendar months. [read more] “The lunar calendar of Islam”

Red moon in the darkness

On Wednesday, 15th June 2011 (or Thursday 16th June for certain time zones) is full moon and a total lunar eclipse at the same time. However, it will only be completely visible in the Near and Middle East. In Asia and Australia, the moon will be already set and in Europe and Africa, the moon will be just rising by the time the lunar eclipse takes place. In America, this event won’t be visible at all. [read more] “Red moon in the darkness”

The origin of the Moon

The Moon has not always been there. And although, no one has been present to observe its creation, scientists today, largely share the view that our Moon originates from a collision between Earth and another planet 4.5 billion years ago.

Our Earth – that looked completely different to how we know it to be today – had been circling with the planet Theia, which was about the size of our Mars, around the Sun. Some day, these two orbs clashed, produced an inconceivably powerful collision that totally destroyed Theia and catapulted an enormous amount of rocks into the orbit of Earth. [read more] “The origin of the Moon”

What has the full moon got to do with Easter?

Quite a lot! The date of Easter is actually determined by the full moon. Quite contrary to Christmas, the Easter date is part of the changing holidays and defined as follows: »Easter is on the Sunday after the first full moon of spring.«

At first glance, this appears to be quite easy: one look at the calendar, beginning of spring is mostly on 21st March and then simply search for the next full moon and the weekend after will be Easter. [read more] “What has the full moon got to do with Easter?”

The reverse side of the Moon

As is generally known, the Moon is not a disc but a sphere and one could ask the question if we actually get to see different sides of this Moon sphere? The answer is: no! At least this is true for the observer from Earth.

Indeed, we always see one half of the Moon. This is because the Moon is locked into the Earth rotation. This is called »synchronous rotation«. It means that we are never able to see the side of the Moon facing away from us. And until it was possible to photograph the reverse of the Moon with space probes, nobody knew what we would find or how it would look. [read more] “The reverse side of the Moon”

The bigger, the better?

Maybe it lies within the plan of creation that we are so susceptible to everything that is bigger than what we already know or have already experienced. However, the following merely relates to heavenly bodies …

As we recently wrote in our article  »Sun and moon the same size?« here in our full moon blog, the moon changes its distance to earth due to its unusual orbit and subsequently appears to be of a different size for the observer here on earth, depending on how close it is to earth at the time. Is the moon (or another heavenly body) as close to earth as possible, one speaks of perigee, and if it is the furthest away, it is called apogee. You can confidently forget these terms again, however, you may want to memorise that the moon can appear to us in different sizes. [read more] “The bigger, the better?”

Sun and moon the same size?

Everyone knows that the sun is much larger than the moon and much further away from earth. In this very context lies a fascinating fact: both celestial bodies appear to be of similar size on the firmament, when observed from earth. Which implies that the sun has to be as many times bigger than the moon, as it is further away from the earth than the moon from the earth … [read more] “Sun and moon the same size?”

The hare on the Moon

Have you ever seen a face or shape of an animal in passing by clouds? This tendency of our perception to find structures within an image or a pattern, is called pareidolia (derives from Greek eidolon = picture). Essentially, this is a misperception where we see objects changing subjectively. But this can also be so much fun and inspire our fantasy to search for these shapes and to find them. Children, in particular, are known to be true masters of this game. [read more] “The hare on the Moon”

No terminator on the full moon!

No, this is not about another sequel of the science fiction movie or whether Arnold Schwarzengger is planning a trip to the moon … It is more about an astronomical term, where »terminator« describes the day-night border of a celestial body. This is the visible border between the illuminated side and the dark side of the object, being the border between day and night on the celestial body. The word »terminator« derives from Latin »terminare« = conclude, restrict.

The best way for us people to observe this is on the moon. For example at half moon, the terminator runs through the centre of the moon and therefore creates the visible semicircle. This means that the terminator can be seen during each phase of the moon cycle, with two exceptions: new moon and full moon. As there is either no illuminated side (new moon) or no shadow side (full moon) visible, hence no light-shadow border.

But even when there is no terminator during full moon, it immediately emerges afterwards. »I’ll be back« … doesn’t this sound familiar?