The summer triangle Deneb, Vega, Altair is nicely visible in the South in the evening skies. Deep sky observing is best from midnight to 2.30 am.
Mercury is best seen from next week onwards and for a short while only around 9.30 pm in the constellation Cancer. Venus is best seen from 9.20 pm to 9.50 pm in the West in the constellation Leo. The visibility of Venus will be shorter and shorter. Mars is only 11° West from the Sun in the morning and is best seen around 4.30 am in the constellation of Gemini. Jupiter is best seen from 9.35 pm to 10.20 pm in the constellation Leo. Saturn is best seen from 10.10 pm to 1.20 am in the constellation Libra. To see Uranus you will need a small telescope of binocular. Uranus is best seen from 1.20 am to 2.25 am in the constellation Pisces and will be visible longer and longer.
The Moon is in First Quarter on Thursday 23 July. The Sun rises at 5.09 am and sets at 9.18 pm. After a week the Sun rises about 10 minutes later and sets about 11 earlier.
Wednesday 22 July
Today in the year 2381? The maximum theoretical length for a British total eclipse is 5.5 minutes. The eclipse of 16 June 885 lasted for almost 5 minutes and the same will be true for the Scottish total eclipse of 22 July 2381. None of us will witness … unless you freeze yourself in …
The Moon is visible with Earthshine for a few evenings. Look at about 10 pm before it sets in the West.
The International Space Station (ISS) appears at 2.39 am in the South at 28°. Culmination at 2.40 am in the South South East at 31°. ISS disappears at 2.45 am in the Eastern horizon. ISS appears again at 4.11 am in the West South West. Culmination at 4.16 am in the South at 65° and disappears at 4.21 am.
Thursday 23 July
Today it is the 20th Anniversary (1995) of the discovery of Comet Hale-Bopp by Alan Hale and Tom Bopp.
Mercury is in conjunction with Sun at 8.25 pm conjunction The planet is 1.6° separated from center of Sun. At about 10 pm Earthshine will be visible on the Moon.
At 11.09 pm a flare is visible in the West at an altitude of 26° in the constellation of Coma Berenices. Another flare appears after midnight at 0.26 am in the South West at altitude 46° in the constellation Hercules.
ISS appears at 1.47 am in the South East at 20° and disappears after a few minutes at 1.52 am in the Eastern horizon. ISS appears again at 3.20 am in the West South West at 15°. At 3.22 am ISS is close to Altair in Aquila with a separation of only 0.111°. The highest point in the sky or culmination is at 3.23 am in the South South East at 57°. ISS disappears at 3.28 am in the Eastern horizon. ISS appears again at 4.54 am at the Western horizon. Culmination at 4.59 am in the South at 62°. ISS disappears at 5.04 am at the East South East horizon.
At 5.04 am the Moon is in First Quarter
Friday 24 July
At 9.45 pm an Iridium flare appears in the North North East at altitude 76° in the constellation Draco. Another flare at 11.12 pm in the West at altitude 22° in the constellation Coma Berenices. And another flare after midnight at 0.20 am in the South West at altitude 46° in the constellation Hercules.
ISS appears after midnight at 0.56 am in the East South East at 9° and disappears already after 2 minutes at 0.58 am at the Eastern horizon. An Iridium flare is visible at 1.56 am in the South at altitude 54° in the constellation Pegasus. ISS appears again at 2.29 am in the South South West at 34°. Culmination at 2.30 am in the South South East at 45°. ISS disappears at 2.35 am in the Eastern horizon. Once more, after an orbit of approximately 90 minutes, ISS appears again at 4.01 am in the West. Culmination at 4.06 am in the South at 67°. ISS disappears at 4.11 am in the Eastern horizon.
The minor planet Ceres is in opposition to the Sun at 8.50 am. Ceres is visible with a small telescope or binocular in the constellation Sagittarius.
Saturday 25 July
Today in 1978 Louise Joy Brown, the first test tube baby was born in Oldham. And today the space craft Cassini does flyby the Saturn Moon Titan from a distance.
After midnight at 0.10 am the Moon is close to the planet Saturn. Separation is 5° or about 11 lunar diameters. At 0.20 am the Moon is close to the star Zuben Elakrab in Libra. The limb separation is 3° or 5 lunar diameters.
ISS appears at 1.37 am in the South East at 30° and already disappears after a few minutes at 1.42 am in the Eastern horizon. ISS appears again at 3.10 am in the West South West at 12°. Culmination at 3.13 am in the South at 66°. ISS disappears at 3.18 am in the Eastern horizon. ISS appears once more at 4.44 am in the West. Culmination at 4.49 am in the South South West at 48°. ISS disappears at 4.54 am at the East South East horizon. Close the morning off with a very bright Iridium flare at dawn at 5.04 am in the West South West at an altitude of 74° in the constellation Lacerta.
Sunday 26 July
The planet Uranus is stationary in the sky. And for your information … at 11.51 am equation of time is at minimum with -6.53 minutes. So the sundials are late. The equation of time reaches a minor minimum and the Sun culminates after the mean noon. At 5.30 pm the Moon’s Golden Handle is visible. Look up to 1.25 am for the Moon. The Sun rises on the Jura mountains, while Sinus Iridium is still in shadow. Take a small binocular to see the details on the Moon. The Moon is still rather close to Saturn in the low in the South.
At 11.09 pm a bright flare is visible in the West North West at altitude 20° in the constellation Coma Berenices. ISS appears shortly at 0.46 am in the East at 13° and disappears already after 3 minutes at 0.49 am at the Eastern horizon. ISS appears again at 2.18 am in the West South West at 32°. Culmination at 2.20 am at 59° in the South and disappears at 2.25 am in the East.
Be aware at about 2.35 am the Milky Way is good for observation! ISS appears once more at 3.51 am in the West. Culmination at 3.56 am in the South at 59° and disappears at 4.01 am at the East South East horizon.
Monday 27 July
Today in 1586 Sir Walter Raleigh brought the first tobacco to England from Virginia. Also today in 1586 potatoes were introduced to Britain by Sir Thomas Harriot, an English scientist and mathematician. Today the spacecraft Cassini makes it distant flyby of Saturn’s Moons Dione and Enceladus.
At 11.51 am the Moon in maximum Libration West. The Crater Grimaldi is tipped into view of the Earth.
At 10.50 pm an Iridium flare in the North at altitude only 8° in the constellation Auriga. Another flare at 11.13 pm in the West North West at altitude 18° in the constellation Coma Berenices. And once more a flare at 0.11 am in the West South West at altitude 42° in the constellation Hercules.
The International Space Station (ISS) appears at 1.27 am in the South East at 45° but disappears already after a few minutes at 1.32 am in the Eastern horizon.
At about 2.30 am the Milky Way is good for observation. ISS appears again at 2.59 am in the West at about 10°. Culmination at 3.03 am in the South at 66°. ISS disappears at 3.08 am in the Eastern horizon.
And we observe a few more flares. One at 3.13 am in the West North West at altitude 44° in the constellation Hercules. And one flare a few minutes after at 3.15 am West North West at altitude 42° also in the constellation Hercules.
At 4.37 am the Moon is in maximum Libration. ISS appears again at 4.34 am in the West. Culmination at 4.39 am in the South South West at 34°. ISS disappears at 4.44 am in the South East.
Tuesday 28 July
At 6.30 pm the Moon is in maximum declination South. The declination is -18.345°. An Iridium flare at 10.35 pm in the North at altitude 10° in the constellation Auriga. And another flare at 11.16 pm in the West North West at altitude 16° in the constellation Coma Berenices. ISS appears shortly at 0.35 am in the East at 18° and disappears after 4 minutes at 0.39 am in the Eastern horizon.
At 0.57 am the Moon is in maximum Libration South. The South Pole of the Moon is tipped into view of the Earth.
At 1.41 am an Iridium flare in the South at altitude 53° in the constellation Delphinus. ISS appears once more at 2.08 am in the West South West at 27°. Culmination at 2.10 am in the South at 67° and disappears at 2.15 am in the Eastern horizon.
The Milky Way is best to see around 2.25 am in the morning. Though, the observation is affected by the Moon with phase of 92%, just before Full Moon. A flare at 3.09 am in the West North West at altitude 42° in the constellation Hercules.
The meteor shower Beta-Cassiopeids is best seen from 10.50 pm to 3.30 am in the North East. The local hour rate is estimated at 4.8 and their velocity is 51.6km/s, which is considered as rather rapid. Look for the constellation Cassiopeia, “W” shape.
ISS appears once more at 3.41 am in the West. Culmination at 3.46 am in the South South West at 45°. ISS disappears at 3.51 am in the East South East horizon.
Wednesday 29 July
A double Iridium flare appearance at 10.19 pm. One in the North North West at altitude 14° in the constellation Auriga. And at the same time one in the West North West at altitude 13° in constellation Coma Berenices. At midnight the planet Mars is close to the star P78 Geminorum.
ISS appears shortly at 1.17 am in the South South East at 61° and disappears at 1.22 am in the Eastern horizon. The Milky Way is in the Zenith at about 2.25 am. The observation will be affected by the Moon though. The Moon phase is 97%, just before Full Moon. ISS appears again after its rotation of about 90 minutes at 2.49 am in the West. Culmination at 2.53 am in the South South West at 57°. ISS disappears at 2.58 am in the East South East horizon.
Look again for the meteor shower Beta-Cassiopeids. Best seen from 10.50 pm to 3.40 am. Local hour rate expected to be 5.8 and velocity is 51.6km/s, which is rather rapid. Maximum is not visible and is at 8 am. The stream is active from 3 July to 19 August.
ISS appears once more at 4.24 am in the West. Culmination at 4.29 am in the South South West at 22°. ISS disappears at 4.34 am in the South East horizon.
Get in touch with me via www.patrickpoitevin.weebly.com if you need more information.
Ashbourne SKY WATCH Special Rare atmospheric sightings
How come we see different colors in the sky when clear, sunny, cloudy, snowy, etc?
On a Derbyshire “normal day” we see the usual white light. At least when it is a clear sky. The sunlight penetrates into the eye and becomes blood red. Although you do not notice, the sunlight even goes through our eyelids. In general the field of vision is colored red. You will see this mainly on dark objects. You will notice this very well when you overshadow your eye and let it see freely. When you go back inside and are looking in the dimmed light, the retina remains tired by red light. The surroundings seem to be green. Or when we are in the hammock in the Sun, the eyes closed and protected by the eyelids, the scenery in the shadow seems green or green blue.
When the sky is colorful, it is mainly due to scattering of light, particles and/or pollution. How and why do the colors at Sunrise and Sunset appear? Then the light has an indirect route compared for when the Sun is high in the sky. The light particles split up in the atmosphere called scattering. The color of the sky by day, and with a clear sky, is blue because the blue color shines more across the edges than the longer wavelengths. At Sunset or Sunrise the light comes frontally from the Sun and bears off by refraction. Then the light travels a longer distance through the atmosphere so that most of the blue color is already scattered. The red color is dominant so that the color is in fact a mixture of gold, orange and red. The so called romantic evenings or mornings?
When the sky is covered with dark clouds, with exception of one open strip, then the color will be yellow. The irradiation of the light through the atmosphere is scattered per mile or kilometer so that a limited intensity of light remains. In other words, bigger wavelengths are not scattered enough by the air, which is irradiated by the Sun. Shorter wavelengths, on the contrary, are weakened too much when passing through the airway.
The maximum, the color that reaches us with the biggest power, moves more and more from blue to red, as the illuminated part of the air is further away from us. After a snow shower, there will be a green sky. At a cloudless sky, the green color gets mixed up with blue and together they produce white. When there are gaps in the blanket of clouds, various ranges of coloring can appear. When seen from altitude, as here from an airplane, the color of the sky varies from pale to dark at elevations approaching the zenith.
Over the rainbow …
A rainbow is an optical phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in our atmosphere. It takes the form of a multicolored arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun, but originate no further than 42 degrees above the horizon for observers on the ground. To see them at higher angles, an observer would need to be in an airplane or near a mountaintop since the rainbow would otherwise be below the horizon. The bigger the droplets which formed the rainbow, the brighter it will be. Rainbows are known to be most common near afternoon thunderstorms during the summer.
A single reflection of raindrops produces a rainbow with an angular size on the sky that ranges from 40° to 42° with red on the outside. Double rainbows are produced by two internal reflections with angular size of 50.5° to 54° with violet on the outside. Within the "primary rainbow", the lowest, and also normally the brightest rainbow, the arc of a rainbow shows red on the outer or upper part of the arc, and violet on the inner section. This rainbow is caused by light being reflected once in droplets of water. In a double rainbow, a second arc may be seen above and outside the primary arc, and has the order of its colors reversed; red faces inward toward the other rainbow, in both rainbows. This second rainbow is caused by light reflecting twice inside water droplets. The region between a double rainbow is dark. The reason for this dark band is that, while light below the primary rainbow comes from droplet reflection, and light above the upper or secondary rainbow also comes from droplet reflection, there is no mechanism for the region between a double rainbow to show any light reflected from water drops, at all.
A rainbow spans a continuous spectrum of colors; the distinct bands, including the number of bands, are an artifact of human color vision, and no banding of any type is seen in a black-and-white photograph of a rainbow. Only a smooth gradation of intensity to a maxima, then fading to a minima at the other side of the arc. For colors seen by a normal human eye, the most commonly cited and remembered sequence, is Newton's sevenfold red, orange, yellow, green, blue, indigo and violet. It is popularly memorized by mnemonics like Roy G. Biv. However, color-blind persons will see fewer colors. Rainbows can be caused by many forms of airborne water. These include not only rain, but also mist, spray, and airborne dew. Rainbows are the result of a combination of internal reflection and dispersive refraction of light in raindrops. Because rainbows are seen on the opposite side of the sky as the Sun, rainbows are more prominent the closer the Sun is to the horizon due to their greater distance apart.
Dogs in the sky?
Scattering ice crystals and other particles in the atmosphere are responsible for what we call halos, afterglows, coronas, rays of sunlight, and sun dogs. The variation in these kinds of phenomena is due to different particle sizes and geometries.
A halo also known as a nimbus, icebow or Gloriole is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky. Many are near the Sun or Moon but others are elsewhere and even in the opposite part of the sky. They can also form around artificial lights in very cold weather when ice crystals called diamond dust are floating in the nearby air.
Sun dogs known also as sundogs or mock suns, these brightly colored spots appear on either side of the Sun. Sun dogs are visible when the Sun is near the horizon and on the same horizontal plane as the observer and the ice crystals. As sunlight passes through the ice crystals, it is bent by 22 degrees before reaching our eyes. Sun dogs are caused commonly by plate-shaped hexagonal ice crystals in high and cold cirrus or cirrostratus clouds or, during very cold weather, by ice crystals called diamond dust drifting in the air at low levels. The crystals act as prisms, bending the light rays passing through them with a minimum deflection of 22°. If the crystals become horizontally aligned as they sink through air, sunlight is refracted to the left and right, which causes the two Sun dogs to be seen. Sun dogs can appear either as mirror images of the Sun on either side of its actual location, or as bright patches of light along partial halos horizontal to the Sun's location
As the Sun rises higher, the rays passing through the crystals are increasingly skewed from the horizontal plane. Their angle of deviation increases and the Sun dogs move further from the Sun. However, they always stay at the same elevation as the Sun. Sun dogs are red-colored at the side nearest the Sun. Farther out the colors grade to blue or violet. However, the colors overlap considerably and so are muted, rarely pure or saturated. The colors of the Sun dog finally merge into the white of the parhelic circle, if the latter is visible.
Circumzenithal arcs can be viewed when the Sun's elevation is lower than 32° above the horizon. Hexagonal plate-shaped ice crystals having a preferred orientation are responsible for these arcs. Their vivid colors are produced by the refraction of light rays passing through the 90° prisms of the oriented plates - light enters upper horizontal faces and passes out through vertical sides.
Atmospheric refraction causes astronomical objects to appear higher in the sky than they actually are. For this reason, sailors will only shoot a star when 20° or more above the horizon, and astronomers try to schedule observations when an object is highest in the sky.
Mirages are optical phenomena in which light rays are bent due to thermal variations in the refraction index of air, producing displaced or heavily distorted images of distant objects. Other optical phenomena associated with this include the Novaya Zemlya effect where the Sun appears to rise earlier or set later than predicted with a distorted shape. A spectacular form of refraction occurs with a temperature inversion called the Fata Morgana where objects on the horizon or even beyond the horizon, such as islands, cliffs, ships or icebergs, appear elongated and elevated, like "fairy tale castles".
And there is more … Subsun, Sun pillar, Cloud iridescence, Giant Mountains lens, …