January 2009, Pedro Castle 7.00 pm

The extremely bright object high in the western sky is the planet Venus.
Venus is the second-closest planet to the Sun, orbiting it every 224.7 Earth days.
The planet is named after Venus, the Roman goddess of love. It is the brightest natural object in the night sky, except for the Moon, reaching an apparent magnitude of −4.6. Because Venus is an inferior planet from Earth, it never appears to venture far from the Sun: its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it is often called the Morning Star or the Evening Star.
Classified as a terrestrial planet, it is sometimes called Earth's "sister planet," because they are similar in size, gravity, and bulk composition. Venus is covered with an opaque layer of highly reflective clouds of sulfuric acid, preventing its surface from being seen from space in visible light; this was a subject of great speculation until some of its secrets were revealed by planetary science in the twentieth century. Venus has the densest atmosphere of all the terrestrial planets, consisting mostly of carbon dioxide, as it has no carbon cycle to lock carbon back into rocks and surface features, nor organic life to absorb it in biomass. It has become so hot that the earth-like oceans that the young Venus is believed to have possessed have totally evaporated, leaving a dusty dry desertscape with many slab-like rocks. The best hypothesis is that the evaporated water has dissociated, and with the lack of a planetary magnetic field, the hydrogen has been swept into interplanetary space by the solar wind. The atmospheric pressure at the planet's surface is 92 times that of the Earth.
Venus rotates once every 243 days—by far the slowest rotation period of any of the major planets. To an observer on the surface of Venus the time from one sunrise to the next would be 116.75 days.
As the brightest point-like object in the sky, Venus is a commonly misreported 'unidentified flying object'. U.S. President Jimmy Carter reported having seen a UFO in 1969, which later analysis suggested was probably the planet, and countless other people have mistaken Venus for something more exotic.
As it moves around its orbit, Venus displays phases in a telescopic view like those of the Moon: In the phases of Venus the planet presents a small "full" image when it is on the opposite side of the Sun. It shows a larger "quarter phase" when it is at its maximum elongations from the Sun. Venus is at its brightest in the night sky and presents a much larger "thin crescent" in telescopic views as it comes around to the near side between the Earth and the Sun. Venus is at its largest and presents its "new passes" when it is between the Earth and the Sun. Since it has an atmosphere it can be seen in a telescope by the halo of light refracted around the planet.
Venus was known in the Hindu Jyotisha since early times as the planet Shukra.
In the West, before the advent of the telescope, Venus was known as a 'wandering star'.
Several cultures historically held its appearances as a morning and evening star to be those of two separate bodies. Pythagoras is usually credited with recognizing in the sixth century BC that the morning and evening stars were a single body, though he thought that Venus orbited the Earth. When Galileo first observed the planet in the early 17th century, he found that it showed phases like the Moon's, varying from crescent to gibbous to full and vice versa. This could be possible only if Venus orbited the Sun, and this was among the first observations to clearly contradict the Ptolemaic geocentric model that the solar system was concentric and centered on the Earth.
There is a spacecraft operating in orbit around the planet now. Venus Express probe was designed and built by the European Space Agency. Launched on November 9, 2005 by a Russian Soyuz-Fregat rocket it successfully assumed a polar orbit around Venus on April 11, 2006. The probe is undertaking a detailed study of the Venusian atmosphere and clouds, and is also mapping the planet's plasma environment and surface characteristics, particularly temperatures.
As one of the brightest objects in the sky, Venus has been known since prehistoric times and as such has gained an entrenched position in human culture. It is described in Babylonian cuneiform texts such as the Venus tablet of Ammisaduqa, which relates observations that possibly date from 1600 BC. The Babylonians named the planet Ishtar , the personification of womanhood, and goddess of love.
The Ancient Egyptians believed Venus to be two separate bodies and knew the morning star as Tioumoutiri and the evening star as Ouaiti.
Likewise believing Venus to be two bodies, the Ancient Greeks called the morning star, Phosphoro, the "Bringer of Light". The evening star they called Hesperos, the "star of the evening", but by Hellenistic times, they realized the two were the same planet. Hesperos would be translated into Latin as Vesper and Phosphoros as Lucifer ("Light Bearer"), a poetic term later used to refer to the fallen angel cast out of heaven.
The Romans would later name the planet in honor of their goddess of love, Venus, whereas the Greeks used the name of her Greek counterpart, Aphrodite (Phoenician Astarte).
Venus was important to the Maya civilization, who developed a religious calendar based in part upon its motions, and held the motions of Venus to determine the propitious time for events such as war. They named it Noh Ek', the Great Star, and Xux Ek', the Wasp Star. The Maya were aware of the planet's synodic period, and could compute it to within a hundredth part of a day.
The Maasai people named the planet Kileken, and have an oral tradition about it called The Orphan Boy.
Venus is important in many Australian aboriginal cultures, such as that of the Yolngu people in Northern Australia. The Yolngu gather after sunset to await the rising of Venus, which they call Barnumbirr. As she approaches, in the early hours before dawn, she draws behind her a rope of light attached to the Earth, and along this rope, with the aid of a richly decorated "Morning Star Pole", the people are able to communicate with their dead loved ones, showing that they still love and remember them. Barnumbirr is also an important creator-spirit in the Dreaming, and "sang" much of the country into life.

December 30th 2008

The prominent constellations of winter are now rising in the early part of the evening, Taurus, the Bull, illustrated above, being among the first.
Taurus is marked by a V-shaped pattern of stars that outlines the bull's face. Bright red Aldebaran, the "eye" of the bull, stands at one point of the V. This pattern is part of a cluster of stars called the Hyades — the second-closest star cluster to Earth. It consists of several hundred stars that lie about 130 light-years away.
Aldebaran outshines all the other stars that outline the bull's face. But Aldebaran isn't a member of the Hyades cluster — it just lies in the same direction. It's about 70 light-years away, half as far as the stars of the Hyades. Aldebaran is a red-giant — an old, bloated star that's used up most of its nuclear fuel. It's much larger and much brighter than our own middle-aged Sun.
On the other side of the sky, Venus is shining bright in the west.

November 30th, 2008, Pedro Castle 6.30 p.m.

I don’t know about you, but I have seen very little in the media about India’s successful mission to the Moon.
“In a historic event, the Indian space programme achieved a unique feat today (November 14, 2008) with the placing of Indian tricolour on the Moon's surface on Pandit Jawaharlal Nehru's birthday. The Indian flag was painted on the sides of Moon Impact Probe (MIP), one of the 11 payloads of Chandrayaan-1 spacecraft, that successfully hit the lunar surface today at 20:31 hrs (8:31 pm) IST. This is the first Indian built object to reach the surface of the moon. The point of MIP's impact was near the Moon's South Polar Region. It may be recalled that the modern Indian space programme was initiated in 1962 when Pandit Jawaharlal Nehru was the Prime Minister of India.”
As of writing this, everything is going as planned; the instruments have been activated and are operating correctly. And Mumbai is suffering.

Venus and Jupiter have been getting closer to each other and on viewing night will be joined by the crescent moon. Look to the west after dusk and watch the planets approach each other.
Dec. 1st is the best night of all. The now-15% crescent Moon moves in closer to form an isosceles triangle with Venus and Jupiter as opposing vertices. The three brightest objects in the night sky will be gathered so tightly together, you can hide them all behind your thumb held at arm's length.

Pedro Castle, October 30th 6.30 p.m.

This is what the sky will look like at 7.00 on viewing night.
I am going to continue with the theme of the Summer Triangle while it is still high in the early evening sky.
The alpha star of Aquila, Altair, is a vertex of the Summer Triangle asterism.
Aquila (Latin: eagle; sometimes named the Vulture), is one of the 48 constellations listed by Ptolemy, also mentioned by Eudoxus (4th century BC) and Aratus (3rd century BC) and now also part of the list of 88 constellations acknowledged by the IAU. It lies roughly at the celestial equator.
NASA's Pioneer 11 mission, which flew by Jupiter and Saturn (in 1974 and 1979 respectively) will pass near one of the stars in the constellation in about four million years.

The constellation resembles a wide winged, soaring, short necked, bird, which the ancients identified as an eagle. In classical Greek mythology, it was identified as the eagle which carried the thunderbolts of Zeus and was sent by him to carry the shepherd boy Ganymede who he desired, represented by the neighbouring Aquarius, to Mount Olympus where he became the wine-pourer for all the gods. This explains why the largest moon of Jupiter was called Ganymede, Jupiter being the Roman name of Zeus. The eagle was used to carry or retrieve the lightning bolts that were thrown by Zeus.
In the Chinese love story of Qi Xi, Niu Lang (Altair) and his two children (β and γ Aquilae) are separated forever from their wife and mother Zhi Nu (Vega in Lyra, another vertex of the Summer Triangle) who is on the far side of the river, the Milky Way.
In Hinduism, the constellation Aquila is identified with the half eagle, half human deity, Garuda.
Altair (α Alpha Aquilae) is the brightest star in the constellation Aquila and the twelfth brightest star in the nighttime sky, at visual magnitude 0.77. It is an "A" type or white star located 17 light-years (5.2 pc) away from Earth, one of the closest stars visible to the naked eye.
The name "Altaïr" is Arabic for "the bird". The spelling "Atair" is also used frequently. The name was given by Arabic astronomers and adopted by Western astronomers.

Pedro Castle,Thursday, 2nd October, 7.00 p.m.

As darkness falls on viewing night, the constellation of Cygnus, the Swan, is overhead, in the orientation that is shown above, up being north.
Because of the pattern of its main stars, it is sometimes known as the Northern Cross (in contrast to the Southern Cross).
One of the most recognizable constellations of the northern summer and autumn, it resembles a swan flying south along the Milky Way. Albireo, a double star with blue and yellow components is at the "head". Deneb, its brightest star, is at the tail and is one star of the summer triangle.
The Summer Triangle is an astronomical asterism involving an imaginary triangle drawn on the northern hemisphere's celestial sphere, with its defining vertices at Altair, Deneb, and Vega. This triangle connects the constellations of Aquila, Cygnus, and Lyra.
Looking toward the south, Jupiter, the fourth brightest object in the sky, is in the constellation of Sagittarius. Venus is setting in the west.

Wednesday 3rd September 2008. Pedro Castle 7.30 pm

There are “winds” in space as well as around the Cayman Islands, albeit of a very different nature.
A stellar wind is a flow of neutral or charged gas ejected from the upper atmosphere of a star.
Different types of stars have different types of stellar winds.
Post-main sequence stars nearing the ends of their lives often eject large quantities of mass in massive slow winds. These include red giants and supergiants, and asymptotic giant branch stars. These winds are likely to be driven by radiation pressure on dust condensing in the upper atmosphere of the stars.
G stars like the Earth's Sun have a wind driven by their hot, magnetized corona. The Sun's wind is called the solar wind. These winds consist mostly of high-energy electrons and protons (about 1 keV) that are able to escape the star's gravity because of the high temperature of the corona.
Massive stars of types O and B have stellar winds with lower mass loss rates but very high velocities. Such winds are driven by radiation pressure on the resonance absorption lines of heavy elements such as carbon and nitrogen. These high-energy stellar winds blow stellar wind bubbles.
Although stellar winds from main sequence stars do not strongly influence the evolution of the stars, during the later, post-main sequence phase, mass lost by stellar winds can decide the fate of the star. Many intermediate mass stars become white dwarfs at the ends of their lives rather than exploding as supernovae only because they lost enough mass in their winds.
A Stellar wind bubble is the astronomical term usually used to describe a cavity light years across filled with hot gas blown into the interstellar medium by the high-velocity (several thousand km/s) stellar wind from a single massive star of type O or B. Weaker stellar winds still blow bubble structures though, and these are also called astrospheres.
The heliosphere blown by the solar wind, within which all the major planets of the Solar System are embedded, is in fact a small example of a stellar wind bubble.

Above is a Hubble Space Telescope image of a bubble-like cavity, called N44F, 35 light-years in diameter, which is being inflated by a stellar wind from a very hot star once buried inside a cold dense cloud. The central star in N44F is ejecting mass at a rate greater than a 100 million times that in the solar wind. The particles in this stellar wind move at 7 million kilometers per hour, compared with about 1.5 million km per hour in the case of the Sun. N44F is located about 160,000 light-years away in the Large Magellanic Cloud.
Jupiter will be high in the south on Wednesday, easily spotted in the Teapot of Sagittarius, which is pouring onto the tail of the scorpion, Scorpius.

Pedro Castle, Monnday, 4th August 2008

The constellation Hercules is overhead when darkness falls. Although it holds no first magnitude stars, it is easy to distinguish the “Keystone” asterism.
Hercules contains two of the most conspicuous globular clusters: M13, the brightest globular cluster in the northern hemisphere, and M92.
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is derived from the Latin globulus—a small sphere. A globular cluster is sometimes known more simply as a globular.
Globular clusters, which are found in the halo of a galaxy, contain considerably more stars and are much older than the less dense galactic, or open clusters, which are found in the disk. Globular clusters are fairly common; there are about 158 currently known globular clusters in the Milky Way, with perhaps 10–20 more undiscovered. Large galaxies can have more: Andromeda, for instance, may have as many as 500. Some giant elliptical galaxies, such as M87, may have as many as 10,000 globular clusters. These globular clusters orbit the galaxy out to large radii, 40 kiloparsecs (approximately 131 thousand light-years) or more.
The Great Globular Cluster in Hercules was discovered by Edmond Halley in 1714, and catalogued by Charles Messier on June 1, 1764.
Its real diameter is about 145 light-years, and at its distance of 25,100 light years, its angular diameter of 20' corresponds to a linear 145 light years - visually, it is perhaps 13' large, and it is composed of several hundred thousand stars.
There are seven stars in Hercules known to be orbited by extrasolar planets. They were discovered in 1996, 2005, 2006, and the last four in 2007.
Four of the planets in our solar system are visible in the night sky, Venus setting in the west, closely followed by Saturn and Mars, and Jupiter can be seen in the south, close to the “Teapot” of Sagittarius.