July Night Skies
JULY NIGHT SKIES
By Dr N T Jiwaji
ntjiwaji at yahoo.com
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· Rare Meteorite from Tanzania
· Phoenix has found water on Mar, and soil with nutrients to support life
· Seals that use stars for navigation
· Interplay of planets – 6th July bunch up
· Jupiter seen brilliant whole nigh 9th July
· Scorpio constellation dominates
· North and south pointers falling westwards
· Look for the International Space Station on 16th July
Ivuna Meteorite from Tanzania
Astronomy came home last month when news about the Ivuna meteorite that landed in Tanzania in 1938 flashed around the world after UK’s Natural History Museum bought a rare sample of this rare meteorite from a private collection in the US. It is one of only 9 meteorites of this type which holds clues to the formation of the solar system and understanding the origin of our solar system.
Water on Mars
Another exciting discovery is that of water on Mars! Phoenix Mars Lander spacecraft, which made a perfect landing on Mars, has found water ice just below the surface of Mars, raising hopes of finding traces of life in our nearest neighbor. The experimental chamber in the spacecraft tests for gases such as water vapour and carbon dioxide after heating the soil sample.
Human Travel to Mars
Presence of water also allows humans to think about visiting the planet since energy to return back to earth can be produced using the sun’s energy to produce electricity which in turn can be used to split the water into its components, Hydrogen and Oxygen which can be used to power the spacecraft back home.
The soil has also been found to be alkaline with traces of magnesium, sodium, potassium and other elements that can support life. It means Mars provides a conducive environment for life if it existed, exists or will exist.
Seals use stars
In another interesting story, seals have been shown to use astronomy to navigate in the wide expanses of the seas. They show “skyhopping” behavior when they pop out of water when they must be scanning the skies to look for familiar groups of stars to guide them at night (humans use groupings which we call constellations). Read universetoday.com for many other interesting astronomy news stories from space.
Planetary interplay
The month starts with a close encounter of Mars and Regulus, the neck star of Leo. Over the past month, Mars has been inching slowly closer to Regulus with a climax on 6th July when four celestial bodies bunch up. Mars and Regulus will be joined by Saturn and Moon to form a closely clumped group. A few days later, on 11th July, Saturn and Mars will be closest together within less than a degree visible in the sky as a gap of less than a finger held at arm length. Be ready for even more close encounters at the beginning of August between Moon and Venus on 2nd August and the next day
This month ushers in a new planet in the evening skies, Venus, which becomes visible in the western skies just after sunset towards the end of the month. This planet is set to rival Jupiter that is already visible in the east. By 9th July Jupiter will rise at sunset so it can be seen throughout the night and sets the next morning in the west at sunrise. During evening hours though, the two planets will rival each other. While Venus dazzles because it is closest to us, Jupiter, though ten times farther away, reflects sunlight brilliantly because it is the largest planet.
Moon
New Moon is on 3rd July. After its rendezvous for the spectacular clumping on 6th, it will attain Quarter phase on 10th. This is the best time to view it through binoculars or a telescope since its craters can be seen in high contrast due to long shadows they cast from the nearly horizontal sun. After that it rises high and far into the eastern skies for a close approach to Jupiter on 16th and 17th.
Next month on 1st August will bring a total solar eclipse across Serbia in Russia and in China when the moons shadow covers up the sun. However it will not be visible here in Tanzania, thought the August 16th partial lunar eclipse will be visible in Tanzania in the early part of the night around 10 pm.
Stars and Constellations
The Big Dipper and the Southern Cross, which are the north and south direction pointers respectively, are still high enough in the evening skies. Scorpius is the easiest constellation to recognize this month in overhead sky. Its three stars forming tentacles, the red star Antares its neck and a long winding trail of stars make its tail that ends in a close stellar pair forming the sting. Scorpius is unmistakable to even a casual stargazer so use this month’s golden opportunity to start (or continue) your stargazing hobby by independently identifying this constellation and continue to nearby ones! Below Scorpius, try to identify Sagittarius (the archer). This constellation marks the direction of the center of our Milky Way galaxy and you will notice dense concentration of stars here. The band marking the Milky Way contains numerous stars and dust patches and stretches from the southwest, passing through the Southern Cross and Sagittarius and up to Cygnus (the swan) in the northeast. Leo (the lion) with its distinctive inverted question mark head is low in the western horizon and will be lost after this month.
Among the brightest stars noticeable in the July skies are: Alpha and Beta Centauri in the south form the pair that points continuously towards the Southern Cross; the fourth brightest star Arcturus is overhead towards the north and the fifth brightest star Vega rises in the northeast. Other bright stars you will easily notice are Altair which rises in the east and Spica, the brightest star in the Virgo constellation can be seen almost overhead towards the west.
Satellites
The International Space Station (ISS) will trace a brilliant path shining at magnitude -2.5 (as bright as Venus) on 16th July rising at around 7 pm in south west and rising in the sky to about 55 degrees, until it sets in the north east after 5 minutes. Refine your timings by going to http://spaceweather.com/flybys and choosing the correct location. Another good website for information about the ISS, Hubble and many other satellites is http://heavens-above.com where you will also need to choose your location.
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