The night sky

Crawley Astronomical Society Sky Notes May & June 2008

THE SUN

The Sun has has remained almost blank apart from one short lived spot in its southerm hemisphere,

only the third of cycle 24 which began in December 2007. There have been as a consequence no

bright Aurora. There is always the possibility of a sudden Flare or Coronal Mass Ejection.

The possibility of a more active Sun has increased in the last few days with unusually active

prominences being seen on the Solar limb. We can only wait to see what happens next

The Sun reaches its most Northerly point on 21st June , The Summer Solstice.

There will be a Solar Eclipse on 1st August --More details of the event will be in next months Sky Notes.

THE MOON

The Moon is Full on 20th May and 8th June and New on 3rd June and 3rd July.

We have just experienced a sever Earthquake in China along a seduction zone where the Indian

and Tibetan Plates meet.

It may not be appreciated the Moon not only raises tides within the Earths oceans , but also exerts

a force upon the rocks of the Earths crust which float above the Earths mantle.

As stresses build up along the fracture zones on the plate boundaries these tidal forces may be

the final trigger that sets of the rupture in the rocks that we term an Earthquake.

MERCURY.

Mercury is just finishing its best appearance of the year as an evening star. Viewing conditions

have been good on a number of nights which has enabled us to glimpse this elusive planet in the dusk.

The next favourable appearance of Mercury will be in late October when Mercury will be visible in

the dawn as a a morning star. For those who like visiting the Internet log on to NASA/ Messenger

for the latest close up pictures of this enigmatic planets surface...

VENUS.

Venus is too close to the Sun to observe. The planet reaches Superior Conjunction on 9th June .

(On the far side of its orbit from us and thereby directly behind the Sun)

Venus will not be visible again until September when it will return as an Evening Star.

THE EARTH

Mid Summer is when we await the twilight Noctulucent Clouds - usually low in the northern sky

close to the bright star Capella. This year they made their first appearance on 5th May.

Neil Bone has predicted 2008 will be a good year for these clouds formation .

Look north about 60 to 90 minutes after sunset to spot the clouds which may look similar to

Cirrus or Wave clouds with a blue haze surrounding them. It is thought they are composed of

ice frozen on to tiny meteor particles . They lie about 50miles above the Earth and are seen

because the sun is still lighting them when we below are in the earths shadow .

MARS.

In May Mars moves from Gemini into Cancer. Between the 22nd and 25th May Mars passes in front

of the open Star cluster Praespe also known as the Beehive . Binoculars will show the event well.

By June Mars will be lost in the evening twilight.

JUPITER

Jupiter rises just after midnight in mid May . Jupiter will not rise more than 17 degrees above the

horizon this summer . By early July Jupiter will rise just after sunset but viewing Jupiter will be

difficult as we will be seeing the planet through a long column of humid and turbulent air.

The most we can hope to see are its four major moons and perhaps the north and south

equatorial bands..

SATURN.

Saturn is in the evening sky in the constellation of Leo. As with Mars it is rapidly being hidden by the

summer twilight. By mid June Saturn will be too close to the Sun to observe.

THE STARS

The hours of darkness are short now . High in the south at dusk is the bright red star Arcturus

and below Spica the leading star of the constellation Virgo.

The Summer Triangle of Vega , Altair and Deneb now begin to dominate the late evening sky.

Running through this area of the sky is the summer Milky Way with its myriads of faint stars

so well seen in binoculars. Here is a rich hunting ground fror Nova which although most are faint

may spring a surprise and produce a NEW STAR easily seen with the naked eye.

N Morrison 13May 2008