July's clear nights provide an excellent opportunity to become familiar with the night sky. One of the best ways to do so is to download a monthly sky description from the Sydney Observatory website, go outside with the drink of your choice and an mp3 player and then settle down comfortably to watch the sky and listen to the description.
With these beautiful clear winter days we get plenty of calls about golden "comets" in the early morning or late afternoon. Sadly these celestial delights are nothing more that plane condensation trails reflecting the unscattered longer wavelength light from the sun.
Are these the same object? Q. "Hi im from bateau bay n.s.w.tonight 6.20pm i saw a meteor going from west to east fizzing out over the sea could this be a fragment of yesterdays report of a near miss of a much larger object , my sighting showed a brilliant long tale slow moving" A.
It can be difficult to explain the large scale of our solar system. Diagrams in books invariably are not to scale as the innermost planets like Venus and Earth are so much closer to the Sun than the outer planets like Jupiter and Saturn.
The main camera on the Hubble Space Telescope is the Advanced Camera for Surveys (ACS). In the middle of June power supply problems in the camera forced NASA engineers to shut down the camera to protect the CCD detectors.
Each new moon weekend a group of amateur astronomers from the Sutherland Astronomical Society head to a dark site at Bargo outside Sydney to do some serious observing. Last Saturday (24 June) Les Dalrymple thought that he had discovered an exploding star or supernova.
This Monday evening will be a great time to view the Moon as it is at first quarter phase, the phase when most detail is visible. The amateur group Sydney City Skywatchers will hold a Moon observing practical night at Sydney Observatory on Monday 3 July at 6:30 pm.
Q. John Tebbutt first made his name when he discovered a comet in 1861. Could you give me the official name for this comet? I know Tebbutt's name was in there, there were some numbers as well. Another comet discovered by him twenty years later, has I think the official name, Comet Tebbutt 1881 (III).
On Monday 3 July a space rock with the designation 2004 XP14 will pass relatively close to the Earth. The rock is between half and one kilometres in width, but there is no need to worry as at its closest it will still be 430,000 km away or just over the distance of the Moon from the Earth.
Q. Do you know of anywhere i can get details of the Solar and Lunar azimuth angles from Sydney? As i would like to make a model Stonehenge for the backyard. But of cause I can't use the original layout, being in a different lat.
Two new moons of Pluto were discovered in 2005 and confirmed by the Hubble Space Telescope earlier this year. Until now they were referred to as S/2005 P1 and S/2005 P2, names that do not roll smoothly off the tongue.
Today 21 June is the shortest day of the year and from now on days will become longer. However, that does not mean that the Sun rises earlier from now on. In fact, over the next week it will rise up to a minute later.
Too many badly directed lights are a concern to anyone involved in astronomy. Noone wants a dark city, but lights can be directed downwards and many lights are just badly directed decorative lights which do not add to anyone's feeling of security.