Latest Posts

A figure-of-eight

July 19, 2006

Q. At 12.00 midday each day (weather permitting) I mark the shadow cast by the top corner of the building. I have been recording this since Sept 23 2005, and the shape has taken a nice elongated figure 8 shape (infinity symbol).

How dark can we go?

July 18, 2006

This coming Friday and Saturday evenings (July 21 & 22) Sydney Observatory is holding its second annual Festival of the Stars. The Sydney Harbour Bridge floodlights will be turned off for the events and a number of City and North Sydney buildings will be turning off their exterior signage.

Double event at the Observatory

July 18, 2006

On Monday 7 August from 6:30 pm there will be a double event at Sydney Observatory. First there will be the opening of a spectacular photographic display. This is from the 2006 "David Malin" Awards that was held during the CWAS Astrofest in July.

Just how much fun can you have in one day!

July 13, 2006

Every School Holidays we hold numerous family events. Yesterday we ran our “Lost in Space Family Fun Day”. Aimed at children, all the activities were included in the ticket price of just $10 per child.

Surge on Sun

July 13, 2006

Sunspots on the Sun indicate regions of strong activity and magnetic fields. The number of spots tends to vary with a cycle of 11-years called, not surprisingly, the sunspot cycle. In 2006 the Sun is at a minumum in the cycle and there are generally few spots visible.

Listen to the night sky

July 11, 2006

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.

Fireball reports

July 7, 2006

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.

Solar system model and the stars

July 6, 2006

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.

Hubble camera working again

July 3, 2006

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.

A supernova discovered (almost)

June 28, 2006

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.

Moon night at Sydney Observatory

June 28, 2006

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.

19th century Australian astronomer John Tebbutt & his comets

June 28, 2006

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).

Close pass by space rock

June 28, 2006

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.

Backyard Stonehenge

June 26, 2006

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.