Announcements of current events in Astronomy, published by Perth Observatory

'Night Sky' for 28.07.03 -


Tomorrow's new moon (no moon) begins a new lunar cycle. On Wednesday evening, the thin new crescent moon should be just visible near the horizon in the west-northwest at dusk, with Jupiter above and to the left of it. Have a look at about 6:20 to 6:25pm (moonset 6:35pm). From Thursday on, the waxing crescent moon will dominate the evening sky. Jupiter will carry on "going west" and will be lost in the sun's glare within a week or so.

Mercury's gaining altitude in the west-northwest at dusk, day by day. It's above and to the right of Jupiter, and will soon be the only planet you can see at nightfall. Mars rises just to the south of east at about 8:15pm. Its brightness and redness make it pretty obvious. It culminates around 2:40am, and is prominent well up in the western sky at dawn.

Sex seems to be all-pervading these days. The total number of stars in the universe has recently been estimated at 70 "sextillion". Apparently this means 70 thousand million million million. This information comes courtesy of Dr Simon Driver of the ANU Research School of Astronomy and Astrophysics.

The above information is provided by Perth Observatory, 337 Walnut Rd, Bickley 6076. Ph 9293-8255, fax 9293-8138.
A guided public tour of the Observatory facilities is held on the first Sunday of each month, at 2pm. That's this Sunday!


posted by Greg at 9:31 PM

'Night Sky' for July 21, 2003 -


Mercury is coming in for its best period of evening visibility this year. If the weather gods are kind, you should be able to watch Mercury sneaking up on Jupiter from below on Thursday, Friday and Saturday. The two planets will be close together on Saturday evening. You'll need a clear view to the west-northwest, at about 6:30 to 6:45pm. Mercury's obvious movement against the backdrop of the stars is the most dramatic example of planetary motion. "Planet" comes from the Greek for "wanderer".

Jupiter's really going west now, and will only be visible for another couple of weeks. It sets in the west-northwest at about 7pm. Mars rises from the eastern horizon around 8:45pm, culminates high up in the north about 3am, and dominates the western sky at dawn. The waning moon is at last quarter, the morning half-moon phase, today: 50% phase is at 3:01pm today. Note: that doesn't mean you can SEE it at 3:01pm - it doesn't rise until about 1am tonight. The waning crescent phases will continue on to new moon on the 29th.

The Canadian Space Agency launched its first space telescope on June 30th. It's a suitcase-sized but very sophisticated package dubbed MOST (the Microvariability and Oscillations of Stars mission). Described as a new-generation microtelescope, MOST combines clever technology with much-reduced costs and ease of handling and launching.

Information provided by Perth Observatory, 337 Walnut Rd, Bickley 6076. Phone 9293-8255, fax 9293-8138.

posted by Greg at 10:47 PM

'Night Sky' for July 14, 2003 -


See the full moon in twilight last night? To the "eyeball" observer it'll be just as full tonight, but rises about 30 min. after sunset. Full phase was actually at 3:21 this morning. So the moon is now waning - last quarter will be next Monday. Another object worth watching in the evenings is the International Space Station (ISS). The following predictions for the ISS come from "www.heavens-above.com" based at the German Space Operations Centre. Tonight: from low in SSW at 6:24pm, to 31º up in SE at 6:27pm, to fade in E at 6:28pm. Tomorrow: from low in WSW at 7:02pm, to 40º up in NW at 7:05pm, to fade in N at 7:06pm. Wednesday, in twilight: from low in SW at 6:04pm, to 68º up - almost overhead - in SE at 6:07pm, to low in NE at 6:09pm. Predictions are for Perth area and are approximate.

Jupiter is the brightest starlike object in the evenings, but not for long - it sets in the west-northwest at about 7:25pm. No other planet is bright enough to be seen, until Mars appears on the eastern horizon around 9pm. It's brighter than Jupiter, with a distinctive reddish colour. Mars culminates high up in the north about 3:30am, and is high in the western sky at dawn. NASA's "Opportunity" spacecraft is Mars-bound after more than a week of delays, so there are now four probes heading to the only other (almost) inhabitable planet.

Information provided by Perth Observatory, 337 Walnut Rd, Bickley 6076. Ph 9293-8255. Fax 9293-8138. Email perthobs@calm.wa.gov.au.
posted by Greg at 10:05 PM

'Night Sky' for 7.07.03 -


The much heralded opposition of Mars will be upon us in late August, but skywatchers will have noticed the red, bright planet by now: it risesin the east about 9:30pm. The Mars Express spacecraft launched by the ESA is now well on its way. It should arrive at Mars in December to release a robotic rover onto the surface to search for signs of past or present life. The new tracking station at New Norcia is playing a crucial role in this mission. Baby-boomers may recall the halycon days of the Carnarvon tracking station in the 1960s. The new ESA station, situated about 8km south of New Norcia, provides the major link between ESA and its spacecraft. The isolated position of WA means we can be very important in such missions when continuous communication is needed. Perth Observatory is often asked to join in international campaigns in order to cover parts of the sky not visible from the Northern Hemisphere. Expect some important Mars announcements in the coming months.

The Moon is waxing, with full moon due next Sunday night, the 13th: 100% phase is at 3:21am Monday. You can admire the big, bright moon on both Sunday and Monday evenings. On Sunday moonrise is about 40 min. before sunset, and on Monday moonrise is about 30 min. after sunset.

Sunday's full moon brings the triennial International Astronomical Union General Assembly. Sydney will see thousands of astronomers arriving from all around the world to discuss the latest astronomy research, and to plan programs for the future. This is the likely venue for important research results to be announced, so there should be substantial media coverage.

The Perth Observatory Star Viewing Nights get underway in late August to feature Mars at its closest. Bookings now are open: ph 9293-8255, fax 92938138, email perthobs@calm.wa.gov.au.

posted by Greg at 1:11 AM