Astroblog

The First Quarter Moon is Thursday, May 20.

Whole sky at 18:49 ACST  (90 minutes after

  

Similar views will be seen elsewhere at the equivalent local time (90 minutes after sunset). click to embiggen.

Evening twilight sky on Thursday May 13 looking west as seen from Adelaide at 17:49 ACST (30 minutes after sunset). Venus is just above the horizon, not far from the crescent Moon with Mercury above. You will need a clear level horizon and probably binoculars to see Venus.




Similar views will be seen throughout Australia at the equivalent local time (30 minutes after sunset, click to embiggen).

 

Evening sky at 18:49 ACST (90 minutes after sunset), on Sunday May 16 facing north-west as seen from Adelaide.

Mars is two finger-widths from the crescent Moon.


 

 

 

 

Similar views will be seen elsewhere in Australia at the equivalent local time 

 

  

Labels: weekly sky

# posted by Ian Musgrave @ 11:03 pm 0 comments

The ISS passing through Canis Major (Sirius lower far right) as seen from Adelaide on the evening of Saturday 8 May at 21:04-21:05 ACST. Click to embiggen.	Tonight's ISS pass between the Southern Cross and the False Cross in the late twilight as seen from Adelaide (Sunday 9 May at 18:17-18:22 ACST. Click to embiggen.

Failed to see the tumbling rocket booster CZ-5B which splashed down near the Maldives. Caught two bright and impressive passes of the ISS on my new Canon IXUS 285 HS, my old workhorse's battery compartment has failed, so I have had to replace it. 

Still getting used to the new one and it's quirks (long shutter mode seems stuck on ISO 80, no matter what I do, making it pretty useless, although it comes out okay stacked), which is why the first one is off centre. 

Stacked in Deep-Sky stacker which dropped frames for no discernible reason, brightness adjusted with GIMP. 

Labels: astrophotography, ISS, Satellite, unaided eye

# posted by Ian Musgrave @ 10:17 pm 0 comments

Labels: eta aquarid, Meteors, unaided eye

# posted by Ian Musgrave @ 9:48 pm 0 comments

The ISS as seen from Brisbane  on the evening of  Sunday 9 May  at 18:48 AEST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.	The ISS  as seen from Adelaide on the evening of  Sunday 9 May at 18:15:30 ACST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.	The ISS as seen from Perth on the evening of  Sunday 9 May at 18:19 AWST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.
All sky chart showing local times from Heavens Above for Sunday 9 May for Brisbane.	All sky chart showing local  times from Heavens Above for Sunday 9 May for Adelaide.	All sky chart showing local times from Heavens Above for  Sunday 9 May for Perth.

Passes from Hobart (AEST)

Passes from Melbourne (AEST)

Passes from Perth (AWST)

Passes from Sydney (AEST)

When and what you will see is VERY location dependent, so you need to use  Heavens Above  to get site specific predictions for your location, a small difference in location can mean the difference between the ISS passing over a star or planet or missing it completely. As always, start looking several minutes before the pass is going to start to get yourself oriented and your eyes dark adapted. Be patient, there may be slight differences in the time of the ISS appearing due to orbit changes not picked up by the predictions. Use the most recent prediction for your site.

Labels: ISS, Satellite, unaided eye

# posted by Ian Musgrave @ 10:11 pm 2 comments

The New Moon is Wednesday, May 12. The Moon is at apogee, when it is furthest from the Earth, at this time.

Morning sky on Saturday

  

Similar views will be seen elsewhere at the equivalent local time (90 minutes after sunset). click to embiggen.

Evening twilight sky on Thursday May 13 looking west as seen from Adelaide at 17:49 ACST (30 minutes after sunset). Venus is just above the horizon, not far from the crescent Moon with Mercury above. You will need a clear level horizon and probably binoculars to see Venus.




Similar views will be seen throughout Australia at the equivalent local time (30 minutes after sunset, click to embiggen).

Evening sky at19:06 ACST (90 minutes after sunset), on Monday May 10 facing north-west as seen from Adelaide.

Mars is less than half a finger-width from Mebsuta, epsilon geminorum.


 

 

 

Similar views will be seen elsewhere in Australia at the equivalent local time 

The north-eastern Horizon as seen from Adelaide at 4:30 am ACST, the eta Aquariid radiant is marked with a starburst. Similar views will be seen elsewhere in Australia at the equivalent local time (click to embiggen). 

 

The eta Aquariid meteor shower, which is produced by the debris from Halley’s Comet, is best seen on the mornings of the 7th, 8th and 9th from 3:00 AM to 5:00 AM

The eta Aquarids are debris from Halleys comet. the best time to see the eta Aquariid meteor shower between around 4 and 5 am, when Aquarius is fairly high above the horizon and the crescent Moon is low. You may see between a meteor every 3-4  minutes at this time. The radiant of the shower is about five hand-spans up from the eastern horizon, and three hand-spans to the left of due east at 4:30 am (see diagram above). More details and rate predictions for different cities here.

  

Labels: weekly sky

# posted by Ian Musgrave @ 8:42 pm 0 comments

Morning sky on Monday,  May 3 showing the eastern sky as seen from Adelaide  at 4:30 am ACST. Saturn and Jupiter form a line in the morning sky with the waning Moon above. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes before sunrise), click to embiggen.	Morning sky on Tuesday,  May 4 showing the eastern sky as seen from Adelaide  at 4:30 am ACST. Saturn and Jupiter form a line in the morning sky with the Last Quarter Moon being close to Saturn. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes before sunrise), click to embiggen.
Morning sky on Wednesday,  May 5 showing the eastern sky as seen from Adelaide  at 4:30 am ACST. Saturn and Jupiter form a line in the morning sky and the waning Moon is close to Jupiter. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes before sunrise), click to embiggen.	Morning sky on Thursday,  May 6 showing the eastern sky as seen from Adelaide  at 4:30 am ACST. Saturn and Jupiter form a line in the morning sky with the waning Moon is close to Jupiter. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes before sunrise), click to embiggen.

If you are up early in the morning from the 3rd to the 6th you will see a beautiful dance between the planets Saturn and Jupiter and the waning Moon. On the 3rd the waning Moon forms a line with Saturn and Jupiter. On the 4th the last quarter Moon is close to Saturn. On the 5th the Moon is between Saturn and Mars and on the 6th the crescent Moon forms a line with Saturn and Jupiter again.You can see the three objects from 2 am (local time) on.

Labels: Jupiter, Moon, Saturn, unaided eye

# posted by Ian Musgrave @ 12:41 am 0 comments

The north-eastern Horizon as seen from Adelaide at 4:30 am ACST, the eta Aquariid radiant is marked with a starburst. Similar views will be seen elsewhere in Australia at the equivalent local time (click to embiggen). 

While the peak is on the morning of the 6th during daylight, the peak is really broad and viewing from the 7-9 will give you decent rates (see table below). Based on the NASA meteor flux program (see below) and my own excel spreadsheet using Jennisken's eta Aquariid stream parameters the best rates will be seen from Australia on the mornings of the 8th and 9th (see table below, but the 7th is very worthwhile too, even the 10th if the other nights are clouded out, as you can see the rate difference between the nights is fairly marginal).

The waning Moon is very close to the radiant on the 6th and the 7th, even on the 8th and 9th the crescent Moon’s light will have an effect so try and find a position to watch the meteors where the Moon is blocked from view,

People in the suburbs should see a meteor around once every 6 minutes, and in the country about once every 3 minutes. The radiant of the shower is about five hand-spans up from the eastern horizon, and three hand-spans to the left of due east at 4 am (see spotter chart at 4:30 am above).

Weather prediction looks good with clear mornings for most of Australia (except the bit where I live)

You may have read that this year the eta Aquariids have a predicted ZHR of 50 meteors. The figure ZHR is zenithal hourly rate. This is the number of meteors that a single observer would see per hour if the shower's "point of origin", or radiant, were at the zenith and the sky was dark enough for 6.5-magnitude stars to be visible to the naked eye.

In practice, you will never see this many meteors as the radiant will be some distance below the zenith. Also, unless you are out deep in the countryside, the darkness will be less than ideal. How many are you likely to see in reality? 

The table below gives predictions below for various towns, but they are only predictions and while based on average steam density there may be some differences year to year, but good rates were seen in previous years, and dark sky sites may possibly see one meteor every 4-5 minutes or so. There were many bright ones reported with persistent trains in 2014. People in the suburbs maybe will see less, but at least one every 6 minutes should be possible. 

Predicted meteor rates for selected towns (taken from NASA shower Flux estimator below). If your city is not on the list you can expect a meteor rate similar to the closest city to you in latitude.

Town	Morning May 7	Morning May 8	Morning May 9
Adelaide	14 meteors/hr	16 meteors/hr	15 meteors/hr
Brisbane	15 meteors/hr	17 meteors/hr	16 meteors/hr
Darwin	16 meteors/hr	18 meteors/hr	17bmeteors/hr
Perth	15 meteors/hr	17 meteors/hr	15 meteors/hr
Melbourne	13 meteors/hr	16 meteors/hr	15 meteors/hr
Hobart	13 meteors/hr	16 meteors/hr	15 meteors/hr
Sydney	14 meteors/hr	17 meteors/hr	15 meteors/hr

The radiant of the shower is about five hand-spans up from the eastern horizon and three hand-spans to the left of due east at 4 am (see above for a spotter chart at 5 am). When looking, be sure to let your eyes adjust for at least 5 minutes so your eyes can be properly adapted to the dark.

Don't look directly at the radiant site, because the meteors will often start their "burn" some distance from it, but around a hand-span up or to the side. The best way to watch the Eta Aquariids is to let your eye rove around the entire patch of the sky above the north-east horizon, between the only two obvious bright stars in the northeast, Altair and Fomalhaut, and Jupiter and Saturn as the centre of your field (again, see the spotter chart at 4:30 am above).

Be patient, although you should see an average of a meteor every 3 to 6 minutes, a whole stretch of time can go by without a meteor, then a whole bunch turn up one after the other.

Make yourself comfortable, choose an observing site that has little to obstruct the eastern horizon, have a comfortable chair to sit in (a banana lounger is best), or blankets and pillows. Rug up against the cold.  A hot Thermos of something to drink and plenty of mosquito protection will complete your observing preparations. As well as meteors, keep an eye out for satellites (see Heavens Above for predictions from your site).  The Milky way will arch above you, with Jupiter and Saturn just above te radiant.

Use the NASA  meteor shower flux estimator for an estimate of what the shower will be like from your location (you may need to enter your longitude and latitude, surprisingly, while Adelaide and Brisbane are hard-wired in, Sydney and Melbourne are not). See the image to the left for typical output. The peak is rather sharp.

Unfortunately, both Chrome and Firefox have changed their security settings to prevent plugins from running, and the flux estimator only runs under Internet Explorer now.

You need to choose 31 Eta Aquariids and remember to set the date to  7-8 or 8-9 May 2021 and turn off daylight saving time. You can follow the progress of the shower at the IMO live Aquariid site.

Guides for taking meteor photos are here and here.

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

Labels: eta aquarid, Meteors, unaided eye

# posted by Ian Musgrave @ 10:21 pm 1 comments

The planetary action moves to the evening sky with Mercury and Venus returning. Saturn and Jupiter put on a good show in the morning early in the month and begin to appear in the evening skies later in the month.

1 May; Mars in a binocular distance of the open cluster M35. 4 May; Saturn close to the crescent Moon in the morning. 5 May; Saturn, Jupiter and the crescent Moon form a triangle in the morning. 6 May; Jupiter above the crescent Moon in the morning. 7-8 May; Eta Aquariid meteor shower. May 12; Moon at Apogee. May 13; crescent Moon between Mercury and Venus low in the twilight. 14 May, crescent Moon above Mercury. May 16; Mars and crescent Moon close. May 26; Moon at perigee (perigee Full Moon, "super" Moon) with total Lunar eclipse.

 Mercury returns to the evening twilight and is visible after the first week of May. On the 13th the thin crescent Moon forms a line with Venus and Mercury low in the twilight, best seen half an hour after sunset with a level, unobstructed western horizon, you may need binoculars to see Venus.

Venus returns to the evening skies being visible low in the twilight from around the 10th on. On the 13th the thin crescent Moon forms a line with Venus and Mercury low in the twilight, best seen half an hour after sunset with a level, unobstructed horizon, you may need binoculars to see Venus. 

Mars  iis visible low in the north-western to western evening sky. Mars is long past opposition, but despite being as bright as gamma crucis it is still readily identifiable from its colour. Mars is low above the western horizon, best seen an hour and a half after sunset. Mars is in Gemini this month. On the 1st Mars forms a triangle with the brightish stars mu and eta geminorum, and is within a binocular field of the open cluster M35. 

 Jupiter begins to rise before midnight from mid-month but is still best seen in the morning. On the 4th, 5th and 6th the crescent Moon, Saturn and Jupiter have interesting encounters. On the 3rd the Moon and two planets form a line, On the 4th the last quarter Moon is close to Saturn then on the 5th the crescent Moon is between Saturn and Jupiter (but much closer to Jupiter) finally on the 6th the thin crescent Moon is below Jupiter forming a line with the two planets again. Then again on the 30th the moon is above Saturn and on the 31st the Moon is between Saturn and Jupiter.

Saturn begins to rise before midnight from the beginning of the month but is still best seen in the morning. On the 4th, 5th and 6th the crescent Moon, Saturn, and Jupiter have interesting encounters. On the 3rd the Moon and two planets from a line, On the 4th the last quarter Moon is close to Saturn then on the 5th the crescent Moon is between Saturn and Jupiter (but much closer to Jupiter) finally on the 6th the thin crescent Moon is below Jupiter forming a line with the two planets again. Then again on the 30th the moon is above Saturn and on the 31st the Moon is between Saturn and Jupiter. Apogee April 15; Moon at perigee April 28 (1 am 11 hours after Full so a super moon, May will be better).

The Eta Aquariid meteor shower officially peaks after sunrise on the morning of the 6th (Australian time), for Australia the best time to see the eta-Aquariids is in the early mornings of May 7, 8 and 9, between around 4 and 5 am, when Aquarius is fairly high above the horizon.

May 12; Moon at Apogee. May 26; Moon at perigee (perigee Full Moon, "super" Moon) with total Lunar eclipse.

You don't need special filters or fancy equipment to watch the lunar eclipse, you just need your eyes and somewhere comfortable to sit and watch. Watching the shadow of earth creep across the Moons face is quite entrancing. The moon doesn't go completely dark, but will be a deep coppery red due to light scattered from Earth's atmosphere. The eclipse will start in the early evening (twilight WA) and is visible throughout Australia. 

Labels: southern skywatch

# posted by Ian Musgrave @ 8:15 am 0 comments

The Last Quarter Moon is Tuesday, May 4.

Morning sky on Wednesday

  

Similar views will be seen elsewhere at the equivalent local time (90 minutes after sunset). click to embiggen.

Evening sky at 19:06 ACST  (90 minutes after sunset), on Saturday, May 1  facing north-west as seen from Adelaide.  

Mars forms a triangle with the brightish stars mu (Tejat) and eta geminorum, and is within binocular distance of M35. The inset shows the approximate binocular view at this time. 


Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes after sunset), click to embiggen.

   

The eta Aquariid meteor shower peaks on the morning of 6 May, sadly after sunrise in Australia, although good rates will be seen on the mornings of the 7th, 8th and 9th from 3:00 AM to 5:00 AM

The eta Aquarids are debris from Halleys comet. the best time to see the eta Aquariid meteor shower between around 4 and 5 am, when Aquarius is fairly high above the horizon and the crescent Moon is low. You may see between a meteor every 3-4  minutes at this time. The radiant of the shower is about five hand-spans up from the eastern horizon, and three hand-spans to the left of due east at 4 am (see diagram above). 

 

 

Labels: weekly sky

# posted by Ian Musgrave @ 8:38 pm 0 comments