Wednesday, August 31, 2016
Astrophiz Podcast 9 is Out
Dr Julie Banfield introduces the Radio Galaxy Zoo Citizen Science Project, Dr Nadeshzda Cherbakov on the 'Radio Widow' and 'Sorry, no aliens there!' I talk about 'Starshot' and what to look for in the sky this week, and in 'Ian's Tangent' I tells you about the stars in the Centaur - Alpha, Beta and Proxima.
In the news: Proxima Centauri b, Astrophotography tips, New SKA HQ, Dark Matter Galaxy, Black holes, SETI 'signal' unconfirmed.
Labels: Astrophiz
Tuesday, August 30, 2016
The Sky This Week - Thursday September 1 to Thursday September 8
The New Moon is Thursday
September 1. Venus, Jupiter and Mercury form a triangle in the twilight and are visited by the crescent Moon on the 3rd.
Mars and Saturn are visible all evening long and form a triangle with the red star Antares. There are a series of good International Space Station Passes.
The New Moon is Thursday September 1. The Moon is at apogee, when it is furthest from the Earth, on September 7.
Evening sky on Saturday September 3 looking west at 40 minutes after
sunset.
Jupiter, Venus and Mercury form a triangle with the Moon inside it. Similar views
will be seen throughout Australia at the equivalent local time. (click
to embiggen).
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth.
Jupiter is low in the western evening sky as the sun sets, and is too close to the horizon for decent telescopic observation. Jupiter's Moons will be visible in binoculars for a short while before it sets.
Venus continues to rise above the twilight glow this week. Venus and fleet Mercury are sufficiently high in the dusk sky to be seen easily. From a little after half an hour to an hour after sunset to a bit over an hour after sunset, Venus, Mercury, Jupiter make a nice triangle the dusk sky. If you extend a line from the apex formed by Venus up it meets the triangle formed by Mars, Anatres and Saturn.
Mercury continues to return to the horizon.
Jupiter, Mercury and Venus form a triangle in the dusk, becoming more elongated as Venus rises and Mercury and Jupiter race each other to the horizon. On the 3rd the thin crescent Moon sits inside the triangle, just below Venus.
Evening sky on Saturday September 3 looking west as seen from
Adelaide at 22:00 ACST. Mars, Saturn and Antares form a triangle. Similar views
will be seen elsewhere in Australia at the equivalent local time. (click to embiggen).
Mars is high in the western evening skies in the body of the Scorpion (strictly, it is in the constellation of Ophiuchus, as is Saturn).
Mars moves further down the body of the Scorpion this week, moving away from Saturn and the red star Antares. The triangle they form continues to lengthen. All week Mars is within binocular distance of the globular cluster M19. It can only be seen in binoculars or a small telescope, but the paring with Mars, which is closest on the 6th and 7th, will be very nice. Details for this event are here.
Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and you may even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible next toScorpius. Saturn is still high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
The ISS passes near Venus and Jupiter, as seen from Melbourne on the evening of Friday 2 September at 18:59 AEST. Simulated in Stellarium (the ISS will actually be a
bright dot), click to embiggen.
Until Saturday 3 September there is series of bright passes of the International Space Station occurring in the evening twilight. In middle and Southern Australia the ISS will pass close to Mars and Antares at varying times . However, the most spectacular events are when the ISS shoots between (or very close to) Venus and Jupiter on the 2nd (Canberra and Sydney) or the 3rd (Perth, Adelaide, Melbourne. Details and viewing hints are here.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.
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/
The New Moon is Thursday September 1. The Moon is at apogee, when it is furthest from the Earth, on September 7.
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth.
Jupiter is low in the western evening sky as the sun sets, and is too close to the horizon for decent telescopic observation. Jupiter's Moons will be visible in binoculars for a short while before it sets.
Venus continues to rise above the twilight glow this week. Venus and fleet Mercury are sufficiently high in the dusk sky to be seen easily. From a little after half an hour to an hour after sunset to a bit over an hour after sunset, Venus, Mercury, Jupiter make a nice triangle the dusk sky. If you extend a line from the apex formed by Venus up it meets the triangle formed by Mars, Anatres and Saturn.
Mercury continues to return to the horizon.
Jupiter, Mercury and Venus form a triangle in the dusk, becoming more elongated as Venus rises and Mercury and Jupiter race each other to the horizon. On the 3rd the thin crescent Moon sits inside the triangle, just below Venus.
Evening sky on Saturday September 3 looking west as seen from
Adelaide at 22:00 ACST. Mars, Saturn and Antares form a triangle. Similar views
will be seen elsewhere in Australia at the equivalent local time. (click to embiggen).Mars is high in the western evening skies in the body of the Scorpion (strictly, it is in the constellation of Ophiuchus, as is Saturn).
Mars moves further down the body of the Scorpion this week, moving away from Saturn and the red star Antares. The triangle they form continues to lengthen. All week Mars is within binocular distance of the globular cluster M19. It can only be seen in binoculars or a small telescope, but the paring with Mars, which is closest on the 6th and 7th, will be very nice. Details for this event are here.
Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and you may even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible next toScorpius. Saturn is still high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
The ISS passes near Venus and Jupiter, as seen from Melbourne on the evening of Friday 2 September at 18:59 AEST. Simulated in Stellarium (the ISS will actually be a
bright dot), click to embiggen.Until Saturday 3 September there is series of bright passes of the International Space Station occurring in the evening twilight. In middle and Southern Australia the ISS will pass close to Mars and Antares at varying times . However, the most spectacular events are when the ISS shoots between (or very close to) Venus and Jupiter on the 2nd (Canberra and Sydney) or the 3rd (Perth, Adelaide, Melbourne. Details and viewing hints are here.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.
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: weekly sky
The ISS meets Venus and Jupiter (30 August- 3 September)
 |  |  |
| The ISS passes between Venus and Jupiter, as seen from Adelaide on the evening of Friday 2 September at 18:28 ACST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen. | The ISS passes near Venus and Jupiter, as seen from Melbourne on the evening of Friday 2 September at 18:59 AEST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen. | The ISS passes near Venus and Jupiter, as seen from Perth on the evening of Friday 2 September at 18:33 AWST. Simulated in Stellarium (the ISS 0will actually be a bright dot), click to embiggen. |
 |  |  |
| All sky chart showing local times from Heavens Above for Friday 2 September for Adelaide. | All sky chart showing local times from Heavens Above for Friday 2 September for Melbourne. | All sky chart showing local times from Heavens Above for Friday 2 September for Perth. |
From tonight (Tuesday 30 August) until Saturday 3 September there is series of bright passes of the International Space Station occurring in the evening twilight. In middle and Southern Australia the ISS will pass close to Mars and Antares at varying times (on Wednesday 31 August from Adelaide the ISS will almost go over Antares), However, the most spectacular events are when the ISS shoots between (or very close to) Venus and Jupiter.
Friday evening (2August) sees the ISS pass just below Mercury and Jupiter in the twilight as seen from Perth, between Venus and Jupiter as seen from Adelaide and Adelaide and almost on top of Venus as seen from Melbourne. You will need a fairly unobstructed, level horizon to see this clearly, and the twilight glow will dim the ISS somewhat.
For Sydney and Canberra, the ISS passes above the trio of Venus, Jupiter and Mercury on Thursday September 1. This will be still quite spectacular to see, and somewhat easier as the ISS is higer in the sky. Points north (Brisbane, Alice Springs, Darwin) miss out on this event.
On both dates there are also closish passes to various other bright stars (like the pointers and Crux).
When and what you will see is VERY location dependent, so you need to use either Heavens Above or CalSky to get site specific predictions for your location, a small difference in location can mean the difference between the ISS passing over Venus and missing it completely.
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, Jupiter, Mars, Satellite, unaided eye, Venus
Monday, August 29, 2016
Aurora Watch (29-30 August, 2016)
The Australian Space Weather Service (SWS ) has now issued an Aurora Watch for
29-30 August UT from the high speed solar wind stream in the previous alert.
Evening and morning skies are Moon free, but cloud is problematic. It is
possible aurora may be seen in Tasmania and Southern Victoria if the minor
storms eventuate. As of the last few hours, conditions have shown no sign of a storm, but the ACE spacecraft has seen what looks like a solar wind front
passing so it may hit in the early hours of the 30th, or later that
evening.
Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen, as well as bright proton arcs and "picket fences".
Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.
The all sky aurora camera in Northern Tasmania at Cressy may be helpful.
<http://www.ips.gov.au/Geophysical/4/2>
SUBJ: SWS AURORA WATCH
ISSUED AT 0549 UT ON 29 Aug 2016 by Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
Minor geomagnetic storming expected tonight and tomorrow. There is a
possibility that aurora will be visible in Tasmania and the southern
Australian regions during local nighttime hours. Aurora alerts will
follow should favourable space weather activity eventuate.
Further monitoring at
http://www.ips.gov.au
Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen, as well as bright proton arcs and "picket fences".
Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.
The all sky aurora camera in Northern Tasmania at Cressy may be helpful.
<http://www.ips.gov.au/Geophysical/4/2>
SUBJ: SWS AURORA WATCH
ISSUED AT 0549 UT ON 29 Aug 2016 by Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
Minor geomagnetic storming expected tonight and tomorrow. There is a
possibility that aurora will be visible in Tasmania and the southern
Australian regions during local nighttime hours. Aurora alerts will
follow should favourable space weather activity eventuate.
Further monitoring at
http://www.ips.gov.au
Labels: aurora
Sunday, August 28, 2016
GeomagneticWarning (29-30 August, 2016)
The Australian Space Weather Service (SWS ) has now issued a Geomagnetic Warning and on 29-30 August UT from high speed solar wind stream a coronal
hole. This translates out to being around the 30th to possibly the 31st for
Australians. Evening and morning skies are Moon free, but cloud is problematic.
It is possible aurora may be seen in Tasmania and Southern Victoria if the minor
storms eventuate.
Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen, as well as bright proton arcs and "picket fences".
As don't forget the continuing "Planet dance". All five bright planets are visible in the early evening sky to the west. While Venus and Jupiter were at their best on Sunday the 28th, they will look great for weeks to come, with the Moon jining Venus, Mercury and Jupiter on September 3.
http://astroblogger.blogspot.com.au/2016/07/a-rare-planet-dance-in-august-2016.html
Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.
The all sky aurora camera in Northern Tasmania at Cressy may be helpful.
<http://www.ips.gov.au/Geophysical/4/2>
SUBJ: SWS GEOMAGNETIC DISTURBANCE WARNING 16/35
ISSUED AT 2342UT/27 AUGUST 2016
BY THE AUSTRALIAN SPACE FORECAST CENTRE.
The effect of a high speed solar wind stream from a recurrent
coronal hole may raise the geomagnetic activity to unsettled
to minor storm levels on 29 and 30 August.
INCREASED GEOMAGNETIC ACTIVITY EXPECTED
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FROM 29-30 AUGUST 2016
_____________________________________________________________
GEOMAGNETIC ACTIVITY FORECAST
29 Aug: Unsettled to minor storm
30 Aug: Unsettled to minor storm
Further monitoring at
http://www.ips.gov.au
Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen, as well as bright proton arcs and "picket fences".
As don't forget the continuing "Planet dance". All five bright planets are visible in the early evening sky to the west. While Venus and Jupiter were at their best on Sunday the 28th, they will look great for weeks to come, with the Moon jining Venus, Mercury and Jupiter on September 3.
http://astroblogger.blogspot.com.au/2016/07/a-rare-planet-dance-in-august-2016.html
Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.
The all sky aurora camera in Northern Tasmania at Cressy may be helpful.
<http://www.ips.gov.au/Geophysical/4/2>
SUBJ: SWS GEOMAGNETIC DISTURBANCE WARNING 16/35
ISSUED AT 2342UT/27 AUGUST 2016
BY THE AUSTRALIAN SPACE FORECAST CENTRE.
The effect of a high speed solar wind stream from a recurrent
coronal hole may raise the geomagnetic activity to unsettled
to minor storm levels on 29 and 30 August.
INCREASED GEOMAGNETIC ACTIVITY EXPECTED
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FROM 29-30 AUGUST 2016
_____________________________________________________________
GEOMAGNETIC ACTIVITY FORECAST
29 Aug: Unsettled to minor storm
30 Aug: Unsettled to minor storm
Further monitoring at
http://www.ips.gov.au
Labels: aurora
Venus and Jupiter at Closest Approach (Sunday August 28, 2016)
 |  |
| Venus and Jupiter in conjunction with Mercury nearby, Sunday August 28, 2016. Inset shows 3 x Zoomed Venus and Jupiter, with Mercury visible at top left and beta Virginis just visible near Jupiter. Image taken with a Canon IXUS, 6 second exposure, 400 ASA at 6:50 pm ACST. Click to embiggen. | Venus (bottom) and Jupiter and its Moonsin a 25mm eyepiece with my 114 mm Newtonian reflector. You can see Callisto (furthest) Europa near Jupiter) and Ganymede and Io merged almost on top of Jupiter. Significant tree interference. Click to embiggen. |
After a clear day and beautiful warm weather, the clouds invaded the evening sky again. This tie there were enough breaks in the cloud to get my telescope out and do some imaging just before the trees got in the way. Sadly I couldn't adjust the exposure down, and the refraction spikes you see are from the tree branches, but the Galillean satellites came out nicely.
Igot some good non telescope exposures, despite thin cloud hanging around. The twilight colours were muted by the cloud, but the pair of Venus and Jupiter, with Mercury nearby, was absolutely brilliant. I pointed them out to some joggers who had to vere around my kit, they were suitably impressed as well.
We won't see Jupiter and Venus this close and accessible for decades. So I am somewhat pleased to have seen them (and helped others see them). The planet dance isn't over, and on September 3 Venus, Jupiter and Mercury are joined by the thin crescent Moon.
Labels: Conjunction, Jupiter, Mercury, telescope, unaided eye, Venus
Proxima Centauri b, The Exoplanet Next Door
When I was in high school (mumble) years ago, our zoology teacher was a bit of a science fiction buff, which gave her extra credit points in the eyes of a science fiction loving teenager. She set us one assignment to write about organisms on a tidally locked world. A key intersection of my twin loves of biology and astronomy, I turned in a fairly ummm...average assignment none the less, about burrowing animals on the dessert like sunny side of the world (I didn't think much about the atmospherics and hot pole/cold pole heat transfer).
This was all brought back by the announcement of a planet orbiting Proxima Centauri. Proxima Centauri is part of the triple star system Alpha Centauri. Alpha A and B are orange sun-like stars, but Proxima is a red dwarf orbiting somewhat distant from the other two.
 |  |
| The sky as seen from the southern hemisphere and hour and a half after sunset. Proxima Centauri is almost mid way between Riget Kent (alpha Centauri) and the dim star alpha Circinus off to the left. Click to embiggen | A binocular field view of the location of Proxima Centauri. Proxima is too dim (magnitude 11) to be seen in binoculars, but is visible intelescopes and long duration exposures. But is hard to tell from the other stars. Click to embiggen. |
The planet around Proxima is both "earth-like" and in the habitable zone. This is particularly exciting. Proxima is only 4.26 light years away, so in principle future instruments might be able to resolve it. If we are really lucky, the planet will transit its sun, so we can get some ideas about its diameter and atmosphere without new instruments.
As well, Proxima Centauri is the closest star to us, only a hop skip and a jump galactically speaking. To be sure, the technical challenge is enormous. Our current speediest spacecraft, Voyager 1 and New Horizons, woul take on the order of 8,000 years to get there. These craft travel at only around 0.005% of the speed of light, a recent proposal for a fleet of "starchips"; postage sized spacecraft carried on light salis, could reach 20% of light speed and get to Proxima b in a lifetime (including development).
The challenges of such a spacecraft are enormous, but not insurmountable. It will be very interesting to see what the next decade brings.
"Earth like" merely means it is small and rocky, "habitable zone measn nothing more than it is in the region around the star that liquid water can possibly exist on. But as a reminder, both Venus (searing hell) and Mars (frozen wasteland) are also (just) in the Sun's habitable zone. Whether liquid water exists on the world depends on if it has an atmosphere, and how dense it is. The occasional flares from the star, more powerful than our solar flares, will be a challenge to atmospheric stability, let alone life.
I have as usual made a Celestia file for the system. Original paper here. Copy the data here to a plain text file (Proximab.ssc) and copy the file to the Celestia extras folder.
=======================================8<==cut===8<===Proximab.ssc=======================================================
"b" "Proxima"
# Earth-like world that orbits the red dwarf star Proxima Centauri, the closest star to the Solar system
# Nature 536, 437–440 (25 August 2016) doi:10.1038/nature19106
# http://www.nature.com/nature/journal/v536/n7617/full/nature19106.html
{
Texture "venussurface.*"
# Using Venus as it is close to the leading edge of the habitable zone.
Mass 1.27 # M.sin(i) = 1.27 (1.10-1.46)
Radius 6300 # 1.27 Earth Mass radius a guess
#InfoURL "http://en.wikipedia.org/wiki/Alpha_Centauri_Bb"
EllipticalOrbit {
Period 0.0306251
SemiMajorAxis 0.0485
Eccentricity 0.0 #fixed
ArgOfPericenter 310 #from paper
Inclination 90.0322 #guess
#MeanAnomaly 271
}
# likely to be in captured synchronous rotation
}
AltSurface "limit of knowledge" "Proxima/b"
{
Texture "venussurface.*"
OverlayTexture "ganymede-lok-mask.png"
}
}
===================================8<==cut===8<===================================================================
Labels: celestia, exoplanet, extrasolar planet
Saturday, August 27, 2016
Venus and Jupiter Conjunction, Saturday 27 August 2016
Last night clouded out the narrowing gap between Venus and Jupiter (which was lucky, as my kid taxi duties stopped me seeing it anyway) but today dawned sunny and clear but for a few wisps of cloud. It stayed that way for most of the day, so I organised with some friends we would meet on the esplanade above the beach and I would bring the telescope.
So of course it clouded over just after we made the arrangements. I took the scope up anyway, on the off chance there was a break in the cloud, and we stood around waiting while the kids circled us on their scooters.
And there was a break, or rather a thinning and for about 10 minutes of so we could see the pair together above an ominous cloud bank. I had the scope set up and was able to show the kids Venus and Jupiter together in the 114 mm Newtonian with 20 mm eyepiece, sky was too bright and cloudy to see Jupiter's Moons though. I got a few shots off and was even able to see Mercury in the zoomed images (not visible to the unaided eye).
Then the ominous cloud bank completely swallowed the planets, much to everyone's dismay. By the time I had slewed the scope to Saturn to assuage the sadness, the cloud bank covered it (and Mars) too.
With any luck tomorrow, When Jupiter and Venus are closest, will be clear.
Labels: Conjunction, Jupiter, Mercury, unaided eye, Venus
Thursday, August 25, 2016
Venus and Jupiter Meet in the Twilight (27, 28 August 2016)
 |  |  |
| Western evening sky on Saturday August 27 looking west at 40 minutes after sunset. Jupiter and Venus are around a lunar diameter apart with Mercury nearby. Similar views will be seen throughout Australia at the equivalent local time. (click to embiggen). | Western evening sky on Sunday August 28 looking west at 40 minutes after sunset. Jupiter is spectacularly close to Venus with Mercury nearby. Similar views will be seen throughout Australia at the equivalent local time. (click to embiggen). | Simulated telescopic view of Jupiter and its Moons, Venus and the star Zavijava. The field of view of a 24mm eyepiece in a 114 mm Newtonian refractor is simulated. Click to embiggen. |
If you have been watching the western twilight over the past week or so you will have seen two bright dots coming closer together. These are Venus and Jupiter, and on Saturday and Sunday they meet in the most awesome event of the current Planet Dance.
With speedy Mercury nearby, the planetary pair form a long pointy triangle. On Saturday and Sunday Venus and Jupiter will be around a lunar diameter apart (33 arc minute and 28 arc minutes respectively, if you want to get technical). That's about half a finger-width (when you hold your finger out at arms length).
That means not only will they be together in binocular fields (and Mercury, just), but they will be together in wide field telescope eyepieces. You should be able to see the bands on Jupiter (just) and the Galilean Moons together with Venus. Venus will be painfully bright in a telescope eyepiece, and is featureless gibbous shape, but seeing the two planets together will be great. The second brightest star in Virgo, Zavijava, should also be visible in telescope eyepieces.
While the three planets are visible in the western sky from half an hour after local sunset to at least and hour and a half after sunset, the best time to look is between 40 minutes to an hour after local sunset. This is when the sky is dark enough to see all three easily, but there is still plenty of twilight colour to make the sky dramatic and the planets are hight enough above the horizon that most normal horizon clutter doesn't get in the way.
Venus and Jupiter are the brightest objects in the sky once the sun has set, and Mercury is the third brightest object above the western horizon just near Venus and Jupiter, so spotting the trio should be easy.
 |  |
| 40 minutes after sunset Venus, Jupiter and Mercury gleam above the twilight colours (25 gust). Click to embigen | An hour after sunset sunset Venus, Jupiter and Mercury are brilliant above the horizon (24 August). Venus's light forms a path in the sea. Click to embigen |
Even if there is a bit of cloud about, pop out now and again to see if you can get a glimpse of the wonderful line-up.
Labels: Conjunction, Jupiter, Mercury, unaided eye, Venus
Wednesday, August 24, 2016
Carnival of Space #472 is Here!
Carnival of Space #472 is now up at Everyday Spacer. There is planets around Proxima Centauri, Keeping Mars warm, a rare nova and much, much more. Head on over and have a read.
Labels: carnival of space
Astrophiz Podcast 8 is Out
Dr Cherbakov tells us about the discoveries and passing of Owen Slee, and explains how neutron stars form, and how some become pulsars. I continue ‘the dance of the planets’, and introduce ‘Ian’s Tangent’ a new segment, and this week it is about observing the moons of Jupiter using binoculars and 'What's up in the sky this week'.
In the news this week: the LOFAR Array, @Astrokatie nails some misconceptions, a 5th force of nature? … and exploding white dwarf stars.
https://soundcloud.com/astrophiz/astrophiz-podcast-8-dr-cherbakov-neutron-stars-dr-musgrave-whats-up-this-week
Labels: Astrophiz
Tuesday, August 23, 2016
Mars, Antares and Saturn from a Straight Line (Wednesday August 24, 2016)
 |  |
| Mars is almost between the red star Antares and Saturn on the evening of 23 August. Canon IXUS, ASA 400, 15 second exposure, 10x images stacked in Deep Sky Stacker. Click to embiggen. | Mars forms a triangle with the red star Antares and Saturn on the evening of 8 August. Canon IXUS, ASA 400, 15 second exposure, 10x images stacked in Deep Sky Stacker. Click to embiggen. |
While most of the attention has been on the dance of Venus, Mercury and Jupiter in the twilight, if you have been watching Mars in the evening over the past month, you have seen it enter the head of the Scorpion. forming a triangle with the red star Antares and Saturn, you will have seen the triangle get shorter and shorter. Tomorrow night is the climax of this movement, with Mars being almost directly between Antares (the name means "rival of Mars") and Saturn.
If you have clear skies, pop out any time after 8:00 pm and look to the west. the Scorpion, Antares and the two planets will be very obvious, it should look very lovely.
Labels: Conjunction, Mars, Saturn, unaided eye
The Sky This Week - Thursday August 25 to Thursday September 1
The Last Quarter Moon is Thursday August 25. The New Moon is Thursday September 1. Venus and Jupiter are spectacularly close on the 27th and 28th.
Mars and Saturn are visible all evening long. Mars is almost directly between the red star Antares and Saturn on the 25th. In the morning skies on the 26th the waning Moon is close to the bright star Aldebaran.
The Last Quarter Moon is Thursday August 25. The New Moon is Thursday September 1.
Evening sky on Sunday August 28 looking west at 60 minutes after
sunset.
Jupiter is spectacularly close to Venus with Mercury nearby. Similar views
will be seen throughout Australia at the equivalent local time. (click
to embiggen).
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth.
Jupiter is in the western evening sky as the sun sets, and is too close to the horizon for decent telescopic observation. Jupiter's Moons will be an still be excellent sight in binoculars for a short while before it sets.
Venus continues to rise above the twilight glow this week. Venus and fleet Mercury are sufficiently high in the dusk sky to be seen easily. From a little after half an hour to an hour after sunset to a bit over an hour after sunset, Venus, Mercury, Jupiter make a nice triangle the dusk sky. If you extend a line from the apex up it meets Mars, Anatres and Saturn.
Mercury continues to return to the horizon.
Jupiter, Mercury and Venus form a triangle in the dusk, with Jupiter coming closer and closer to Venus during the week, becoming very close on the 27th and spectacularly close the 28th. A detailed guide to this rare event (the next one will be in 2065) is here.
After this Venus and Jupiter draw apart once more making a broad triangle with Mercury.
Evening sky on Thursday August 25 looking west as seen from
Adelaide
at 22:00 ACST. Mars, Saturn and Antares form a straight line. Similar views
will be seen elsewhere in Australia at the equivalent local time. (click
to embiggen).
Mars is high in the western evening skies in the body of the Scorpion.
Mars moves further down the body of the Scorpion this week. Mars starts the week almost directly between Antares and Saturn. During the week. Mars moves away from Saturn and the red star Antares once more froming a triangle with them.
Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and youmay even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible below Scorpius. Saturn is still high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
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/
The Last Quarter Moon is Thursday August 25. The New Moon is Thursday September 1.
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth.
Jupiter is in the western evening sky as the sun sets, and is too close to the horizon for decent telescopic observation. Jupiter's Moons will be an still be excellent sight in binoculars for a short while before it sets.
Venus continues to rise above the twilight glow this week. Venus and fleet Mercury are sufficiently high in the dusk sky to be seen easily. From a little after half an hour to an hour after sunset to a bit over an hour after sunset, Venus, Mercury, Jupiter make a nice triangle the dusk sky. If you extend a line from the apex up it meets Mars, Anatres and Saturn.
Mercury continues to return to the horizon.
Jupiter, Mercury and Venus form a triangle in the dusk, with Jupiter coming closer and closer to Venus during the week, becoming very close on the 27th and spectacularly close the 28th. A detailed guide to this rare event (the next one will be in 2065) is here.
After this Venus and Jupiter draw apart once more making a broad triangle with Mercury.
Mars is high in the western evening skies in the body of the Scorpion.
Mars moves further down the body of the Scorpion this week. Mars starts the week almost directly between Antares and Saturn. During the week. Mars moves away from Saturn and the red star Antares once more froming a triangle with them.
Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and youmay even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible below Scorpius. Saturn is still high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
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: weekly sky
Monday, August 22, 2016
Venus, Mercury and Jupiter 22 August 2016
 |  |
| From bottom to top, Venus, Jupiter and (dim) Mercury on the evening of 22 August (Canon IXUS ASA 400, 1 second exposure) at 6:33 pm ACST. Click to embigen. | From bottom to top, Venus, Mercury and Jupiter on the evening of 17 August (Canon IXUS ASA 400, 1 second exposure) at 6:33 pm ACST. Click to embigen. |
Another entry in our Planet Dance, Venus is rising higher, Mercury and Jupiter are dropping lower, and the triangle formed by our trio becomes more acute (see previous shots here, here and here). Venus and Jupiter will continue to move closer, leading up to their spectacular close approach on the 27-29th.
Labels: Jupiter, Mercury, unaided eye, Venus
Sunday, August 21, 2016
Venus, Mercury and Jupiter 17 August 2016
|  |
| From bottom to top, Venus, Mercury and Jupiter on the evening of 17 August (Canon IXUS ASA 400, 1 second exposure) at 6:33 pm ACST. Click to embigen. | From bottom to top, Venus, Mercury and Jupiter on the evening of 14 August (Canon IXUS ASA 400, 1 second exposure) at 6:33 pm ACST. Click to embigen. |
Continuing our Planet Dance, Venus is rising higher, Mercury and Jupiter are dropping lower, and the trio now form a definite triangle (see previous shots here and here). Venus and Jupiter will continue to move closer, leading up to their spectacular close approach on the 27-29th. Now if only the clouds woudl go away.
Labels: Jupiter, Mercury, unaided eye, Venus
Thursday, August 18, 2016
The ISS crosses the Moon in Adelaide (Sunday Morning 21 August and Monday Morning 22 August 2016)
 |  |
| The ISS crosses the face of the Moon at 7:34:12 am ACST as seen from Adelaide. Click to embiggen. | Close up of the ISS crossing the face of the Moon as seen from Adelaide. Click to embiggen. |
 |  |
| More detailed timing chart showing the position of the ISS at one second intervals on the 21st. | Centreline of the pass on the 21st (where people will see the ISS go through the exact centre of the Moon. |
UPDATE: Of course it was clouded out, wasn't it. The sky waited until I had set the telescope up at the end of the street to cover the Moon thoroughly. Maybe Monday
What is better than seeing the International Space Station glide cross the sky? Seeing it pass in front of the Moon!
This Sunday and Monday mornings (21st and 22nd August), some Adelaidiens have the chance to see the ISS cross the face of the Moon. Unfortunately, A) the pass is in daylight and B) the ISS crosses the Moon in about 1.5 seconds C) the Moon is pretty close to the horizon.
This all makes for challenging viewing. At the least you will need a telescope with a clear western horizon. On the 21st the Moon is 10 degrees above the horizon when the Moon passes over it, on the 22nd the Moon is a more friendly 27 degrees above the horizon, but the ISS is further from the centre line, meaning it spend less time in front of the Moon.
You will also need an unwavering gaze, as the ISS will be a tiny black dot flashing cross in one and a bit seconds. If you can do it try and capture video through your scope, running from about 1 minute before to one minute after the predicted time of the pass.
For Sunday, the various predicted pass start times are 7:34:12, 7:34:14 and 7:34:19 (see what I mean about recording a minute before hand)
For Monday, currently I only have 6:42:35 and 6:42:32
For you location, times may vary, it is best to check with Heavens Above (click on all passes so the daylight passes can be seen and choose the pass at 7:34 on the 21st and 6:40 on the 2nd) or CalSky (follow the link to Sun Moon crossings of the ISS) to get timings for your site.
Of course, this assumes that it is not bucketing down rain. Good luck and good viewing
Wednesday, August 17, 2016
Iridium Flare Near Mars (18 August 6:07 pm)
 |  |
| South-Western sky at twilight | - |
For Adelaideans there will be a bit of a treat tomorrow (18 August) in the twilight. There will be an extremely bright Iridium Flare near Mars and Saturn. While the flare occurs at around civil twilight, it is brighter than Venus, so should be easily seen. However, unlike International Space Station passes, the flares last only a few seconds so you have to be alert to catch them. The flare is predicted at 18:07:31, but you should start watching a minute or so beforehand just in case the timing changes (and to make sure you are looking at the right bit of sky).
While the timing should be similar for most of Adelaide, you can get exact predictions for your site at Heavens Above. My guide to imaging Iridium Flares is here (but in the twilight 15 second exposures are far to long, one second or less are needed)
| Flare Details (from Heavens Above) | |
| Date: | 18 August 2016 |
| Time: | 18:07:31 |
| Brightness: | -8 |
| Altitude: | 66° |
| Azimuth: | 158° |
| Satellite: | Iridium 60 |
| Distance to satellite: | 860 km |
| Angle off flare centre-line: | 0.2° |
| Distance to flare centre: | 3 km |
| Flare producing antenna: | right |
| Sun altitude: | -4.8° |
Labels: iridium flares, Satellite, unaided eye
Carnival of Space #471 is Here!
Carnival of Space #471 is now up at Links Through Space. There is 3D Pizza Printers, asteroid mining missions, exoearths, Taby's Star and much, much more. Head on over and have a read.
Labels: carnival of space
Astrophiz Podcast 7 is Out
Astrophiz Podcast 7 is out now.Dr Lisa Harvey-Smith talks about building the world's biggest radio telescope, sciencing with indigenous communities and national science Week. I wrap up the Perseids, explain magnitudes and 'What's up in the sky this week'. Dr Nadeshzda Cherbakov introduces Pulsars, and their discoverer, Dame Jocelyn Bell. In the news this week: Science week, Primordial Black Holes, a trip to Proxima Centauri and building a home radio telescope to study the sun.
https://soundcloud.com/astrophiz/astrophiz-podcast-7-dr-lisa-harvey-smith-quiet-zones-dr-musgrave-whats-up-this-week
Labels: Astrophiz
Tuesday, August 16, 2016
It's National Science Week This Week (13-21 August 2016)
It's National Science Week This Week (13-21 August 2016). Check the Science Week page for lots of great activities in your area. I'll be going to Professor Flint's A Brief History of Life the Universe & Everything with SmallestOne, but there are lots of good events on.
Labels: public outreach, science week
The Sky This Week - Thursday August 18 to Thursday August 25
The Last Quarter Moon is Thursday August 25. Venus rises higher in
the early
evening sky while Jupiter and Mercury lowers towards it. Mercury and Jupiter are
close on the 18th-21st.
Mars and Saturn are visible all evening long. Mars is directly between the red star Antares and Saturn on the 24th.
The Last Quarter Moon is Thursday August 25. The Moon is at Perigee, when it is closest tothe earth, on the 22nd.
Evening sky on Saturday August 20 looking west at 60 minutes after
sunset.
Jupiter forms a triangle with Venus and Mercury. Similar views
will be seen throughout Australia at the equivalent local time. (click
to embiggen).
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth.
Jupiter is in the western evening sky as the sun sets, and is too close to the horizon for decent telescopic observation. Jupiter's Moons will be an still be excellent sight in binoculars for a short while before t sets.
Venus continues to rise above the twilight glow this week. Venus and fleet Mercury are now sufficiently high in the dusk sky to be seen easily. From a little after half an hour to an hour after sunset, Venus, and Jupiter (with Mercury nearby) make a nice line-up in the dusk sky which if continued on meets up with Mars, Anatres and Saturn.
This week Mercury begins to return to the horizon. From the 18th to the 21st Mercury is closest to Jupiter.
Jupiter, Mercury and Venus form a triangle in the dusk, with Jupiter coming closer and closer to Venus during the week, ahead of the spectacular finale on the 28th.
Evening sky on Wednesday August 24 looking west as seen from
Adelaide
at 22:00 ACST. Mars, Saturn and Antares form a straight line. Similar views
will be seen elsewhere in Australia at the equivalent local time. (click
to embiggen).
Mars is high in the evening skies in the body of the Scorpion.
Mars moves further down the body of the Scorpion this week. Mars forms a line with the star Dschubba in the head of the Scorpion and Antares. Mars draws away from Dschubba heading towards Antares and Saturn during the week. Mars forms a (shrinking) triangle with Saturn and the red star Antares. By the 24th, at the end of the week, Mars is directly between Antares and Saturn.
Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and you may even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible below Scorpius. Saturn forms a triangle with Mars and the red star Antares. It is now high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
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/
The Last Quarter Moon is Thursday August 25. The Moon is at Perigee, when it is closest tothe earth, on the 22nd.
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth.
Jupiter is in the western evening sky as the sun sets, and is too close to the horizon for decent telescopic observation. Jupiter's Moons will be an still be excellent sight in binoculars for a short while before t sets.
Venus continues to rise above the twilight glow this week. Venus and fleet Mercury are now sufficiently high in the dusk sky to be seen easily. From a little after half an hour to an hour after sunset, Venus, and Jupiter (with Mercury nearby) make a nice line-up in the dusk sky which if continued on meets up with Mars, Anatres and Saturn.
This week Mercury begins to return to the horizon. From the 18th to the 21st Mercury is closest to Jupiter.
Jupiter, Mercury and Venus form a triangle in the dusk, with Jupiter coming closer and closer to Venus during the week, ahead of the spectacular finale on the 28th.
Mars is high in the evening skies in the body of the Scorpion.
Mars moves further down the body of the Scorpion this week. Mars forms a line with the star Dschubba in the head of the Scorpion and Antares. Mars draws away from Dschubba heading towards Antares and Saturn during the week. Mars forms a (shrinking) triangle with Saturn and the red star Antares. By the 24th, at the end of the week, Mars is directly between Antares and Saturn.
Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and you may even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible below Scorpius. Saturn forms a triangle with Mars and the red star Antares. It is now high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
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: weekly sky
Sunday, August 14, 2016
Venus, Mercury and Jupiter 14 August 2016
 |  |
| From bottom to top, Venus, Mercury and Jupiter on the evening of 14 August (Canon IXUS ASA 400, 1 second exposure) at 6:33 pm ACST. Click to embigen. | For comparison Venus, Mercury, Jupiter and the Moon on the evening of 7 August (Canon IXUS ASA 400, 1 second exposure) at 6:27 pm ACST. Click to embigen to see Mercury. |
After nearly a week of cloud obscuring the Planet Dance, I finally got another glimpse. Mercury is now very obvious in the twilight, and this is probably the best time to see it this year. Compared to the evening of the7th, Venus and Mercury are higher, and Jupiter lower. Jupiter, Mercury and Venus form a distinct triangle, as opposed to the battered line previously. over the week Mercury will rapidly rise towards Jupiter, Venus rises more slowly. Mercury will be highest above the horizon on the 17th, then returns towards the horizon. Between the 18th to the 21st it will be close to Jupiter.
Labels: Jupiter, Mercury, Venus
Thursday, August 11, 2016
Perseids 2016 Live Wecams (12-13 August 2016)
If you are clouded out, or south of Brisbane, or just don't want to get up at 4:00 am, you can try watching the following web cams in the northern hemisphere to catch the Perseids:
Space.com
http://www.space.com/19195-night-sky-planets-asteroids-webcasts.html
(10 am AEST August 12, that's 0000 GMT on Aug. 12)
NASA web cams via ustream http://www.ustream.tv/channel/nasa-msfc
https://blogs.nasa.gov/Watch_the_Skies/2016/08/02/look-up-perseid-meteor-shower-peaks-aug-11-12/
(12 am AEST August 12 and again 12 am AEST August 13)
The (semi) live International Meteor Organisation Perseid counts can be found here
http://www.imo.net/live/perseids2016/
And just a reminder, my viewing hints and charts for Australia are here
http://astroblogger.blogspot.com.au/2016/08/australian-perseid-meteor-shower.html
Labels: Meteors
Wednesday, August 10, 2016
Astrophiz Podcast 6 is Out
Astrophiz Podcast 6
is out. Dr Karen Lee-Wadell tells us about her research with CSIRO on tidal
dwarf galaxies. Ian tells us more about the Perseid Meteor Shower, the
'Dance of the Planets' and what's up in the sky this week. Dr Nadeshzda
tells us about the discovery or radio waves from Jupiter.
In the news: Help find black holes by joining a citizen science project at radio.galaxyzoo.org and we explain how the colours of auroras happen.
https://soundcloud.com/astrophiz/astrophiz-podcast-6-dr-karen-lee-wadell-tidal-dwarf-galaxies-dr-musgrave-whats-up
In the news: Help find black holes by joining a citizen science project at radio.galaxyzoo.org and we explain how the colours of auroras happen.
https://soundcloud.com/astrophiz/astrophiz-podcast-6-dr-karen-lee-wadell-tidal-dwarf-galaxies-dr-musgrave-whats-up
Labels: Astrophiz
Tuesday, August 09, 2016
The Sky This Week - Thursday August 11 to Thursday August 18
The Full Moon is Thursday August 18. Venus and Mercury rise higher in the early
evening sky while Jupiter lowers towards them. Mercury and Jupiter are close on the 18th..
Mars and Saturn are visible all evening long. The Moon forms a triangle with Mars, Saturn and Antares on the 12th. The Perseid meteor shower will be visible from northern Australia on the morning of the 13th
The Full Moon is Thursday August 18.
Evening sky on Saturday August 13 looking west at 60 minutes after
sunset.
Jupiter is above Venus and Mercury. Similar views
will be seen throughout Australia at the equivalent local time. (click
to embiggen).
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth. Jupiter will be an excellent telescopic target but s rapidly coming too close to the horizon.
Jupiter is in the north-western evening sky as the sun sets, and is good for telescopic observation from around 18:00 on until around 20:00 when it will be a little too close to the horizon. Jupiter's Moons will be an still be excellent sight.
Venus and Mercury continue to rise above the twilight glow this week. They are now sufficiently high in the dusk sky to see easily. From a little after half an hour to an hour after sunset, Venus, Mercury, Jupiter and the bright star Spica make a nice line-up in the dusk sky which if continued on meets up with Mars, Anatres and Saturn.
This week Mercury will be furthest from the Sun (and highest above the horizon) on the 17th. From the 18th to the 21st Mercury is closest to Jupiter.
Evening sky on Friday August 12 looking west as seen from
Adelaide
at 22:00 ACST. Mars, Saturn and Antares form a triangle. The Moon makes a larger triangle with them. Similar views
will be seen elsewhere in Australia at the equivalent local time. (click
to embiggen).
Mars is high in the evening skies near the head of the Scorpion.
Mars moves down the body of the Scorpion this week. Mars forms a line with the star Dschubba in the head of the Scorpion and Antares. Mars draws away from Dschubba heading towards Antares and Saturn during the week.
Mars forms a (shrinking) triangle with Saturn and the red star Antares. Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and youmay even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible below Scorpius. Saturn forms a triangle with Mars and the red star Antares. It is now high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
Perseid radiant as seen from Darwin at 5:00 am local time, August the 13th, looking north.
Perseid Meteor Shower runs from July 17–August 24, and peaks on between 11:00 pm Friday August 12 - 1:30 am Saturday August 13 AEST (August 12, 13:00h to 15:30 UT). The best time to observe is on the morning of the 13th between 4:30 am to 5:30 am AEST when the shower radiant is highest above the horizon.
Despite this being a quite reasonable meteor shower in the Northern Hemisphere, for most of Australia and a large chunk of the Southern Hemisphere the radiant is below the horizon, and only the very occasional meteor will be seen shooting up from the northern horizon.
Basically, anywhere south of the latitude of Brisbane (27.3 degrees South) will see few, if any, meteors under ideal conditions. This year, with Moonless skies and a better than normal peak occurring not to too far from radiant rise, northern Australia can expect rates of between 2-4 meteors every minute. For details and more charts and viewing hints see my Perseid page.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The
The Full Moon is Thursday August 18.
Jupiter was at opposition on the March 8th, when it was biggest and brightest as seen from Earth. Jupiter will be an excellent telescopic target but s rapidly coming too close to the horizon.
Jupiter is in the north-western evening sky as the sun sets, and is good for telescopic observation from around 18:00 on until around 20:00 when it will be a little too close to the horizon. Jupiter's Moons will be an still be excellent sight.
Venus and Mercury continue to rise above the twilight glow this week. They are now sufficiently high in the dusk sky to see easily. From a little after half an hour to an hour after sunset, Venus, Mercury, Jupiter and the bright star Spica make a nice line-up in the dusk sky which if continued on meets up with Mars, Anatres and Saturn.
This week Mercury will be furthest from the Sun (and highest above the horizon) on the 17th. From the 18th to the 21st Mercury is closest to Jupiter.
Mars is high in the evening skies near the head of the Scorpion.
Mars moves down the body of the Scorpion this week. Mars forms a line with the star Dschubba in the head of the Scorpion and Antares. Mars draws away from Dschubba heading towards Antares and Saturn during the week.
Mars forms a (shrinking) triangle with Saturn and the red star Antares. Mars was at opposition on May 22, and is still visibly dimming, but is still a modest telescope object. It is visible all evening long. In even small telescopes Mars will be a visible disk, and youmay even be able to see its markings.
Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere near as spectacular as Mars's, and Saturn will be a reasonable telescopic object for many weeks. Saturn is reasonably high in the evening sky and is readily visible below Scorpius. Saturn forms a triangle with Mars and the red star Antares. It is now high enough for good telescopic observation in the evening. In even small telescopes its distinctive rings are obvious.
Perseid radiant as seen from Darwin at 5:00 am local time, August the 13th, looking north.Perseid Meteor Shower runs from July 17–August 24, and peaks on between 11:00 pm Friday August 12 - 1:30 am Saturday August 13 AEST (August 12, 13:00h to 15:30 UT). The best time to observe is on the morning of the 13th between 4:30 am to 5:30 am AEST when the shower radiant is highest above the horizon.
Despite this being a quite reasonable meteor shower in the Northern Hemisphere, for most of Australia and a large chunk of the Southern Hemisphere the radiant is below the horizon, and only the very occasional meteor will be seen shooting up from the northern horizon.
Basically, anywhere south of the latitude of Brisbane (27.3 degrees South) will see few, if any, meteors under ideal conditions. This year, with Moonless skies and a better than normal peak occurring not to too far from radiant rise, northern Australia can expect rates of between 2-4 meteors every minute. For details and more charts and viewing hints see my Perseid page.
There are lots of interesting things in the sky to view with a telescope. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The
Labels: weekly sky
Sunday, August 07, 2016
Planet Dance on 6th and 7th August 2016
 |  |
| From bottom to top, Venus, Mercury, Jupiter and the Moon on the evening of 6 August (Canon IXUS ASA 400, 1 second exposure) Click to embigen. | From bottom to top, Venus, Mercury, Jupiter and the Moon on the evening of 7 August (Canon IXUS ASA 400, 1 second exposure) Click to embigen. |
After being clouded/rained out on the early pat of the Planet Dance (4th and 5th), the 6th and 7th were clear, the 6th stunningly so. Had to go out to the opera on the 6th (the Co-opera group which gave a recital of "The Clemency of Tito" at the Port Adelaide Flour Warehouse - not a high culture event) so I couldn't get images of the Moon and Jupiter close together.
The colours in the sky on Saturday the 6th were stunning, on Sunday the 7th there was a lot of horizon cloud, nd I had to wait until a bit later for Venus to come out from behind the cloud, so the effect was not as pronounced.
Labels: alignment, Jupiter, Mercury, Moon, Venus
Saturday, August 06, 2016
Jupiter Meets the Moon (6 August 2016)
The inset is the telescopic view of Jupiter and the Moon. at this time. Similar views will be seen elsewhere in Australia at the equivalent local time (but see below). (click to embiggen).
This Saturday evening (August 6), the crescent Moon and the bright planet Jupiter will be very close together, just above the western horizon.
Unfortunately, while at their closest from most of Australia Jupiter is mostly less than half a lunar diameter from Moon (that is about a quarter of a finger-width). This occurs at around 3:00 pm local time when the sun is still in the sky. By the time the sun has set the Moon is around a Lunar diameter from Jupiter, and by half an hour after sunset it will be two lunar diameters away.
They will be visible together in binoculars and wide field eyepieces of telescopes. For telescope user, a 24 mm eyepiece (rough field of view 1 degree) will have the pair together shortly after sunset.
Photographing the pair will be a challenge, as it will be difficult to get a good exposure of Jupiter and its Moons without over exposing the Moon, you may have to make a mosiac with different exposure times.
Labels: Conjunction, Jupiter, Moon
Friday, August 05, 2016
Australian Perseid Meteor Shower - Morning August 13, 2016
 |  |
| Perseid radiant as seen from Darwin at 5:00 am local time, August the 13th, looking north. Click to embiggen. | Perseid radiant as seen from Brisbane at 5:00 am local time, August the 13th, looking north. Note how much lower the radiant is than in Darwin. |
The Perseid Meteor Shower runs from July 17–August 24, and peaks on between 11:00 pm Friday August 12 - 1:30 am Saturday August 13 AEST (August 12, 13:00h to 15:30 UT). See the International Meteor Calendar for 2016 for further details.
Despite this being a quite reasonable meteor shower in the northern hemisphere, for most of Australia the radiant is below the horizon, and only the very occasional meteor will be seen shooting up from the northern horizon. Only observers in northern Australia (at the latitude of Brisbane or further north) will have decent rates.
This is a good year, while the peak occurs before the radiant rises (or at least is at its closest to the horizon) in Australia, it still occurs reasonably close to radiant rise and there is no Moon to ruin the shower. Also this years peak is higher than usual (with a ZHR of 150 meteors per hour predicted).
However, these ZHR predictions are ideal rates for sites with the meteor radiant directly overhead, under the darkest possible skies with nothing obscuring the sky. From Australia, we will see much lower rates than these ideal ones. Anyone south of Brisbane will see only the occasional meteor, say maybe one or two per hour (or less), the further north of Brisbane you are, the more meteors you will see.
People around the latitude of Darwin have the best chance of seeing meteors, possibly as many as one every 2 minutes at the peak (see table below). Next is places with the latitude of Cairns (around a meteor every 3 minutes), then with the latitude of Mackay (like Port Headland and Mt Isa), and the places with the latitude of Alice Springs (again,see table below).
To see the meteors, you will need to be up from around 3:00 am local time on the 12th, 13th or 14th (yes, a really horrible hour of the morning), with best views 4:00 am-5:30 am on the 13th. The meteor shower will be located due North, with the radiant just above the northern horizon (see charts above). Cloud cover predictions can be found at SkippySky.
When you get up, allow at least 5 minutes for your eyes to adjust, and be patient, it may be several minutes before you are rewarded with you first meteor, then a couple will come along in quick succession. Choose a viewing spot where you can see a large swathe of sky without trees or buildings getting in the way, or with street lights getting in your eyes. The darker the spot the better (but do be sensible, don't choose a spot in an unsalubrious park for example).
A lawn chair or something similar will make your observing comfortable (or a picnic rug spread on the ground and a nice pillow), and having a Thermos of hot coffee, tea or chocolate to swig while watching will increase your comfort. (Here's some hints on dark adaptation of your eyes so you can see meteors better).
The following table show the predicted peak rates at around 5 am local time on the mornings of the 12th, 13 and 14th of August for a number of cities under dark sky conditions. Rates will be similar at the same latitude as these cities, and rates will be intermediate at spots between these cities.
| Town | Morning August 12 | Morning August 13 | Morning August 14 |
| Alice Springs | 8 meteors/hr | 12 meteors/hr | 7 meteors/hr |
| Brisbane | 5 meteors/hr | 7 meteors/hr | 4 meteors/hr |
| Cairns | 15 meteors/hr | 23 meteors/hr | 12 meteors/hr |
| Darwin | 19 meteors/hr | 28 meteors/hr | 16 meteors/hr |
| Mackay | 11 meteors/hr | 16 meteors/hr | 9 meteors/hr |
Rates on the morning of the 15th are similar to that of the 14th. Note, those of you who have Stellarium, in version 13 they have added meteor shower radiants (rates set in the planets dialogue, F4). However while the radiants are shown, the simulated meteors come from random points in the sky, not the radiants.
Labels: Meteors
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