Astroblog

To be read in conjunction with the "Tangent" section of the astrophiz podcast #235
https://soundcloud.com/astrophiz/astrophiz-235-june-2026-sky-guide

 There is a video going around on that wretched hive of villainy and scum called twitter labelled “Comets are not what we’ve been told”.  It shows some very nice time lapses of bright comets with the caption ‘Watch how it moves in lockstep with the stars” …. And that’s it. That’s the argument. 

Now, many people think because bright comets with the luminous tails look “swooshy” they must move perceptibly, like meteors. So perhaps the the lack of perceptible movement meant the comets were something else due to their naive expectations .... hence the earth is flat for .. reasons.  But comets are exactly what we have been told (and the earth is not flat).

In a single night, when viewed from afar, most comets will not seem to move against the background stars, especially as the time window before they set is short. But through a telescope (or telescopic lens) you can see them move a bit. For C/2024 G3 and C/2025 R3 I had a roughly 20 minute window for imaging, so I wasn’t going to see much motion, but for C/20025 R3 I could compare my images with those by other astrophotographers in the Southern Hemisphere, and see for example, images taken a few hours previous in New Zealand showed the comet had move compared to my images.

And night after night they are against different stars as the follow their orbit. Comet C/2025 R3 was particularly lovely, not bright but drifting past the sword of Orion’s belt each night was memorable.  

Comet C/2025R3 and Orion on the 10th May. Can't really see the tail against the light pollution. My image, long exposure (left) vs stellarium.	Comet C/2025R3 and Orion on the 10th May as simulated in stellarium.. Compare with my image, long exposure on the right.

Comet C/2025R3 and Orion on the 11th May. Sort of got a stubby tail against the light pollution. My image, long exposure (left) vs stellarium.	Comet C/2025R3 and Orion on the 11th May as simulated in stellarium.. Compare with my image, long exposure on the right.

Comet C/2025 R3, at the time it was crossing Orion’s belt, was moving around 1 degree every 24 hours, slow compared to the moon, which moves ~13.2 degrees every 24 hours, but not too different from the movement Venus, which moves on Average ~1.2 degrees per day and fleet Mercury which moves on average ~1.3833 degrees per day (0.5 degrees is roughly the diameter of the moon, which moves approximately one lunar diameter per hour). Mars moves ~ 0.5242 degrees per day and Jupiter, Saturn and the rest much less. This is why Jupiter and Saturn seem to stay in roughly the same place night after night. This is complicated by retrograde motion, where earth overtakes the planets in their orbits. 

Mercury and Venus have a narrow window before they set to see them move in a single night. On the 20th and 21st you have about a 2 hour window to see Venus move against the background stars of the Beehive cluster, you do need a flat level horizon for this. (of course, day to day they move quite a bit with close approaches to other planets and stars over a matter of days).  

Western sky on the evening of Saturday, June 20 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen).  Venus is at its closest to the Beehive Cluster (M44).	Binocular view Venus and the Beehive at 18:11 ACST	Binocular view Venus and the Beehive at 19:41 ACST. Venus has slightly, but perceptibly moved against the stars of the Beehive.

We tend not to notice the relatively rapid movement on the Moon during the night, not may people are out looking at the sky for hours on end. Only when the moon is close to a very bright star do we sometime take notice. 

On the 23rd you can follow the waxing Moon as it comes closer to the bright star Spica, in binoculars you will be able to see it come close to the star 49 Virginis over the span of a few hours. Of course on the 28th, in the early Morning you can watch the moon occult (or graze) Antares. 

The Moon at the evening of Tuesday, June 21 as seen from Adelaide at 18:12 ACST (60 minutes after sunset, click to embiggen). The Moon is close to the bright star Spica	The Moon as seen through binoculars  at 18:12 ACST (60 minutes after sunset, click to embiggen). The Moon is near the star 49 Virginis	The Moon as seen through binoculars  at 22:00 ACST. The Moon is now beside the star 49 Virginis and visibly closer to Spica.

Labels: Astrophiz, comet, Moon.

The First Quarter Moon is Monday June 22. The "Lunar X" can be seen at this time. Earth is at solstice on the 21st. In the morning Saturn and Mars form a line. In the evening, on the 18th, the Moon is close to Venus and the Beehive cluster. On the 20th, Venus and the Beehive are at their closest. On the 25th Mercury and Jupiter are close in the twilight.

The First Quarter Moon is Monday June 22. The "Lunar X" can be seen at this time. Earth is at solstice, when the days are shortest,  on the 21st.

Eastern horizon on the morning of Saturday, June 20 as seen from Adelaide at 5:52 ACST (90 minutes before sunrise, click to embiggen). 

Saturn and Mars form a long line in the twilight. Saturn is now high enough for telescopic observation, and its rings are widening. 

The inset shows the telescopic view of Saturn at this time.   

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Western sky on the evening of Thursday, June 18 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen). 

Venus, Jupiter and Mercury form a line with the waxing Moon.

Venus is close to the waxing Moon and the inset shows the telescopic view of Venus at this time. 

  

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Western sky on the evening of Saturday, June 20 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen). 

Venus is at its closest to the Beehive Cluster (M44). The inset is the binocular view of Venus and the Beehive. 

 

  

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Western sky on the evening of Monday, June 22 as seen from Adelaide at 20:11 ACST. 

The First Quarter Moon is high above the western horizon and the lunar "X" and "V" are easily seen in a small telescope. 

the inset shows the telescopic view at this time.  

 

 

 

 Similar views will be seen from the rest of Australia at roughly the times indicated below:

Date	UT	AEST	ACST	AWST
June 22	09:41	20:41	20:11	17:41 (WA: X visible at twilight better when sky is full dark)

Western sky on the evening of Thursday, June  25 as seen from Adelaide at 18:12 ACST (60 minutes after sunset, click to embiggen). 

Mercury and Jupiter are at their closest, with Venus above. Venus is coming closer to the Bright Star Regulus. 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Labels: weekly sky

Despite the hopeful predictions, it looks like the last set of CME's completely missed earth. Fingers crossed this time.

The Earth is expected to become influenced by a recurrent coronal hole on June 12 (Universal time, probably morning of the 13th in Australia) to induce G1 geomagnetic activity with a chance of G2. 

A CME launched on 11 June is expected to arrive with a glancing blow early on UT day 13 June to induce G2 geomagnetic conditions. Residual disturbances are likely to continue into 14 June, giving G1 geomagnetic conditions with a chance for G2 periods on this day.

If storms eventuate, visible aurora may be seen in Tasmania southern parts of Victoria, and possibly southern South Australia, Western Australia and NSW during local night hours. In the early evening the planetary massing of Mercury, Jupiter and Venus in the east will add spice to your aurora hunting.

The Moon is approaching New. In the early morning it is close to Mars on the 13th,It will not interfere too seeing aurora in the early morning.  Keep an eye out and be patient, as the magnetic polarity of the wind fluctuates significantly and aurora may come and go.

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, mostly green at the moment.

Cloud cover predictions can be found at SkippySky. https://www.skippysky.com.au/Australia/index.html
Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/
_____________________________________________________________

INCREASED GEOMAGNETIC ACTIVITY EXPECTED 
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FROM 12-14 JUNE 2026
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST
12 Jun:  G1, chance G2
13 Jun:  G2
14 Jun:  G1, chance G2 

Labels: aurora

The New Moon is Monday June 15. In the morning Saturn and Mars form a line. On the 11th the crescent Moon is close to Saturn, then on the 13th the thin crescent Moon is close to Mars. Venus is close to Jupiter in the evening sky. On the 15th, Venus is midway between Jupiter and the Beehive Cluster (M44). On the 17th Mercury, Jupiter and the thin crescent Moon form a triangle.

The New Moon is Monday June 15. The Moon is at perigee  when it is closest to the Earth, on the 15th.

Eastern horizon on the morning of Thursday, June 11 as seen from Adelaide at 5:49 ACST (90 minutes before sunrise, click to embiggen). 

Saturn and Mars form a line in the twilight. Saturn is now high enough for telescopic observation, and its rings are widening. The crescent Moon is below Saturn.

The inset shows the telescopic view of Saturn at this time.   

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise).  

Eastern horizon on the morning of Saturday, June 13 as seen from Adelaide at 5:50 ACST (90 minutes before sunrise, click to embiggen). 

Saturn and Mars form a line in the twilight. 

The thin crescent Moon is below Mars.

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise).  

Western sky on the evening of Monday, June 15 as seen from Adelaide at 18:10 ACST (60 minutes after sunset, click to embiggen). 

Venus, Jupiter and Mercury form a line. Jupiter, Mercury and Pollux form a triangle. 

Venus is midway between Jupiter and the Beehive Cluster (M44). The beehive cluster is indicated by brackets. 

  

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Western sky on the evening of Wednesday, June  17 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen). 

Mercury, Jupiter and the thin crescent Moon form a triangle with Venus above forming another triangle with the Moon and Jupiter.

The inset shows the telescopic views of Jupiter and Venus at this time.   

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Labels: weekly sky

The last set of CME's caused a brief G2 storm around 11 pm on the 5th. The northern hemisphere got some decent displays but I've not heard much from the Southern Hemisphere.

The Australian Space Weather Forecasting Centre reports a fast partial halo coronal mass 
ejection (CME) erupted from the Sun from 06/1411 UT and is expected to arrive at Earth 
from 08/1300 UT (that's 11 pm AEST). 

This CME is expected to cause G2-G3 geomagnetic conditions on 8 June, 
and easing to G1-G2 geomagnetic conditions by 9 June.

If storms eventuate, visible aurora may be seen in Tasmania southern parts of Victoria, and possibly southern South Australia, Western Australia and NSW during local night hours around midnight. The Moon is at last Last Quarter. It will not interfere too much with seeing aurora in the early morning.  Keep an eye out and be patient, as the magnetic polarity of the wind fluctuates significantly and aurora may come and go.

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, mostly green at the moment.

Cloud cover predictions can be found at SkippySky. https://www.skippysky.com.au/Australia/index.html
Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/
_____________________________________________________________

INCREASED GEOMAGNETIC ACTIVITY EXPECTED 
DUE TO CORONAL MASS EJECTION
FROM 08-09 JUNE 2026
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST
08 Jun:  G2-G3
09 Jun:  G1-G2

The Australian Space Weather Forecasting Centre reports three coronal mass ejections (CMEs) have been observed associated with two M-class and one X-class flares from region 4455. 

Modelling indicates the second and third CMEs have an estimated arrival at Earth on 05-Jun at 10:00UT +/- 10 hrs (anywhere from 2pm the 5th AEST to 6 am the 6th AEST). G2 planetary geomagnetic conditions are expected, with a chance of G3.

If storms eventuate, visible aurora may be seen in Tasmania and possibly southern parts of Victoria, South Australia and Western Australia during local night hours. 

The Moon is waning and heading towards Last Quarter. It will interfere with seeing aurora in the early morning.  Keep an eye out and be patient, as the magnetic polarity of the wind fluctuates significantly and aurora may come and go.

Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.

Current K index is 2 and 
Solar Wind Parameters Used: Date: 05 06 2026 0706 UT
Velocity: 454 km/sec
Bz: -1.0 nT
Density = 8.0 p/cc

As always look to the south for shifting red/green glows, mostly green at the moment.

Cloud cover predictions can be found at SkippySky. https://www.skippysky.com.au/Australia/index.html
Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/
_____________________________________________________________

INCREASED GEOMAGNETIC ACTIVITY EXPECTED 
DUE TO CORONAL MASS EJECTION
FROM 05-06 JUNE 2026
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST

05 Jun:  G2, chance G3
06 Jun:  G0-G1
====================================================

Labels: aurora

The Last Quarter Moon is Monday June 8. In the morning Saturn and Mars form a line and are joined by the crescent Moon later in the week. Venus is close to Jupiter. On the 4th Venus, Jupiter and the bright star Pollux form an attractive triangle. Between the 8th and 9th Venus is less than 2° from Jupiter and forms a line with Pollux. Mercury returns to the evening sky below Venus and Jupiter.

The Last Quarter Moon is Monday June 8.

Eastern horizon on the morning of Saturday, June 6 as seen from Adelaide at 6:18 ACST (60 minutes before sunrise, click to embiggen). 

Saturn and Mars form a line in the twilight. Saturn is now high enough for telescopic observation, and its rings are widening.

The inset shows the telescopic view of Saturn at this time.   

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes before sunrise).  

Western sky on the evening of Thursday, June 4 as seen from Adelaide at 18:41 ACST (90 minutes after sunset, click to embiggen). 

Venus, Jupiter and the bright star Pollux form an attractive triangle. 

The inset shows the telescopic views of Jupiter and Venus at this time.  

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes after sunset).

Western sky on the evening of Wednesday, June  8 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen). Venus Jupiter, Pollux and Castor form a battered line, with Mercury below, very close to epsilon Geminorum.  

The inset shows the telescopic views of Jupiter and Venus at this time.  

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Labels: weekly sky