Thursday, November 29, 2012
Still More Solar Eclipse Images (Port Douglas Edition)
My Blog friend and correspondent Cynthia Ma was at Four Mile Beach, Port Douglas for the Total Eclipse. The clouds played hide and seek with the Sun, just as it did for me, but the clouds parted enough for her to get some great shots, including one of the corona.
For these shots Cynthia used a Panasonic Lumix DC with Baader solar film. Terrific results with a really simple setup.
For these shots Cynthia used a Panasonic Lumix DC with Baader solar film. Terrific results with a really simple setup.
Labels: Cynthia Ma, eclipse, solar, Sun
22 degree Halo round the Sun
First Look, Penumbral Eclipse 29 November, 2012
The Moon at 11:30 pm, 28 November, just as the penumbral eclipse started | The Moon at 1:03 am, 29 November, at maximal penumbral eclipse, a subtle darkening is seen |
Wednesday, November 28, 2012
Moon Dog (while waiting for eclipse)
You may have heard of Sundogs, rainbow coloured patches of light that occur 22º form the Sun when plate shaped hexagonal ce crystals in cirrus clouds refract light hen the Sun is low to the horizon.
Well, the same effect occurs with the Moon, here's a Moon Dog I got tonight just after Moon rise, while waiting for the penumbral eclipse later tonight. Jupiter is the dot off to the bottom right of the Moon (click to embiggen for parselenial goodness). 8 second exposure at 400 ASA, canon IXUS.
Well, the same effect occurs with the Moon, here's a Moon Dog I got tonight just after Moon rise, while waiting for the penumbral eclipse later tonight. Jupiter is the dot off to the bottom right of the Moon (click to embiggen for parselenial goodness). 8 second exposure at 400 ASA, canon IXUS.
Labels: Moon, Moonbow, weather
Tuesday, November 27, 2012
Penumbral Lunar Eclipse, November 28-29 2012.
Evening sky looking north as seen
from Adelaide at 1:00 am local daylight time on
Thursday November 29. The Moon is not far from Aldebaran and Jupiter. At
this time the penumbral eclipse will be at its darkest. The keen eyed
may see a slight darkening of the northern half of the Moon. Similar
views will
be seen
elsewhere at the equivalent local time. Click
to embiggen.
From the late evening of the 28th November to the early morning of the 29th November there will be a penumbral eclipse of the Moon. It will be visible in all of Australia, New Zealand and most of Asia.
In a penumbral eclipse, the Moon only enters the outer part of Earth's shadow. This will results in a subtle darkening of the Moons northern half (although it is a relatively deep penumbral eclipse, it still doesn't get very dark). Depending on how good your eyesight is, it could be reasonably visible, or only visible via photography.
The table below shows the time of the eclipse from Eastern, Central and Western Australia. For Eastern and Central Australia subtract an hour for non-daylight saving states. The early parts of the eclipse will be effectively invisible to the unaided eye. When around 2/3 of the Moons disk is immersed in the penumbra, then you will see an effect (around half an hour either side of maximum eclipse).
For everywhere in Australia except WA, the eclipse occurs around midnight, you will have to be dedicated to stay up for this. For other regions, see here for UT timings.
From the late evening of the 28th November to the early morning of the 29th November there will be a penumbral eclipse of the Moon. It will be visible in all of Australia, New Zealand and most of Asia.
In a penumbral eclipse, the Moon only enters the outer part of Earth's shadow. This will results in a subtle darkening of the Moons northern half (although it is a relatively deep penumbral eclipse, it still doesn't get very dark). Depending on how good your eyesight is, it could be reasonably visible, or only visible via photography.
The table below shows the time of the eclipse from Eastern, Central and Western Australia. For Eastern and Central Australia subtract an hour for non-daylight saving states. The early parts of the eclipse will be effectively invisible to the unaided eye. When around 2/3 of the Moons disk is immersed in the penumbra, then you will see an effect (around half an hour either side of maximum eclipse).
Penumbral Eclipse Begins | Maximum Eclipse | Penumbral Eclipse Ends |
11:12pm AEDST 28 Nov | 01:33 am AEDST 29 Nov | 03:53 am AEDST 29 Nov |
10:42pm ACDST 28 Nov | 01:03 am ACDST 29 Nov | 03:23 am AECST 29 Nov |
8:12pm AWST 28 Nov | 10:33 am AWST 28 Nov | 12:53 am AWST 29 Nov |
For everywhere in Australia except WA, the eclipse occurs around midnight, you will have to be dedicated to stay up for this. For other regions, see here for UT timings.
The Sky This Week - Thursday November 29 to Thursday December 6
The Full Moon is Thursday November 29, at this time there is a penumbral eclipse. Mars is in Sagittarius. Jupiter is visible in the late evening sky and is visited by the Moon on the 29th. Jupiter is at opposition on December 3. In the morning skies Venus is low on the horizon. Saturn is visible low in the morning sky not far from Venus. Mercury is in the morning sky below Venus.
Morning sky on Sunday December 2 looking east as seen from Adelaide at 5:15 am local daylight saving time in South Australia. Saturn and Venus are drawing apart, Mercury is just on the horizon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
The Full Moon is Thursday November 29, at this time there is a penumbral eclipse.
This is for real enthusiasts only, starting at 10:12 pm AEST on the 28th, with maximum at 12:33 AEST on the 29th (add one hour for daylight saving time), you will see only a faint darkening of the northern part of the Moon as it traverses Earth's outer shadow.
Bright white Venus is now quite low above the eastern horizon, and hard to see from cluttered horizons. Venus looks like a waxing Moon when seen through even a small telescope. Venus is in the constellation of Virgo.
Saturn is now visible above the eastern horizon before dawn. Saturn climbs higher in the morning sky and moves away from Venus during the week.
Mercury returns to the morning sky, but is difficult to see in the twilight below Venus. You will need a flat, unobscured horizon (like the ocean) to see it. Mercury is at its furthest from the Sun on the 5th.
Evening sky looking north as seen from Adelaide at 1:00 am local daylight time on Thursday November 29. The Moon is not far from Aldebaran and Jupiter. At this time the penumbral eclipse will be at its darkest. The keen eyed may see a slight darkening of the northern half of the Moon. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
Mars is in the constellation Sagittarius. Mars is now the brightest object in the western sky as the red star Antares, is lost in the twilight. Mars's distinctive red colour makes it relatively easy to spot.
Mars will be in binocular range of M22, one of the finest globular clusters in the sky, for most of the week.
Mars sets shortly after 9:30 pm local daylight saving time.
Mars was at opposition on March 4, when it was biggest and brightest as seen from Earth. Sadly, this is a poor opposition and Mars will be fairly small in modest telescopes.
Jupiter is still seen above the north-western horizon in the early morning sky. Jupiter is at opposition on December 3, when it is biggest and brightest as seen from Earth.
Jupiter is below the Hyades, between the red star Aldebaran and the dimmer blue white star Elnath, although closer to Aldebaran. Jupiter moves slowly towards Aldebaran during the week, making it look as if the Bull has two eyes.
Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long thin triangle in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful sight.
Jupiter is easily seen in the late evening sky, rising around 8:30 pm local daylight saving time and is moderately high by midnight. Now is the best time to observe Jupiter with a small (or large) telescope. Jupiters' Moons are easily seen in binoculars, and can be followed from night to night changing position.
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 AEDST, Western sky at 10 pm AEDST. For further details and more information on what's up in the sky, see Southern Skywatch.
Cloud cover predictions can be found at SkippySky.
Morning sky on Sunday December 2 looking east as seen from Adelaide at 5:15 am local daylight saving time in South Australia. Saturn and Venus are drawing apart, Mercury is just on the horizon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
The Full Moon is Thursday November 29, at this time there is a penumbral eclipse.
This is for real enthusiasts only, starting at 10:12 pm AEST on the 28th, with maximum at 12:33 AEST on the 29th (add one hour for daylight saving time), you will see only a faint darkening of the northern part of the Moon as it traverses Earth's outer shadow.
Bright white Venus is now quite low above the eastern horizon, and hard to see from cluttered horizons. Venus looks like a waxing Moon when seen through even a small telescope. Venus is in the constellation of Virgo.
Saturn is now visible above the eastern horizon before dawn. Saturn climbs higher in the morning sky and moves away from Venus during the week.
Mercury returns to the morning sky, but is difficult to see in the twilight below Venus. You will need a flat, unobscured horizon (like the ocean) to see it. Mercury is at its furthest from the Sun on the 5th.
Evening sky looking north as seen from Adelaide at 1:00 am local daylight time on Thursday November 29. The Moon is not far from Aldebaran and Jupiter. At this time the penumbral eclipse will be at its darkest. The keen eyed may see a slight darkening of the northern half of the Moon. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
Mars is in the constellation Sagittarius. Mars is now the brightest object in the western sky as the red star Antares, is lost in the twilight. Mars's distinctive red colour makes it relatively easy to spot.
Mars will be in binocular range of M22, one of the finest globular clusters in the sky, for most of the week.
Mars sets shortly after 9:30 pm local daylight saving time.
Mars was at opposition on March 4, when it was biggest and brightest as seen from Earth. Sadly, this is a poor opposition and Mars will be fairly small in modest telescopes.
Jupiter is still seen above the north-western horizon in the early morning sky. Jupiter is at opposition on December 3, when it is biggest and brightest as seen from Earth.
Jupiter is below the Hyades, between the red star Aldebaran and the dimmer blue white star Elnath, although closer to Aldebaran. Jupiter moves slowly towards Aldebaran during the week, making it look as if the Bull has two eyes.
Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long thin triangle in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful sight.
Jupiter is easily seen in the late evening sky, rising around 8:30 pm local daylight saving time and is moderately high by midnight. Now is the best time to observe Jupiter with a small (or large) telescope. Jupiters' Moons are easily seen in binoculars, and can be followed from night to night changing position.
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 AEDST, Western sky at 10 pm AEDST. For further details and more information on what's up in the sky, see Southern Skywatch.
Cloud cover predictions can be found at SkippySky.
Labels: weekly sky
Radar Portraits of Asteroid 2012 PA8
Image Credit NASA /JPL-Caltec
You may remember my post on catching the flyby of Asteroid 2012 PA8 when it zipped by at 16.8 Earth-Moon distances on November 5. Well, NASA's Goldstone radar caught these portraits of the asteroid as it zoomed by.
You may remember my post on catching the flyby of Asteroid 2012 PA8 when it zipped by at 16.8 Earth-Moon distances on November 5. Well, NASA's Goldstone radar caught these portraits of the asteroid as it zoomed by.
Carnival of Space #277 is Here!
Carnival of Space #277 is now up at The Venus Transit. There's astronomy podcasts, blimps in space, laser fusion, commercial flights to the Moon and some nice vintage space. Grab a balloon and float on over.
Labels: carnival of space
Sunday, November 25, 2012
More Solar Eclipse Goodness
Just thought I should mention CometAl's excellent account of his partial solar eclipse experience.
Labels: Comet Al, eclipse, solar, Sun
Saturday, November 24, 2012
Planetary Alignments and X-Class Solar Flares, Just by Chance
Planets as seen at the time of the Carrington Event, this is not much of an alignment (simulated in Celestia, click to embiggen)
Hot on the heels of claims about alignments and earthquakes, comes the notion that planetary alignments are associated with solar flares. A recent video points out that the Carrington event, the most massive solar flare ever recorded, occurred during an "alignment" (see also here). It then goes on to draw a very long bow to try and associate solar flares with planetary alignments.
Again, people apparently think that because planets are large, they will have significant gravitational/tidal effects that might affect the Sun, but as we have previously seen, these effects fall off rapidly with distance, with Venus having less than a millionth of the tidal force of the Moon, for example.
The problem is that, during a solar maximum, there are a lot of flares. There are also a lot of alignments (depending on how you define alignment, well get to that later). By chance alone you would expect to see flares and alignments overlap occasionally.
Planets as seen at the time of the1989 Event, which blacked out much of Canada. No alignment (simulated in Celestia, click to embiggen)
How frequent are flares? Well, it depends on the size of the flare and the time. The rarest and most powerful events are the X-class flares (the Carrington Event was a super X flare), and we have the most of these during solar maximum.
According to this document, there is an average of one X-class flare a month during solar maximum (which would mean that alignments and flares would pretty well occur often by chance alone). M and C class flares are even more common, the amount of data makes it hard to work with.
Of course, the flares are not evenly distributed, with far more occurring during the peak years than the start years.
I've approached the issue of alignments and flares in two ways.
For example, for the alignment on the "Night of the Smiley Face Fritz", Venus, Jupiter and the crescent Moon were all together within 3º of each other. On the same night, Mars, Mercury and the Sun were all within 3º of each other (there weren't any X-class flares though).
The "alignment" at the time of the Carrington Event had Mercury, Venus, Mars and Saturn strung out in a line that covered 12º, with Venus 7 º from the Sun. This is pretty marginal as alignments go.
For example, much tighter and closer alignments have not produced any significant solar flares. Like the 17 June 1872 conjunction when Venus, Mars and Mercury were all within 1º of each other and 7º from the Sun, nothing happened, or 22 August 1891, when Mars and Venus were 0.01º from each other and 7º from the Sun, or 19 June 1904 when Mars and Venus were 0.3º from each other and 5º from the Sun.
Or 24 August 1987, when Venus and Mars were lees than 30' (arc seconds) apart, 1º from the Sun, the Moon 3º away and Mercury 4º away, Zilch (solar flare wise).
But these are isolated examples, to get an unbiased picture of what is going on, we need to look at statistically valid samples of flares and alignments.
Which brings us back to what an alignment is.
For the purposes of this exercise, for a single planet to be aligned with the Sun, it has to be within 5º of it. For multiple planets, I've allowed that two planets must be within at last 10º of each other and at least one member of the group within 15º of the Sun.
So with those definitions, what does the flare/alignment profile look like.
Table 1. The most powerful X class flares since 1976 and their association with alignments. Alignments found using the events tool in SkyMap. Alignments defined as described above.
A Carrington Event style alignment on 15 May 2002. No flares occurred at this time (click to embiggen).
As you can see, there were no alignments during the most powerful X-class flare recorded since 1976, and neither was there an alignment during the 1989 flare that blacked out Canada. Mercury comes close to the Sun (in the absence of other planets nearby) during a few flares, but as Mercury comes close to the Sun often that is expected by chance alone.
So far not looking good for alignments and flares.
So lets look at alignments during the 2001-2003 peak of the last solar maximum.
Table 2. Planetary alignments during the last solar Maximum (2001-2003) and their association with X class flares. These are the dates when Venus and the Moon were aligned (minimum separation distance of 5º between Venus and the Moon, and maximum distance of 15º from the Sun). Other planets identified as being within either 5º of Venus or the Moon. Alignments identified using the events tool in SkyMap. Flare list from NASA, a flare occurring in the same month as any alignment was counted as positive.
Again, not looking good for flares and alignments. While there were other occasions when planets were close together they all occur too far away from the Sun (>20º) to be meaningful in the solar flare context. Also, in quiet years alignments go on quite happily, without any flares (I leave this as an exercise for the reader).
Everything we have seen is entirely consistent with chance association with flares and alignments.
The video does give some predictions, but they are very fuzzy "may result in exaggerated solar activity" this could mean anything from mere M class flares to high rating X class flares. Certainly The two X class flares we have had since July (13 July X1.4 and 23 October X1.6), were not predicted. The predicted dates of August 22 and September 21 (and the days either side) are devoid of flare activity greater than C8. October 3 and October 14 (and the days either side) miss out on anything and October 21 has an M class flare.
Hardly an encouraging hit rate, given that since July we have had roughly a C8 or larger flare roughly every 4 days. You could do better by flipping a coin.
Planetary alignments and solar flares? Just say no!
Hot on the heels of claims about alignments and earthquakes, comes the notion that planetary alignments are associated with solar flares. A recent video points out that the Carrington event, the most massive solar flare ever recorded, occurred during an "alignment" (see also here). It then goes on to draw a very long bow to try and associate solar flares with planetary alignments.
Again, people apparently think that because planets are large, they will have significant gravitational/tidal effects that might affect the Sun, but as we have previously seen, these effects fall off rapidly with distance, with Venus having less than a millionth of the tidal force of the Moon, for example.
The problem is that, during a solar maximum, there are a lot of flares. There are also a lot of alignments (depending on how you define alignment, well get to that later). By chance alone you would expect to see flares and alignments overlap occasionally.
Planets as seen at the time of the1989 Event, which blacked out much of Canada. No alignment (simulated in Celestia, click to embiggen)
How frequent are flares? Well, it depends on the size of the flare and the time. The rarest and most powerful events are the X-class flares (the Carrington Event was a super X flare), and we have the most of these during solar maximum.
According to this document, there is an average of one X-class flare a month during solar maximum (which would mean that alignments and flares would pretty well occur often by chance alone). M and C class flares are even more common, the amount of data makes it hard to work with.
Of course, the flares are not evenly distributed, with far more occurring during the peak years than the start years.
I've approached the issue of alignments and flares in two ways.
- I've taken the list of most powerful X class flares since 1976 and looked at whether there were alignments close to or during these times.
- I've looked at all alignments during the 2001-2003 solar maximum, when there were the most X-class flares, and looked to see if they are significantly associated with flares.
For example, for the alignment on the "Night of the Smiley Face Fritz", Venus, Jupiter and the crescent Moon were all together within 3º of each other. On the same night, Mars, Mercury and the Sun were all within 3º of each other (there weren't any X-class flares though).
The "alignment" at the time of the Carrington Event had Mercury, Venus, Mars and Saturn strung out in a line that covered 12º, with Venus 7 º from the Sun. This is pretty marginal as alignments go.
For example, much tighter and closer alignments have not produced any significant solar flares. Like the 17 June 1872 conjunction when Venus, Mars and Mercury were all within 1º of each other and 7º from the Sun, nothing happened, or 22 August 1891, when Mars and Venus were 0.01º from each other and 7º from the Sun, or 19 June 1904 when Mars and Venus were 0.3º from each other and 5º from the Sun.
Or 24 August 1987, when Venus and Mars were lees than 30' (arc seconds) apart, 1º from the Sun, the Moon 3º away and Mercury 4º away, Zilch (solar flare wise).
But these are isolated examples, to get an unbiased picture of what is going on, we need to look at statistically valid samples of flares and alignments.
Which brings us back to what an alignment is.
For the purposes of this exercise, for a single planet to be aligned with the Sun, it has to be within 5º of it. For multiple planets, I've allowed that two planets must be within at last 10º of each other and at least one member of the group within 15º of the Sun.
So with those definitions, what does the flare/alignment profile look like.
Table 1. The most powerful X class flares since 1976 and their association with alignments. Alignments found using the events tool in SkyMap. Alignments defined as described above.
------- | ------------------------------- | -------- | |
Ranking | Day/Month/Year | ||
------- | ------------------------------- | X-Ray Class | Alignment Present? |
1 | 4/11/2003 | X28+ | No |
2 | 2/04/2001 | X20.0 | No |
2 | 16/08/1989 | X20.0 | No |
3 | 28/10/2003 | X17.2 | Mercury 2 degrees from Sun |
4 | 7/09/2005 | X17 | Venus and Moon close, but 40 degrees from Sun |
5 | 6/03/1989 | X15.0 | No |
5 | 11/07/1978 | X15.0 | Jupiter 25' from Sun |
6 | 15/04/2001 | X14.4 | No |
7 | 24/04/1984 | X13.0 | Mercury 3 degrees from Sun |
7 | 19/10/1989 | X13.0 | No |
8 | 15/12/1982 | X12.9 | Moon 4 degrees away |
9 | 6/06/1982 | X12.0 | No |
9 | 1/06/1991 | X12.0 | No |
9 | 4/06/1991 | X12.0 | No |
9 | 6/06/1991 | X12.0 | No |
9 | 11/06/1991 | X12.0 | No |
9 | 15/06/1991 | X12.0 | Mercury 3 degrees from Sun |
10 | 17/12/1982 | X10.1 | Mercury, Venus 2 degrees from each other, 7 degrees from Sun |
10 | 20/05/1984 | X10.1 | No |
11 | 29/10/2003 | X10 | Mercury 2 degrees from Sun |
11 | 25/01/1991 | X10.0 | No |
11 | 9/06/1991 | X10.0 | No |
12 | 9/07/1982 | X 9.8 | No |
12 | 29/09/1989 | X 9.8 | Mars 1 degree from Sun, Mercury and Moon 2 degrees appart 10 degress from Sun |
13 | 22/03/1991 | X 9.4 | No |
13 | 6/11/1997 | X 9.4 | No |
14 | 24/05/1990 | X 9.3 | Moon 8 degrees away |
15 | 5/12/2006 | X 9.0 | Mars, Mercury, Jupiter within 6 degrees of each other, Jupiter 10 degrees from Sun |
15 | 6/11/1980 | X 9.0 | No |
15 | 2/11/1992 | X 9.0 | No |
A Carrington Event style alignment on 15 May 2002. No flares occurred at this time (click to embiggen).
As you can see, there were no alignments during the most powerful X-class flare recorded since 1976, and neither was there an alignment during the 1989 flare that blacked out Canada. Mercury comes close to the Sun (in the absence of other planets nearby) during a few flares, but as Mercury comes close to the Sun often that is expected by chance alone.
So far not looking good for alignments and flares.
So lets look at alignments during the 2001-2003 peak of the last solar maximum.
Table 2. Planetary alignments during the last solar Maximum (2001-2003) and their association with X class flares. These are the dates when Venus and the Moon were aligned (minimum separation distance of 5º between Venus and the Moon, and maximum distance of 15º from the Sun). Other planets identified as being within either 5º of Venus or the Moon. Alignments identified using the events tool in SkyMap. Flare list from NASA, a flare occurring in the same month as any alignment was counted as positive.
Date of Alignment | X-Class Flares? | Other Planet? |
25 Mar 2001 | Yes | No |
14 Nov 2001 | Yes | No |
14 Dec 2001 | Yes | No |
13 Jan 2002 | No | Mercury |
12 Feb 2002 | No | No |
15 May 2002 | No | No |
04 Nov 2002 | No | Mercury |
28 Jun 2003 | Yes | No |
28 Jul 2003 | No | Saturn |
27 Aug 2003 | No | Jupiter |
26 Sep 2003 | No | Mercury |
Again, not looking good for flares and alignments. While there were other occasions when planets were close together they all occur too far away from the Sun (>20º) to be meaningful in the solar flare context. Also, in quiet years alignments go on quite happily, without any flares (I leave this as an exercise for the reader).
Everything we have seen is entirely consistent with chance association with flares and alignments.
The video does give some predictions, but they are very fuzzy "may result in exaggerated solar activity" this could mean anything from mere M class flares to high rating X class flares. Certainly The two X class flares we have had since July (13 July X1.4 and 23 October X1.6), were not predicted. The predicted dates of August 22 and September 21 (and the days either side) are devoid of flare activity greater than C8. October 3 and October 14 (and the days either side) miss out on anything and October 21 has an M class flare.
Hardly an encouraging hit rate, given that since July we have had roughly a C8 or larger flare roughly every 4 days. You could do better by flipping a coin.
Planetary alignments and solar flares? Just say no!
Labels: alignment, Moon, Pseudoscience, Solar flare, Sun
Friday, November 23, 2012
Will the Alignments of November 28 Cause Earthquakes? (No, but you knew that)
Morning sky on Tuesday November 27 looking east as seen from Adelaide at 5:15 am local daylight saving time in
South Australia. Saturn and Venus are at their closest, Mercury is just on the horizon. Similar views will be
seen elsewhere at the equivalent local time
(click to embiggen).
On November 28 there will be a penumbral eclipse of the Moon. At this time Mars will be "close" to Pluto (over 4 degrees, the width of 4 fingers when you arm is outstretched, or 10 lunar diameters away from each other) and Venus and Saturn will be a much more impressive half a degree away (although that is in daylight on the 27th).
The Saturn-Venus alignments will be attractive (but difficult to see in the twilight), while Mars-Pluto will be invisible to all but serious telescopes (although Mars will be very close to the attractive globular cluster M22, a worthwhile binocular or small telescope sight).
Inner Solar system on November 28 (Pluto is too far away to fit in, click to embiggen).
And wouldn't you know, someone is claiming that these alignments will cause a magnitude 7.8 or so earthquake.
Yeah, alignments, I'm not sure why people seem to think planetary alignments are causing earthquakes. Maybe because planets are big and there's this gravity thing and uuumm, they're ALIGNMENTS man!
And there is the tide.
Now, the Moon raises not only tides in the ocean, but also tides in the crust of the Earth. Small to be sure, around 30 cm. However, you can imagine that the flexing of the Earth as the lithosphere tide passes through the Earth might set off an earthquake that was already “ready to blow” as it were. Indeed, there is a weak correlation between the lithospheric tides associated with Full/New Moon and a subclass of shallow earthquakes (increasing the probability of this subclass of earthquakes by less than 1%).
So if the Moon raises a tide, why can't the planets? And why can not the sum of the planets tidal force be big enough during an alignment to have an effect.
Now, I'm going to repeat a famous Douglas Adams line.
Tidal forces acting on Earth on November 28. Planetary orbits and planet sizes not to scale (otherwise they wouldn't fit on the image, click to embiggen).
Now, ever since this bloke called Newton got gravities measure we can actually do the calculations to work out what the tidal force between the various planets and Earth is.
There are a number of versions of the tidal force equations, and I've used a couple of them, they give much the same answers.
However, the respective Mars-Pluto and Saturn-Venus alignments are around 30 degrees from the Moon-Sun axis (see the figure above).
If you remember your tides, tidal heights are lower when the Moon and Sun are not directly aligned, so if anything, the tidal hight of ocean and earth tides will be LOWER and the risk of earthquakes less due to the Mars-Pluto, Saturn-Venus alignments.
So when I calculated the tidal forces I used a version of the equations that take the angles into account.
Tidal Force = 3/2 x GmM x (r/R3) x sin 2Theta, where G is the gravitational constant, m is the mass of earth, M is the mass of the tidally interacting body, r is the radius of Earth, R is the separation between earth and the the object and Theta is than angle between the object and the Earth-Sun axis. The spreadsheet is here so you can do your own calculations.
In the figure above, I've expressed the figures as µg and rounded up (1.72 x 10-7 g is 0.2 µg on the figure).
An analytical solution to the tidal forces shows that the tidal force due to the Earth-Moon-Sun line-up on November 28 is 1.72230242 x 10-7 g (where g is the force of gravity at Earths' Surface, yes the tidal force is rather weak, that's why tides aren't huge), adding in the tidal forces of Mars-Pluto and Venus Saturn line-ups give us 1.72230248 x 10-7 g.
That is the Mars-Pluto, Saturn-Venus line-ups add 0.00000006 x 10-7 g force to the G force produced by the Sun and Moon.
This is 106 times smaller than the variation in gravitational force due to variations in the Moons orbit (which, as we know, has virtually no effect on earthquakes). You can check this yourself via the spreadsheet.
So tremble in fear, not.
I've dealt with earthquakes and planetary and lunar alignments extensively, especially frequency and probability issues, see the lists of posts here.
David Greg has a series of videos on the various problems with prediction earthquakes from alignments (and why these predictions fail), see here and especially here.
On November 28 there will be a penumbral eclipse of the Moon. At this time Mars will be "close" to Pluto (over 4 degrees, the width of 4 fingers when you arm is outstretched, or 10 lunar diameters away from each other) and Venus and Saturn will be a much more impressive half a degree away (although that is in daylight on the 27th).
The Saturn-Venus alignments will be attractive (but difficult to see in the twilight), while Mars-Pluto will be invisible to all but serious telescopes (although Mars will be very close to the attractive globular cluster M22, a worthwhile binocular or small telescope sight).
Inner Solar system on November 28 (Pluto is too far away to fit in, click to embiggen).
And wouldn't you know, someone is claiming that these alignments will cause a magnitude 7.8 or so earthquake.
Yeah, alignments, I'm not sure why people seem to think planetary alignments are causing earthquakes. Maybe because planets are big and there's this gravity thing and uuumm, they're ALIGNMENTS man!
And there is the tide.
Now, the Moon raises not only tides in the ocean, but also tides in the crust of the Earth. Small to be sure, around 30 cm. However, you can imagine that the flexing of the Earth as the lithosphere tide passes through the Earth might set off an earthquake that was already “ready to blow” as it were. Indeed, there is a weak correlation between the lithospheric tides associated with Full/New Moon and a subclass of shallow earthquakes (increasing the probability of this subclass of earthquakes by less than 1%).
So if the Moon raises a tide, why can't the planets? And why can not the sum of the planets tidal force be big enough during an alignment to have an effect.
Now, I'm going to repeat a famous Douglas Adams line.
"Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."Sure planets are big, but space is bigger. Gravity holds it all together, but gravitational tidal force falls off rapidly with distance (as the cube of the distance, this is what we call "a lot" in technical terms) .
Tidal forces acting on Earth on November 28. Planetary orbits and planet sizes not to scale (otherwise they wouldn't fit on the image, click to embiggen).
Now, ever since this bloke called Newton got gravities measure we can actually do the calculations to work out what the tidal force between the various planets and Earth is.
There are a number of versions of the tidal force equations, and I've used a couple of them, they give much the same answers.
However, the respective Mars-Pluto and Saturn-Venus alignments are around 30 degrees from the Moon-Sun axis (see the figure above).
If you remember your tides, tidal heights are lower when the Moon and Sun are not directly aligned, so if anything, the tidal hight of ocean and earth tides will be LOWER and the risk of earthquakes less due to the Mars-Pluto, Saturn-Venus alignments.
So when I calculated the tidal forces I used a version of the equations that take the angles into account.
Tidal Force = 3/2 x GmM x (r/R3) x sin 2Theta, where G is the gravitational constant, m is the mass of earth, M is the mass of the tidally interacting body, r is the radius of Earth, R is the separation between earth and the the object and Theta is than angle between the object and the Earth-Sun axis. The spreadsheet is here so you can do your own calculations.
In the figure above, I've expressed the figures as µg and rounded up (1.72 x 10-7 g is 0.2 µg on the figure).
An analytical solution to the tidal forces shows that the tidal force due to the Earth-Moon-Sun line-up on November 28 is 1.72230242 x 10-7 g (where g is the force of gravity at Earths' Surface, yes the tidal force is rather weak, that's why tides aren't huge), adding in the tidal forces of Mars-Pluto and Venus Saturn line-ups give us 1.72230248 x 10-7 g.
That is the Mars-Pluto, Saturn-Venus line-ups add 0.00000006 x 10-7 g force to the G force produced by the Sun and Moon.
This is 106 times smaller than the variation in gravitational force due to variations in the Moons orbit (which, as we know, has virtually no effect on earthquakes). You can check this yourself via the spreadsheet.
So tremble in fear, not.
I've dealt with earthquakes and planetary and lunar alignments extensively, especially frequency and probability issues, see the lists of posts here.
David Greg has a series of videos on the various problems with prediction earthquakes from alignments (and why these predictions fail), see here and especially here.
Labels: earthquakes, Mars, Moon, Pluto, Pseudoscience, Saturn, Sun, tide, Venus
Thursday, November 22, 2012
More Eclipse Images (From NewZealand)
The beautiful image of the eclipse comes from the talented Tony Travaglia of Otago, New Zealand (click to embiggen).
The clouds give it a nice atmospheric effect, and the sunspots are crisp and clear.
The clouds give it a nice atmospheric effect, and the sunspots are crisp and clear.
Labels: eclipse, solar, Sun, Tony Travaglia
Mobile Rainbows, Tramstop Edition
Wednesday, November 21, 2012
Images from the November 14, 2012 Total Eclipse (part 2)
As well as my Olympus camera with the solar filter (images here, story here), I had my binoculars set up for projection to monitor the eclipse. This has the advantage that the image of the Sun is larger, and a number of people can watch it (which they did).
On the down side the wind and occasional patches of rain messed up my mounting, so the projection was sometimes a little wonky. But I was still able to catch parts of the eclipse that I missed due to the Olympus deciding that focussing was for other cameras.
On the day, you could see the Sunspots quite clearly, but focusing the Canon IXUS on the projected image was difficult. Still, I have a nice progression of images to complement my images taken with the solar filter.
On the down side the wind and occasional patches of rain messed up my mounting, so the projection was sometimes a little wonky. But I was still able to catch parts of the eclipse that I missed due to the Olympus deciding that focussing was for other cameras.
On the day, you could see the Sunspots quite clearly, but focusing the Canon IXUS on the projected image was difficult. Still, I have a nice progression of images to complement my images taken with the solar filter.
My binocular projection setup (with my special iTelescope astronomy hat). | Crescent Shadows of leaves on the wall near my set-up. Click on the image to embigggen |
The cresent begins to come back (I was too busy snapping shots with the Olympus to do the early exit with the projection system) | The crescent gets fatter (the image is inverted compared to the shots taken with the Olympus) |
More cresecent | More |
The moon is almost off the Sun (look closely and you can see some blurry sunspots) | And it's almost farewell to the Moon. |
Tuesday, November 20, 2012
My Leonids, 2012
Not just cloud this time, but humongous lightning. I was up with my Mum, on the way back from the eclipse, when when the Leonid peak occurred. This was at the same time as the super-storms that hurtled through Brisbane.
So, even though I was up at Dark O'Clock, the sky was completely clouded out, illuminated with flashes of lightning, making me worry I would miss my plane.
So, even though I was up at Dark O'Clock, the sky was completely clouded out, illuminated with flashes of lightning, making me worry I would miss my plane.
Carnival of Space #276 is Here!
Carnival of Space #276 is now up at Starry Critters. There's an eclipse round-up, Kepler's extended mission, talking to spacecraft and much, much more. Hop on over and have a read.
Labels: carnival of space
The Sky This Week - Thursday November 22 to Thursday November 29
The Full Moon is Thursday November 29. Mars is in Sagittarius and is close to the globular clusters M28 and M22. Mercury returns to the morning sky. Jupiter is visible in the late evening sky and is visited by the Moon on the 28th. In the morning skies Venus is low on the horizon. Saturn is visible low in the morning sky and is closest to Venus on the 27th.
Morning sky on Tuesday November 27 looking east as seen from Adelaide at 5:15 am local daylight saving time in South Australia. Saturn and Venus are at their closest, Mercury is just on the horizon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
The Full Moon is Thursday November 29.
Bright white Venus is now low above the eastern horizon, but is still not too difficult to see.
Venus is in the constellation of Virgo. Venus is relatively low to the horizon, but still clearly visible in twlight skies. It will become harder to see over the coming weeks.
Venus will still be bright, but hard to see from cluttered horizons. Venus looks like a waxing Moon when seen through even a small telescope.
Saturn is now visible above the horizon before dawn. Saturn rises towards Venus during the week with the pair closest on the 27th.
Mercury returns to the morning sky, but is difficult to see in the twilight.
Evening sky looking west as seen from Adelaide at 9:00 pm local daylight time on Saturday November 24. Mars is in Sagittarius near the globular cluster M28. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
Mars is in the constellation Sagittarius. Mars is now the brightest object in the western sky as the red star Antares, is lost in the twilight. Mars's distinctive red colour makes it relatively easy to spot.
Mars will be in binocular range of several beautiful clusters for most of the month, but is closest to two signature globular clusters this week. On the 24th Mars is closest to M28, a nice litte binocular cluster, and on the 28th it is closest to M22, one of the finest globular clusters in the sky.
Mars sets shortly after 10:30 pm local daylight saving time.
Mars was at opposition on March 4, when it was biggest and brightest as seen from Earth. Sadly, this is a poor opposition and Mars will be fairly small in modest telescopes.
Jupiter is still seen above the north-western horizon in the early morning sky. Jupiter is below the Hyades, between the red star Aldebaran and the dimmer blue white star Elnath, although closer to Aldebaran. Jupiter moves slowly towards Aldebaran during the week, making it look as if the Bull has two eyes.
Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long thin triangle in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful sight.
Jupiter is now seen in the late evening sky, rising around 9:00 pm local daylight saving time and is moderately high by midnight. It is now a reasonable telescopic object in the evening. Jupiters' Moons are easily seen in binoculars, and can be follwed from night to night changing position.
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 AEDST, Western sky at 10 pm AEDST. For further details and more information on what's up in the sky, see Southern Skywatch.
Cloud cover predictions can be found at SkippySky.
Morning sky on Tuesday November 27 looking east as seen from Adelaide at 5:15 am local daylight saving time in South Australia. Saturn and Venus are at their closest, Mercury is just on the horizon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
The Full Moon is Thursday November 29.
Bright white Venus is now low above the eastern horizon, but is still not too difficult to see.
Venus is in the constellation of Virgo. Venus is relatively low to the horizon, but still clearly visible in twlight skies. It will become harder to see over the coming weeks.
Venus will still be bright, but hard to see from cluttered horizons. Venus looks like a waxing Moon when seen through even a small telescope.
Saturn is now visible above the horizon before dawn. Saturn rises towards Venus during the week with the pair closest on the 27th.
Mercury returns to the morning sky, but is difficult to see in the twilight.
Evening sky looking west as seen from Adelaide at 9:00 pm local daylight time on Saturday November 24. Mars is in Sagittarius near the globular cluster M28. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
Mars is in the constellation Sagittarius. Mars is now the brightest object in the western sky as the red star Antares, is lost in the twilight. Mars's distinctive red colour makes it relatively easy to spot.
Mars will be in binocular range of several beautiful clusters for most of the month, but is closest to two signature globular clusters this week. On the 24th Mars is closest to M28, a nice litte binocular cluster, and on the 28th it is closest to M22, one of the finest globular clusters in the sky.
Mars sets shortly after 10:30 pm local daylight saving time.
Mars was at opposition on March 4, when it was biggest and brightest as seen from Earth. Sadly, this is a poor opposition and Mars will be fairly small in modest telescopes.
Jupiter is still seen above the north-western horizon in the early morning sky. Jupiter is below the Hyades, between the red star Aldebaran and the dimmer blue white star Elnath, although closer to Aldebaran. Jupiter moves slowly towards Aldebaran during the week, making it look as if the Bull has two eyes.
Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long thin triangle in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful sight.
Jupiter is now seen in the late evening sky, rising around 9:00 pm local daylight saving time and is moderately high by midnight. It is now a reasonable telescopic object in the evening. Jupiters' Moons are easily seen in binoculars, and can be follwed from night to night changing position.
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 AEDST, Western sky at 10 pm AEDST. For further details and more information on what's up in the sky, see Southern Skywatch.
Cloud cover predictions can be found at SkippySky.
Labels: weekly sky
Monday, November 19, 2012
Images from the November 14, 2012 Total Eclipse (part 1)
On the day of the Eclipse, after much agonising, I went for a simple set-up with my Olympus SZ-14 with a hand constructed solar filter, and a binocular projection set-up using my Canon IXUS to take photos of the projected images.
Here's the (mostly) Olympus images. The commentary that goes with these images is here. Click on any image to embiggen.
So, despite the cloud it was pretty amazing. Not just the images (made more dramatic by the tension surrounding the cloud), but also the camaraderie of the folks on the hill. I'll post the projection images later.
Here's the (mostly) Olympus images. The commentary that goes with these images is here. Click on any image to embiggen.
Shortly after Sunrise from the top of Yorkeys Knob. The clouds looked so innocent then. | The Yorkeys Knob Crew, they gave a big cheer during my telephone interview with 891 ABC radio. |
The Eclipse begins, and the clouds start in earnest | Going ... |
Going... | Going... |
Moments before totality, a big cloud had come and squatted toad like on the Sun. Note the streamers of light from behind the cloud, and the patch of Sun underneath... | .. . which disappear when totality hits. The scene was much darker than this, the Olympus auto adjusts the exposure with no manual override. It was supposed to go eerily quite, but every one was cheering and going WOW! |
Is that the Diamond Ring effect or just varying cloud thickness? | A wire thin crescent Sun returns. |
Coming back... | Coming Back.. (and here is where the Olympus decided to lose focus for about half an hour [Frustration]) |
Coming back... | Almost at the end (the Olympus again decides that focussing is for wimps) |
So, despite the cloud it was pretty amazing. Not just the images (made more dramatic by the tension surrounding the cloud), but also the camaraderie of the folks on the hill. I'll post the projection images later.