Venus, Jupiter and the Moon, Cosmic Ballet in February and March 2012.

For those who have been paying attention to the sky over the past few months, you will have seen Venus crawl out of the evening twilight, and Jupiter sink towards it.  These two VERY naked eye planets (both outshine even the brightest stars) are now only about 15 degrees apart (about the spread of your fingers held out at arms length), with that value set to shrink to about 3 degrees over the next 3 weeks.  Get the popcorn is ‘cos its gonna be a fantastic show!

The ballet is highlighted in the sequence below.

Venus Jupiter conjunction of 2012 (click to enlarge)

A) t= 0.  Jupiter and Venus hang in the evening sky.  Venus, by far the brighter of the two lies below Jupiter, and the pair are separated by about 15 degrees.  For reference, the Moon and Sun are about half a degree in diameter, and your outstretched fingers at arms length are about 15 degrees in angular size.

B) t= 5days.  The moons orbit takes it out of the solar glare and by the 26th it resides between Venus and Jupiter.  This will be a spectacular sight for those who get to see it, with the 2nd, 3rd and 4th brightest objects so close together in the sky.  The angular distance between the two planets has now closed to about 10 degrees.  Most of this apparent motion of Jupiter is due to the Earth moving around the Sun, while with Venus, about half of the apparent motion comes from this planet orbiting the Sun.

C) t~21 days. The Venus, Jupiter conjunction of 2012.  The two most spectacularly bright planets appear at their closest  (~3 degrees).

D) t~33days.  The Moon has now made a complete orbit since it last visited these planets.  When it last did, Jupiter was the higher, and Venus the lower.  The second time the moon visits these planets the order is reversed!  Venus the beguiling bright is now the higher of the two objects!  The objects are again separated by about 10 degrees.

For those who want to see what this looks like in animation form, take a look!  Download the  free solar system visualization software Celestia (http://www.shatters.net/celestia/)

A Night looking at Uranus!

Uranus is frequently overlooked and for many reasons.  Firstly, lets just say its name hasn’t phonetically aged well.  Secondly it’s small and faint, barely visible to the naked eye, and even the most powerful telescopes show little more than a tiny featureless grey-green disk.

Most powerful telescopes will show the five main moons of Uranus, Miranda, Ariel, Umbriel, Titania and Oberon.  The innermost of these Miranda, has, if memory serves the highest cliffs in the solar system (due to being previously (presumably) smashed by an impact) and has an orbital period of about 1.5 days.  That means you should be able to easily see its movement over the period of a night.

Now I had tried this previously, and had been surprised that the planets movement was comparable to the movement of its moons, but that night had been scuppered by a flat battery.

The stars in the background are fixed. The two picture of Uranus are taken a few hours apart, and while the moons (relatively close to the planet) don't move much, the planet conspicuously moves against the background stars!) (click to enlarge)

So it was that I set out with my scope on the evening of 22^nd Aug 2011 to see what could be captured.  I decided to head up to an observatory site that had previously seemed good up near the top of the somewhat active volcano, Lassen Peak.  The site is high, almost 2 miles up, but the seeing was less than perfect (a very constant ~ 5mile an hour wind, which was probably a blessing in that it bought warmer air from somewhere, but was also a curse due to the wind chill- I was surrounded by snow fields!).

Nonetheless, at prime focus of the 11in CPC1100 with ~1000 iso and 4 second exposure on a canon 60D seemed to bring out easily at least 4 of the moons of Uranus.

After that, I just had to maintain the kit for 8 or so hour.  A pain in the ass, as there were several pieces of kit that all need to work or the night would be ‘lost’.  So you basically have to periodically check all the batteries on the various time lapse and tracking kit are working functionally.  The bottom line is you can actually get quite a lot of sleep, but its horribly disjointed. The practical upshot of which was the next day I was wiped out to the point where I had actually planned to head up into Oregon to do something, but for the first time ever on a road trip I did something I’d never countenanced before.  I stayed a night in a motel!!  First time in 5 years!  A motel 6 I should add!  All I wanted was somewhere where I could get a shower, a bed for the night, and damn, just sit back for a moment, put my feet up, and have a glass of wine……ahhhhhh.

I was REALLY happy when I processed this, not really for what I had hoped to achieve, which was to get the motion of the moons, as while it was visible, it wasn’t that great.  But what was great was the motion of the whole Uranus system against the background stars.  I knew this MIGHT be visible, but I really didn’t expect it to looks as cool as it did!  Now it should be said that most of the motion you see here is probably not due to the motion of Uranus, but due to the motion of the Earth.  Nonetheless, its still really cool!

The finished results!