The late hours of Monday night (24.08.09) brought an opportunity to take in a quick observation of Jupiter with the 25×100 binoculars. Initially I could only discern three of the Galilean moons, but further investigation revealed the fourth elusive satellite — Io — hugging close by Europa. Upon checking ‘The Night Sky’ section in my August edition of Astronomy Now I realised that I was witnessing a burgeoning occultation as Io converged upon Europa. Unfortunately I was unable to watch this entire Jovian event unfold, but it was fascinating to see the wafer-thin gap between the shimmering moons slowly disappear as they drifted towards their celestial rendezvous.
Posts Tagged ‘Jupiter’
Jul
15
2009
Three Times the Charm
Jupiter, the majestic giant of the solar system, has always been my favourite planet. While Saturn delivers undeniably glorious views; Jupiter, at least for me, has always stolen the show. Having suffered a grueling month of cloudy evenings, and twilight nights, the chance to take in an observation of this dazzling planetary behemoth early on Saturday morning was a welcome one.
The fact that Jupiter was in conjunction with Neptune, and the star µ (Mu) Capricorni just added to the celestial spectacle. My view however was to be a short lived one. Due to the urban geography of the neighbourhood; both planets remained in my sights for only 16 minutes before disappearing behind the row of three storey buildings that line the front of the house.
A Planetary Dance
Despite my brief window of opportunity I was afforded a stunning observation. The 25mm Celestron plössl revealed the equatorial belts of Jupiter as rust coloured bands, while the four moons: Callisto, Ganymede, Io, and Europa beamed like a string of brilliant diamonds against the dark sky. Having conducted my most recent observations of Jupiter with the 25×100 Strathspey binoculars; it was a real pleasure to see this distant world with such clarity.
While Jupiter made a striking impression; Neptune, bathing in the alabaster light of the waning gibbous Moon, was just discernible as a faint point of light with a hazy turquoise hue. This is the second time that I have been fortunate enough to view this remote ice giant which sits just over 2 billion miles from the Earth. Gazing upon this diminutive speck you realise that you are actually looking at the end of planetary space beyond which begins the Kupier belt, the Oort cloud, and finally galactic space. An amazing, but rather humbling thought.
In between this planetary dance µ Capricorni, a yellow-white F3 IV type subgiant that lies 90.2 light years away, cast it’s white incandescent light upon the scene. Subgiants are stars which have, or are in the process of ending hydrogen fusion. Beyond this point in it’s evolution µ Capricorni is destined to become a red giant that may, at some point in the far flung future, bloom into a planetary nebula.
As quickly as Jupiter, and Neptune had risen above the roof tops then no sooner were they gone. Hidden from view by the suburban sprawl. Left alone with the Moon, which made for a very tempting target, I decided to make the most of it by taking in one more special observation before packing up.
One Giant Leap
Forty years ago, on the 20th of July 1969, NASA realised the mandate that the late President John F. Kennedy had laid down eight years earlier: to land a man on the Moon, and return him safely to the Earth. Apollo 11, carrying the astronauts Neil Armstrong, Michael Collins, and Edwin ‘Buzz’ Aldrin, set down near the south western shore of the Mare Tranquillitatis, and made history.
It was here that I aimed the telescope in search of three small craterlets: Aldrin, Collins, and Armstrong; all of which form a chain just east of the larger impact craters Ritter, and Sabine. After ten minutes of continued scrutiny the 6mm plössl finally resolved these three small monuments to the first manned lunar landing. In reality Aldrin, Collins, and Armstrong range in size from 2.4 Km to 4.6 Km giving some idea of just how vast this region of the Moon really is.
Letting my gaze drift down not far from Collins I imagined the quiescent remnants of Tranquility Base, also known as Statio Tranquillitatis, forever frozen in time by the vacuum of space. A lasting testament not only to the triumph of Apollo 11, or the United States of America, but probably the single greatest achievement Mankind has ever made. Where the 21st Century will take space exploration is anyone’s guess, but hopefully one day humanity will find itself once again voyaging to the Moon, and beyond.
If you have the time then why not follow in the footsteps of the Apollo 11 astronauts by tracking down the craterlets Aldrin, Collins, and Armstrong yourself. The best time to do this is nearer the end of the month, on the 27th of July, five days after the new Moon. I’d also recommend that you take in an view of Jupiter, and Neptune as they drift past one another in the night sky. This is the second of three conjunctions that will take place between these two planets during the year, with the third one to occur on the 20th of December. Have fun, and happy observing!
Mar
06
2009
Europan Dreams
The Jovian moon of Europa is surrounded by plenty of mystery and lots of speculation. Slightly smaller than our own moon, it is composed largely of silicate rock with a tenuous exosphere of molecular oxygen and a possible iron core. The surface is predominantly made of ice and while it is checkered with streaks and fractures it is in fact one of the smoothest in the whole solar system. This smooth but variegated surface resembles images of sea ice as seen on Earth and has led many planetary scientists to believe that there is a vast subsurface ocean of liquid water below the frozen crust.
Tentative evidence for this ocean can be seen by looking at what has been termed ‘chaos terrain’, an area where some believe the subsurface ocean has melted through the icy exterior due to tidal up-welling. Other evidence can be found in the data that the Galileo probe obtained, showing that Europa has a weak magnetic field induced through Jupiter’s own, suggesting the presence of a conductive sub layer i.e an ocean of liquid saltwater .
If indeed there is an ocean under the frigid surface, then it is plausible to think that extraterrestrial life might exist, but what kind of life? This proposition hinges on one fact: the temperature of Europa’s ocean. While the moon may possess an internal energy source, it is insufficient to provide the necessary heat to help maintain biological processes. However, the orbital resonance between Jupiter, Io, Europa and Ganymede probably heats the interior of the moon through tidal flexing which would ensure that the ocean remained liquid. The energy from the tidal flexing could also possibly be released through hydrothermal vents much like the black and white smokers that are found on Earth’s ocean floor. Europa’s hydrothermal vents could provide the ideal conditions for a more modest ecosystem than those found around Earth’s vents but they would support a hot, nutrient rich environment in which micro organisms like anaerobes and archaea could potentially thrive.
The only way that we will know for sure what lies beneath Europa’s mysterious surface is by going there, and it looks like we’re going to get our chance. NASA and ESA announced near the end of last month that they were going to undertake a joint mission to launch two probes by the end of the next decade to study Jupiter and it’s four moons. Just what discoveries will be made about Europa is anyone’s guess, but they’re sure to be extremely exciting and very compelling.
Feb
18
2009
Domain of the Titans
Over the course of my previous observing sessions I have taken every opportunity to take in a view of the magnificent outer planet Saturn. A small telescope or a pair of high powered binoculars will reveal some of the moons as well as the majestic rings which are a fantastic sight to behold. Saturn can currently be found under the constellation of Leo just below the star Chertan (a simple finder chart can be downloaded from here), and at magnitude 0.93 it’s looking pretty bright. From 21:30 UT onwards Saturn is well placed for observation and is on show the whole night/morning through, not beginning to set until 06:19 UT. From my own experiences so far (using a pair of 25×100 binoculars) I have been able to observe the rings as well as two moons: Titan and Hyperion. However for a truly in-depth observation I would highly recommend a telescope with a long focal length - a 60mm refractor with a minimum focal length of 800mm will easily be up to the task.
Physically Saturn is very similar to Jupiter - composed mainly of hydrogen and helium with trace amounts of ethane, ammonia, methane, phosphine and acetylene. What differentiates Saturn from Jupiter is it’s stunning yet mysterious system of rings. Made from fragments of ice and rock, the rings extend 4,ooo miles above the cloud decks of Saturn out to 46,250 miles. The material in these rings is made up of 99.9 percent pure water ice and range in size from dust particels to objects a few meters across. There are various theories regarding the formation of the rings - the French scientist Édouard Roche promoted the idea that the rings were the detritus of a moon torn apart by tidal forces after it strayed too close to Saturn. Others suggest that the rings are the remains of the material from which Saturn was formed or the debris from a small moon that was obliterated by a comet/asteroid impact. The formation of the rings will probably forever remain a mystery, but either way they are one of the most awe inspiring marvels in our cosmic backyard. So the next time you are out observing, take a moment to turn your binoculars or telescope on to this wonderful planet and drink in the view.
[Image editied: 18.02.09]
Dec
26
2008
Navigating the Static
December has proved to be a difficult month for observing in my neck of the woods. While the weather held out for the lunar occultation of Venus on the 1st of December, the rest of the month has all but disappeared under a carpet of overcast cloud. Following right on the back of the occultation was the Geminid meteor shower which for everyone concerned was more or less a washout due to a full moon. Any hopes I had of getting out to try and observe even just a few of the brighter Geminid meteors were squashed by this ever predictable weather. The Ursid shower looked like my last hope for a meteoric display before the year was out, but with the elements set against me I wasn’t optimistic of my chances.
A tweet from fellow Twitterer TaviGreiner changed all that. A keen astrophotographer, Tavi was featured over at universetoday.com for her stunning picture of the triple conjunction of the Moon, Venus and Jupiter back at the beginning of the month which you can see here.
Tavi’s tweet was a reminder about the Ursids peak on the 22nd/23rd of December and included a link to the fantastic web site SpaceWeather.com. Here you could listen in on the Ursids via an audio stream coming from their FM receiving station as the meteoroids entered the atmosphere. Albeit that this was on the other side of the world I was highly delighted as it meant it no longer mattered if I was able to visually observe the Ursid shower or not. Between 23:24 - 02:00 UT I listened in and picked up seven fairly prominent pings (when a meteoroid enters the atmosphere) which is pretty good going I think considering it was my first time taking part in any kind of radio astronomy. The great thing about this kind of observing is that you don’t have to bear the freezing cold temperatures of the winter nights. The down side is that you don’t get the wow factor of visually catching the meteoroids blazing a trail across the sky, but it is great fun nonetheless.
Coming from a sound engineering background this kind of thing has really piqued my curiosity and I’m giving serious thought to setting up my own radio meteor observatory so that I can listen in as the various major meteor showers occur above my local area. If this sounds like you’re kind of thing or you’re just interested in finding out more I would recommend taking a look at this great web site: www.radiodesignservices.co.uk