30 Dec 2007
Allow me to be a two-faced for a moment - in a good way. Like Janus, the ancient Italian deity who is depicted with two faces, one looking forward and one looking back, and for whom our month January is named, let's take a quick look back at 2007, and get ready for some events happening in 2008.
The last year in astronomy was not too too exciting for amateur astronomers. I mean, we didn’t have any local solar eclipses, or devastating supernovae, or spectacular meteor storms. But we did have our planet buddies to keep us company, and several nice comets. They, and the ever present starry firmament, are there every year and always making looking up well worth the effort.
It was a very good year as far as the technological side of astronomy is concerned. We touched down on Titan, Saturn’s largest moon, and saw for the first time its cloud-covered surface. Streams of data are still coming back from spacecraft on or around Mars and Jupiter and Saturn, all giving us unprecedented looks at these ancient planets, all helping us to refine our knowledge of our solar system, a sui generis work of art.
Astronomers also found more planets outside our solar system. Their discoveries bring joy to two groups of people: to one group who exclaims "Lots more planets means lots more chances for life!" and to those who because of the hellish nature of these new planets reason, "There's no place like home... There's no place like home..."
And after a 13-year wait, we saw first signs of life in the world's largest scientific instrument, the Large Hadron Collider in Switzerland. This critter, we hope and pray, when fully operational will be able to simulate conditions in the universe when it was a mere babe, just billionths of a second old.
Now for this coming year, 2008, there will be all kinds of wonderful techie and cosmological stuff revealed and discovered, to be sure. But what can we backyard astronomers do in the meantime, between press releases? Here are some suggestions.
On February 20, at sunset, the full Moon will rise in the east. So what? It will be announcing the opening act of a total lunar eclipse. We in Southern California will be able to watch the whole play unfold over the next several hours. Make sure you see it. We will not have another total lunar eclipse until late 2010!
If you can get a look at Saturn through a telescope this spring, do. Next year will be disappointing. Why? Saturn, like most planets, has a tilt. This year it is still slightly tilted with respect to us, so the rings still are a thing of beauty. But next year we see the glorious rings edge-on and they, in essence, vanish. Boring!
Coincidentally, Saturn will be right next to the Moon during February's eclipse extravaganza.
Here are several things you might want to try this year, as well. One would be to commit to seeing a meteor shower; they are scattered throughout the year. Another might be to see an asteroid, like the great Ceres. Or you can attempt to see all the planets in a calendar year. Perhaps subscribe to an astronomy magazine like Astronomy or Sky and Telescope. Read newspaper articles on the latest cosmological discoveries. Have deep discussions with friends and family about the philosophical and even theological implications of all that is going on in the heavens.
Learning from the past and committing to a future of deeper understanding and appreciation of the cosmos is a win-win situation. It helps us see better our place in the whole wonderful Grand Scheme of Things.
Until next time, clear skies, and a happy 2008!
12 Dec 2007
'Tis the season when many Americans celebrate a special birth that took place more than 2000 years ago. Some wise men were led to the birthplace by a star in the east, what many of us call the "Star of Bethlehem."
Well, we who love the night sky will have plenty of stars in the east to watch this Christmas season. They portend nothing nearly as significant as that other star, but they give us reason to pause in wonder, nevertheless.
If you are patient - and dressed warmly enough - you can behold the rising of three planets, "stars" as they were called in days of old, rising in the east throughout the night this month.
First up is Mars. It first peers over the eastern horizon at about 6 PM. It is at its closest to us this year this week, a mere 55 million miles away. You will notice right away that even though it is "close," it is not as "big as the Full Moon" as those false internet rumors tell us annually.
It is easy to spot, a lone, bright, pinkish "star" to the left of Orion and below the Pleiades. Should you have a telescope or be getting one for the holidays, take a look. Now is the best time. You should be able to make out surface features on the Red Planet, we are that close.
Wait a few hours and the earth will have turned right into Saturn's neighborhood. Rising in the east at about 11 PM, this gas giant is not as bright as Mars, but through a telescope will make your jaw drop.
Wait until this "star" rises higher into the sky before you take a look, though. The heat from the horizon and the turbulence it brings can make a mess of seeing. If you can't stay up past midnight for that, fear not, for I bring you tidings of joy. Over the next months Saturn will keep rising earlier in the evening. By about February the Ringed One will be perfectly placed for the best evening viewing.
Now, for the faithful and stout-hearted, if you can wait until about 4 in the morning you can spot our third "star in the east," blazing Venus. She will rise in full glory before sunrise. It might be more convenient for you to just wake up early some time in the next couple weeks and see all three together in the early morning skies.
In the five o'clock hour, before sunrise, all three will be strewn across the sky in almost a straight line from east to west, like celestial Christmas lights; Venus in the east, Saturn up above, and Mars ready to set in the west.
All three will define the line astronomers call the ecliptic, the imaginary line that the planets all ride along throughout the year. By summer, Jupiter will be on this same line in our evening skies.
Here is a challenge: Be a wise man - or woman - yourself this Christmas season. Take a break in the next couple weeks from the hustle and bustle of this busy, stressful time of the year and go outside during the evening. Take a deep breath, look up at a star in
the east, and peacefully reflect on the greater things in life. It'll do you a world of good.
Until next time, clear skies - and blessed holidays!
02 Dec 2007
Have you spotted the sun lately? No, I don't mean a naked eye glance up to our blinding friend. I mean, have you recently seen a satellite image of our sun or have you seen it through a filtered telescope? If so, you'll have noticed something. Actually you will have noticed a lack of something. It seems the sun has lost its spots.
Go to the website for the Solar and Heliospheric Observatory, SOHO. (It is at http://sohowww.nascom.nasa.gov/) There you will see for yourself one cleaned-up, near-pristine sun. It's like someone took spot remover to it and wiped away any imperfections. The sunspots are all gone!
Where did they go?
Right now we are in the middle of an expected quiet period for our star. The sun actually cycles through periods of sunspotting. It takes about eleven years to go through the cycle from lots of spots to nearly none and back to heavy. The last spotty period, also know as Solar Max, was back in 2002. Back then the sun was speckled like a leopard.
Since then the spots have gradually diminished to a point where there are essentially none today. They will return, though. The next Solar Max is expected about 2012.
But what are the sunspots and why do they come and go? It has to do with magnetic fields.
Planet Earth has a magnetic field that is relatively nice and stable and, like a giant protective bubble, diverts incoming nasty solar particles around us. It really is a wonderful effect of our planet's interior makeup.
The sun has a magnetic field, as well, a monstrous one. But it has this spinning problem. Earth spins at the same rate everywhere. Whether one is in northern Alaska or on the equator, it takes 24 hours to make one trip around.
On the sun, it ain't so. The equator of the sun spins around faster then the poles do. It can do that because it is not a solid.
But - long story short - this means the sun can actually wrap itself up in its own magnetic field. It is not unlike those rhythmic gymnasts who, if they spin fast enough, can get wrapped up in their flowing ribbon thingies.
These wrapped up magnetic field lines can squirm around like giant magnetic worms along the sun's surface. When one kinks, like when one kinks a water hose, the magnetic kink can break through the surface of the sun.
Where this happens, the sun's heat has a tough time breaking out of the sun and it is cooler there. We see these cooler areas as sunspots.
A lot of sunspots means the sun is pretty active; it is a jumbling, living, energetic surface full of energy and tangled magnetic lines and spots and prominences and flares and coronal mass ejections. Oh my!
What a mess!
But eventually it reorders itself. The sunspots disappear. Things quiet down. The sun takes a breath before the next act. We are there now, at the sun's intermission.
What does the next Solar Max hold? It's coming, there is no getting around that. But will it be a milder one as some scientists predict, or will it be up to 40% worse than the last as some computer models are showing us?
Will extra heavy activity have a minimal effect on earth's climate, or will it trigger something more profound, especially since the climate situation is getting more precarious all the time?
One way or another, for the die-hard astro fans out there, watch the sun over the next 5 years and see the slow return of the spots for yourself. But use a filter!