May 04

What’s Up in the Sky

What’s Up in the Sky – May, 2014

We May Have Showers After Flowers

“April showers bring May flowers” is an old saying that most of us in Holland hope will ring true for Tulip Time. But this year I am hoping for a May shower of a different kind. In fact many astronomers are hoping it will be a storm . . . of meteors.

Most of us are familiar with meteor showers like the Perseids or Leonids, where we sit outside for several hours well into the night and watch for “shooting stars”. If we are able to spot a couple of dozen, it was a good night. But this month we may be in for a real treat.

As many of you know, a meteor shower occurs when the Earth passes through the trail of debris left by a comet after a close encounter with a planet (in this case, Jupiter) or the Sun. Particles ranging in size from dust to small pebbles are released during each passage and continue to follow the comet’s path. The same gravitational forces responsible for the disturbance also tend to”herd” the debris into clumps or streams that continue to orbit the Sun. Next month it is possible that these past dust trails may pile up on one another thus increasing the number of meteors visible.

At this point I must warn you that there are no guarantees in meteor astronomy and estimates range from less than 100 to over 400 meteors per hour. Experts are very cautious with their predictions and often add disclaimers like “rates might be much lower” and “I would not bet on a meteor storm”.

On the positive side, several favorable factors will increase the chance of a good show. There will be no bright Moon to interfere, and the meteors will be unusually slow-moving and are likely to be very bright. And there may be more than one peak of activity, but you will have to be watching between 3-4 a.m. on Saturday, May 24. Hey, just stay up really late Friday night. It’s a long weekend.

If that is too early (or late, as the case may be), the very next morning, Sunday, May 25, look toward the eastern horizon one hour before sunrise for a spectacular pairing of the crescent Moon and Venus. There is no doubt you will be able to see this as long as the weather cooperates.
So, whether high or low, there are good things to see this month up in the sky.

This month in history:
May 5: Alan Shepard becomes first American in space – 1961
May 11: Launch of first geostationary weather satellite – 1974
May 14: Skylab is launched – 1973
May 20: Pioneer-Venus 1 launched – 1978
May 29: First experimental test of Einstein’s General Theory of Relativity performed during total solar eclipse – 1919

Apr 04

What’s Up in the Sky

What’s Up in the Sky – April, 2014

Ever Seen an Occultation?

When I began researching topics for this month’s column, I was excited to see that there will be a total lunar eclipse this month. Unfortunately, you will have to stay up past 4 a.m. in order to witness the whole thing. Not to worry, though, as Mars will put on quite a show and the Moon will occult (pass in front of) several stars. Now, if we can get some clear weather, this could be a good month.

Astronomical observations do not have to be complicated or require expensive equipment. Some of the best events I have observed have been with the naked eye or binoculars and we will have just such an opportunity on the evening of Thursday, April 3. On that date the Moon will pass in front of (occult) several fairly bright stars in the Hyades star cluster.

On the plus side this occultation takes place at a good time and the objects involved will be easy to find. On the minus side it happens near the horizon so we will need an unobstructed view and good weather. That being said, I strongly recommend the use of binoculars and a good clock. The binocs will help you see it and the clock will tell you when to look, which is pretty important.

Go out around 10 p.m. and look due west near the horizon. The crescent Moon should be easily visible between Orion on the left and the Pleiades on the right. Right next to the Moon you should spot a V-shaped group of about five or six stars. Now watch as the Moon approaches the stars, getting closer and closer until, at about 10:15, the star will disappear behind the unlit side of the Moon.

There are two things I like about this observation. First, you are seeing two apparent motions of the Moon – it moves closer to the horizon due to the rotation of the Earth and it gets closer to the star cluster due to its own orbital motion around the Earth. Second, as the separation between the star and Moon decreases, it becomes possible to actually witness the Moon’s motion with respect to the background stars – not an easy thing to see usually.

As for the lunar eclipse, if you plan to be up all night on the 14th, definitely check it out. And yes, Mars is close this month and up all night, but it is only well placed for viewing after midnight. It will be earlier next month.

So this month, the lunar occultation will be your best chance to enjoy what’s up in the sky.

This month in history:
April 2: First photograph of Sun taken – 1845
April 12: Yuri Gagarin becomes first human in space – 1961
April 12: Columbia is first space shuttle to be launched – 1981
April 17: Apollo 13 returns to Earth – 1970
April 20: Shapley-Curtis debate on the distance and nature of spiral nebulae – 1920
April 25: Deployment of Hubble Space Telescope – 1990

Mar 10

What’s Up in the Sky

 

What’s Up in the Sky – March, 2014

Remembering Dobson

“You should build a telescope”, said the gentleman from the Vivekananda Monastery in Ganges, MI. The year was 1990, the place was Fennville HS, and the person leading the telescope building workshop was John Dobson.

So that summer, with my school’s support, I spent five days constructing a 10-inch dobsonian telescope. I knew at the time that building a telescope with John Dobson, (the dobsonian telescope is his namesake), would be like constructing a violin with Antonio Stradivari, but I was not prepared for what was to follow.

Dobson was a genius but his skills as an instructor were, shall we say, unique. There were about a half dozen participants in the workshop and he had no patience for slackers or whiners and he did not mince words. His style of pointing out and correcting our mistakes was sometimes described as scolding, and one or two folks left after only a couple of days. But the rest of us took his comments in stride and soon learned to gain his respect and support through hard work and adherence to instructions.

We built our telescopes out of cardboard tubing. plywood, PVC, and common items such as LPs and carpet scraps. We ground the mirrors and constructed the boxes all by hand. In fact, we probably spent four out of the five days on the mirror. My mirror blank was a circular piece of glass two inches thick and ten inches in diameter. The grinding process involves simply rubbing two pieces of glass together (the mirror blank on top of the “tool”) and with water and fine sand or “grit” one becomes concave and the other convex. Of course, “simply” doesn’t count the fact that the blank weighed over ten pounds and I did it for about twenty five hours. I remember after one day of grinding one of my pinkies was completely numb.

During this process the curvature of the glass is closely tested and measured since that is a critical factor in the mirror’s final quality. The last fine step is called “figuring” or fine-tuning the curve. I remember being delayed the last morning and when I arrived, John had figured my mirror himself. I always felt that this was a tremendous complement because he NEVER did any of our work for us and rarely gave verbal praise. So when he did the most critical step himself, I felt pretty good.

John was a man of simple means who devoted his life to amateur astronomy, introducing tens of thousands of people to the wonders of the night sky. During his time in West Michigan he spoke at my school and the local astronomy club as well as doing public observing and telescope making at Vivekananda.

John Dobson died January 15. He will be greatly missed and fondly remembered by those who enjoy looking up in the sky.

This month in history:
March 2: Pioneer 10 launched – 1972
March 6: Kepler Observatory launched – 2009
March 14: Albert Einstein born – 1879; Gene Cernan born – 1934
March 18: Soviet rocket explosion at launch pad kills 50 workers – 1980
March 22: Comet Hale-Bopp passes closest to Earth – 1997
March 31: Mariner 10 makes first flyby of Mercury – 1974

JohnDobson-PeterBurkey

John Dobson and Peter Burkey

JohnDobson

John Dobson in 1990

 

Feb 05

What’s Up in the Sky

What’s Up in the Sky – February, 2014

Everyone Loves Jupiter

When choosing the topics for this column I always try to consider the demographics of my readership. Should I really devote an entire story to observing faint galaxies that rise after midnight or a close Moon/planet pairing that occurs an hour before sunrise? In February? With this weather? I doubt many readers are devoted enough to undertake such endeavors. I know I’m not.

I was thinking about this recently when the phone rang and I heard my friend Phil Kloske’s voice asking about an “incredibly bright” object in the sky. Phil was in San Diego and, even with the help of a phone app, he was not able to identify what he was seeing.

Bingo. That’s the demographic I serve: those who not only enjoy observing the sky, but also are interested in identifying and learning about what they see.

The “star” of February’s show, so to speak, is actually a planet – Jupiter – and that is what caught my friend’s eye. Jupiter is well up in the southeast each evening reaching its greatest height above the horizon well before midnight, making it an excellent target for a small telescope.

The planet is easy to find since it’s by far the brightest non-lunar object up there. Go out around 9 p.m., look south and you will see Orion and his three distinctive belt stars. If you follow the line of belt stars down and to the left you will see a very bright object that is not Jupiter, but Sirius, the brightest star in our sky. Look above and to the left of Orion and Jupiter should jump out at you. Ir’s about half way between Orion’s belt and the twin stars Castor and Pollux in Gemini. If you have any doubts, check out the scene on February 10th when the Moon will appear to be directly below the planet.

A neat thing about Jupiter is it’s easy to observe really cool stuff. Binoculars steadied on a tripod or even a signpost reveal its four brightest moons. With a small telescope you can observe events such as transits (when a moon passes in front of the planet) and eclipses (when a moon passes through the shadow of the planet). But even with the naked eye, the beauty and brilliance of Jupiter remind us why the ancients made it the King of all that was up in the sky.
This month in history:
Feb. 1: Shuttle Columbia breaks apart during reentry killing all 7 astronauts – 2003
Feb. 7: First untethered spacewalk made by Bruce McCandless – 1984
Feb. 14: Voyager 1 looks back to take photo of solar system – 1990
Feb. 18: Pluto discovered – 1930
Feb. 23: Light from supernova 1987a reaches Earth – 1987
Feb. 28: Charles Bassett and Elliot See, Gemini IX crew, die in plane crash – 1966

 

Jan 05

What’s Up in the Sky

What’s Up in the Sky – January, 2014

An Interesting Time of the Year

A Private Universe is a classic video documentary produced by the Harvard-Smithsonian Center for Astrophysics that examines the mystery of why the most basic scientific concepts are so widely misunderstood. I was reminded of the famous opening scene at Harvard graduation recently when I was visiting a highly regarded, first class local exhibition. In short, the wording on one of the descriptive placards led us to believe that it is summer in Australia at Christmas because the earth’s axis is tilted so that the southern hemisphere is closer to the sun than we in the north are.

I was astounded! This was not a ninth grade paper I was reading, but an explanatory placard of very high quality written by an obviously well-educated individual working for a prestigious institution. So, I wondered, why are the most basic scientific concepts so widely misunderstood? Therefore, here goes my contribution to the effort to reverse this trend.

Yes, Australia is a little closer to the Sun this time of year. But consider this: the entire earth is two million miles closer to the Sun than it is in July. That’s over 350 times the diameter of our entire planet so I can’t believe being in the south makes that much difference. If the campfire feels the same if you take two steps toward it, I’m sure your nose is as warm as your forehead.

So what does cause the seasons? Google does a splendid job on this so let me just suggest a wee demo: shine a flashlight straight down on the floor and notice the area lit up. Then change the angle of the flashlight and notice that the same amount of light is now spread over a larger area. So in the winter the same amount of heat from the Sun is spread over a larger area so the average temperature drops. Plus, winter days are short so the entire hemisphere receives less sunlight over a given day.

I was also recently asked this question: why don’t the earliest sunset and latest sunrise occur on the shortest day of the year? That one is beyond the scope of this column and requires extensive knowledge of what’s up in the sky.

This month in history:
Jan. 1: Isaac Azimov born – 1920
Jan. 13: Galileo discovers Ganymede, moon of Jupiter – 1610
Jan. 15: Samples of comet dust returned by Stardust spacecraft – 2006
Jan. 22: Apollo 5 launched = 1968
Jan. 27: Apollo 1 astronauts Chaffee, White and Grissom die in fire in capsule-1967
Jan. 28: Seven astronauts killed when Space Shuttle Challenger explodes during launch – 1986

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