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

Nov 07

What’s Up in the Sky

What’s Up in the Sky – November, 2013

Royal Sky Has Visitor (We Hope)

Robert Wade is the most accomplished and dedicated amateur astronomer I have ever known. A group of us were out observing in November of 2001, dutifully recording what we saw in our log books when Robert suddenly realized that, in twenty years of observing, this was the first entry he had ever made in his journal dated November. He was probably more surprised than we were, but this is a testimonial to the weather around here at this time of year.

If we luck out again this year, your best bets for observing this month will include the crescent Moon and Venus in the southwest one hour after sunset on Wednesday, November 6.

Later in the month you may be hearing a lot about Comet ISON, which may or may not be spectacular in December. It is currently on its way in toward the sun and will pass within 725,000 miles of its surface (less than one solar diameter) on Thanksgiving Day. This could either make for a very nice tail or destroy the nucleus, we won’t know for a while.

Do not despair, though, because it may be possible to spot it before it almost burns up. On the weekend before Thanksgiving, go outside about 7 a.m. and look toward the southeastern horizon. You should be able to spot two “stars” (actually Mercury and Saturn) close together near the horizon. With a pair of binoculars, scan to their right and you should be able to see the comet. This whole endeavor requires a clear horizon at dawn in November. Good luck with that.

Regardless of the weather we can always enjoy the mythology of the stars and this month we have some interesting figures to enjoy. Facing north, look almost directly overhead for the Great Square of Pegasus and use binoculars to scan straight up for the Andromeda Galaxy. Farther north you will see the “W” – shaped Cassiopeia.

Because of her boastful vanity, Queen Cassiopeia is ordered to sacrifice her beautiful daughter Andromeda to the sea monster, Cetus. Andromeda is chained to a rock on the sea coast but is saved by Perseus who kills the monster after her parents agree offer their daughter’s hand in marriage. The two are joyfully married, but the gods are still angry with Cassiopeia and she must spend half of every night upside-down.

What more could you ask for up in the sky.

This month in history:
Nov. 3: The dog Laika is first living creature to orbit Earth, aboard Sputnik 2 – 1957
Nov. 9: Carl Sagan born. – 1934
Nov. 13: Mariner 9 is first spacecraft to orbit Mars – 1971
Nov. 18: Alan Shepard born – 1923
Nov. 27: First photograph of a meteor shower – 1885

Oct 01

What’s Up in the Sky

What’s Up in the Sky – October, 2013

Eagles and Dolphins and Swans, Oh My!

If you are reading this, you probably know about the Summer Triangle. Vega, Deneb, and Altair make up this asterism which is almost directly overhead and visible all month. Let’s take a look at some of the mythology surrounding these constellations and then see how we can use them as guides to cool stuff.

Face south. Look up. Better yet, lie down on a lawn chair. You will see a triangle of stars standing on its point. The brightest, Vega (VEE-ga), is in the constellation Lyra (the Lyre), which appears as a small equilateral triangle attached to a parallelogram below it. The lyre, a small, stringed instrument like a little harp, was by some accounts, invented by the god Hermes. He gave it to his half-brother Apollo, who passed it along to Orpheus, his son. So talented on the instrument was Orpheus that he was able to use it to charm Pluto and the guardians of the underworld to allow his wife, Eurydice, the victim of a viper bite, to return with him to earth. Of course, there were conditions: he would have to walk ahead of her and was not look back until they had both returned to the upper world. You can probably guess how that turned out.

At the top left of the triangle is Deneb, the tail of Cygnus, the Swan, and at the bottom is Altair, in the constellation Aquilla, the Eagle. The swan is usually depicted as flying down the Milky Way toward the horizon while the eagle is seen as flying in the opposite direction.

According to legend, Aquilla was the bird of Zeus and when the king of the gods needed an errand run between heaven and earth, he called on Aquilla. The bird was rewarded for his loyal service with a place among the stars.

Between the swan and the eagle are two little constellations that are fun to learn. Look right above Altair for a small group of four stars. This is Sagitta, the Arrow, and is sometimes described as having been shot at the eagle by Sagittarius, the Archer (luckily it missed). Sometimes the arrow is shown in Aquilla’s talons and other times it is associated with Cupid’s arrow.

Just to the left of Sagitta is one of my personal favorites, Delphinus, the Dolphin. It looks like a little diamond of stars with a tail. There is an interesting story about two of the stars in this constellation, Sualocin and Rotanev. The names were first published in a star catalogue compiled at the Palermo (Italy) observatory in 1814. Turns out that if you reverse the spelling you get Nicholaus Venator, an assistant astronomer at the observatory!

I guess that’s one way to get you name up in the sky.

This month in history:
Oct. 1: NASA founded – 1958
Oct. 5: Robert Goddard born – 1882
Oct. 8: MESSENGER spacecraft makes second flyby of Mercury – 2008
Oct. 14: Chuck Yeager breaks sound barrier – 1947
Oct. 22: First record of solar eclipse – 2136 BCE
Oct. 30: STS-61A Challenger Space Shuttle launched – 1985

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