# Monthly Archives: February 2013

## A Leap of… Imprecise Astronomical Calculations

Simulated image of the path of the Sun during the Winter Solstice created by

February 28th is the last day of the month, which means that this is not a Leap Year. As you probably know, every four years we add an extra day onto February assuming that we didn’t do so in the last 300 years. Since this is a somewhat confusing and imprecise system, I thought I’d devote some time to explaining it here.

The reason we don’t have a precise calendar with a nice round 365 day year is because calendars are based around a rather imprecise clock- The Earth. Because of the Earth’s dizzying running pace of 19 miles per second around the Sun, it actually turns nearly four extra quarter turns on its axis, which adds up to one extra day, and that is why we add an extra day on February 29th. But here’s the catch- it’s not actually a complete day, which means that after a few centuries, the accumulated time we lose by adding a day means that we get off track with the Earth’s cycle around the Sun. This is why we skip a leap year every 400 years. The year 2000 was a leap year, but the year 2100 won’t be.

I found this nifty little algorithm to help you figure out whether or not the current year is a leap year:

Ithe year is divisible by 400 then
it  is a leap_year
If the year is divisible by 100 then
not_leap_year
If the year is divisible by 4 then it is a leap year.

In this video, you can see a fun look about the science and history behind this phenomenon, and how it relates to, -gasp- MY FAVORITE STAR- SIRIUS:

As you can see from the video, the human race has evolved a great deal of calendars over the years to precisely track the motions of the planet around the Sun: the Egyptian, Mayan, the Julian, and Gregorian. Even today, with our cesium laser powered atomic clocks, we still use this system as the basis for how the world tells time; as mammals we still respond to the cycle of our planet, its Sun, and its moon, and we depend on that to keep our lives in sync with the rhythm of the cosmos. Imperfect though it may be, it is what links us with the rest of creation.

So enjoy this non-leap year, and while you do, take a little time to think about how you are part of this great cosmic dance, and how our planet knows the steps even after 4.6 billion years.

Happy Stargazing!

Paul

## A Shining Proposal

Real Moon dust from NASA, currently being studied by the University of Boulder Colorado

Last week I got my fiancee her wedding ring, just in time for Valentine’s day. Although she was thrilled, I was kind of taken aback when I read in the New York Times about a far stranger love gesture- giving the girl you like a spoon full of Moon-dust!

As you can see, lunar dust (pictured left), has a grayish charcoal-like appearance. The astronauts from Apollo 11 even said it smells like gunpowder as it coated the boots of their space suits. It actually cut up parts of the ship like finely ground glass.

In this particular story, a young male astronomer who was examining lunar dust, (possibly at the University of Boulder Colorado), wanted to impress his sweetheart, so he gave her a spoonful of the lunar dust. Before the university could confiscate the valuable material, SHE ATE IT! According to Dava Sobel, an astronomy reporter from the New York Times, (and a personal friend of the woman in question), The lunar dust was incredibly shiny and bright, and seemed to take on a mystical quality as it entered the woman’s body:

I exaggerate the romance of the incident in my reverie, so that as the moon dust enters Carolyn’s mouth, it ignites on contact with her saliva, shooting sparks that lodge in her every cell. Crystalline and alien, it illuminates her body’s dark recesses like pixie powder, thrums the senseless tune of a wind chime through her veins. By its sacred presence it changes her very nature: Carolyn the moon goddess (excerpt from New York Times.com 10/1/95)

It is probably not true that lunar dust could actually shine from within you, but it is true that lunar rocks reflect a lot of light, which is why the Moon shines like a mirror at night when the Sun hits it. The dust itself is also very jagged and shiny like finely ground glass, which is why eating lunar dust in great quantities could pose some great health risks, as scientist Jennifer Hedmann explains in this video.

Some studies suggest that breathing Moon-dust could actually damage a person’s lungs. With their fine powder, the dust particles could damage the fine air sacks in the lungs that we need to provide oxygen-rich blood to our cells, in a fashion similar to Stone-Cutters disease. So in the future, if human beings ever do return to the Moon, they will have to be very careful about dusting.

Unfortunately, this romantic gesture didn’t quite work- the woman in question never married her astronomer boyfriend, and soon he and the Moon dust in her body just… slipped away. So I suppose if there is a lesson to ladies looking for a man to give them the Moon and the stars it’s probably this: some men are good for your heart, but not good for  your lungs. And to the men I say, “stick to Earth rocks.”

Till next time, Happy Star gazing!

Paul

## Updates For This Week 2/18- 2/24

Hi everyone,

I’m playing a little bit of catch up, since I spent yesterday enjoying my birthday, so here’s the topics I’ll be covering for the rest of the week:

Comparison in scale between planets of the solar system, and Kepler 37b (NASA- public domain)

Today In Space History: Today I’ve posted a brand new discovery of the extrasolar planet Kepler 37b- the smallest planet ever discovered! It’s only about the size of the moon, and orbits its closest star in less than a month.

Map of the zodiac constellations with Pisces emphasized.

This Month In Astrology: Pisces. My birthday, (like Copernicus’) falls on the zodiac sign Pisces, which runs from February 19th-March 20th. Tonight I’ll be writing some interesting details about my own star sign- the placement in the sky, the elements. and the dominant characteristics that a Piscean such as myself is supposed to have. I’ll also be writing a post where I’ll teach you to create your own horoscope!

Image of Taurus the Bull, taken from 15th century Norman astrology book.

Astronomy Myths and Legends: Taurus Right now, the Moon and the planet Jupiter are right in the eye of the constellation Taurus the Bull. I thought I’d give you guys some insight into this zodiac constellation, and the somewhat curious myth that spawned it.

Dr. Neil DeGrasse Tyson, listens during a meeting of the council at the Rayburn Building on Capitol Hill.

Special Post (Today In Space History) Dr. Neil DeGrasse Tyson, one of the greatest astrophysicists of our time, and director of the Heyden Planetarium.

Asteroid DA 14, which will pass the Earth at a distance of about 17,000 miles February 15th.

Special Post- How to Survive an Asteroid Impact!

Enjoy all this as the week goes on!

-Paul

## Happy Birthday Copernicus (and also ME!)

Hello everyone!

Today is my birthday, as well as the Renaissance scholar and astronomer Nicholas Copernicus, who helped prove that the Earth revolves around the Sun. To be honest, I’m taking a little break today to enjoy my own birthday, so in my absence, enjoy this documentary about Copernicus, and I’ll be back tomorrow.

See you,

Paul

## Doom From the Skies- week of 2/11-2/17

Photo of the meteor that disintegrated over Russia’s Ural mountains on February 15th.

HOOLY COW! What a week it has been- between the asteroids going across the globe, a comet in Australia, meteors in Russia, and lightning strikes in Rome; it seems like the gods of astronomy are working overtime to make this a very fascinating week. I have posted a recap of this week’s events on Today In Astronomy to fill you in on anything you missed, with the best reporting the web can offer!

Enjoy!

-Paul

## Best Way To See the Asteroid Tonight

Hi stargazers!

Asteroid DA 14, which will pass the Earth at a distance of about 17,000 miles February 15th.

Asteroid DA 14 is due in the skies in North America in the next two hours, so I thought I’d provide links to the best live coverage. First, here’s a

live feed from NASA that begins at 9PM EST:

http://www.ustream.tv/channel/nasa-msfc

Secondly, here’s a compilation of clips from astronomers at SLOOH.com, which was featured on Dateline last night:

That’s all I got for now, I gotta get ready for the tour tonight!

Happy asteroid-viewing!

Ursa Major, otherwise known as The Big Dipper

Hi everyone!

Since it is Black History Month, I wanted to talk about a constellation that plays a very important part of African American history; the constellations of Ursa Major and Ursa Minor. During the time around the Civil War, runaway slaves used this group of stars to help find their way to the free states.

The constellation Ursa Minor has the star Polaris at the end of its handle. Polaris is a circumpolar star, meaning it is always over the North Pole

At the end of the handle of the Little Dipper lies Polaris, a star that is always directly over the North Star. This means you can find north, by following the cup of the big dipper, to the end of the handle of the Little Dipper.

Circumpolar stars, or stars that revolve around the North Pole.

Most ancient star charts imagine all the other stars and constellations revolving around Polaris as in this picture. The practical upshot is that, using the North Star as a guide, the runaway slaves could flee to the northern states, as long as they kept their plans secret, which is why their secret plans were encoded into the lyrics of a famous African-American song, “Follow the Drinkin’ Gourd” Scholars debate how often the song was actually used for real slave smuggling, but it remains a poignant testament to the courage and ingenuity of the brave men and women who fought to find their freedom in a time of injustice.

Part of the genius of “Follow the Drinkin’ Gourd” is that the lyrics were completely innocuous. If a slave were singing the song to his children, there’s nothing in the lyrics that give it away directly as instructions on how to escape to the north. Below is a video of the song with the lyrics to the right:

When the sun comes back and the first quail calls,
For the old man is waiting for to carry you to freedom,
If you follow the Drinking Gourd.

The river bank is a very good road                                     Follow the Drinkin’ Gourd                                                    The dead trees show the way,                                                 Left foot, peg foot goin’ on,

The river ends between two hills,                                     Follow the Drinkin’ GourdAnother river on the other side                                                Follow the Drinkin’ Gourd                                                        When the little river                                                                   Meets the great big one, the old man waits– Follow the Drinkin’ Gourd.

According to legend, the “old man” was an Underground Railroad conductor called Peg Leg Joe, who would take the slaves from Alabama and Mississippi the rest of the way to free states. The lyrics detail the path up to the Tombigbee River, (which runs through Mississippi, Alabama, and parts of Georgia), up to the Ohio River Valley. You can view an interactive map of this journey here, but in the meantime, here’s a map with an explanation of how the lyrics worked to direct the slaves from Alabama and Mississippi up north.

The lyrics indicate that the slaves were to follow the Tombigbee river north, over the hills, where it meets the Tennessee River. From there, Peg Leg Joe would conduct the slaves over to the Ohio River, and from there on to to the free states!

So there’s a little insight into how astronomy is more than just a study of stars and planets, it’s part of history and a time-tested measurement of time and distance. Next week, I’ll delve more into the mythology and scientific history of this constellation as it relates to other cultures in addition to our own.

Till next time,

Paul

## Progress 50 is LIVE NOW!

Hello all!,

As you read this, there is a NASA mission going on to send a supply ship to the International Space Station. I’ve included a live feed from the mission on the Today In Space History Page. Please click on this page and enjoy watching this once-in-a-lifetime space mission!

Progress 50 spacecraft, which will launch from Earth and dock with the International Space Station on Monday, February 11th.

I’ve also included the ISS tracker, so while the spacecraft is docking with the station, you can figure out when it passes over your hometown! Click here to access it: http://www.isstracker.com/&vm=r

## Happy Chinese New Year!

Today is the first day of the Chinese New Year, also known as Spring Festival; the time in the Chinese lunarsolar calendar that signifies the beginning of the Spring. It is also the beginning of the new Chinese zodiac sign, which begins every 12 years. Each year is associated with one of the 12 signs of the Chinese Zodiac. I found this handy little chart from Chinese Zodiac.com. This year is actually the Year Of the Snake.

28 Mansions of the Chinese Astronomy

A person’s zodiac was determined by marrying a person’s year animal, their birth element- earth, water, fire, metal, and wood, which were associated with the 5 planets of the solar system- wood for Jupiter, fire for Mars, Earth for Saturn, metal for Venus, and water for Mercury. Like the European astrologers and philosophers, these elements and planets also had a powerful influence on the human body.

The belief that the stars can control human bodies and destinies was one reason that the Chinese became such good astronomers, as this video demonstrates:

Many astronomers believe the Chinese had the best astronomers in the world in the period before the Arabs. Even before the Greeks, the Chinese figured out how to predict eclipses, and to navigate by the North Star. By the fourth century, they had charted most of the night sky. This chart on the left, accurately depicts the 28 Chinese constellations.

So enjoy your Chinese New Year day, and good fortune in the new year!

## Stay tuned for a Historic Space Docking!

Progress 50 spacecraft, which will launch from Earth and dock with the International Space Station on Monday, February 11th.

Tomorrow a re-supply ship will dock with the ISS, and you’ll get to watch the whole thing live HERE! I’ll provide you with a little history on the ISS, and of course, the live feed from NASA. So don’t miss it! The launch begins tomorrow at 9:40 AM.

Enjoy!