StarDate

Snow blanketed the launch pad, and the rocketeers sipped hot malted milk to ward off the chill. But the launch they conducted a century ago today turned the idea of space travel from fantasy to possibility – and provided the first small step toward the Moon.

The rocket was designed by Robert Goddard, a physics professor at Clark University in Massachusetts. Goddard was brilliant but secretive. He refused to collaborate with other scientists, and seldom even talked about his research. Instead, he
spent his time building, testing, and flying rockets.

At the time he started, all rockets were powered by solid fuels, such as gunpowder. But solid fuels are inefficient and hard to control. So Goddard built a rocket powered by liquid fuels – gasoline and liquid oxygen. It was a potent mixture that provided far more energy per pound than solids.

Goddard and his wife and assistants launched the first liquid-fueled rocket in history on March 16th, 1926. It was airborne for just two and a half seconds, and climbed just 41 feet. But it proved that liquid fuels could propel a rocket skyward.

Goddard spent two more decades experimenting with rockets. German engineers used many of his innovations in the V-2, which bombarded England during World War II. Transplanted to the United States after the war, many of these engineers developed the rockets that boosted satellites into space – and sent astronauts to the Moon.

Script by Damond Benningfield

A three-way tug-of-war isn’t a common sight – unless you look toward the constellation Leo. Three galaxies there are tugging at one another, producing some spectacular results.

The galaxies are M65, M66, and NGC 3628 – the Leo Triplet. All three galaxies are about the same size as our home galaxy, the Milky Way. And each may resemble the Milky Way – a beautiful spiral with a long “bar” of stars across its middle.

The triplets are close enough together that the gravity of each galaxy exerts a strong pull on the others.

That’s given M66 a slightly “wonky” look. The galaxy’s core is a little off-center. Its spiral arms are loosely wound, and they aren’t symmetrical. And the arms are lined with knots of starbirth. Some of the stars in these regions are huge. Such a star burns out quickly, then explodes as a supernova. And since 1973, we’ve seen five supernovas in M66 – compared to zero in the Milky Way.

We see NGC 3628 edge-on, so it’s hard to know its exact shape. What we do see is a lane of dark dust sandwiched between brighter layers. We also see a “tail” that’s 300,000 light-years long – three times the size of the galaxy itself. It’s a ribbon of stars pulled out by the other galaxies in their ongoing “tug-of-war.”

Leo is in the east at nightfall. The triplet is to the upper right of Denebola, the star at the lion’s tail. It’s an easy target for a small telescope.

Script by Damond Benningfield

It sounds like a toddler’s attempt to say “Friday” or, even better, a day to gorge on apple crumb or coconut cream. Alas, “Pi Day” is something completely different. It’s a commemoration of a mathematical constant that’s represented by the Greek letter pi – one of the most important quantities in science.

Pi is the ratio of a circle’s diameter to its circumference. When it’s rounded off to two digits, it’s 3.14 – the numerical equivalent of March 14th.

Astronomers use pi to calculate the volume and density of a star or planet, the details of an orbit, and much more. Other scientists use it as well.

But pi is an “irrational” number. That means that no matter how long you calculate its exact value, you never reach the end – whether you go to a thousand decimal places, a million, or rbrm eleventy-jillion. There’s never a conclusion, and no group of numbers ever repeats. Mathematicians have used various techniques to try to calculate the exact value, without success. The record so far is more than a hundred trillion places to the right of the decimal.

Trying to calculate an exact value has been an important plot point in science fiction. Any time a computer is getting too uppity, it’s commanded to calculate pi to the last digit. That impossible task overloads the computer, allowing the heroes to regain control. Whether we’ll need it to rein in A-I – well, have a slice of pie – the tasty variety – while you ponder it.

Script by Damond Benningfield

To the eye alone, the brightest star in the night sky is Sirius, the leading light of Canis Major, the big dog. It’s well up in the south at nightfall – a brilliant beacon less than nine light-years away.

If we could shift the sensitivity of our eyes to shorter wavelengths, the brightest star would appear a little below Sirius. Adhara is already the second-brightest star in the constellation. But it produces most of its energy in the extreme ultraviolet – wavelengths that are far too short to see with the human eye. At those wavelengths, Adhara would be the brightest object in the entire night sky.

The star is an ultraviolet powerhouse because it’s tens of thousands of degrees hotter than the Sun. The hotter an object, the more U-V it produces. And Adhara is huge – more than 10 times the Sun’s diameter. So there’s a lot of real estate for beaming its radiation into space.

The U-V zaps molecules of gas and dust anywhere close to the star, splitting them apart and making them glow. But the star has been around long enough that it’s already cleared out most of the space around it.

More than four million years ago, Adhara was much closer to the Sun than it is today. That made it the brightest star at visible wavelengths as well. It shined as brightly as Venus, the morning or evening star. But Adhara’s motion through the galaxy has carried the star much farther from us – allowing Sirius to outshine this sizzling star.

Script by Damond Benningfield

For Charles Messier, star clusters were a nuisance. The French astronomer was mainly interested in comets. In the 18th century, finding a comet could bring fame and fortune – kings sometimes awarded medals and fat stipends for their discovery.

Through a telescope, star clusters could resemble comets. Messier and others might spend time following a cluster, only to find out that it wasn’t the prize. So Messier compiled a catalog of clusters and similar nuisances – a list of objects to ignore.

Four of the clusters follow a narrow path near Canis Major, the big dog: M46, 47, 48, and 50 – a Messier “highway.”

Although they’re close together in our sky, the clusters are not close together in space. Their distances range from about 1600 light-years to more than five thousand. So there’s no relationship among them.

They appear close together because they all lie along the Milky Way – the glowing outline of the disk of the Milky Way Galaxy. In that direction, we’re looking into the most densely populated region of the galaxy, so we see many more stars and star clusters – including the “pesky” clusters cataloged by Charles Messier.

The clusters are in the southeastern quadrant of the sky as night falls. Look for Sirius, the brightest star in the night sky, due south. The clusters spread out to the left and upper left of Sirius. All of them are easy targets for binoculars.

Script by Damond Benningfield