StarDate Podcast

When NASA set out to send people into space, it handed the job to its oldest facility. Langley Research Center had been operating on the banks of Chesapeake Bay for four decades. To handle the new task, its engineers formed the Space Task Group. The group oversaw the design and construction of the Mercury spacecraft, and selected and trained the original astronauts — the center’s first big step into space exploration.

Langley is commemorating its hundredth anniversary this week. Construction began on its first facility in July of 1917. It wasn’t part of NASA at the time, though — NASA didn’t even exist. Instead, it was part of the N-A-C-A — the National Advisory Committee on Aeronautics.

Langley was the first civilian aviation research center in the country. It built a series of wind tunnels for testing airplanes and their systems. That work helped improve aircraft performance and safety.

When NASA was formed, in 1958, it inherited the NACA facilities. Langley continued its aviation work, but also branched out into space.

Its engineers developed the concept that Apollo used for getting the Moon. They managed a set of robotic orbiters that mapped the lunar surface, and built simulators to help astronauts maneuver in space and land on the Moon. Langley also managed the successful Viking missions to Mars.

Langley continues its work today, with projects involving aviation, space, and other fields — a century after its birth.

Script by Damond Benningfield

A scorpion’s most fearsome feature isn’t its claws, although those are pretty scary-looking. Instead, its the stinger — the part that injects venom. And the celestial scorpion has a good one: two stars at the end of its curving tail.

Scorpius is low in the south as darkness falls. The stinger is well to the lower left of Antares, the scorpion’s bright orange heart. It consists of two stars that are side by side, with the one on the left a bit brighter than the one at the stinger’s tip.

Both stars are almost 600 light-years away. The fact that they’re visible to the unaided eye from that distance means they’re extremely bright — among the brightest stars in the galaxy.

The brighter star is Lambda Scorpii. It consists of three stars. Two of them are Class “B” stars — among the hottest and brightest in the galaxy. And at least one of them is destined to explode as a supernova.

The third member of the system is so young that it’s not yet shining as a true star. Instead, it’s a protostar — an object that’s still collapsing to become a star. It should ignite the fires of nuclear fusion before long, joining its older siblings as full-fledged stars.

The stinger’s fainter star is Upsilon Scorpii. It’s a single star. And like the main members of Lambda Scorpii, it’s class B, so it shines many thousands of times brighter than the Sun. It, too, is fated to explode as a supernova — briefly adding to the fearsomeness of the scorpion’s stinger.

Script by Damond Benningfield

Everything about Scorpius is impressive. It’s a prominent constellation that really does resemble its namesake. Its leading light, Antares, is one of the brightest stars in the night sky. And its wide “head” contains many stars, some of which are destined for brilliant final acts.

Scorpius is in the south at nightfall. The scorpion’s head stands to the upper right of bright orange Antares, and is outlined by three stars. From top to bottom, they’re Beta, Delta, and Pi Scorpii.

Beta is actually a system of at least six stars, which are divided into two tight-knit groups. A couple of the stars are more than 20,000 times brighter than the Sun. Delta Scorpii consists of two stars, and one of those also shines fiercely. And Pi Scorpii has at least three stars, including one more brilliant beacon.

All or most of these stars formed from a vast complex of gas and dust that spans Scorpius and the nearby constellation Centaurus. In the last 15 million years or so, it’s given birth to thousands of stars. And quite a few of them are especially heavy, which makes them especially hot and bright.

The stars at the top end of the weight scale will live short lives — in fact, some of them probably will expire in the next few million years. And when they die, they’ll blast themselves to bits. For a while, such a conflagration will outshine anything in the night sky except the Moon — briefly adding to the impressiveness of the scorpion.

Script by Damond Benningfield

Our brains tend to find patterns just about everywhere. Some of them are real, but many are just imagined. A cloud, for example, might look like a dragon or a fairy-land castle. An eroded mesa on Mars can look like a human face. And patterns of stars might look like a dolphin, a lion, or a scorpion.

In fact, the celestial scorpion is one of the highlights of summer nights. It’s in the south as darkness falls, quite low above the horizon, and wheels across the southwest later on. Many cultures have seen a wide head, a slightly curved body, and a sharply curved tail complete with stinger — the perfect outline of a scorpion.

The outline itself is just a coincidence. But the fact that so many bright stars appear in that part of the sky isn’t. Scorpius is embedded in the hazy band of light known as the Milky Way — the glow of countless stars that define the disk of the Milky Way galaxy. And it’s roughly in the direction of the galaxy’s heart, where we’re looking into a great thicket of stars. So it’s like gazing into the densest part of a forest — there are big trees everywhere you look.

Clouds of gas and dust in that direction are giving birth to many new stars. Many of these newborns are especially big and bright — stars that really stand out. Several of these standouts are among the stars that form the pattern that we see as the scorpion.

Three of these stars form the scorpion’s head, and we’ll have more about them tomorrow.

Script by Damond Benningfield

Two of the most striking objects in the night sky are meeting in the east before dawn over the next couple of weeks: the planet Venus and the star Aldebaran. Venus is the brilliant “morning star,” so you can’t miss it. And Aldebaran shines bright orange — the baleful eye of the celestial bull.

Tomorrow, Venus will stand almost directly above Aldebaran. Over the next few days, though, Aldebaran will pass Venus as it climbs higher into the sky. And after that, it’ll pull away from the brilliant planet, quickly leaving it behind.

Their motions are different because of their different positions relative to Earth.

Aldebaran and the other true stars are so far away that they appear to move across the sky as a group — the relative positions of any two stars always stays the same. But Venus is a planet, so it’s much closer to us. In fact, it’s the closest planet of all.

Venus orbits the Sun inside Earth’s orbit. So Venus and Earth are like two runners on a circular track, with Venus on the inside lane and Earth farther out. Because Venus has a shorter distance to cover, it takes less time to complete each lap. So its position against the background of more-distant objects — the stars — changes from day to day. The change is especially noticeable when Venus is passing by an especially bright star such as Aldebaran.

So watch Venus and Aldebaran as they cruise past each other in the early morning sky over the next couple of weeks.

Script by Damond Benningfield

With another spring only a memory now, one of the season’s leading star patterns is plunging from view in the evening sky.

Leo, the lion, is in the west as darkness falls. It’s dropping head first, like a real lion pouncing on its prey. Its brightest star, Regulus, is quite low in the sky, so any trees or buildings along the horizon will block it from view.

The lion’s head and mane spread out to the upper right of Regulus. His body is above Regulus, with his tail, the star Denebola, far to the upper left of Regulus.

Leo is associated with spring because it springs highest across the sky then, and is in view for most of the night. But every night, the stars rise and set about four minutes earlier than the night before. So as the weeks roll by, so do the stars. Those that are prominent during spring disappear during the longer nights of summer.

And on the opposite side of the sky, stars that were hidden during spring evenings rise to prominence. So while Leo and other spring constellations vanish, Scorpius and Sagittarius line up for their own prime-time appearances.

Leo isn’t quite done, though. The Sun is setting a little earlier each night, which gives Leo a bit of extra time before it vanishes from the evening sky. Look for it low in the west as the color of twilight drains away. Regulus will disappear by month’s end, with the rest of the lion following as we head into August.

Tomorrow: the eye of the bull in the morning sky.

Script by Damond Benningfield

Thunderstorms can roll across much of the country at this time of year. They can bring strong winds, hail, and flooding rains. That seasonal pattern is reflected in one of the names of July’s full Moon: the Thunder Moon.

The most commonly used full-Moon names are the Harvest Moon, in September or October, and the following Hunter’s Moon. But every full Moon has its own name. And they all reflect what’s happening in nature at that time of year.

Most of the names were created by the native tribes and nations of North America. The names were part of a system for tracking the turning of the seasons. June, for example, had the Rose or Strawberry Moon, and August has the Green Corn Moon. These names helped people know when to plant or harvest crops, or when to move to grounds with better hunting or better weather for the coming season.

Some cultures relied on more than just the Moon, though. They tracked the Sun’s progress along the horizon, for example, and followed the appearances of key stars. These astronomical cues made it easier to follow the seasons — year in and year out.

And the Moon will be full at 11:07 Central Daylight Time tonight, as it lines up opposite the Sun. The Sun will illuminate the entire lunar hemisphere that faces Earth, lighting up the sometimes stormy night skies of early summer.

Tomorrow: An encounter in the morning sky.

Script by Damond Benningfield

A bright star with a much brighter future scoots quite low across the sky on these early July evenings. To see it, though, you need to be south of about Dallas or Charleston.

Alpha Lupi is the leading light of the constellation Lupus, the wolf. The star is due south as darkness falls, and sets in the southwest a few hours later.

Alpha Lupi is classified as a blue giant. The “blue” part means its surface is many thousands of degrees hotter than the surface of the Sun. And the “giant” part means the star is many times bigger than the Sun. Add them up and the star shines about 20,000 times brighter than the Sun.

Alpha Lupi is likely to get a lot brighter over the next few million years, though — a result of its fast evolution. Even though it’s only a few percent the age of the Sun, it’s already at the end of its normal lifetime. It’s probably converted the original hydrogen fuel in its core to helium. Now, it’s burning the helium to make heavier elements. Radiation from the hot core is pushing outward on the surrounding layers of gas, causing the star to puff up.

As Alpha Lupi continues to evolve over the next few million years, it’s likely to become bigger and brighter.

Eventually, though, the core will no longer be able to produce nuclear reactions. At that point, the star is likely to explode as a supernova. For a few weeks or months, it’ll shine as brightly as billions of normal stars — bringing its bright but short life to a brilliant end.

Script by Damond Benningfield

The Moon has a beautiful companion tonight: the planet Saturn. It’s quite close to the lower right of the Moon at nightfall, and looks like a bright golden star. It stays close to the Moon all night long.

The Moon is a dead world. But in centuries past, many thought the Moon had water, air — and life. In the 17th century, for example, German astronomer Johannes Kepler described a world populated by snakelike creatures with wings.

Kepler is one of the pioneers of modern astronomy. He was the first to describe the orbits of the planets mathematically, proving that Earth is not the center of the solar system.

Kepler wrote about an imaginary journey to the Moon in a book called “The Dream,” which was published after his death. Many have described it as the first science-fiction story.

Kepler wrote that Moon creatures lived inside cave-like fortresses built to protect them from the Sun. These creatures were heavier than people, and looked like snakes. Some had wings, but others lived in the water. They rested during the long lunar day — which is equal to 14 Earth days — and were active during the night.

Late in his life, Kepler used a new device to study the lunar surface: the telescope. He thought the lunar craters must have been made by the Moon creatures.

Today, though, we know that the craters were carved by the impacts of mountain-sized boulders long ago. One crater is named for Johannes Kepler — a man who dreamed of a living Moon.

Script by Damond Benningfield

A stellar corpse in the constellation Scorpius isn’t a good neighbor. It’s blasting a small companion star with a particle beam. That causes the companion to flare up every couple of minutes.

AR Scorpii stands close to Antares, the scorpion’s bright orange heart, which is not far to the lower right of the Moon at nightfall. AR Scorpii is quite faint, though, so it takes a big telescope to spot it.

The system consists of two stars. One of them is a white dwarf — the hot, dense “corpse” of a once-normal star. The other is a red dwarf — a small, cool star that’s still in the prime of life. The two are separated by about half a million miles, which is only twice the distance between Earth and the Moon.

The white dwarf spins once every couple of hours — a fast rate for a white dwarf. It might have spun up by “stealing” gas from its companion. As the gas poured onto the white dwarf, it sped up the star’s rotation like a parent pushing a child on a merry-go-round.

That high-speed ride helps the white dwarf generate a powerful magnetic field, which accelerates charged particles near the white dwarf to almost the speed of light. As the white dwarf rotates, that creates twin beams, like those from a lighthouse.

The beams sweep across the companion star every couple of minutes. That zaps the surface of the star, making it much hotter for a few seconds. So AR Scorpii grows noticeably brighter every two minutes — as a dead star zaps its close companion.

Script by Damond Benningfield