StarDate

In April, engineers had to shut down one of the scientific instruments aboard the Voyager 1 spacecraft. The device had been studying charged particles in the interstellar medium – the space between the stars. But Voyager is slowly losing power, so the instrument was shut down to help extend the craft’s life.

Voyager 1 is the most-distant object ever sent into space – 16 billion miles from Earth. At that range, it takes almost 24 hours for its radio transmissions to reach Earth.

The craft and its twin, Voyager 2, were launched in the summer of 1977. Their mission was to study the giant planets Jupiter and Saturn. Voyager 2 continued on to Uranus and Neptune.

Since then, both craft have just kept on going. In 2012, Voyager 1 became the first craft to leave the solar system. It passed outside the magnetic “bubble” generated by the Sun. Voyager 2 followed in 2018.

Both Voyagers are powered by the radioactive decay of plutonium. Today, that generates less than half as much energy as it did at launch. So as the power levels have dropped, engineers have shut off most of the scientific instruments. Two instruments are still going on Voyager 1 – studying the space between the stars.

In 300,000 years, the craft is expected to fly about one light-year from a small, faint star that’s 47 light-years away – a dead emissary from the people of Earth.

Script by Damond Benningfield

The religion of ancient Egypt said that when a king died, his soul ascended to the heavens to join with the god Osiris, in the modern-day constellation Orion.

His tomb was filled with items he might need to help him on his way. And in the case of at least one pharaoh, some of those items probably came from the heavens.

The tomb of King Tutankhamen contained thousands of artifacts. Many of them were made of gold, including a dagger buried inside his coffin. But the boy king also had a second dagger, made of iron.

When Tut was buried, more than 3300 years ago, Egypt hadn’t started to work with iron ore, so the dagger probably was made from an iron meteorite – a space rock that fell to Earth. The composition of the dagger’s metal is much like that of a metallic meteorite – a mixture of iron and nickel, with a pinch of cobalt.

Another Tut artifact was an elaborate piece of jewelry known as a pectoral. Its centerpiece is a scarab beetle carved from yellow glass.

The glass formed about 26 million years ago, when an asteroid or comet plunged toward Earth. It either hit the surface or exploded in the atmosphere. Heat from the explosion melted some of the desert sand, creating chunks of glass. One of those chunks eventually made its way to an Egyptian artist, and then to Tut’s tomb – a piece of glass from the heavens for a king traveling to the heavens.

Tomorrow: into the void.

Script by Damond Benningfield

Planetary scientists have had a hard time classifying a world that orbits a faint star in Ophiuchus. Since the planet’s discovery in 2009, they’ve described it as a super-Earth, a mini-Neptune, and a super-Venus. In other words, it’s not like anything in our own solar system.

The planet orbits the star GJ 1214. It’s in the serpent bearer, which is high above the Moon this evening. The star is less than 50 light-years away. But it’s less than one percent as bright as the Sun, so you need a good-sized telescope to see it.

A few years ago, the International Astronomical Union assigned formal names to both the planet and the star. The names come from Kenya, from the Maa language. The star is Orkaria, from the name of a red pigment used by warriors in tribal ceremonies – the color of the star. The planet is Enaiposha – a word for lake or sea, or for their stormy nature.

The planet is bigger and heavier than Earth. That led to its early classification as a super-Earth. But it’s not very dense, which makes it more like a miniature version of Neptune – the smallest of the Sun’s giant planets.

Enaiposha has a thick atmosphere, which is hot because the planet is quite close to the star. Observations by Webb Space Telescope suggest the atmosphere contains a lot of carbon dioxide. That hot C-O-2 atmosphere makes the planet like Venus – one of several identities for this hard-to-classify world.

Script by Damond Benningfield

Cygnus X-1 contains the first black hole ever confirmed. And it recently recorded another first. Astronomers measured the details of twin “jets” of particles that shoot into space from its poles. The jets are firing at almost half the speed of light. And they have the power of 10,000 Suns.

The system consists of the black hole and a supergiant star. The black hole, which was discovered in 1964, is 20 times the mass of the Sun. The star is twice that mass.

The star is extremely hot and bright. It blows a thick wind of hot gas into space. The black hole captures some of the gas, which forms a swirling, super-hot disk around it. Magnetic fields grab some of the gas before it falls into the black hole, and fire it back into space through the jets.

Astronomers have seen jets from many black holes. But this is the first time they’ve precisely measured a jet’s power and speed. Those details are important because the jets can have a big influence on the surroundings. They can blow away gas and dust, preventing the birth of more stars. Or they can squeeze clouds of gas and dust, triggering the birth of stars. So the details help us understand the role of black holes in the evolution of entire galaxies.

Cygnus is in the eastern sky at nightfall. Although Cygnus X-1 is too faint to see, it’s about half way between the swan’s bill and the intersection of its body and wings.

Script by Damond Benningfield

Stars follow a life-long weight-loss program. They blow hot gas off their surfaces. Over time, the amount of material in these “winds” can add up. Heavier stars, in fact, can expel enough gas to make several stars as massive as the Sun.

An example is Antares, the leading light of Scorpius. It’s in good view tonight, to the left of the Moon as night falls.

Antares is a supergiant – one of the biggest and brightest stars in the galaxy. It’s more than a dozen times the Sun’s mass. And it’s so big that if you placed it at the center of the solar system, it would extend past the orbit of Mars.

But when Antares was born, about 11 million years ago, it was even heavier. Studies in recent years have placed its initial mass at about 15 to 17 times the Sun’s mass. Most of the difference has been blown into space on the star’s winds.

Antares has lost so much of its original weight because it was heavy to begin with. A massive star “burns” through its nuclear fuel quickly, making its core extremely hot. Radiation from the core causes the star’s outer layers to puff outward. That far from the core, the surface gravity is fairly low, so it’s easy for radiation to push gas out into space.

Antares is fated to expel even more of its mass. At the end of its life, its core will collapse, causing its outer layers to explode as a supernova – blasting most of its remaining gas out into the galaxy.

Script by Damond Benningfield