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StarDate Podcast

Science Podcasts

StarDate, the longest-running national radio science feature in the U.S., tells listeners what to look for in the night sky.

StarDate, the longest-running national radio science feature in the U.S., tells listeners what to look for in the night sky.

Location:

United States

Description:

StarDate, the longest-running national radio science feature in the U.S., tells listeners what to look for in the night sky.

Twitter:

@stardate

Language:

English

Contact:

512-475-6760


Episodes

Vesta

3/1/2021
Vesta is the second-largest member of the asteroid belt, but it may be the best understood. A spacecraft orbited the little world for more than a year. And pieces of it have been found here on Earth — more than 1200 of them. On average, Vesta is about 330 miles in diameter — about half the size of Ceres, the giant of the asteroid belt. But it passes closer to Earth, and its surface is brighter, so it’s easier to see and study. The Dawn spacecraft arrived at Vesta in 2011. It found that...

Duration:00:02:14

Christine Kirch

2/28/2021
Until the last century, few women earned a living in astronomy. The first one to get paid for her work, in fact, didn’t receive a regular salary until 1740. And she received that only because her brother had passed away. Christine Kirch was born in Germany around 1696 — 325 years ago. She was a member of an entire family of astronomers. Her father was the first astronomer at the Berlin Observatory. And her mother helped him make observations and create calendars — an important line of work...

Duration:00:02:14

Alphard

2/27/2021
Hydra, the water snake, goes on and on and on. It’s the longest of the 88 constellations. At midnight tonight, in fact, its head stands halfway up the southwestern sky, while its tail is just clearing the horizon in the southeast. Yet the snake is hard to follow, because most of its stars are faint. The brightest one is only second magnitude. That puts it well down the list of the night sky’s leading lights. Alphard looks so faint because it’s about 180 light-years away. In reality, it’s...

Duration:00:02:14

Big Detectors

2/26/2021
About 85 percent of all the matter in the universe appears to be dark matter. Yet scientists haven’t been able to find it. But a recent study suggests a new way to look for it: by taking the temperature of many planets in other star systems. Dark matter almost never interacts with everyday matter — the stuff that makes up stars, planets, and people. But astronomers know it’s there because it exerts a gravitational pull on the stars and galaxies around it. Dark matter is thought to be made...

Duration:00:02:14

Moon and Regulus

2/25/2021
A bright star follows the bright Moon across the sky tonight: Regulus, the heart of the lion. It’s below the Moon as night falls, and closer to the left of the Moon at first light. If the weather conditions are just right, you might see another bright companion for the Moon: a ring of light. If it’s there, it’ll be huge — it’ll extend well beyond Regulus. Such a ring is known as a Moon ring or a winter halo. It’s caused by moonlight passing through cirrus clouds. Such clouds are thin, so...

Duration:00:02:14

Sakurai’s Star

2/24/2021
Some stars just don’t know how to stay dead. Consider Sakurai’s Object. It had already “died.” But 25 years ago this week, an amateur astronomer in Japan reported that the star had flared back to life. This “rebirth” won’t last long, though — the star is already back on its earlier track. Originally, Sakurai’s star probably was several times the mass of the Sun. It aged quickly, and puffed up to form a giant. About 8,000 years ago, it expelled its outer layers into space. Today, those...

Duration:00:02:14

Moon and Gemini

2/23/2021
Sextuplets are rare — only a couple of hundred sets have been recorded. And they’re rare among stars as well — astronomers have recorded only about a dozen of them. The most famous is Castor, one of the twins of Gemini. It’s one of the two dozen brightest star systems in the night sky, so it’s easy to pick out. The system consists of three sets of twins. The stars in each set are so close together that we can’t see them as individual stars, even through the largest telescopes. Astronomers...

Duration:00:02:14

Faint Ripples

2/22/2021
Like waves rippling across the ocean, the aftermath of a stellar explosion is rippling across our region of the galaxy. It forms a thin arc that runs between the big and little dippers. Astronomers first saw evidence of the ripples in 2006. A space telescope detected a thin, straight line produced by X-rays. It was a couple of degrees long — the width of your finger held at arm’s length. A few years ago, other astronomers followed up on the discovery. And they found that the line kept on...

Duration:00:02:14

Joseph Walker

2/21/2021
One of America’s first astronauts never flew in a NASA spacecraft, and never became a household name. Yet he was the first person to reach outer space more than once. Joseph Walker poses with the X-15 Joseph Walker was born 100 years ago yesterday, in Pennsylvania. He earned a degree in physics, then flew fighters during World War II. After the war he became a test pilot for the N-A-C-A — the predecessor to NASA. Over the years, he checked out fighter jets, bombers, and rocket planes. In...

Duration:00:02:14

Moon and Aldebaran

2/20/2021
It’s a bit hard to believe when you look at it, but we’re not seeing the star Aldebaran at its best. Aldebaran stands to the lower right of the Moon this evening. It shines brightly even through the lunar glare. In fact, it’s the 14th-brightest star system in the night sky, so it’s always easy to spot. At visible wavelengths, Aldebaran shines about 150 times brighter than the Sun. That’s mainly because the star is much bigger than the Sun, so there’s a lot more surface area to radiate...

Duration:00:02:14

Morning Planets

2/19/2021
Mercury, Saturn, and Jupiter form a tight triangle in the dawn sky for the next few days. Unfortunately, they’re quite low, so they’re tough to see. The view is better as you go farther south. The planets are in the east-southeast as the sky brightens. Mercury and Saturn stand highest. They’re almost side by side, with Mercury on the left. Jupiter is below them, and is brighter than its two siblings. Mercury is the Sun’s closest and smallest planet. It’s a bare ball of rock and metal...

Duration:00:02:14

Moon and Mars

2/18/2021
Big pollywogs wiggle across parts of Mars. But they’re not like pollywogs on Earth. Instead of small tadpoles, they’re craters with channels cut through their rims. They’re called pollywogs because that’s what the outline of the crater and channel resemble. Present-day Mars is drier than any desert on Earth. Its atmosphere is too thin to allow liquid water to stand on the surface. In the distant past, though, it was much wetter. And some of the pollywogs could have been filled with water...

Duration:00:02:14

Navi

2/17/2021
The proper names of most stars date back hundreds or even thousands of years. They were bestowed by the skywatchers of the ancient Mediterranean. But the brightest star of one prominent star picture was bestowed only about half a century ago. Navi is the middle star in the letter M or W that marks Cassiopeia the queen. It’s the brightest of the letter’s five stars. Until the late 1960s, though, it was known only by catalog or scientific names — mainly Gamma Cassiopeia. The star is 550...

Duration:00:02:14

Little Black Hole

2/16/2021
The Sun is more than a hundred times wider than Earth, and more than 300 thousand times heavier. But imagine cramming three Suns into a ball about the size of Colorado Springs, Tulsa, or Lubbock. That would give you a black hole the size of one recently discovered in Auriga — the smallest black hole yet seen — or not seen. The black hole itself produces no energy, so there’s no way to see it directly. But it has a companion star. The system is known by a catalog number, which we’ll shorten...

Duration:00:02:14

Arrival at Mars II

2/15/2021
Once upon a time, Jezero Crater would have been prime real estate on Mars. The crater held a lake about as big as Lake Tahoe. And water flowed both in and out, keeping it fresh. The crater’s rim would have been a great spot for a summer home. The lake vanished by three and a half billion years ago. But Jezero is set to once again become prime real estate. An American rover is scheduled to land there on Thursday. It’ll trundle across the landscape for years, digging into the sediments on the...

Duration:00:02:14

Leo Minor

2/14/2021
The night sky is like a quilt with 88 patches. Each “patch” is a constellation. In ancient times, though, the quilt had a lot of blank spaces. The blanks were patches of sky with no bright stars. No one bothered to create pictures or stories for them. Astronomers began to fill in those patches in the 17th century. In 1687, for example, Johannes Hevelius created ten new constellations. Seven of them are still in use today. That includes Leo Minor, the little lion. It represents a cub of...

Duration:00:02:14

Cancer

2/13/2021
Hercules was fighting a nine-headed serpent when another critter decided to join the fray. The crab was sent by the goddess Hera, who didn’t exactly get along with Hercules. The crab latched on to the strongman’s toe and wouldn’t let go. This fight didn’t last long, though — Hercules crushed the crab with his foot. But as a reward for its sacrifice, Hera placed the crab in the stars — as the constellation Cancer. The crab is about a third of the way up the eastern sky at nightfall. But it...

Duration:00:02:14

Cursa

2/12/2021
The profile of the star Cursa reads like this: It’s about twice as heavy as the Sun, two-and-a-half times as wide, and 50 times brighter. But every one of those numbers depends on one more: the star’s distance of 89 light-years. Astronomers use a technique known as parallax to measure the distance to a nearby star. They compare its position to the background of stars when Earth is on opposite sides of the Sun. The star moves a little against that background between measurements. The amount...

Duration:00:02:14

Out of the Fire

2/11/2021
Many observatories are built in beautiful locations — atop mountains, where they’re surrounded by trees and fields. The high ground puts them above much of Earth’s blurring atmosphere, giving them a sharper view of the universe. But there’s also a downside to the locations: fires. In recent years, big fires have threatened, damaged, and even destroyed observatories. The most recent threat came last August. A massive wildfire outside San Jose, California, threatened Lick Observatory. The...

Duration:00:02:14

Arrival at Mars

2/10/2021
If everything is going to plan, a flotilla of spacecraft is arriving at Mars about now. The fleet includes a rover sent by the United States and an orbiter by the United Arab Emirates. Another is a combination orbiter, lander, and rover sent by China. The mission is known as Tianwen 1. The name comes from an ancient Chinese poem, and means “heavenly questions.” The craft was launched in July. After entering orbit, it’ll spend a couple of months checking out possible landing sites before its...

Duration:00:02:14