StarDate Podcast

by McDonald Observatory · · · · 10 subscribers

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

Moon and Saturn Aug. 2, 2020

If you want to escape the summer heat by plunging into a cool lake or sea, there are only two places in the solar system to do so: Earth, and Titan, the largest moon of Saturn. The big difference is what’s filling those features. On Earth, it’s water. But on Titan, it’s liquid methane and ethane — hydrocarbons that are chilled to hundreds of degrees below zero. Titan is about half again the size of Earth’s moon. It has a thick atmosphere that’s topped by smog — an orange haze of hydrocarbons. Methane and ethane clouds drift through the sky, …

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Tags: dark matter', skywatching, natural sciences, stars, dark energy, science & medicine, space travel, moon, stargazing, milky way, constellations, planets, 'itunes:owner', astronomy, solar system, black holes

Older Episodes

Moon and Planets Aug. 1, 2020
A brilliant triangle slides across the south tonight: the Moon and the planets Jupiter and Saturn. Jupiter looks like a brilliant star above the Moon at nightfall. Fainter Saturn stands to the left of the Moon. The Moon is almost full, so almost the entire hemisphere that faces our way …
Eating (Lunar) Dust July 31, 2020
If cockroaches ever find their way into habitats on the Moon, they’re likely to thrive. In a study a half century ago, roaches that were fed lunar dirt grew a bit faster than those that weren’t. Before the first Apollo astronauts landed on the Moon, some scientists were concerned they …
Shorter Days July 30, 2020
If there just aren’t enough hours in the day for you, think of this: Earth’s day is longer now than it used to be. A recent study found that 70 million years ago, it was a half-hour shorter than it is now. And as you go even farther into the …
Moon and Antares July 29, 2020
Stars are funny things. Despite what you might expect, the biggest stars are among the coolest — at least on the outside. On the inside, they’re the hottest. An example is Antares, the brightest star of the scorpion. It’s close below the Moon at nightfall. It’s a bit harder to …
Brighter Vega July 28, 2020
Vega is already the fifth-brightest star in the night sky, and the second- brightest north of the celestial equator. But it’s going to get even brighter. It’s moving toward our solar system. And when it’s at its closest, it’ll appear almost four times brighter than it is now. Vega is …
Busy Vega July 27, 2020
A bright star crowns the sky this evening. Vega is the leading light of Lyra, the harp. It’s the fifth-brightest star in the entire night sky, so it’s hard to miss. There’s a lot going on at Vega. The star itself is dynamic, and it’s encircled by a wide ring …
Epsilon Lyrae July 26, 2020
If you look toward Lyra, the harp, on a dark summer night, you might think you’re seeing double. And if you look with a telescope, you’ll see double double. That’s because one of the constellation’s stars is known as the Double Double. It consists of two pairs of stars that …
Hercules Galaxies July 25, 2020
Stars pass by each other without much effect. That’s because the average distance between stars is millions or billions of times the size of the stars themselves. But it’s a different story with galaxies. These massive “cities” of stars are so big that there’s not a lot of space between …
Hunting by Gravity July 24, 2020
Astronomers are following the trail to Planet Nine. The trail is marked by chunks of ice and rock far from the Sun. The way their orbits line up suggests they’re being “herded” by the gravity of a planet. It would be tens of billions of miles from the Sun, and …
Operation Overcast July 23, 2020
The issue of _Life_ magazine published 75 years ago today featured an **[amazing story](http://books.google.com/books?id=30kEAAAAMBAJ&pg=PA78#v=onepage&q&f=false)**. German scientists, it said, had been working on placing a giant mirror in space. The mirror would reflect the Sun’s rays to the surface below — starting wide-spread fires or incinerating cities. The project never got …
Morning Mercury July 22, 2020
The young solar system was a dangerous place for planets. Several of today’s worlds got blasted by other planets. Earth was hit by a planet as big as Mars, giving birth to the Moon. And Uranus was hit by an even bigger planet, knocking it over on its side. [**Mercury**](http://stardate.org/astro-guide/ssguide/mercury)probably …
Comet NeoWise July 21, 2020
A comet that defied the odds is in view in the evening sky. It’s fairly bright, although you need binoculars to get the best view. Comet C/2020 F3 NeoWise was discovered on March 27th by a NASA spacecraft. The comet passed closest to the Sun on July 3rd — about …
Saturn at Opposition III July 21, 2020
[**Saturn**](http://guide/ssguide/saturn)continues to shine at its best. The planet is low in the southeast at nightfall, to the lower left of brilliant Jupiter. Saturn looks like a bright golden star, and it’s in view all night. Saturn looks so bright in part because of its rings. They’re tilted toward Earth right …
Saturn at Opposition II July 20, 2020
Every planet orbits the Sun in the same direction. If you viewed the solar system from above the Sun’s north pole, they’d all be moving counterclockwise. But what we see doesn’t always reflect that. Right now, for example, the giant planets **[Jupiter](http://stardate.org/astro-guide/ssguide/jupiter)** and **[Saturn](http://stardate.org/astro-guide/ssguide/saturn)** are moving backwards — a motion …
Saturn at Opposition July 19, 2020
If planets had feelings, then **[Saturn](http://stardate.org/astro- guide/ssguide/saturn)** might have an inferiority complex. Although it’s a giant, it ranks second to **[Jupiter](http://stardate.org/astro- guide/ssguide/jupiter)** in just about every category. Jupiter is about 10 percent wider than Saturn, and about three times as heavy. And as seen from Earth, Jupiter is much brighter. …
Future North Poles July 18, 2020
Perhaps the most famous star in the night sky is Polaris. It’s not especially bright or close by. Instead, it’s famous for its location. It marks the north celestial pole, so it’s also known as the North Star or Pole Star. Today, it’s about two-thirds of a degree from the …
Heading for Mars IV July 17, 2020
Mars is getting crowded. As of late May, eight probes were operating on the surface or in orbit around the Red Planet. As many as three more missions have been scheduled for launch this month. And as many as five are on the books for the next few years. The …
Heading for Mars III July 16, 2020
NASA’s next Mars rover will have a lot on its plate. It will scour an ancient lakebed for signs of life. It’ll carry a small helicopter to help scout its path. It’ll gather about 30 samples for possible return to Earth by a follow- up mission. And if that’s not …
Heading for Mars II July 15, 2020
One of the main reasons for exploring Mars is to hunt for life, past or present — especially microscopic life. But scientists want to make sure that if they find microbes on Mars, they’re actually Martian. So every Mars lander is kept especially clean to ensure it doesn’t carry any …