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Jack Horkheimer: Star Gazer

Star Gazer is the world's only weekly television series on naked eye astronomy. Each weekly episode features selected objects for naked eye viewing for the following week. This video podcast contains the 10 most recent episodes of Jack Horkheimer: Star Gazer.

FaviconStar Gazers 1 Min. Dec. 30, 2013- Jan 5, 2013 13 Nov 2013, 4:10 pm

Here Comes The Sun

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FaviconStar Gazers 5 Min. Dec. 30, 2013- Jan 5, 2013 13 Nov 2013, 4:09 pm

Here Comes The Sun

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FaviconStar Gazers 1 Min. Dec. 23-29, 2013 13 Nov 2013, 4:08 pm

Bye-Bye Venus,Good-bye And Celebrate The New Year With The New Year's Eve Star

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FaviconStar Gazers 5 Min. Dec. 23-29, 2013 13 Nov 2013, 4:06 pm

Bye-Bye Venus,Good-bye And Celebrate The New Year With The New Year's Eve Star

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FaviconStar Gazers 1 Min. Dec. 16-22, 2013 13 Nov 2013, 4:03 pm

Off To The Races With Venus And Jupiter

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Science @ NASA Feature Stories Podcast

The mission of Science@NASA is to help the public understand how exciting NASA research is and to help NASA scientists fulfill their outreach responsibilities.

FaviconGeminid Meteors Defy Explanation 9 Dec 2010, 3:00 pm

The annual Geminid meteor shower peaks this year on Dec. 13th and 14th. Researchers don't fully understand the Geminids, and new measurements make it more mysterious than ever.

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Favicon"Arsenic-Bug" Redefines Life as We Know It 2 Dec 2010, 3:00 pm

NASA-supported researchers have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism, which lives in California's Mono Lake, substitutes arsenic for phosphorus in the backbone of its DNA.

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FaviconAlien Comets Invade the Solar System 23 Nov 2010, 3:00 pm

Some of the comets in our Solar System probably came from other stars, according to new research by NASA-supported scientists. Studying these 'alien' comets, they say, could reveal new information about stellar systems far, far away.

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FaviconHubble Observes Possible Asteroid Collision 13 Oct 2010, 2:00 am

NASA's Hubble Space Telescope has captured rare images of a suspected asteroid collision. The snapshots show a bizarre X-shaped object at the head of a comet-like trail of material. Their findings will be published in the Oct. 14th issue of Nature.

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StarDate Online

FaviconStar Time 25 Oct 2014, 1:18 am

A postcard depicts the Elgin Watch Company Observatory in Elgin, Illinois. The observatory's telescopes used the stars to accurately record the time, which was fed to the adjacent watch factory. Elgin used the observatory as part of its national advertising campaign. Although the company and factory are gone, the observatory is still standing.

Postcard of the historic Elgin Watch Company Observatory in Illinois

Text ©2014 The University of Texas at Austin McDonald Observatory

For more skywatching tips, astronomy news, and much more, read StarDate magazine.
The one constant in the Universe: StarDate magazine

FaviconCapella 25 Oct 2014, 1:00 am

Capella is one of the brightest beacons in the night sky. The yellow-orange star is in good view in the northeast by mid-evening, and stands high overhead a couple of hours before dawn. It’s the sixth-brightest star system in all the night sky, so it’s hard to miss.

Because of its brilliance, Capella served as a navigational beacon for the seafarers of ancient Polynesia, where it was known as “the canoe bailer of Makali’i.” Along with several other bright stars, it guided sailors across hundreds of miles of open ocean with pinpoint accuracy.

Capella also played a key role in ancient Greece — not as a guiding light, but as a bit of mythology. The star represented a goat that nursed the young Zeus, the king of the gods. Later, the goat’s horn broke off, so Zeus transformed it into a cornucopia — a “horn of plenty” that provided unending food and drink.

Originally, Capella was its own constellation — a single star representing the goat. But a couple of thousand years ago, it was merged with the next-door constellation Auriga, the charioteer. So today, it’s still a goat, but it’s sitting on the shoulder of the charioteer.

Although Capella looks like a single pinpoint of light, it’s actually a system of at least four stars. Two of them are red dwarfs — cosmic embers too faint to see with the eye alone. What we see as Capella consists of two stellar giants — stars in the final stage of life. We’ll have more about that pair tomorrow.

 

Script by Damond Benningfield, Copyright 2014


For more skywatching tips, astronomy news, and much more, read StarDate magazine.
The one constant in the Universe: StarDate magazine

FaviconMore Polaris 24 Oct 2014, 1:00 am

A half-century ago, the North Star had a little hiccup. Today, astronomers are still trying to understand what happened.

Polaris is a stellar supergiant that’s nearing the end of its life. The nuclear “engine” in its core is changing the way it produces energy. And that’s made the star unstable. Its outer layers pulse in and out like a beating heart, with each “beat” taking about four days.

Until 1963, Polaris’s brightness varied by about 10 percent with each beat. And the pulses were getting longer — by about four seconds per year. From 1963 to ’66, though, things changed. The change in brightness with each beat dropped, and the length of a beat began to grow shorter.

After that, the pulses began getting longer again, at about the same rate as before the glitch. But the variation in brightness remained small.

Just what caused the change is uncertain. One possibility is that the star’s average diameter shrank by less than one-tenth of a percent. Another is that the star swallowed a massive planet.

Astronomers continue to monitor the changes in Polaris, helping them better understand the final stages of life for such giant stars.

Look for Polaris due north every night of the year. It’s not all that bright, but there’s an easy trick for finding it. Line up the stars at the outer edge of the bowl of the Big Dipper. Then follow that line up and away from the bowl until you come to the first moderately bright star — the unsteady North Star.

 

Script by Damond Benningfield, Copyright 2014


For more skywatching tips, astronomy news, and much more, read StarDate magazine.
The one constant in the Universe: StarDate magazine

FaviconPolaris 23 Oct 2014, 1:00 am

Astronomers have been keeping a close eye on the North Star, Polaris, for centuries. That’s allowed them to compile an impressive dossier. They know that the system actually consists of several stars, for example — a brilliant one that’s visible to the eye alone, plus some fainter companions. They know that the bright star is a supergiant that’s much bigger and heavier than the Sun. And they know that it pulses in and out like a beating heart.

Even so, there are a lot of open questions about Polaris. One of the most important is its distance.

The most direct method for measuring a star’s distance is parallax. Astronomers look at the star when Earth is on opposite sides of the Sun. That lets them see the star shift back and forth a tiny bit against the background of more-distant stars. The size of that shift reveals the star’s distance — in this case, about 430 light-years.

Astronomers use other techniques to measure distances as well, and those don’t all agree with the parallax distance. One technique makes detailed measurements of the individual wavelengths of the star’s light and compares them to models of how stars behave. Using that technique, a study a couple of years ago came up with a distance of just 325 light-years.

Most astronomers go with the parallax measurement. Even so, there’s still a bit of wiggle room in measuring the distance to the North Star.

We’ll talk about another mystery of the North Star tomorrow.

 

Script by Damond Benningfield, Copyright 2014


For more skywatching tips, astronomy news, and much more, read StarDate magazine.
The one constant in the Universe: StarDate magazine

FaviconSolar Eclipse 22 Oct 2014, 1:00 am

The afternoon sky will get a little darker than normal for most of the United States tomorrow. That’s because there’s a partial solar eclipse.

A solar eclipse occurs when the new Moon passes directly between Earth and the Sun. Most months, the Moon skims just above or below the Sun as seen from Earth, so there’s no eclipse at all.

This eclipse is only partial — the Moon will cover only a portion of the Sun’s disk. So the sky will resemble an early dusk, and the temperature may drop a little bit.

The eclipse begins when the Moon’s shadow first touches Earth, over Siberia, around 2:30 p.m. Central Time. The shadow then spreads to the southeast, crossing Alaska, Canada, then the Lower 48 states.

The eclipse will be deeper from points farther north and west. From Anchorage, for example, the Moon will cover more than half of the Sun’s disk at the point of greatest eclipse. Only a third of the Sun will be eclipsed from Los Angeles and Dallas, though, and only a tiny notch will be missing as seen from New York and Miami.

In fact, for those in the eastern third of the country, the eclipse will still be in progress at sunset.

Keep in mind that it’s not safe to look at the eclipse directly — the Sun is still bright enough to damage your eyes. Instead, look through dark welder’s glass. You can also track the eclipse by looking at the ground under a leafy tree, where the gaps in the leaves create neat little pictures of this celestial lineup.

 

Script by Damond Benningfield, Copyright 2014


For more skywatching tips, astronomy news, and much more, read StarDate magazine.
The one constant in the Universe: StarDate magazine

ESOcast HD

ESOcast is a video podcast series dedicated to bringing you the latest news and research from ESO, the European Southern Observatory. Here we explore the Universe's ultimate frontier with our host Doctor J, a.k.a. Dr. Joe Liske.

FaviconESOcast 68: ESO Opens its Doors 24 Oct 2014, 11:00 am

On 11 October 2014 the ESO Headquarters in Garching, Germany, once more opened their doors to the public. Some 3 300 people used this special opportunity of the Open House Day to visit the centre of the world's foremost astronomical organisation.

FaviconESOcast 67: ESO People at Work and Play 11 Sep 2014, 6:00 am

This new ESOcast features six specialists in different areas who work at ESO in Germany and in Chile. Get to know the work they do at ESO, but also learn about interesting hobbies they pursue in their free time and how these hobbies may be connected to their work.

FaviconESOcast 66: A Groundbreaking Event for the E-ELT 2 Jul 2014, 9:00 am

On 19 June 2014, a major milestone on the road to the construction of the European Extremely Large Telescope was reached. Part of the 3000-metre peak of Cerro Armazones was blasted away as a step towards levelling the summit. This paves the way for the largest optical/infrared telescope in the world.

FaviconESOcast 65: The Chilean Sky in Ultra High Definition 30 May 2014, 12:00 pm

In the Spring of 2014, a team of ESO Photo ambassadors embarked on a pioneering expedition to ESO's three observatories in Chile. Their mission was to capture a wide range of images and time-lapses of the magnificent Chilean night sky and landscape in crisp Ultra High Definition. Join our heroes in their adventures in the arid Atacama Desert as they bring our Universe closer than ever before.

FaviconESOcast 64: First Ring System Around Asteroid 26 Mar 2014, 2:00 pm

This ESOcast shows how observations at many sites in South America, including ESO's La Silla Observatory, have made the surprise discovery that the remote asteroid Chariklo is surrounded by two dense and narrow rings.

HD - NASA's Jet Propulsion Laboratory

High-definition (HD) videos from NASA's Jet Propulsion Laboratory feature the latest news on space and science findings from JPL and NASA. Topics include discoveries made by spacecraft studying planets in our solar system, including Mars, Saturn and our home planet, Earth. Missions also study stars and galaxies in our universe.

FaviconNASA's Mars Odyssey Maneuvers to Image Comet Siding Spring 17 Oct 2014, 3:00 am



Mars program Chief Engineer Robert Shotwell describes Mars Odyssey's unprecedented view of comet Siding Spring as the comet sweeps by the Red Planet on Oct. 19 and how it will maneuver to take images.



FaviconThousands Explore the JPL Universe at Open House 2014 15 Oct 2014, 3:00 am



JPL hosted a record 45,000 visitors during its 2014 Open House event on Oct. 11 and 12, which showcased the laboratory's missions and science.



FaviconComet Siding Spring: A Close Encounter with Mars 9 Oct 2014, 3:00 am



Comet C/2013 A1 Siding Spring will make a close flyby of Mars on Oct. 19. At a distance of only 87,000 miles, it's a near miss of the Red Planet.



FaviconRapidScat installation on the International Space Station 6 Oct 2014, 3:00 am



Time-lapse footage of the RapidScat "wind watcher" instrument being installed on the International Space Station, followed by reaction by the team after its activation.



FaviconWhat's Up - October 2014 30 Sep 2014, 3:00 am



What's Up for October? A lunar eclipse, a solar eclipse and Mars has a close encounter with a comet.