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.
Please vote for this podcast at PodcastAlley!
Get this podcast story.
(audio/mpeg; 3.66 MB)
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.
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.
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.
(audio/mpeg; 3.18 MB)
One of the biggest black holes in the universe seems to have fired a bullet into the intergalactic void. And it’s moving more or less in our direction at record speed.
The fast-moving bullet is a star cluster in the constellation Virgo, which is low in the southeastern sky at nightfall. The cluster lies in the same direction as M87, an elliptical galaxy that’s much bigger and heavier than our own galaxy, the Milky Way.
An enormous black hole inhabits the center of M87. It’s almost seven billion times more massive than the Sun — one of the heaviest black holes yet measured. The star cluster may have passed close to the black hole, whose powerful gravity hurled it away.
Like most galaxies, M87 is moving away from us. Astronomers see this because as the galaxy’s light waves travel toward us, the expanding universe stretches those waves to longer, redder wavelengths, producing a so-called redshift.
But the star cluster doesn’t have a redshift. Instead, it has a blueshift, which means it’s moving toward us. Moreover, it’s racing toward us faster than any known star, star cluster, or galaxy — more than two million miles per hour.
The cluster isn’t a danger to the Milky Way, though. It’s moving at a tangent to our galaxy, so it won’t hit us. Instead, it’s a celestial record breaker, likely owing its superlative qualities to a superlative black hole at the heart of a giant galaxy.
Script by Ken Croswell, Copyright 2015
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
In 1990, estimates of the age of the universe ranged from 10 billion to 20 billion years. Today, just a quarter of a century later, there’s widespread agreement that the universe is a bit less than 14 billion years old.
That’s one of the most important discoveries made with Hubble Space Telescope, which was launched 25 years ago today. It’s provided new insights into everything from our own solar system to the most-distant quasars — giant disks of hot gas around supermassive black holes. It’s peered into stellar nurseries, stellar retirement centers, and even stellar graveyards. And it’s provided dazzling pictures of some of the most beautiful objects in the universe.
Nailing down the age of the universe may be one of its most important contributions.
To determine the age, scientists used Hubble to measure the distances to pulsating stars in other galaxies. How fast the stars pulsate reveals just how bright they are, which in turn reveals how far away they are. Hubble’s observations also determined how fast the host galaxies were moving away from us as a result of the expansion of the universe. The combination of the distance and the expansion rate helped reveal when the universe began expanding in the Big Bang.
No one knows how much longer Hubble Space Telescope will operate. All we know for sure is that, no matter how long it lasts, it’ll continue to dazzle us with its discoveries about our amazing universe.
Script by Damond Benningfield, Copyright 2015
NASA released this Hubble Space Telescope image of a busy star cluster to commemorate the 25th anniversary of the telescope's launch. Known as Westerlund 2, the cluster contains about 3,000 infant stars, plus the raw materials for making many more stars. The cluster is about 20,000 light-years away, in the southern constellation Carina, the keel. It is about two million years old and is dominated by hot, massive stars. These stars produce strong winds and torrents of ultraviolet radiation, which erode the clouds of gas and dust that are giving birth to new stars. [NASA/ESA/Hubble Heritage Team/A. Nota/Westerlund 2 Science Team]
Text ©2015 The University of Texas at Austin McDonald Observatory
In late 1990, a “Far Side” cartoon depicted a jittery flying saucer with a jittery planet in the background. The caption read, “Another photograph from the Hubble telescope.”
Hubble was launched 25 years ago tomorrow amid much fanfare. Within weeks, though, it was a national joke. Time magazine called it the “Blunder of the Century,” and columnist Dave Barry christened it the “Hubble Space paperweight.” David Letterman offered a “Top 10 Hubble Telescope Excuses” list, which included “The guy at Sears promised it would work fine.”
Even though the telescope was years late and hundreds of millions of dollars over budget, its main mirror was flawed. Its curved surface had been ground to the wrong shape. It wasn’t a big error — it was off by less than the width of a human hair. Yet that tiny flaw turned what should have been pinpoint images of stars into out-of-focus blobs.
An investigation showed that the contractor hadn’t properly tested the mirror’s shape, and had ignored test results that showed possible problems. And NASA had provided poor oversight of the testing process.
Fortunately for Hubble and NASA, though, a clever scientist devised a way to overcome the problem — a set of optics that would act like contact lenses, bringing the view into proper focus. Space shuttle astronauts installed the system a few years later. It turned the space telescope from a national disgrace to a national treasure. More about that tomorrow.
It was years late and hundreds of millions of dollars over budget, but 25 years ago this week, Hubble Space Telescope was finally ready to fly.
The telescope was designed to provide especially sharp views of the universe by escaping Earth’s atmosphere, which blurs the view and blocks some wavelengths of energy. It included a 96-inch mirror to gather and focus starlight, and a set of instruments to study that light.
PAO: 3, 2, 1, and liftoff of the space shuttle Discovery with the Hubble Space Telescope, our window on the universe.
Discovery carried Hubble into orbit on April 24th, 1990. And the following day, the crew was ready to send the telescope on its way. But there was a problem: One of Hubble’s two solar arrays wouldn’t open.
DISCOVERY: Houston, Discovery, it looks like motion stopped with just about one panel showing.
Without both arrays, Hubble wouldn’t have enough power to do its work. And there wasn’t much time to get it open. Mission Control ordered two astronauts to suit up for a possible spacewalk to fix the problem.
At the last minute, though, controllers discovered the culprit — a faulty sensor. They bypassed it, and the array opened perfectly. So one orbit late, Houston was ready to give Discovery the green light:
AUDIO: GC? Go. Network? Go. Payloads, waiting on you. Flight, payloads, we are go. Capcom, we have a go for release. Discovery, go for Hubble release.
Minutes later, Hubble was on its way. Yet even then, things weren’t quite right. More about that tomorrow.
When the first images from Hubble Space Telescope were too blurry, JPL's scientists and engineers devised a genius fix: a camera with corrective vision.
JPLers pounded the pavement in celebration of a Mars marathon milestone. Opportunity rover took 11 years and 2 months to clock 26.2 miles. The team’s time was considerably less.
A total lunar eclipse that takes place on the night of a full moon and, later this month, the Lyrid meteor shower.
A total solar eclipse in the North Atlantic and tips to prepare for the next U.S. eclipse.
On March 6, the Dawn spacecraft will slip into orbit around Ceres, a dwarf planet located in the main asteroid belt.