Fraser Cain, Author at Universe Today

October 29, 2007December 26, 2015 by Fraser Cain

Astronomy Cast Research

Thanks to everyone who responded to our listener survey a few months ago. As promised, the results of the survey are now available, and have actually been published in a research journal. So if you’re interested in learning about who’s listening to Astronomy Cast, check out the premier issue of Communicating Astronomy with the Public, published by the International Astronomical Union.

Our article is called, Astronomy Cast: Evaluation of a podcast audienceâ€™s content needs and listening habits. I guess the title sort of explains it all.

So once again, thanks to everyone who participated, you’ve given us great feedback, and helped us make some really pretty bar charts.

If I had to take away one piece of information, that really makes the whole podcasting thing worth while, it’s the change in interest towards astronomy. Check this out.

We found that 25% of our listener respondents had no interest or a passive interest in astronomy prior to listening to astronomy-related podcasts. After listening to astronomy-related podcasts, 70% of these individuals had begun to actively seek astronomy content or had become amateur astronomers.

You can download our specific article here.

Fraser Cain
Publisher, Universe Today (and co-host of Astronomy Cast)

October 29, 2007December 26, 2015 by Fraser Cain

Hundreds of Hidden Black Holes Discovered

Astronomers now believe there are supermassive black holes at the heart of every galaxy. When these black holes are actively feeding on material, they blaze with radiation, visible across the Universe. These active galaxies are known as quasars, and they were thought to be very common in the early Universe. But astronomers were having trouble finding almost any of them. It turns out, they were just hiding.

Supermassive black holes live at the very centre of galaxies, regions that can be thick with gas and dust. As the supermassive black hole goes into its actively feeding stage, the torrents of radiation that pour out collide with the dust. Instead of shining across the Universe, the radiation is smothered by dust.

These black holes are hidden, but they’re not entirely undetectable. Astronomers used NASA’s Spitzer Space Telescope to study 1,000 dusty, massive galaxies known to be furiously making stars. With all this gas and dust tearing around, you would think the supermassive black holes would be actively feeding, and blazing as quasars. But no quasars were seen.

Spitzer’s infrared view, however, allowed astronomers to pierce through the dusty veil surrounding the supermassive black hole, and see that 200 of the galaxies were producing an unusual amount of infrared light. The quasars heat up the dust in the surrounding doughnut cloud, and this cloud gives off the radiation detected by Spitzer.

These quasars are between 9 and 11 billion light-years away. In other words, we see the light they gave off when they were only 2.5 – 4.5 billion years old. Before now, only the rare, extremely energetic quasar was visible – after they had cleared away the surrounding gas and dust. This expanded population gives astronomers a much better understanding of galaxy evolution in the early Universe.

This discovery also downplays the role that galaxy collisions might have had in the early Universe, “theorists thought that mergers between galaxies were required to initiate this quasar activity, but we now see that quasars can be active in unharassed galaxies,” said co-author David Alexander of Durham University, United Kingdom.

The observations were made as part of the Great Observatories Origins Deep Survey, the most sensitive survey to date of the distant universe at multiple wavelengths.

Original Source: NASA News Release

October 29, 2007December 26, 2015 by Fraser Cain

Tropical Storm Noel… from Space

I don’t usually talk about the weather, but look at this picture… wow. It’s an image of tropical storm Noel, currently moving westward across the Caribbean Sea, and captured by ESA’s Envisat environmental monitoring satellite. When the image was taken, it was still just a depression, but it was upgraded to a tropical storm on Sunday. Noel is the 14th storm of the Atlantic hurricane season, and has tropical storm force winds stretch out 225 km from its centre.

Original Source: ESA News Release

October 29, 2007December 26, 2015 by Fraser Cain

Podcast: Questions on Inflation

It’s about time for a question show again, so we’ll have one last interruption to our planetary tour, to deal with the questions that arose from our inflation show. So if you still donâ€™t understand inflation, take a listen to this week’s show and as always, send us your questions.
Click here to download the episode

Questions on Inflation – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

October 29, 2007December 26, 2015 by Fraser Cain

Harmony Module Installed onto the Station, Damage Discovered

NASA astronauts added the newest module to the International Space Station on Friday morning, clearing the way for several new laboratory modules and increasing the sleeping capacity. Astronauts Scott E. Parazynski and Col. Douglas H. Wheelock spent their morning on Friday, suspended above the planet, attaching the newly delivered Harmony module to the station. During the second spacewalk on Sunday, the astronauts discovered damage to one of the joints that orient the station’s solar arrays.

First Spacewalk – Friday
Once the shuttle docked on Thursday, the first scheduled spacewalk began early the next day. Parazynski and Wheelock went outside the station at 6 a.m. EDT, and prepared Harmony for its removal from the shuttle’s payload bay.

Inside the station, Stephanie D. Wilson and Daniel M. Tani operated the station’s robotic arm, to help remove the module from the shuttle’s cargo bay and transfer it over to the station.

The spacewalk itself went quickly, and mostly without incident. The astronauts struggled briefly to remove some of holding bolts and hose connectors. And there were a few situations where frozen ammonia drifted away from some of the hoses. This ammonia could contaminate the station’s atmosphere if it got back inside, so the astronauts carefully avoided coming into contact with any of the substance.

Second Spacewalk – Sunday
For the second spacewalk on Sunday, Scott Parazynski was joined by Daniel M. Tani. Their task was to unbuckle a solar array atop the station so that it can be relocated. They also began outfitting the exterior of the newly attached Harmony module.

After removing a protective cover, Tani discovered what appeared to be metallic shavings in one of the station’s rotating joint assemblies. He collected up some samples with tape so that engineers can study it, and figure out what could be going on. Station controllers had noticed that a joint on the right-hand side of the station was experiencing unusual vibrations as it rotated, so these two events could be connected.

The best theory right now is that the foil backing on an aluminum cover is rubbing against the mechanism that turns the station’s solar arrays to orient towards the Sun. This material is shredding off the cover and getting into the mechanism.

NASA is considering whether they’ll have the astronauts open up all 21 covers to see if any are the source of the damage. This could be done during a currently planned spacewalk, or it could become another spacewalk all on its own. Even if the source of the metal is discovered, it might be impossible to clean.

Original Source: NASA Station Coverage

October 28, 2007December 26, 2015 by Fraser Cain

Astrosphere for October 28th, 2007

I hope you’re all enjoying this lazy Sunday. Sorry for the lack of updates, things have been busy for me. Of course, you’ll be wanting an image of Comet Holmes. This one was captured by Phil22 from the forum, but there are lots more there, so check them all out.

Lots of people are talking about Comet 17P/Holmes. Astroprof captured an image of the comet above his house. And here’s an image captured by Steve Tuttle. And here’s a cool series showing its evolution from Slacker Astronomy. And another nice one from Tom’s Astronomy Blog. And finally, here’s a sketch made by Bill Greer.

And everyone else is out at the X-Prize Cup. Jeff Foust uploaded a bunch of images. And here’s a video of Armadillo Aerospace’s unsuccessful attempt to win the first lunar prize. And here’s some coverage from Alan Boyle’s Cosmic Log. Finally, here’s Wired Science’s excellent coverage. Orbital Outfitters showed off their new prototype commercial pilot spacesuit.

October 24, 2007January 24, 2021 by Fraser Cain

Comet 17P/Holmes Erupts in the Sky

Astronomers from Europe and Asia are reporting that the normally dim Comet 17P/Holmes has had an eruption. Instead of being 17th magnitude – only visible to powerful telescopes – it’s now 3rd magnitude. This makes it easy to spot with the unaided eye, even in cities with heavy light pollution.

To confirm this discovery, head outside after the skies are dark, and look to the Northeast. The comet is currently in the constellation Perseus, which is below the more familiar Cassiopeia. If you’re familiar with the constellations at all, you’ll now see a new, bright yellow star. A telescope reveals the fuzzy corona surrounding the comet.

One report from Japan says, “Perseus does not look ‘Perseus’ familiar to us due to the bright stellar object now.”

Spaceweather and Bad Astronomy have more details.

Thanks to BAUT member Keith G for the photograph. Here’s a link to the forum where people are discussing it.

October 24, 2007December 26, 2015 by Fraser Cain

Ancient Salt Deposits in a Martian Crater

Here’s an interesting image released today captured by NASA’s Mars Reconnaissance Orbiter. It’s of an unnamed crater on Mars in the Terra Cimmeria region that could contain ancient deposits of chloride salts. The region is one of the most geologically interesting on Mars. It’s riddled with impact craters, crisscrossed by dried up river channels, and sculpted by wind. Water probably acted on the region a long time ago, building up the salt deposits.

This region of Mars is of great interest to scientists. Three separate missions have studied the area in great detail: Mars Global Surveyor, Mars Odyssey, and now the Mars Reconnaissance Orbiter. Over the years, they have shown how these small deposits of chloride salts are scattered across the Martian surface.

They’re more widely found in the Noachian (most ancient) regions, and less found in the Hesperian (middle geologic time) terrain. This means that the deposits were probably laid down in the earliest epochs of Martian history, and then later geologic processes resurfaced them.

This image, captured by the HiRISE instrument on NASA’s Mars Reconnaissance Orbiter shows one of these deposits. The photograph reveals an area about 900 metres across, including a partially buried unnamed crater in Terra Cimmeria. The chloride salt deposits in this photograph are the lighter toned colour. The deposits are relatively thin and occur in low lying areas. This one has been heavily eroded, which suggests that it’s very old.

Original Source: HiRISE News Release

October 24, 2007December 26, 2015 by Fraser Cain

Astronauts Study Discovery with Robotic Arm

Although the space shuttle Discovery launched yesterday, it still won’t actually link up with the International Space Station until Thursday. But that doesn’t mean they haven’t got plenty of work today. The astronauts spent part of their Wednesday analyzing the shuttle’s heat absorbing tiles using its robotic arm. Engineers didn’t think that falling ice, or wear and tear on some of the shuttle’s tiles were going to be a problem – now they’ll know for sure.

The astronauts attached a special boom extension to Discovery’s robotic arm today, and used it examine the shuttle’s underside for damage. With the images and radar analysis completed, engineers back on Earth can find any damage, and determine if any of it will be a risk when the shuttle re-enters the Earth’s atmosphere. The comprehensive scan took several hours to complete.

If there is damage, the astronauts have several strategies they can use to patch things up. They can screw down a protective plate, squeeze in a filler, or coat damaged tiles with special heat absorbing paint. These strategies haven’t been necessary yet, since the increased precautions created after the Columbia disaster.

NASA analysts have also studied video of the launch, and did notice chunks of foam dislodge from the external fuel tank. The foam fell later on during the ascent, though. This is good news, since the foam hits the shuttle with less force later on in the launch.

The crew also extended the shuttle’s docking ring, and prepared the tools they will use during the rendezvous and link up with the station. They also did a check out of the spacesuits that will be used during the mission’s 5 scheduled spacewalks.

If all goes well, the two vehicles will meet at 8:33 a.m. EDT on Thursday.

Original Source: NASA Shuttle News

October 24, 2007December 26, 2015 by Fraser Cain

Chinese Moon Mission Blasts Off

The Moon had been lonely for a while, but now there’s no shortage of spacecraft on the way. The latest visitor, China’s Chang’e-1, blasted off today from the Xichang Satellite Launch Centre, Sichuan, atop a Long March 3A rocket. Although this spacecraft is just a lunar orbiter, it begins the country’s journey to putting a lander down on the surface of the Moon before 2020.

Just like the Japanese spacecraft already orbiting the Moon, and the upcoming US Lunar Reconnaissance Orbiter, this Chinese spacecraft will studying the Moon in detail.

It has four major objectives: to map the Moon’s surface in 3-D, to analyze the abundance of 14 chemical elements, to measure the depth of the lunar soil (or regolith), and to study the space weather between the Earth and the Moon.

The ambitious spacecraft weighs in at 2,350 kg, and will transition to a low, circular lunar orbit, skimming just 200 km above the surface. It’s expected to begin its Earth-Moon transfer burn on October 31st, and arrive in lunar orbit on November 5th. It’s expected that Chang’e-1 will take its first images on the Moon in late November, and continue scientific observations for a year.

Original Source: ESA News Release