16-04-2012 22:19 Special Topics in Astrophysics

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Astronomy 250 - Lecture 11 - Video

23-04-2012 18:04 Last week we talked about the orbiter portion of the Viking Missions. But that was only half the adventure. Each Viking spacecraft carried a lander as well, which touched down on the surface of Mars, searching for evidence of past and current life. And what they discovered is still up for debate.

Original post:

Astronomy Cast Ep. 258: Viking Landers - Video

by Fraser Cain on April 23, 2012

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay. He's the forum co-administrator of the Bad Astronomy/Universe Today forum with Bad Astronomer Phil Plait.

See the original post:

Astronomy Cast, Ep: 258: Viking Landers

[UPDATE: American Airlines has agreed not to run the interview! That includes both the audio and print versions.]

[Note: This post contains numerous links to articles showing antivax claims are misleading at best, and pose a huge health risk. I strongly urge you to read those links before leaving a comment.]

In May 2011, an unvaccinated infant infected with measles was brought on board American Airlines flight 3965. Measles is a highly contagious, dangerous, and potentially fatal disease, and because of this public health emergency officials had to track down 100 passengers and quarantine quite a few of them.

This event was not American Airlines fault. However, its hard to see what they learned from it, since they plan on printing and airing an interview with a notorious antivaxxer who makes provably false and incredibly dangerous claims about vaccines and vaccine-preventable diseases.

The antivaxxer in question is Meryl Dorey, an American living in Australia who has made it her lifes work to spread misinformation about vaccines. Her ability to distort the truth to phrase it kindly is nothing short of herculean. As I wrote about her in 2010:

She has said no one dies from pertussis anymore when little four-week-old Dana McCaffery died of that very disease, because herd immunity in her area of Australia was so low. Dorey is an HIV denier. She thinks doctors lie and poison babies. [...] It goes on and on.

So why on Earth would American Airlines choose to run an interview with her in their in-flight magazine and air that interview on the in-flight TVs?

The interview is her usual passel of untruths about vaccinations: she tries to tie them to worsening diseases and autism neither of which is remotely true and then relies on the discredited research of a man the British Medical Journal outright called a "fraud".

Bizarrely, the interviewer for the American Airlines piece apparently didnt even contact an actual doctor to get professional information on this topic. At the very least (the very least) the ability to show Meryl Doreys claims to be completely wrong is a Google search away, a trivial amount of work for an interviewer to do. Her horrid behavior towards Toni and David McCaffery little Danas parents, who had to suffer through Doreys attacks while still grieving over their daughter is also out there for all to see.

So again, why on Earth would American Airlines choose to run an interview with her in their in-flight magazine and air that interview on the in-flight TVs?

View original post here:

American Airlines to air dangerous antivax propaganda | Bad Astronomy

Today is the 22nd anniversary of the launch of the Hubble Space Telescope. I worked on Hubble one way or another for a decade or so, and it changed not just my life, but the lives of astronomers around the world, and of course forever altered for the better! how the public viewed of astronomy.

To acknowledge this, below is a repost of my "Ten Things You Dont Know About Hubble", first put on the blog in 2010, and which I think still holds up. And what better way to celebrate this observatorys anniversary than to get to know it a little better?

Introduction

On April 24, 1990, the Space Shuttle Discovery roared into space, carrying on board a revolution: The Hubble Space Telescope. It was the largest and most sensitive optical-light telescope ever launched into space, and while it suffered initially from a focusing problem, it would soon return some of the most amazing and beautiful astronomical images anyone had ever seen.

Hubble was designed to be periodically upgraded, and even as I write this, astronauts are in the Space Shuttle Atlantis installing two new cameras, fixing two others, and replacing a whole slew of Hubbles parts. This is the last planned mission, ever, to service the venerable scope, so what better time to talk about it?

Plus, its arguably the worlds most famous telescope (its probably the only one people know by name), and yet I suspect that there are lots of things about it that might surprise you. So I present to you Ten Things You Dont Know About the Hubble Space Telescope, part of my Ten Things series. I know, my readers are smart, savvy, exceptionally good-looking, and well-versed in things astronomical. Whenever I do a Ten Things post some goofball always claims they knew all ten. But I am extremely close to being 100% positive that no one who reads this blog will know all ten things here (unless theyve used Hubble themselves). I have one or two big surprises in this one, including some of my own personal interactions with the great observatory!

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Excerpt from:

Happy 22nd, Hubble! | Bad Astronomy

Crave's Nerdy New Mexico series crawls up to 9,200 feet and gawks at the massive Dunn Solar Telescope in the tiny community of Sunspot.

Inside the Dunn Solar Telescope.

SUNSPOT, N.M.--Back in 1950, an order was placed for a grain bin from the Sears Catalog. That bin was delivered up to the far reaches of the Sacramento Mountains in New Mexico, and after some modifications, it became the first solar telescope in Sunspot.

Sunspot may be the geekiest town in America. It's an unincorporated community full of scientists and support staff for the National Solar Observatory. The road leading into town is State Highway 6563, named for a hydrogen emission line wavelength used in stellar astronomy.

Inside a solar telescope We've come a long way from that original grain bin. Built in 1969, the Dunn Solar Telescope is a marvel of engineering and a destination spot for scientists from around the world. It's the largest of several solar telescopes on Sacramento Peak.

This Sears Catalog grain bin became the first telescope in Sunspot. (Click to enlarge.)

An informational plaque inside the telescope building describes it as an iceberg. It rises 13 stories above the ground, but reaches even farther into the earth. The telescope's bottom part consists of 230 feet hidden in the ground. That must have been some dig. The whole thing weighs more than 250 tons.

Visitors are allowed inside the Dunn telescope. It's dim in the observation room, lit only by UFO-looking globes above that cast an orange light. There's a deep hum of instrumentation and a "quiet, scientists at work" vibe.

Massive piles of computers and equipment with colorful glowing lenses surround a lone scientist buried deep in his work. I feel like I've stepped inside a spaceship.

You can't see it from here, but the rotating part of the telescope (all 200 tons of it) is suspended at the top from a massive tank containing 10 tons of mercury. That makes it so easy to rotate, it can be done by hand.

View post:

Astronomy: It's not just for nighttime viewing

Good news: I just received a tweet from the American Airlines Twitter feed:

Yay! They have decided to not air the audio version of the antivax interview. Thats excellent, and I thank American Airlines for that.

However, as far as I can tell, the interview is still slated to run in their in-flight magazine. I will hopefully have more news about that soon as well.

Update: When I asked about the printed version, I got this reply back very quickly:

Yay again!

Again, I thank American Airlines for considering this issue and making the right decision. I also want to sincerely thank everyone who wrote and tweeted about this.

Remember: we have the power to make sure good, accurate science gets told, and bad, inaccurate misinformation does not spread. Never rest, never tire, and never forget that the price of freedom is eternal vigilance.

Visit link:

UPDATE: partial Complete success with American Airlines! | Bad Astronomy

Join the Popular Astronomy Club for a National Astronomy Day celebration at the Moline Public Library, 3210 41st St., from 2-9:30 p.m. Saturday. The educational family event will feature displays, astronomy-themed crafts, demonstrations of comet nucleus forming, a weight station to discover your weight on different planets, gravity explanations, door prizes and refreshments.

See the sun safely with specially filtered telescopes until dusk, then tour the night sky until 9:30 p.m., weather permitting. Venus, Mars and Saturn should be visible, along with star clusters. Sky viewing will take place in the back parking lot of the Moline Public Library.

Dr. Robert Mutel from the Department of Physics and Astronomy at the University of Iowa will present a program for adults at 3 p.m. on Alien Worlds: The Search for Life on Extra-Solar Planets. The program will explore recent developments in the ongoing search for life outside of our solar system.

The free event is sponsored by the Popular Astronomy Club and University of Iowa Speakers Bureau. For more information, call the library at 309-524-2480 or visit molinelibrary.com.

Link:

Moline Public Library to host Astronomy Day

20-01-2012 11:43 bigthink.com Dr. Michio Kaku: At night when you look at the stars and you look at the constellations and you wonder "Is anyone out there?" just realize that somebody out there could be looking back at us and wondering "Gee, is there any life on this ...

Read the original here:

The Holy Grail of Planetary Astronomy: The Search for Earth's Twin - Video

Rocks dislodged in a landslide on Lutetia. Click for larger. Credits: ESA 2011 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

Cool stuff!!

From the ESA site:

ESA’s Rosetta spacecraft has revealed asteroid Lutetia to be a primitive body, left over as the planets were forming in our Solar System. Results from Rosetta’s fleeting flyby also suggest that this mini-world tried to grow a metal heart.

Rosetta flew past Lutetia on 10 July 2010 at a speed of 54 000 km/hr and a closest distance of 3170 km. At the time, the 130 km-long asteroid was the largest encountered by a spacecraft. Since then, scientists have been analysing the data taken during the brief encounter.

Now for the good stuff and more amazing images . . .

Juno's location on it's journey to Jupiter. Click for larger. Image: NASA

Juno is well on it’s way to Jupiter and as you will read in NASA’s update below the spacecraft is operating as expected. The image depicts about where Juno is relative to the Earth. I like the larger image (click the one above) because it illustrates nicely why it will not get to Jupiter until July 2016.

You can get the full size version of the image above and also see the Juno spacecraft’s current position and velocity using NASA’s Eyes on the Solar System 3D interactive (free web browser plugin required) or the NASA/JPL Solar System Simulator by going to the Juno webpage at NASA.

Here’s NASA’s update:

As of October 25, 2011 Juno was approximately 23.3 million miles (37.4 million kilometers) from Earth traveling at a velocity of 66,700 miles per hour (107,300 kilometers per hour) relative to the sun. One way travel time for a signal from Earth is approximately 2 minutes 5 seconds. The spacecraft is in excellent health and is operating nominally.

During the week of October 13-19 the Juno team completed coarse alignment of the spacecraft’s high gain antenna, or HGA with Juno’s spin axis. The HGA is the large, saucer-shaped antenna on Juno’s forward (top) deck. During these calibrations, mission controllers finely adjust the tilt angle of Juno’s three large solar arrays in order to carefully re-balance the spacecraft’s mass and bring the antenna’s pointing in to tight alignment with the spin axis.

Precise antenna alignment is important for gravity science operations at Jupiter, in which the HGA will be pointed directly at Earth in order to track minute changes in Juno’s acceleration within Jupiter’s gravity field.

Crepusular Rays as seen from the ISS. Image credit: NASA / JSC / ISS Crew

Ever seen these? I’m sure you have and now you know what to call them.

These were seen from the above by crew members aboard the ISS and the photo was taken on October 18^th as the ISS was passing over India.

You can get a larger version of the image here (links to the Earth Observatory page) or you can go to the main Earth Observatory page with the image and caption. I’ve included the caption (by William L. Stefanov, Jacobs/ESCG at NASA-JSC) below:

The sight of shafts of light streaming down from the heavens through a layer of clouds has provided many an artist, scientist, and philosopher with inspiration. Atmospheric scientists refer to this phenomenon as “crepuscular rays,” referring to the typical observation times at either sunrise or sunset.

The shadowed areas bounding the rays are formed by clouds or mountain tops that block the path of sunlight or moonlight. However, obstructions alone are not sufficient to create crepuscular rays. The light also must be scattered by airborne dust, aerosols, water droplets, or molecules of air, providing a visible contrast between shadowed and illuminated parts of the sky.

When observed from the ground, crepuscular rays appear to radiate outwards from the source of light due to the effects of distance and perspective. However, the rays are actually parallel. This astronaut photograph from the International Space Station provides an unusual viewing perspective from above the rays and a clear illustration of their parallel nature. The sun was setting to the west (image left) on the Indian subcontinent, and cumulonimbus cloud towers provided the shadowing obstructions. The rays are being projected onto a layer of haze below the clouds.

The latest view of Hyperion by Cassini. Image Credit: NASA/JPL-Caltech/Space Science Institute

The latest view of Hyperion by Cassini.  Image Credit: NASA/JPL-Caltech/Space Science Institute

NASA titled this image quite appropriately “Spongy Hyperion”.  This visible light image taken through a blue filter really does make the little moon look like a sponge.

Hyperion is a little moon being only 168 miles (270 km) across and it isn’t very uniform in shape either as you can tell.  Another interesting thing is the moon doesn’t spin so much as it tumbles its way around Saturn.  Tumble is a better descriptor because it has a variable “spin or tumble” rate and orientation.

Click here to view the embedded video.

From the Carnegie Science Center:

The MESSENGER spacecraft has shown scientists that Mercury doesn’t conform to theory. Its surface material composition differs from both those of the other terrestrial planets and expectations prior to the MESSENGER mission, calling into question current theories for Mercury’s formation. Its magnetic field is unlike any other in the Solar System, and there are huge expanses of volcanic plains surrounding the north polar region of the planet and cover more than 6% of Mercury’s surface

Source

Click here to view the embedded video.

In the first launch of a Soyuz booster rocket since the loss of the Progress 44 back on August 24th was successful.  Close to three tons of food, fuel and supplies should arrive at the ISS on November 2 in the automated docking between Progress and the space station.

Source

“Vertebrate males commonly experience elevations in testosterone levels in response to sexual stimuli, such as presentation of a novel mating partner. Some previous human studies have shown that watching erotic movies increases testosterone levels in males although studies measuring testosterone changes during actual sexual intercourse or masturbation have yielded mixed results. Small sample sizes, “unnatural” lab-based settings, and invasive techniques may help account for mixed human findings. Here, we investigated salivary testosterone levels in men watching (n = 26) versus participating (n = 18) in sexual activity at a large U.S. sex club. The present study entailed minimally invasive sample collection (measuring testosterone in saliva), a naturalistic setting, and a larger number of subjects than previous work to test three hypotheses related to men’s testosterone responses to sexual stimuli. Subjects averaged 40 years of age and participated between 11:00 pm and 2:10 am. Consistent with expectations, results revealed that testosterone levels increased 36% among men during a visit to the sex club, with the magnitude of testosterone change significantly greater among participants (72%) compared with observers (11%). Contrary to expectation, men’s testosterone changes were unrelated to their age. These findings were generally consistent with vertebrate studies indicating elevated male testosterone in response to sexual stimuli, but also point out the importance of study context since participation in sexual behavior had a stronger effect on testosterone increases in this study but unlike some previous human lab-based studies.”

Photo: Flickr/ F3LONY
Thanks to @cqchoi for today’s ROFL!

Related content:
Discoblog: NCBI ROFL: The effects of acute ethanol consumption on sexual response and sexual risk-taking intent.
Discoblog: NCBI ROFL: Women’s bust size and men’s courtship solicitation.
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WTF is NCBI ROFL? Read our FAQ!

What’s the news: Viking legend has it that sailors could hold up crystal sunstones to the sky to help them find their way. Turns out the legend could be true. In a study published this week in the journal Proceedings of the Royal Society B, a team of researchers found that a type of crystal called an Icelandic spar commonly found in that country could accurately reveal the position of the sun in cloudy or near-dark conditions.

How Vikings Got Around:

• Researchers have long wondered and argued about how the Vikings were able to successfully navigate their way around the Northern Hemisphere in the late eighth to 11th centuries, hundreds of years before the magnetic compass reached Europe around 1300. Besides the direction of the wind, waves, and swell, the only way to navigate during the day away from shore is by knowing the sun’s direction. But that’s not so easy on a foggy or stormy day, or during the long twilight of Northern summers.
• Historians have speculated that, due to their optical properties, crystals of calcite (a common form of calcium carbonate) could have been used to tell direction, but until now the theory hadn’t been tested.

The Magic of Calcite:

• Icelandic spars are crystals of calcium carbonate which have a special property called birefringence: light hitting the mineral is split and follows two parallel paths through it, which explains how calcite makes objects look doubled. The relative brightness of the two images—the amount of light following the two different paths—depends on the light’s orientation to the crystal. The researchers showed that this can be used to locate a hard-to-find light source, like the sun on a cloudy day.
• The basic idea is that at a certain orientation to a light source, the crystal produces two light beams of equal brightness, a contrast the eye can measure surprisingly well. If you figure out what orientation of the crystal produces this effect when the sun is visible, you can repeat the procedure in the fog to find the sun.
• Testing the method with various Icelandic spars, the researchers were able to establish the direction of the sun to within 5 degrees.

Is This the Vikings’ Secret?

• So far no crystals have been found in known Viking settlements or artifacts. But one such crystal was recently found in the 1592 shipwreck of an Elizabethan vessel in the English channel. The researchers think its likely to have been used to aid navigation, due to its shape and their calculation that the presence of even the one large cannon found aboard would interfere with compass readings. This suggests these types of sunstones were in use more than 200 years before polarized light was first discovered, and possibly used even earlier by the Vikings to navigate the open seas.

Reference: Guy Ropars, Gabriel Gorre, Albert Le Floch, Jay Enoch, and Vasudevan Lakshminarayanan. A depolarizer as a possible precise sunstone for Viking navigation by polarized skylight. Proceedings of the Royal Society A. Published online 2 November 2011. DOI: 10.1098/rspa.2011.0369

Image credit: WikiMedia Commons 

While my first column for Discover was on the multiverse, the second one is more down to Earth (as these things go): searching for new forces. Of course we are searching for new short-range forces at the Large Hadron Collider and in other particle-physics experiments, but here I’m talking about long-range “fifth forces.” While there are plausible motivations for searching for such forces, and the experimentalists have done an heroic job in constraining them, I argue that the most impressive thing is how we can say what forces are not out there — in particular, anything that would have any important effect on everyday life. There probably are more forces than we know about, but they’re only going to be of direct interest to physicists, I’m afraid. No tractor beams.

The Pine Island Glacier is a massive flowing river of ice on the western Antarctic ice shelf. And by massive, I mean massive: it’s 250 km (150+ miles) long, and has an area of 175,000 square kilometers — that’s bigger than the state of Iowa! Every year, a staggering 79 cubic kilometers (19 cubic miles) of ice drains from this glacier in the ocean, flowing via a tongue of ice floating in the water off the main land.

Flying over the glacier on October 14, scientists aboard a NASA DC-8 airplane as part of the IceBridge mission were startled to see a huge crack across the glacier. Flying back over it on October 26, they were able to photograph and measure this huge rift, and found it will almost certainly soon give birth to a huge iceberg. Check out this lovely picture of the ice crack:

[Click to enfloenate - and you really want to; it's amazingly beautiful.]

Brrrr. The scale of this crack is much larger than you might think: it’s 80 meters wide on average, and about 150 meters wide in the photo above, the size of a football stadium! It runs for 29 km (18 miles), and it’s pretty deep; a topographic map (shown here) indicated it’s 50-60 meters in depth.

Remember, Antarctica is a continent, a land mass, but this part of the glacier is flowing out over the ocean, and is floating. The ice at this point in the glacier is about 500 meters thick — more than a quarter mile! — but cracks like these grow with time. Eventually, it’ll snap, and the seaward part of the ice will float free, a newly-born iceberg that will be something like 800 square kilometers (300+ square miles) in area. Such cracks have been seen before, but never mapped in such detail using airborne observations.

NASA put together a video about the flight over Pine Island:

This is wonderful science, studying how our dynamic planet changes over time. And to get to see such an amazing event as it’s just getting started is very exciting! You can see other pictures from this flight on the NASA Ice Flickr page, and I suggest you do: the images are really cool (har har) and the science they’re doing is important — as the Earth warms (and it is) our ice is disappearing. Missions like IceBridge will help us understand how that is happening and what the effects are.

Credit: Digital Mapping System team and Michael Studinger; NASA/Goddard Space Flight Center/Scientific Visualization Studio

I’m in San Francisco for the Bay Area Science Festival. On Friday at 10 am PST, I’ll be appearing on Forum, a morning show on KQED. Listen here live!