Stunning Noctilucent Clouds Shine Brightly in the UK

Panoramic view of Noctulucent Clouds from Kendal Castle in the UK. Credit: Stu Atkinson

Mysterious “night shining” or Noctilucent Clouds are beautiful to behold, and here are some gorgeous examples what skywatchers in the UK have been experiencing. Stu Atkinson took this stunning panoramic view from Kendal Castle. (Click image for access to a larger version). NLC’s are usually seen during the summertime, appearing at sunset. They are thin, wavy ice clouds that form at very high altitudes and reflect sunlight long after the Sun has dropped below the horizon. Scientists don’t know exactly why they form, and they seem to be appearing more and more in recent times.

See more below.

Science writer Will Gater also had a great view of NCLs this morning. Click the image to see his animation, or see more of his images and animations at his website post.

NLCs seen over the UK on July 1, 2011. Click to see animation. Credit: Will Gater

Another view of Noctilucent Clouds from Kendal Castle in the UK on July 1, 2011. Credit: Stu Atkinson

See more from Stu Atkinson at his Cumbrian Sky website.

Tagged as: Astrophotos, noctilucent clouds, Observing

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The Final Countdown: Fueling the Anticipation

An update on my NASA Tweetup adventure…

The world will be watching - and tweeting! – when Atlantis launches on July 8

The launch of the space shuttle Atlantis is just a week away, and with it the NASA Tweetup event of a lifetime. (Well, my lifetime anyway!) But it’s not just me who’s been having visions of shuttle plumes dancing in his head… there’s 149 other space tweeps (yes, that’s what we call ourselves) who are eagerly counting the days, hours and minutes until then.

Here’s what some of them are saying…

“Wicked excited! (says the Boston gal – who yes, now lives in the Midwest!)” – Leslie Berg

“I’m so excited, and I just can’t hide it….” – David Parmet

“This has been a dream of mine since the first launch. I was so sad when I was unable to attend STS-134 with the delays and so excited when I found out that I could at least see the last launch paid to change my plane ticket to NYC for summer.” Dvora Geller

“It’s an honor to be chosen by NASA to be a part of the last flight in shuttle history.” – Heather Smith

“NASA has continued to fill the history books with their profound and inspirational achievements. I can’t believe I’ll witness another significant page being written for that book, in person, up close, on July 8th!! Bring it!!” – Justin Boddey

With people attending the Tweetup from not only all over the US but also all around the world, this is an awesome representation of the international attention that the final launch is getting.

Also, after some scouting about for the right contact person (thanks Susan!) I managed to get in touch with the metro editor at the Dallas Morning News and he assigned a reporter to cover my story. I had a phone interview this afternoon with her, and the story should be published next Tuesday! In addition they want to feature my Tweets on the news site live from the launch…I sure hope the 3G signal coverage isn’t overwhelmed!

Anyway by this time next week I and 149 others from around the world will be preparing for a very exciting morning… it’s going to be crazy, I’m sure, but totally worth it!

Stay tuned….

“I spend several moments a day suppressing the urge to freak right out over the fact that I’m going to be as close to going into space as I’ve ever been. There’s also a 9 year old in my head screaming SPACE SHUTTLE! all the time. It’s really distracting. I feel so lucky.” – Nicole KT Winchester

“Since the day I found out I was selected to attend the Tweetup, it’s been on my mind every minute of every day. I’m basically trying not to die before July 7th.” – Andres Almeida

“I can pretty much guarantee my reaction to seeing a space shuttle live, in person, will be, ‘Whoah.’ Followed shortly by, ‘That’s pretty.’” – Kara DeFrias

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Jason Major is a graphic designer, photo enthusiast and space blogger. Visit his website Lights in the Dark and follow him on Twitter @JPMajor or on Facebook for the most up-to-date astronomy awesomeness!

Tagged as: Atlantis, KSC, Launch, NASA, shuttle, STS-135, Tweetup

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Podcast: Orion

Orion Nebula. Image credit: Hubble

Most people know how to find two constellations: the Big Dipper, and Orion the Hunter. You can teach a small child to find Orion, and at the right time of year, they’ll find it in seconds. There’s so much going on in this spectacular constellation, from the star formation in the Orion Nebula to mighty red supergiant Betelgeuse, ready to explode. Let’s learn about the history and science of the constellation Orion.

Click here to download the episode.

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

Orion shownotes and transcript.

Tagged as: Observing, Orion, Podcasts

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Neptune: Rocking The Dreidel

When it come to making your head spin, Jupiter revolves on its axis in less than 10 hours. Up until now, it was the only gas planet in our solar system that had an accurate spin measurement. But grab your top and cut it loose, because University of Arizona planetary scientist Erich Karkoschka has clocked Neptune cruising around at a cool 15 hours, 57 minutes and 59 seconds.

“The rotational period of a planet is one of its fundamental properties,” said Karkoschka, a senior staff scientist at the UA’s Lunar and Planetary Laboratory. “Neptune has two features observable with the Hubble Space Telescope that seem to track the interior rotation of the planet. Nothing similar has been seen before on any of the four giant planets.”

Like spinning gelatin, the gas giants – Jupiter, Saturn, Uranus and Neptune – don’t behave in an easy to study manner. By nature they deform as they rotate, making accurate estimates difficult to pin down.

“If you looked at Earth from space, you’d see mountains and other features on the ground rotating with great regularity, but if you looked at the clouds, they wouldn’t because the winds change all the time,” Karkoschka explained. “If you look at the giant planets, you don’t see a surface, just a thick cloudy atmosphere.”

Of course, 350 years ago Giovanni Cassini was able to estimate Jupiter’s rotation by observing the Great Red Spot – an atmospheric condition. Neptune has observable atmospheric conditions, too… But they’re just a bit more transitory. “On Neptune, all you see is moving clouds and features in the planet’s atmosphere. Some move faster, some move slower, some accelerate, but you really don’t know what the rotational period is, if there even is some solid inner core that is rotating.”

Roughly 60 years ago astronomers discovered Jupiter gave out radio signals. These signals originated from its magnetic field generated by the spinning inner core. Unfortunately signals of this type from the outer planets were simply lost in space before they could be detected from here on Earth. “The only way to measure radio waves is to send spacecraft to those planets,” Karkoschka said. “When Voyager 1 and 2 flew past Saturn, they found radio signals and clocked them at exactly 10.66 hours, and they found radio signals for Uranus and Neptune as well. So based on those radio signals, we thought we knew the rotation periods of those planets.”

In this image, the colors and contrasts were modified to emphasize the planet’s atmospheric features. The winds in Neptune’s atmosphere can reach the speed of sound or more. Neptune’s Great Dark Spot stands out as the most prominent feature on the left. Several features, including the fainter Dark Spot 2 and the South Polar Feature, are locked to the planet’s rotation, which allowed Karkoschka to precisely determine how long a day lasts on Neptune. (Image: Erich Karkoschka)

Using the data from the Voyager probes, Karkoschka went to work studying rotation periods and combined it with available images of Neptune from the Hubble Space Telescope archive. Like Cassini’s work, he carefully studied atmospheric features in hundreds upon hundreds of photographs taken over a time sequence… a period of 20 years. He realized an observer watching the massive planet turn from a fixed spot in space would see these features appear exactly every 15.9663 hours, with less than a few seconds of variation. This led him to surmise a hidden interior feature on Neptune drives the mechanism that creates the atmospheric signature.

“So I dug up the images of Neptune that Voyager took in 1989, which have better resolution than the Hubble images, to see whether I could find anything else in the vicinity of those two features. I discovered six more features that rotate with the same speed, but they were too faint to be visible with the Hubble Space Telescope, and visible to Voyager only for a few months, so we wouldn’t know if the rotational period was accurate to the six digits. But they were really connected. So now we have eight features that are locked together on one planet, and that is really exciting.”

Original Story Source: University of Arizona News.

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Most Distant Quasar Opens Window Into Early Universe

Quasar

Astronomers have uncovered yet another clue in their quest to understand the Universe’s early life: the most distant quasar ever observed. At a redshift of 7.1, it is a relic from when the cosmos was just 770 million years old – just 5% of its age today.

Quasars are extremely old, outrageously luminous balls of radiation that were prevalent in the early Universe. Each is thought to have been fueled at its core by an incredibly powerful supermassive black hole. The most recent discovery (which carries the romantic name ULAS J1120+0641) is noteworthy for a couple of reasons. First of all, its supermassive black hole weighs approximately two billion solar masses – an impressive feat of gravity so soon after the Big Bang. It is also incredibly bright, given its great distance. “Objects that lie at such large distance are almost impossible to find in visible-light surveys because their light is stretched by the expansion of the universe,” said Dr. Simon Dye of the University of Nottingham, a member of the team that discovered the object. “This means that by the time their light gets to Earth, most of it ends up in the infrared part of the electromagnetic spectrum.” Due to these effects, only about 100 visible quasars exist in the sky at redshifts higher than 7.

Up until recently, the most distant quasar observed was at a redshift of 6.4; but thanks to this discovery, astronomers can probe 100 million years further into the history of the Universe than ever before. Careful study of ULAS J1120+0641 and its properties will enable scientists to learn more about galaxy formation and supermassive black hole growth in early epochs. The research was published in the June 30 issue of Nature.

For further reading, see related paper by Chris Willot, Monster in the Early Universe

Source: EurekAlert

Tagged as: Cosmology, quasars, redshift

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Spectacular View from LRO of Tycho Crater’s Central Uplifts

Oblique view of Tycho crater. Credit: NASA/GSFC/Arizona State University.

Here’s the Moon like you’ve never seen it before: a dramatic sunrise view of Tycho Crater on the Moon, highlighting the peaks and crags of the crater’s central uplifts. On June 10,2011 the Lunar Reconnaissance Orbiter slewed 65° to the west, allowing the Narrow Angle Camera to capture a “sideways” look at Tycho crater, resulting in a spectacular image. The central peak complex is about 15 km wide southeast to northwest (left to right in this view). Below are more images and a video which spans and zooms in to the entire image.

Tycho Crater is a very popular target with amateur astronomers since it is easily seen from Earth. The crater measures about 82 km (51 miles) in diameter, and the summit of the central peak is 2 km (6562 ft) above the crater floor, and the crater floor is about 4700 m (15,420 ft) below the rim.

Central uplifts form in larger impact craters in response to the impact event.

LROC principal investigator Mark Robinson wrote on the LRO website, “Tycho’s features are so steep and sharp because the crater is young by lunar standards, only about 110 million years old….Were these distinctive outcrops formed as a result of crushing and deformation of the target rock as the peak grew? Or do they represent preexisting rock layers that were brought intact to the surface? Imagine future geologists carefully making their way across these steep slopes, sampling a diversity of rocks brought up from depth.”

Here’s a close-up of the summit. The boulder in the background is 120 meters wide, and the image is about 1200 meters wide.

Oblique view of summit area of Tycho crater central peak. Credit: NASA/GSFC/Arizona State University

And here’s the entire crater:

LROC WAC mosaic of Tycho crater with lighting similar to that when the NAC oblique image was taken. Mosaic is 130 km wide, north is up. Credit: NASA/GSFC/Arizona State University.

Click on the images for larger versions on the LROC website, or see this link for more information on these images.

Source: LROC

Tagged as: Lunar Reconnaissance Orbiter, Moon, Tycho Crater

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Eccentric Binary Creates Dual Gamma-Ray Flares

This diagram, which illustrates the view from Earth, shows the binary's anatomy as well as key events in the pulsar's recent close approach. Credit: NASA/Goddard Space Flight Center/Francis Reddy

It’s a gamma-ray flare – the most extreme form of light so far known. So, what could top it? Try a pair of gamma-ray flares. Way off in the southern constellation of Crux, an extreme team of stars gave a real show to NASA’s Fermi Gamma-ray Space Telescope. In December 2010, they blew past each other at about the distance Venus orbits our Sun. Why was this encounter so unique? Because one member was hot and blue/white… and the other a pulsar.

“Even though we were waiting for this event, it still surprised us,” said Aous Abdo, a Research Assistant Professor at George Mason University in Fairfax, Va., and a leader of the research team.

Astronomers were aware that PSR B1259-63 and LS 2883 made a close pass to each other about every 3 to 4 years and were eagerly anticipating the action. Residing at about 8,000 light years away, the signature signal from PSR B1259-63 was discovered in 1989 by the Parkes radio telescope in Australia. It is suspected to be quite small – about the size of Washington, DC and weighs about twice as much as Sol. What’s cool is it rotates at a dizzying 21 times per second… shooting of a powerful beam of electromagnetic energy that sweeps around like a search light. Next door the blue/white companion star lay embedded in gas, measuring in about 9 times larger size and weighing in at about 24 solar masses. Of these “odd couples” only four are known to produce gamma-rays and only this particular system is known to contain a pulsar… one that punches through the gas disk both coming and going during orbit.

“During these disk passages, energetic particles emitted by the pulsar can interact with the disk, and this can lead to processes that accelerate particles and produce radiation at different energies,” said study co-author Simon Johnston of the Australia Telescope National Facility in Epping, New South Wales. “The frustrating thing for astronomers is that the pulsar follows such an eccentric orbit that these events only happen every 3.4 years.”

On December 15, 2010, all “eyes” and “ears” were turned the system’s way in anticipation of the dual gamma-ray burst. The observatories included Fermi and NASA’s Swift spacecraft; the European space telescopes XMM-Newton and INTEGRAL; the Japan-U.S. Suzaku satellite; the Australia Telescope Compact Array; optical and infrared telescopes in Chile and South Africa; and the High Energy Stereoscopic System (H.E.S.S.), a ground-based observatory in Namibia that can detect gamma rays with energies of trillions of electron volts, beyond Fermi’s range.

“When you know you have a chance of observing this system only once every few years, you try to arrange for as much coverage as you can,” said Abdo, the principal investigator of the NASA-funded international campaign. “Understanding this system, where we know the nature of the compact object, may help us understand the nature of the compact objects in other, similar systems”.

While the EGRET telescope aboard NASA’s Compton Gamma-Ray Observatory had been observing this rare pair since the 1990s, no gamma-ray emission in the billion-electron-volt (GeV) energy range had ever been recorded. But, as the time of passage approached, the Large Area Telescope (LAT) aboard Fermi began to pick up faint gamma-ray emission. “During the first disk passage, which lasted from mid-November to mid-December, the LAT recorded faint yet detectable emission from the binary. We assumed that the second passage would be similar, but in mid-January 2011, as the pulsar began its second passage through the disk, we started seeing surprising flares that were many times stronger than those we saw before,” Abdo said.

To make this strange scenario even more unusual, radio and x-ray readings were nominal as the gamma-rays flared. “The most intense days of the flare were Jan. 20 and 21 and Feb. 2, 2011,” said Abdo. “What really surprised us is that on any of these days, the source was more than 15 times brighter than it was during the entire month-and-a-half-long first passage.”

It won’t happen again until May, 2014… But you can bet astronomers will be tuned in to catch the action!

Original Story Source: NASA / Fermi News.

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