Universe Today

June 26, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast: June 26-28, 2009

Greetings, fellow SkyWatchers! It’s another lunatic weekend as we start off with Regulus and Selene making a close pairing in the Friday evening sky. Why not take a break from difficult galaxy studies and try your hand at some very cool variable stars and multiple systems? It’s time to get out your telescopes and binoculars, pick off a few lunar challenge craters and just kick back and enjoy because… Here’s what’s up!

Friday, June 26, 2009 – Happy Birthday, Charles Messier! Born in 1730 on this date, almost everyone recognizes the name of this French astronomer who discovered 15 comets. He was the first to compile a systematic catalog—the ‘‘M objects.’’ The Messier Catalogue (1784) contains 103 star clusters, nebulae, and galaxies. But did you know Lyman Spitzer, Jr, shared this birthday? Born in 1914, Spitzer advanced our knowledge of physical processes in interstellar space and pioneered efforts to harness nuclear fusion as a clean energy source. He studied star-forming regions and suggested that the brightest stars in spiral galaxies formed recently. Not only that, but Spitzer was the first person to propose placing a large telescope in space, and so launched the development of the Hubble Space Telescope!

Tonight the mighty Regulus will be very close to the Moon, providing a wonderful opportunity for stargazers. Why not grab a telescope and view the lunar surface for a couple of telescopic challenges that are easy to catch? All you have to know is Mare Crisium!

On the southeastern shoreline is a peninsula that reaches into Crisium’s dark basin. This is Promontorium Agarum. On the western shore, bright Proclus lights the banks, but look into the interior for the two dark pockmarks of Pierce to the north and Picard to the south. Be sure to mark them on your notes!

When you’re finished, point your binoculars or telescopes back toward Corona Borealis and about three finger-widths northwest of Alpha for variable star R (RA 15 48 35 Dec +28 09 24). This star is a total enigma. Discovered in 1795, most of the time R carries a magnitude near 6 but can drop to magnitude 14 in a matter of weeks—only to unexpectedly brighten again! It is believed that R emits a carbon cloud, which blocks its light. Oddly enough, scientists can’t even accurately determine the distance to this star! When studied at minimum, the light curve resembles a ‘‘reverse nova’’ and has a peculiar spectrum. It is very possible that this ancient Population II star has used all of its hydrogen fuel and is now fusing helium to form carbon.

Saturday, June 27, 2009 – Tonight we’ll again honor the June 26 birth of Charles Messier by heading toward the lunar surface first, in order to pick off another study object on our list—the twin crater pair Messier and Messier A.

Located in Mare Fecunditatis about a third of its width from west to east, these two craters will be difficult to find in binoculars, but not hard for even a small telescope and intermediate power. Indeed named for the famed French astronomer, the easternmost crater is somewhat oval in shape, with dimensions of 9 by 11 kilometers. At high power, Messier A to the west appears to have overlapped a smaller crater during its formation; and it is slightly larger at 11 by 13 kilometers. Although it is not on the challenge list, you’ll find another point of interest to the northwest. Rima Messier is a long surface crack, which runs diagonally across Mare Fecunditatis’s northwestern flank and reaches a length of 100 kilometers.

For variable star fans, let’s return to and focus our attention on S Coronae Borealis, located just west of Theta and the westernmost star in the constellation’s arc formation (RA 15 21 23 Dec +31 22 02). At magnitude 5.3, this long-term variable takes almost a year to go through its changes—usually far outshining the 7th magnitude star to its northeast—but will drop to a barely visible magnitude14 at minimum. Compare it to the eclipsing binary U Coronae Borealis about a degree northwest. In slightly over 3 days, this Algol-type will range by a full magnitude as its companions draw together.

Sunday, June 28, 2009 – As we head out into the night, let’s observe a moment of silence to remember the 1889 passing on this date of Maria Mitchell, the first professional woman astronomer. While pursuing amateur astronomy, she gained fame from her October 1, 1947, observation of a comet, about which she was the first to report. Mitchell was also the first female member of the American Academy of Arts and Sciences. Said Mitchell, ‘‘The eye that directs a needle in the delicate meshes of embroidery will equally well bisect a star with the spider web of the micrometer.’’

Tonight let’s honor Mitchell by locating the lunar crater named in her honor. Begin by visiting the northeast quadrant of the Moon and identify crater Aristoteles. On its eastern edge, you’ll find Mitchell. Measuring only 30 kilometers in diameter, it is dwarfed by Aristoteles’ 87-kilometer diameter, but Maria Mitchell was never dwarfed in life!

To further honor Mitchell, let’s have a look at the 250-light-year-distant silicon star Iota Librae (RA 15 12 13 Dec -19 47 28). This is a challenge for binoculars, but not because the components are so close. In Iota’s case, the near 5th magnitude primary simply overshadows its 9th magnitude companion!

In 1782, Sir William Herschel measured them and determined they were a true physical pair. Yet, in 1940 Librae A was determined to have an equal-magnitude companion only 0.2’’ away. . .and the secondary was proved to have a companion of its own, which echoes the primary. A four-star system!

Until next week? Keep an eye on the sky for members of the June Draconid meteor shower which peaks Tuesday morning! Wishing you clear skies….

This week’s awesome photos are (in order of appearance): Lyman Spitzer (credit—
courtesy of hubblesite.org), Mare Crisium (credit—Greg Konkel), Mare Fecunditatis and Messier/Messier A (credit—Greg Konkel), S Coronae Borealis (credit—Palomar Observatory, courtesy of Caltech), Aristoteles and Mitchell (credit—Wes Higgins) and Iota Librae (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

June 25, 2009December 24, 2015 by Nancy Atkinson

Spirit Rover Going Nowhere, But Still Making Discoveries

Soft soil exposed when wheels of NASA's Mars Exploration Rover Spirit dug into a patch of ground. Image Credit: NASA/JPL-Caltech/Cornell University

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The Spirit rover on has been stuck in Martian soil, going nowhere, but that doesn’t mean she hasn’t been busy or hasn’t been making new discoveries. Just the opposite. Scientists have taken advantage of what could be a bad situation to learn more about the Red Planet’s environmental history. “By serendipity, Troy (the region where Spirit is stuck) is one of the most interesting places Spirit has been,” said Ray Arvidson, deputy principal investigator for the science payloads on the two Mars rovers. “We are able here to study each layer, each different color of the interesting soils exposed by the wheels.”

While the rover team remains optimistic about getting Spirit unstuck, they have also acknowledged the possibility that the rover might not ever be able to leave Troy. But engineers at JPL are pulling out all the stops, and will be conducting test at the Mars Yard with the engineering rover. (More on that below.)

But Spirit is also benefiting from increased power from wind events in April and May that blew away most of the dust accumulated on the rover’s solar panels. “The exceptional amount of power available from cleaning of Spirit’s solar arrays by the wind enables full use of all of the rover’s science instruments,” said Richard Moddis of the Johnson team. “If your rover is going to get bogged down, it’s nice to have it be at a location so scientifically interesting.”

While engineers are working on a plan for getting Spirit extracted from her predicament, scientists have been studying images and data the rover has sent back. One of the rover’s wheels tore into the site, exposing colored sandy materials and a miniature cliff of cemented sands. Some disturbed material cascaded down, evidence of the looseness that will be a challenge for getting Spirit out. But at the edge of the disturbed patch, the soil is cohesive enough to hold its shape as a steep cross-section.

Close-up view of the soil at Troy from Spirit's Microscopic imager (sol 1945) Credit: NASA/JPL

Spirit has been using tools on its robotic arm to examine tan, yellow, white and dark-red sandy soil at Troy. Stretched-color images from the panoramic camera show the tints best.

“The layers have basaltic sand, sulfate-rich sand and areas with the addition of silica-rich materials, possibly sorted by wind and cemented by the action of thin films of water. We’re still at a stage of multiple working hypotheses,” said Arvidson. “This may be evidence of much more recent processes than the formation of Home Plate…or is Home Plate being slowly stripped back by wind, and we happened to stir up a deposit from billions of years ago before the wind got to it?”

Water seems to have played a role in the different colors seen at the location, and perhaps differences in tints at Troy observed by the panoramic camera may come from differences in the hydration states of iron sulfates.

Meanwhile back on Earth, the rover team has developed a soil mix for testing purposes that has physical properties similar to those of the soil under Spirit at Troy. This soil recipe combines diatomaceous earth, powdered clay and play sand. A crew is shaping a few tons of that mix this week into contours matching Troy’s. The test rover will be commanded through various combinations of maneuvers during the next few weeks to validate the safest way to proceed on Mars.

Spirit’s right-front wheel has been immobile for more than three years, magnifying the challenge. Diagnostic tests on Spirit in early June provided encouragement that the left-middle wheel remains useable despite an earlier stall.

“With the improved power situation, we have the time to explore all the possibilities to get Spirit out,” said JPL’s John Callas, project manager for Spirit and Opportunity. “We are optimistic. The last time Spirit spun its wheels, it was still making progress. The ground testing will help us avoid doing things that could make Spirit’s situation worse.”

Source: JPL

June 25, 2009December 24, 2015 by Mark Mortimer

Book Review: Venus and Mercury

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Have you ever been inspired by the two planets Mercury and Venus? If so, Peter Grego’s book “Venus and Mercury and How to Observe Them” brings to us much of what we’ve learned about them and much of how each of us can learn some more.

Mercury and Venus are the two planets closer to the Sun than Earth. Because of this, they always appear in close proximity in the sky to the Sun. Bright Venus is easily seen when it’s present. Mercury, being quite duller and at best much closer to the horizon is much harder to see. And seeing it as a dot isn’t seeing anything spectacular. In fact, neither planet provides details, even to a viewer using a telescope. But, that doesn’t mean your planetary inspiration should die.

Instead satiate yourself with this book. It provides a number of useful angles for learning more about these two planets. Effectively, it has two parts for each planet. The first part presents our current knowledge. This includes, for example, the atmosphere, complete composition, morphology and magnetic field. Even though technically very thorough, these sections beg the question, so what? After all, unless we have our own satellite, we will never see to this level of detail. The second part answers the, “so what” as it gives tips on viewing them. For this, it has it has a well detailed listing of surface features, each numbered and located on nearby maps. Altogether then, the sections of this book do provide the reader with great amounts of information regarding Mercury and Venus.

As well, common astronomical lore gets inserted amidst the second part of the book. That is, in addition to discussing sky charts and drawing blanks, it recommends binoculars and telescopes, describes challenges to viewing (e.g. saccades), and gives lots of suggestions such as the ever present caution not to look at the Sun. This part of the book, on its own, fully meets the title’s objective on how to observe these two planets. Thus, it’s up to you to decide if you want to pay for the excellent but not necessarily applicable discussions of topics that will never be observable from your personal telescope.

In all, this book would wonderfully grace an intermediate amateur astronomer’s book shelf. It’s got great references for when the skies oblige by being dark and cloud free. And, it’s got plenty of related reading material for other times. There’s a bit of neglect in the proofreading, as sentence structures often are in error. But, the amount of information, especially the large amount that came first hand from the author, makes the book a real treat.

Should the sparkling beauty of Venus or the mystery of Mercury beckon you, heed their call and take to the stars. With Peter Grego’s book “Venus and Mercury and How to Observe Them“, you will have no problem in viewing these two wandering planets and in knowing what’s behind the fuzzy object shown in the lens.

June 25, 2009December 24, 2015 by Anne Minard

The Jury Is In: Exploding Stars Really do Pelt us With Cosmic Rays

The rim of RCW 86. Credit: ESO/E. Helder & NASA/Chandra

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Mmm, pretty … and a tad menacing, at least in its explosive past. This is RCW 86, part of a stellar remnant whose explosion was recorded in 185 AD. By studying the remnant in detail, a team of astronomers has been able to nail down the source of cosmic rays that bombard Earth.

During the Apollo flights 40 years ago, astronauts reported seeing odd flashes of light, visible even with their eyes closed. We have since learned that the cause was cosmic rays — extremely energetic particles from outside the Solar System arriving at the Earth, and constantly bombarding its atmosphere. Once they reach Earth, they still have enough energy to cause glitches in electronic components.

Galactic cosmic rays come from sources inside our home galaxy, the Milky Way, and consist mostly of protons moving at close to the speed of light, the “ultimate speed limit” in the Universe. These protons have been accelerated to energies exceeding by far the energies that even CERN’s Large Hadron Collider will be able to achieve.

“It has long been thought that the super-accelerators that produce these cosmic rays in the Milky Way are the expanding envelopes created by exploded stars, but our observations reveal the smoking gun that proves it,” says Eveline Helder from Utrecht University in the Netherlands, the first author of the new study in this week’s Science Express.

“You could even say that we have now confirmed the caliber of the gun used to accelerate cosmic rays to their tremendous energies,” adds collaborator Jacco Vink, also from the Astronomical Institute Utrecht.

For the first time Helder, Vink and colleagues have come up with a measurement that solves the long-standing astronomical quandary of whether or not stellar explosions produce enough accelerated particles to explain the number of cosmic rays that hit the Earth’s atmosphere. The team’s study indicates that they indeed do and directly tells us how much energy is removed from the shocked gas in the stellar explosion and used to accelerate particles.

“When a star explodes in what we call a supernova a large part of the explosion energy is used for accelerating some particles up to extremely high energies,” says Helder. “The energy that is used for particle acceleration is at the expense of heating the gas, which is therefore much colder than theory predicts.”

The researchers looked at the remnant of a star that exploded in AD 185, as recorded by Chinese astronomers. RCW 86, is located about 8,200 light-years away towards the constellation of Circinus (the Drawing Compass). It is probably the oldest record of the explosion of a star.

Using ESO’s Very Large Telescope, the team measured the temperature of the gas right behind the shock wave created by the stellar explosion. They measured the speed of the shock wave as well, using images taken with NASA’s X-ray Observatory Chandra three years apart. They found it to be moving AT between 1 and 3 percent the speed of light.

The temperature of the gas turned out to be 30 million degrees Celsius. This is quite hot compared to everyday standards, but much lower than expected, given the measured shock wave’s velocity. This should have heated the gas up to at least half a billion degrees.

“The missing energy is what drives the cosmic rays,” concludes Vink.

More about the lead image: North is toward the top right and east to the top left. The image is about 6 arc minutes across. Credit: ESO/E. Helder & NASA/Chandra

Source: ESO

June 25, 2009December 24, 2015 by Nancy Atkinson

Expedition 21 Star Trek Poster

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Is NASA becoming creative, fun and hip in their old (50 plus) age? They are Tweeting and Facebook-ing like crazy, and also getting quite adept at imaginative promotional images. A new poster for the next Expedition crew for the International Space Station is now available and it has a Star Trek theme. This is a great way for NASA to capitalize on the renewed popularity of Star Trek, while bringing the names of faces of the ISS crews to the public in an enjoyable and entertaining way. This Expedition 21 poster is available in downloadable versions in medium and large files (pdf).

See NASA’s entire collection of mission posters here at NASA’s Spaceflight Awareness page.

Check out all the ways NASA is connecting with people online here.

Hat tip to NASA Watch!

June 25, 2009December 24, 2015 by Nancy Atkinson

Volcanic Shockwave Captured by ISS Imagery

Sarychev Volcano as seen from the ISS. Credit: NASA

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These images of Sarychev Volcano were popping up everywhere in the internet yesterday, but unfortunately I was out of intertube contact most of the day. But these images are too awesome not to share! Astronauts on board the International Space Station took these striking views of Sarychev Volcano (Kuril Islands, northeast of Japan) on June 12, 2009. Notice the shock wave around the edge of the volcano’s plume and the “hole” the clouds that the eruption caused. Sarychev Peak is one of the most active volcanoes in the Kuril Island chain, and it is located on the northwestern end of Matua Island. Here are few more images taken in sequence as the ISS flew 354 km (220 miles) overhead:

Second image of Sarychev Volcano. Credit: NASA

Volcanologists say these images are exciting because they capture several phenomena that occur during the earliest stages of an explosive volcanic eruption. The main column is one of a series of plumes that rose above Matua Island on June 12. The plume appears to be a combination of brown ash and white steam. The vigorously rising plume gives the steam a bubble-like appearance. The eruption cleared a circle in the cloud deck. The clearing may result from the shockwave from the eruption or from sinking air around the eruption plume: as the plume rises, air flows down around the sides like water flowing off the back of a surfacing dolphin. As air sinks, it tends to warm and expand; clouds in the air evaporate.

Also visible is material from the eruption falling down the slopes of the volcano.

Third image of the volcano. Credit: NASA

These images were taken by the Expedition 20 crew on the ISS, using a Nikon D2XS digital camera fitted with a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center.

Source: NASA Earth Observatory

June 25, 2009December 24, 2015 by Nancy Atkinson

Where In The Universe #59

Here’s this week’s image for the WITU Challenge, to test your visual knowledge of the cosmos. You know the drill: take a look at this image and see if you can determine where in the universe this image is from; give yourself extra points if you can name the spacecraft responsible for the image. We’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.

If you missed the answer to last week’s WITU Challenge, find it here.

Look back at all previous 58 Where In the Universe Challenges.

UPDATE: The answer has now been posted below.

This is a false-color image of our own Moon, and specificially of Mare Tranquilitatis (Sea of Tranquility) and Mare Serenitatis (Sea of Serenity, or Sea of Peacefullness). As hal9000 so presciently said in the comments (hal, are you becoming sentient?) this image was taken Galileo spacecraft on December 8, 1992, during Galileo’s second Earth/Moon flyby on its way to Jupiter. Here’s a larger version of this image.

Of course, the Sea of Tranquility is well known as being the landing site of Apollo 11 (40th anniversary this year, in case you haven’t heard!) and the Sea of Serenity is the landing site for both Luna 21 and Apollo 17.

Check back next week for another WITU Challenge!

June 25, 2009December 24, 2015 by Tammy Plotner

Kid’s Astronomy – Ophiuchus: The “Snake Charmer”

Hey, Kids! Did you see the crescent of the Moon last night? With the heat and humidity much higher in the northern hemisphere, it looked wonderfully like a cool slice of orange cantaloupe hung in the sky! If you’re looking for something cool to do, then why not get out your binoculars and try a little star gazing? We’ve visited with a lot of different sky characters and it’s time to learn more. Whenever you’re ready, it’s time to head out into the dark shadows and listen to the voices on the wind…

“As night falls, it’s time to look for more royalty in the sky as we locate Corona Borealis – the “Northern Crown” – whose faint main stars form a semicircular arc. Guarded by Hercules on one side and Bootes on another, some tales call it the royal crown of Dionysus. Why not? It’s brightest star’s name is Gemma. But, during the summer, why not think of it as the Native Americans once did? They believed Corona Borealis to be a campfire circle!”

“As you gather around our celestial campfire, let’s talk about the constellation of Ophiuchus. Many believe it to be the thirteenth constellation of the zodiac because it resides mainly on the ecliptic plane – the imaginary path the Sun and Moon takes across the sky. Some legends see Ophiuchus as the “Serpent Bearer” and picture him as holding a huge serpent in either hand – the constellations of Serpens and Serpens Caudia. However, there are more tales to be told about Ophichus!

The ancient Egyptians believed this large set of stars to be the incarnation of Imhotep. One of Imhotep’s legend was that of a doctor and it is often said that he introduced the art of healing and medicines to mankind. If you take a look at today’s modern medical symbol, you’ll see a large serpent! The snake symbol was also used to represent Imhotep.

Using your binoculars and our constellation guide to Ophiuchus, see if you can find a great cluster of Imhotep’s stellar jewels listed as NGC 6633. It takes up about as much area of sky as the full Moon and it is bright enough to be seen with even small binoculars. The light you see from it tonight left 660 million years ago!”

NGC 6633

If you check out the Rho star, a triple, sort of a boat shape with a telescope, you will find, a beautiful blue reflection nebula, listed as IC 4665 that is sometimes known as the “The Fish Spear of Poseidon”.

IC 4665

“Does Ophiuchus look like a snake charmer to you? Or an ancient Egytian?”

Always be sure to pick a safe place to observe and let your parents know where you’ll be. Why not ask them to join you?! After all, you’ve got a lot of wonderful stories and plenty of “star sense” to share!

We like to thank the following folks for their wonderful illustrations: Ophiuchus map courtesy of Windows to the Universe, Corona Borealis and Ophiuchus Images from Hevelius courtesy of Chandra, NGC 6633: Palomar Observatory, courtesy of Caltech and IC 4665 courtesy of Wikipedia. We thank you so much!

June 24, 2009December 24, 2015 by Fraser Cain

Does Mercury Have Rings?

Mercury's limb. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

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Think about the planets in the Solar System; Saturn has rings, so do Jupiter, Uranus and Neptune. So what about Mercury? Does planet Mercury have rings?

Sorry, Mercury doesn’t have rings right now. I say right now, because it’s possible that Mercury has had rings in the past, and it could have them again in the future.

There are two ways that scientists think a planet can get rings. The first is the icy rings around Saturn, Jupiter, Uranus and Neptune. Scientists think that Saturn’s rings come from an icy object or moon that was crushed under Saturn’s gravity, becoming its rings. It’s also possible that the ring material just formed in place back when the Solar System formed. We also know that some of Saturn’s moons, like Enceladus, are continuing to spew fresh material into the rings.

Unfortunately, Mercury could never get rings like this. That’s because it’s too close to the Sun. The powerful solar winds blast out from the Sun, and would melt and destroy any icy rings around Mercury. In fact, ice can’t exist closer to the Sun than the asteroid belt, unless it’s hidden in shadow, or protected by an atmosphere like we have on Earth.

The second way for a ring to form is for an asteroid or moon to get too close to a planet and be torn apart by gravity. For a few million years this crushed asteroid would appear as a ring around Mercury, until the chunks finally fell down onto the planet. Astronomers predict that the Martian moon Phobos will eventually suffer this fate, be torn apart by Mars’ gravity, and form a ring for a while.

Mercury doesn’t have any moons, and there aren’t many asteroids that might interact with it, so it might never get a ring – but maybe one day. One thing’s for sure, though, there are no Mercury rings today.

How many rings does Mercury have? Zero.

We have written many stories about rings here on Universe Today. Here’s an article about the Martian moon Phobos might only have 10 million years to live, and here’s an article about what Saturn’s rings are made of.

If you’d like more information on Mercury, check out NASA’s Solar System Exploration Guide, and here’s a link to NASA’s MESSENGER Misson Page.

We have also recorded a whole episode of Astronomy Cast that’s just about planet Mercury. Listen to it here, Episode 49: Mercury.

Mercurio no tiene anillos?

Reference:
NASA Science for Kids

June 24, 2009December 24, 2015 by Nancy Atkinson

1908 Tunguska Event Caused by Comet, New Research Reveals

Fallen trees from the Tunguska Event in 1908.

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The 1908 Tunguska event has always been mysterious and intriguing because no one has been able to fully explain the explosion that leveled 830 square miles of Siberian forest. But the latest research has concluded that the Tunguska explosion was almost certainly caused by a comet entering the Earth’s atmosphere. And how researcher Michael Kelly from Cornell University came to that conclusion is quite interesting: He analyzed the space shuttle’s exhaust plume and noctilucent clouds.

“It’s almost like putting together a 100-year-old murder mystery,” said Kelley, a professor of Engineering, who led the research team. “The evidence is pretty strong that the Earth was hit by a comet in 1908.” Previous speculation had ranged from comets to meteors.

Noctilucent clouds are brilliant, night-visible clouds made of ice particles and only form at very high altitudes and in extremely cold temperatures. These clouds appeared a day after the Tunguska explosion and also appear following a shuttle mission.

The researchers contend that the massive amount of water vapor spewed into the atmosphere by the 1908 comet’s icy nucleus was caught up in swirling eddies with tremendous energy by a process called two-dimensional turbulence, which explains why the noctilucent clouds formed a day later many thousands of miles away.

Noctilucent clouds over Saimaa. Credit: Wikipedia

Noctilucent clouds are the Earth’s highest clouds, forming naturally in the mesosphere at about 55 miles over the polar regions during the summer months when the mesosphere is around minus 180 degrees Fahrenheit (minus 117 degrees Celsius).

The space shuttle exhaust plume, the researchers say, resembled the comet’s action. A single space shuttle flight injects 300 metric tons of water vapor into the Earth’s thermosphere, and the water particles have been found to travel to the Arctic and Antarctic regions, where they form the clouds after settling into the mesosphere.

Kelley and collaborators saw the noctilucent cloud phenomenon days after the space shuttle Endeavour (STS-118) launched on Aug. 8, 2007. Similar cloud formations had been observed following launches in 1997 and 2003.

Artist impression of the Tunguska event.

Following the Tunguska Event, the night skies shone brightly for several days across Europe, particularly Great Britain — more than 3,000 miles away. Kelley said he became intrigued by the historical eyewitness accounts of the aftermath, and concluded that the bright skies must have been the result of noctilucent clouds. The comet would have started to break up at about the same altitude as the release of the exhaust plume from the space shuttle following launch. In both cases, water vapor was injected into the atmosphere.
The scientists have attempted to answer how this water vapor traveled so far without scattering and diffusing, as conventional physics would predict.

“There is a mean transport of this material for tens of thousands of kilometers in a very short time, and there is no model that predicts that,” Kelley said. “It’s totally new and unexpected physics.”

This “new” physics, the researchers contend, is tied up in counter-rotating eddies with extreme energy. Once the water vapor got caught up in these eddies, the water traveled very quickly — close to 300 feet per second.

Scientists have long tried to study the wind structure in these upper regions of the atmosphere, which is difficult to do by such traditional means as sounding rockets, balloon launches and satellites, explained Charlie Seyler, Cornell professor of electrical engineering and paper co-author.

“Our observations show that current understanding of the mesosphere-lower thermosphere region is quite poor,” Seyler said. The thermosphere is the layer of the atmosphere above the mesosphere.

Read the team’s paper.

Source: NewsWise