Posted on by Tammy Plotner

Delta Leonid Meteors May Show On February 26

If you like keeping track of somewhat obscure meteor showers, tonight will be one of your best opportunities to spot the Delta Leonids. What’s the history of these meteors and when and where do you look? Let’s go outside and find out…

The Delta Leonids aren’t ancient and first came to attention during the early 20th century when W. F. Denning first made record of them in 1911. They were described as slow, with trains – but 16 independent observers report one of them as being at least six times as bright as the planet Venus. At the time, the fall rate was an average of 7 per hour.

Studies continued in 1924 and 1930 as scientists endeavored to pinpoint a radiant and an orbital stream. The results were rather inconclusive and the validity of the stream left to speculation. Are they Delta Leonids? Or the precursors of the Beta stream? From 1961 to 1965 a radio echo survey was employed and the results showed Earth passing through the stream between February 9th to March 12th. After several years of observation, the Western Australia Meteor Section has provided the most positive conculsions to date. While the stream cannot be attributed to any particular comet orbit, it does exist and peaks on (or about) February 26th.

If you’re out and about tonight, keep watch around the constellation of Leo… it will be relatively high in the sky around 10-11:00 pm local time. You’ll find its signature “backwards question mark” asterism along the ecliptic plane – the imaginary path the Sun and Moon take across the sky. With a typical magnitude of 2.8, these slow moving travellers will stand out against a fainter backdrop of stars. However, don’t expect to see a huge amount of activity, because the fall rate only averages about 5 per hour.

So why bother? It won’t hurt to keep an eye on the sky if you’re out walking your dog, or perhaps enjoying social activities which take you out to your car. The Delta Leonids are a temporary meteor stream and won’t be around forever. Catch ’em while you can!

Meteor Photo Credit: Yukihiro Kida/NASA Science

Posted on by Nancy Atkinson

New Record: Telescope Finds 19 Near-Earth Asteroids in One Night

Richard Wainscoat (left) and Marco Micheli study one of the near-Earth asteroids found on January 29. The asteroid is the roundish dot near Wainscoat’s finger. Photo by Karen Teramura

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From a University of Hawaii Institute for Astronomy press release:

The Pan-STARRS PS1 telescope on Haleakala, Maui, discovered 19 near-Earth asteroids on the night of January 29, the most asteroids discovered by one telescope on a single night.

“This record number of discoveries shows that PS1 is the world’s most powerful telescope for this kind of study,” said Nick Kaiser, head of the Pan-STARRS project. “NASA and the U.S. Air Force Research Laboratory’s support of this project illustrates how seriously they are taking the threat from near-Earth asteroids.”

Pan-STARRS software engineer Larry Denneau spent that Saturday night in his University of Hawaii at Manoa office in Honolulu processing the PS1 data as it was transmitted from the telescope over the Internet. During the night and into the next afternoon, he and others came up with 30 possible new near-Earth asteroids.
Asteroids are discovered because they appear to move against the background of stars. To confirm asteroid discoveries, scientists must carefully re-observe them several times within 12-72 hours to define their orbits, otherwise they are likely to be “lost.”

Denneau and colleagues quickly sent their discoveries to the Minor Planet Center in Cambridge, Mass., which collects and disseminates data about asteroids and comets, so that other astronomers can re-observe the objects.

“Usually there are several mainland observatories that would help us confirm our discoveries, but widespread snowstorms there closed down many of them, so we had to scramble to confirm many of the discoveries ourselves,” noted Institute for Astronomy astronomer Richard Wainscoat.

Wainscoat, astronomer David Tholen, and graduate student Marco Micheli spent the next three nights searching for the asteroids using telescopes at Mauna Kea Observatories, Hawaii.

On Sunday night, they confirmed that two of the asteroids were near-Earth asteroids before snow on Mauna Kea forced the telescopes to close. On Monday night, they confirmed nine more before fog set in.
On Tuesday night, they searched for four, but found only one. After Tuesday, the remaining unconfirmed near-Earth asteroids had moved too far to be found again.

Telescopes in Arizona, Illinois, Italy, Japan, Kansas, New Mexico, and the United Kingdom, and the Faulkes Telescope on Haleakala also helped to confirm seven of the discoveries.

Two of the asteroids, it turns out, have orbits that come extremely close to Earth’s. There is no immediate danger, but a collision in the next century or so, while unlikely, cannot yet be ruled out. Astronomers will be paying close attention to these objects.

Posted on by Nancy Atkinson

STS-133 Launch Day Gallery

Discovery just moments after her final liftoff. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

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Here’s a collection of images from the historic final launch of space shuttle Discovery on February 24, 2011.

Discovery's final launch. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
Just after SRB light. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
Discovery just after liftoff. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
Space shuttle Discovery heads to space after lifting off from Launch Pad 39A at NASA's Kennedy Space Center in Florida to begin its final flight to the International Space Station on the STS-133 mission. Launch was at 4:53 p.m. EST. Credit: NASA
STS-134 launch. Credit: Nancy Atkinson
STS-133 launch as seen from the KSC press site. Credit: Jason Rhian
NASA management watch the launch of space shuttle Discovery (STS-133) from the firing room at Kennedy Space Center, Thursday, Feb. 24, 2011, in Cape Canaveral, Fla. Credit: NASA/Bill Ingalls.
In Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida, NASA's Discovery Flow Director Stephanie Stilson, left, STS-133 Assistant Shuttle Launch Director and lead NASA Test Director Charlie Blackwell-Thompson and Shuttle Launch Director Mike Leinbach watch space shuttle Discovery blaze a trail of smoke and steam as it heads toward orbit on the STS-133 mission to the International Space Station. Credit: NASA
Main engine start. Credit: Nancy Atkinson
View from the KSC press site of the STS-133 launch. Credit: Nancy Atkinson
STS-133 launch, just before solid rocket booster separation. Credit: Nancy Atkinson
STS-133 launch. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
A closeup of Discovery in flight. Credit: NASA
The STS-133 crew walks out to head to the launchpad. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
The STS-133 crew in front of the 'Astro Van' that brings them to the launchpad. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

Astronaut Leland Melvin talks with participants in the NASA Tweetup for STS-133 at KSC before the launch. Credit: Nancy Atkinson
Members of the NASA Tweetup for STS-133 gather for a photo. They finally got to see their mission launch, after waiting nearly four months. Surprisingly, over 100 of the original 150 were able to return on Feb. 24 for the launch. Credit: Nancy Atkinson
The media descends on KSC for the STS-133 launch. Credit: Nancy Atkinson
The twin brother of the R2 Robonaut awaits launch of Space Shuttle Discovery on the STS-133 mission, its 39th and final fligh to space. Credit: Ken Kremer
At NASA's Kennedy Space Center in Florida, space shuttle Discovery is seen shortly after the rotating service structure was rolled back at Launch Pad 39A. Image credit: NASA/Jack Pfaller Feb. 23, 2011
Discovery bathed in lights after the RSS was retracted on Feb. 23, 2011. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
The crew of STS-133 stands in front of Discovery on the launchpad. Credit: Alan Walters (awaltersphoto.com) for Universe Today.
Posted on by Nancy Atkinson

SDO Captures a Monster Solar Prominence

A monster solar prominence captured by SDO. Credit: NASA

The Sun continues to be active! A large-sized (M 3.6 class) flare occurred near the edge of the Sun on February 24, 2011, and it blew out a gorgeous, waving mass of erupting plasma that swirled and twisted over a 90-minute period. This event was captured in extreme ultraviolet light by NASA’s Solar Dynamics Observatory spacecraft. Some of the material blew out into space and other portions fell back to the surface. Because SDO images are super-HD, the scienctists can zoom in on the action and still see exquisite details. The video above was created using a cadence of a frame taken every 24 seconds; still, the sense of motion is, by all appearances, seamless. Sit back and enjoy the jaw-dropping solar show. See one of the images, below.

Spaceweather.com reports that Earth was little affected by this blast, as plasma clouds produced by the blast did not come our way.

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The latest active sunspot — #1163 — is currently behind the Sun’s eastern limb, but be turning toward Earth in the days ahead, setting the stage for more activity if the eruptions continue.

Posted on by Nancy Atkinson

STS-133 Launches on Historic Final Mission for Shuttle Discovery

Discovery launches for one final mission. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

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Overcoming a down-to the-last second problem, space shuttle Discovery made history today, launching on its final mission to orbit. The most-traveled orbiter is carrying a crew of six astronauts and one human-like Robonaut, along with a new permanent storeroom and supplies for the International Space Station. After waiting nearly four months following the detection of potentially dangerous cracks in Discovery’s external tank and a leak in the Orbiter Maneuvering System pod, a problem with a computer for the Air Force Range Safety Officer nearly thwarted the long-anticipated launch. The crew of STS-133 finally launched on their historic mission, with reinforced ribs, or stringers, in the tank’s “intertank” section and a leak-free OMS, and — two seconds before the launch window would have closed — a working computer in the Range. “That was about as last second as you can get,” said spokesman Allard Beutel from Kennedy Space Center.

Discovery set off on her final journey from a picture-perfect warm February day at Kennedy Space Center in Florida, thrilling enormous crowds of onlookers, a huge international press corp and dedicated Tweet-up attendees.

But the four month delay was not without consequences, as original STS-133 crew member Tim Kopra was injured in a bike accident, and Steve Bowen was chosen to replace him. The crew – which includes Commander Steve Lindsey, pilot Eric Boe, Nicole Stott, Michael Barratt, and spacewalkers Alvin Drew and Bowen — met at the base of the shuttle before climbing on board in a touching moment, giving each other a group hug before setting off on their mission.

In the payload bay is the Permanent Logistics Module – a glorified closet, with the first human-like robot, affectionately named R2, who will become a permanent crewmember on board the ISS.

STS-133 launch. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

Discovery has been flying since Aug. 30, 1984. It’s first mission was 41-D, where astronauts deployed three communications satellites. Discovery has completed 30 successful missions, more than any other orbiter in NASA’s Shuttle fleet. The orbiter has undergone 99 different upgrades and 88 special safety tests – just since 2002. Discovery was named after several ships of exploration in human history.

Paving the way for the launch was today’s successful docking at the ISS of the ATV-2 Johannes Kepler, a European re-supply ship for the ISS. The Automated Transfer Vehicle 2 is the size of a double-decker bus, and carries 7 tons of supplies for the station’s six-person crew.

Here’s our huge gallery of launch images and here’s a video of the launch from NASA TV:

Posted on by Anne Minard

Meteorites Illuminate Mystery of Chromium in Earth’s Core

It’s generally assumed that the Earth’s overall composition is similar to that of chondritic meteorites, the primitive, undifferentiated building blocks of the solar system. But a new study in Science Express led by Frederic Moynier, of the University of California at Davis, seems to suggest that Earth is a bit of an oddball.

 

 

Thin section of a chondritic meteorite. Credit: NASA

Moynier and his colleagues analyzed the isotope signature of chromium in a variety of meteorites, and found that it differed from chromium’s signature in the mantle.

“We show through high-precision measurements of Cr stable isotopes in a range of meteorites, which deviate by up to ~0.4‰ from the bulk silicate Earth, that Cr depletion resulted from its partitioning into Earth’s core with a preferential enrichment in light isotopes,” the authors write. “Ab-initio calculations suggest that the isotopic signature was established at mid-mantle magma ocean depth as Earth accreted planetary embryos and progressively became more oxidized.”

Chromium’s origins. New evidence suggests that, in the early solar nebula (A), chromium isotopes were divided into two components, one containing light isotopes, the other heavy isotopes. In the early Earth (B), these components formed a homogeneous mixture. During core partitioning (C), the core became enriched with lighter chromium isotopes, and the mantle with heavier isotopes. Courtesy of Science/AAAS

The results point to a process known as “core partitioning,” rather than an alternative process involving the volatilization of certain chromium isotopes so that they would have escaped from the Earth’s mantle. Core partitioning took place early on Earth at high temperatures, when the core separated from the silicate earth, leaving the core with a distinct composition that is enriched with lighter chromium isotopes, notes William McDonough, from the University of Maryland at College Park, in an accompanying Perspective piece.

McDonough writes that chromium, Earth’s 10th most abundant element, is named for the Greek word for color and “adds green to emeralds, red to rubies, brilliance to plated metals, and corrosion-proof quality to stainless steels.” It is distributed roughly equally throughout the planet.

He says the new result “adds another investigative tool for understanding and documenting past and present planetary processes. For the cosmochemistry and meteoritics communities, the findings further bolster the view that the solar nebula was a heterogeneous mixture of different components.”

Source: Science. The McDonough paper will be published online today by the journal Science, at the Science Express website.

Posted on by Nancy Atkinson

Can’t Get to Today’s Launch? See the Space Shuttles in Intricate Detail

Space shuttle Discovery from a unique perspective. Credit: John O'Connor from NASATech

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We’ve mentioned the NASATech website before, but this unique website and the incredible images by John O’Connor bear repeating. And for those of you wishing you were at the STS-133 launch today but can’t be here, seeing John’s high resolution, pan-able images is almost better — you’ll probably never get as close to the orbiters as these images can bring you. The image above is a screen clip of space shuttle Discovery on the launchpad, from the perspective of looking up at the orbiter from standing by the right OMS pod, and I was looking at another of John’s images of Endeavour in the Orbiter Processing Facility where I was able to read the markings on each of the heat-resistant tiles on the orbiter’s underside. John creates extremely high resolution virtual tours, and the interactive 360 degree images he creates are nothing short of stunning — but they are also very bandwidth intensive — so be prepared, and watch out if you don’t have high speed internet or if you have a lot of browsers or windows open on your computer.

Right now on his website you can see different views of Endeavour preparing for the next mission, STS-134, and scroll down a bit to find all sorts of images of Discovery from several different perspectives. See her before she launches on her final mission, STS-133.

John describes his photography work on his website as “featuring the people, the technology, and the mission of the Kennedy Space Center and the Cape Canaveral Air Force Station. Compiled within is a unique gallery of the inner workings of America’s reach for the stars.” Beautiful!

Posted on by Ken Kremer

Discovery and Robonaut Unveiled for February 24 Blast Off

The twin brother of the R2 Robonaut awaits launch of Space Shuttle Discovery on the STS-133 mission, its 39th and final fligh to space. Credit: Ken Kremer

[/caption]Space Shuttle Discovery is unveiled for blastoff at 4:50 p.m. today, Feb. 24 from launch Pad 39 A at the Kennedy Space Center in Florida . This is roughly the moment when Earth’s rotation carries the launch pad into the plane of the orbit of International Space Station (ISS)

The rotating service structure was retracted on Wednesday night starting around 8 p.m. Feb. 23 over about 25 minutes under a light fog.

In a major milestone, the External Fuel tank has been successfully loaded with 535,000 gallons of liquid hydrogen fuel and liquid oxygen to power Discovery’s three main engines during the 8 1/2-minute climb into orbit. A dangerous leak of gaseous hydrogen is what caused the launch scrub last Nov. 5.

Pumps will continue to trickle propellants into the tank to replace the small amounts that evaporate during the countdown.

It’s an absolutely gorgeous day here at KSC with clear blue skies, calm winds and a crackling excitement that permeates the air for everyone here for the launch.

Discovery unveiled for Feb 14 launch with 6 astronauts and R2 Robonaut on STS-133 mission.. Credit: Alan Walters, awalterphoto.com

The weather forecast has been upgraded to 90% GO from 80% yesterday which was cloudy and overcast. A few low lying clouds are the only concern.

Large public crowds have gathered at public viewing areas along Florida’s Space Coast. The hotels are full of folks excited to see the historic final launch of Discovery on its 39th and final mission.

The Johannes Kepler ATV is due to dock at the ISS at about 12 noon. A successful docking is an essential prerequisite to clear Discovery for liftoff.

The countdown clock is ticking down towards the final blastoff of Discovery.

The veteran crew of five men and one woman led by Shuttle Commander Steve Lindsey arrived on Sunday on a wave of T-38 jets.

The primary goal of the STS-133 mission is to deliver the “Leonardo” Permanent Multipurpose Module to the ISS. The R2 Robonaut is packed Inside Leonardo along with science equipment, spare parts, clothing food and assorted gear.

The twin brother of R2 is on hand at KSC to watch his brothers launch. He also sports a fancy new set of wheels patterned after the rocker bogie system of NASA’s Mars rovers Spirit and Opportunity.

Posted on by Nancy Atkinson

Students Will Attempt to Photograph Shuttle Discovery Flight At The Edge of Space

August 2010 Launch site Warner Springs Gliderport is in the middle of this shot from the edge of space. Credit: Quest for Stars

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From a Challenger Center press release:

If all goes according to plan, a balloon with a student-oriented payload will photograph Space Shuttle Discovery as it climbs into space from an altitude of 100,000 feet. There will also be live streaming video from the balloon itself during the mission – sent back by two regular smartphones running Google’s Android operating system.

Co-sponsored by Challenger Center for Space Science Education, this mission is one in a series of flights conducted by Quest for Stars, a California-based non-profit educational organization that uses off-the-shelf hardware and a little ingenuity to allow students to place experiments at the edge of space at exceptionally low cost.

Quest for Stars and Challenger Center for Space Science Education have now joined together to promote the use of these low cost delivery systems. This mission will be the first of what is hoped to be many future collaborations.

A helium-filled balloon carrying the “Robonaut-1” payload (not related to the Robonaut-2 that is launching on board Discovery) will be launched from a location in Florida some distance away from Kennedy Space Center. The time and location of launch will be determined by weather conditions. With a currently planned STS-133 launch time of 4:50 p.m. EST, the balloon will be launched between 3:00 – 3:50 p.m. EST so as to be in position for Discovery’s supersonic transit of the stratosphere. If there is a delay in the launch of Discovery, the team is ready to try again – several times – on subsequent days.

The balloon will rise at a rate of 800-1,000 feet per minute to an altitude of approximately 100,000 feet. After accomplishing its mission, the payload will be released and descend by parachute. After the payload descends for 15-30 minutes, a trained recovery team will retrieve the payload and download its data and imagery.

Onboard Robonaut-1 is a HD Camera Phone Satellite (PHONESAT) that will attempt to capture images of Space Shuttle Discovery as it leaves Earth for space. Multiple cameras and an on-board computer system will ensure that Discovery launch images will be captured during its ascent. Some of those photos will include logos for Quest For Stars, STS-133, Challenger Center, and Motorola. In addition, the payload contains a Motorola i290 mobile phone and a Garmin eTrex GPS system that is connected to a ham radio transmitter. The payload is designed to have multiple means of communication for backup purposes.

Live video of mission activities will also be streamed during the mission. This webcast can be watched at http://www.ustream.tv/channel/chasing-discovery, http://www.challenger.org/live, and at http://onorbit.com/suborbital.

Live video from the Robonaut-1 itself during flight will be available at http://qik.com/robonaut-1.

Updates during the mission including live tracking information during ascent and descent can be obtained by following http://twitter.com/questforstars or on Facebook at http://tinyurl.com/4hu4337.

See more information and images at OnOrbit.com

Posted on by Matt Williams

Tachyon

[/caption]Ever since Einstein unveiled his theory of relativity, the speed of light has been considered to be the physical constant of the universe, interrelating space and time. In short, it was the speed at which light and all other forms of electromagnetic radiation were believed to travel at all times in empty space, regardless of the motion of the source or the inertial frame of reference of the observer. But suppose for a second that there was a particle that defied this law, that could exist within the framework of a relativistic universe, but at the same time defy the foundations on which its built? Sounds impossible, but the existence of such a particle may very well be necessary from a quantum standpoint, resolving key issues that arise in that chaotic theory. It is known as the Tachyon Particle, a hypothetical subatomic particle that can move faster than light and poses a number intriguing problems and possibilities to the field of physics.

In the language of special relativity, a tachyon would be a particle with space-like four-momentum and imaginary proper time. Their existence was first attributed to German physicist Arnold Sommerfeld; even though it was Gerald Feinberg who first coined the term in the 1960s, and several other scientists helped to advance the theoretical framework within which tachyons were believed to exist. They were originally proposed within the framework of quantum field theory as a way of explaining the instability of the system, but have nevertheless posed problems for the theory of special relativity.

For example, if tachyons were conventional, localizable particles that could be used to send signals faster than light, this would lead to violations of causality in special relativity. But in the framework of quantum field theory, tachyons are understood as signifying an instability of the system and treated using a theory known as tachyon condensation, a process that attempts to resolve their existence by explaining them in terms of better understood phenomena, rather than as real faster-than-light particles. Tachyonic fields have appeared theoretically in a variety of contexts, such as the bosonic string theory. In general, string theory states that what we see as “particles” —electrons, photons, gravitons and so forth—are actually different vibrational states of the same underlying string. In this framework, a tachyon would appear as either indication of instability in the D-brane system or within spacetime itself.

Despite the theoretical arguments against the existence of tachyon particles, experimental searches have been conducted to test the assumption against their existence; however, no experimental evidence for the existence of tachyon particles has been found.

We have written many articles about tachyon for Universe Today. Here’s an article about elementary particles, and here’s an article about Einstein’s Theory of Relativity.

If you’d like more info on tachyon, check out these articles from Science World. Also, you may want to browse through a forum discussion about tachyons.

We’ve also recorded an entire episode of Astronomy Cast all about the Theory of Special Relativity. Listen here, Episode 9: Einstein’s Theory of Special Relativity.

Sources:
http://en.wikipedia.org/wiki/Tachyon
http://en.wikipedia.org/wiki/Speed_of_light
http://scienceworld.wolfram.com/physics/Tachyon.html
http://en.wikipedia.org/wiki/D-brane
http://www.nasa.gov/centers/glenn/technology/warp/warp.html