Posted on by Tammy Plotner

Jupiter and Mercury Pair Up in Twilight March 13–16

Credit: Sky & Telescope Magazine

[/caption]According to today’s Sky & Telescope press release, two bright planets will shine close together low in the western twilight from Sunday to Wednesday, March 13th to 16th. Anyone can see them with the naked eye. You’ll just need a clear sky and an open view toward the west roughly 40 minutes after sunset, as twilight fades.

Jupiter is the brighter of the two. “Mercury is pretty hard to spot most of the time, so a lot of people have never recognized it in their lives,” says Alan MacRobert, a senior editor of Sky & Telescope magazine. “With Jupiter guiding the way, now’s your chance.”

Jupiter has dominated the evening sky for several months, but now it’s on its way down and out for the season. It’ll be gone in another couple of weeks. Mercury, on the other hand, will climb a little higher in the western twilight by late March. (This refers to viewers in the world’s mid-northern latitudes, including the United States, Canada, southern Europe, and elsewhere between about 30° and 50° north latitude.)

The graphic here shows where to look.

Find a spot with a clear, open view low to the west, and you can watch Mercury passing Jupiter in twilight from March 13 to 16, 2011. Credit: Sky & Telescope magazine

The two planets will appear closest together on Monday and Tuesday, March 14 and 15, when they’ll be only about 2° apart — about the width of your thumb held at arm’s length.

Although the two planets appear close together, they’re not. Jupiter is more than 5 times farther away, at a distance of 550 million miles compared to Mercury’s 102 million miles. That means the light we see from them takes 49 and 9 minutes, respectively, to reach us.

“Don’t miss this chance to do a little astronomy from your backyard, balcony, or rooftop,” says Sky & Telescope associate editor Tony Flanders. “It’s a big universe, and planets await.”

For more skywatching information and astronomy news, visit SkyandTelescope.com or pick up Sky & Telescope, the essential magazine of astronomy since 1941.

Posted on by Jason Rhian

Discovery: Mission Complete

Commander Steve Lindsey brings space shuttle Discovery home one last time. The orbiter is now scheduled for decommissioning and retirement at the Smithsonian Institute in Washington D.C. Photo Credit: Alan Walters/awaltersphoto.com

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CAPE CANAVERAL – After logging over a year’s worth of flight time in space, the space shuttle Discovery wrapped up a historic career by safely touching down at NASA’s Kennedy Space Center (KSC) in Florida at 11:57 a.m. EDT. The shuttle landed at KSC’s Shuttle Landing Facility on runway 15.

Discovery’s final mission was a resupply flight to the International Space Station (ISS). The shuttle delivered the Leonardo Permanent Multipurpose Module (PMM) to the orbiting outpost. Among other things, the PMM carried the first humanoid robot in space – Robonaut-2 (R2) inside. R2 is also the first robot that the U.S. has flown to the ISS.

The crew that flew Discovery on her final mission consisted of Commander Steve Lindsey, Pilot, Eric Boe and Mission Specialists; Alvin Drew, Nicole Stott, Michael Barratt and Stephen Bowen. Bowen actually was not slated to fly this mission; he was a last-minute replacement for Tim Kopra who broke his hip in a bicycle accident in January.

The lead-up to Discovery’s final mission was one filled with technical hurdles that NASA’s engineers had to overcome before the shuttle thundered one last time to orbit. On the Nov. 5 launch attempt a leak at the Ground Umbilical Carrier Plate (GUCP) caused a scrub. Upon inspection technicians found a section of popped-up foam on the shuttle’s external tank – this led them to discovering numerous, small cracks in the aluminum body of the external tank itself.

STS-133 marks the 39th and final mission for Discovery. The orbiter will now be retired. Photo Credit: Alan Walters/awaltersphoto.com

When Discovery was set to launch on Feb.24, a range issue crept up at the last minute almost scrubbing the launch. It was cleared with only seconds to spare.

Discovery’s service record is a distinguished one. Whenever NASA had a critical mission to fly – Discovery got the nod. The orbiter carried Sen. Jake Garn as well as former Mercury astronaut and Senator John Glenn to orbit. It delivered the Hubble Space Telescope to space. And it returned the U.S. space program to orbit, twice, after the Challenger and Columbia accidents.

“If you think of a vehicle that’s 27 years old, you never see a vehicle that age that never comes back with no flaws, however Discovery did just that, she functioned flawlessly,” said Commander Steve Lindsey upon landing. “This is a tribute to the Kennedy Space Center team.”

Discovery sits on KSC's Shuttle Landing Facility after completing its highly-successful final mission. Photo Credit: Jason Rhian

The next phase of Discovery’s career is retirement; she will now head to the Smithsonian Institute’s Steven F. Udvar Hazy Center in Washington D.C. where she will be put on display. Discovery will take the place where Discovery currently resides.

“Discovery is an amazing spacecraft and she has served her country well,” said NASA Administrator Charles Bolden. “The success of this mission and those that came before it is a testament to the diligence and determination of everyone who has worked on Discovery and the Space Shuttle Program, over these many years. As we celebrate the many accomplishments of this magnificent ship, we look forward to an exciting new era of human spaceflight that lies ahead.”

There are only two missions left in the shuttle program, STS-134 onboard Endeavour which is slated to fly on Apr. 19 and STS-135 which will be flown by Atlantis on June 28.

Discovery touches down at Kennedy Space Center's runway 15, wrapping up a 27 year career. Photo Credit: Jason Rhian
A long-range shot, showing Discovery on approach to the Shuttle Landing Facility. Credit: Jason Rhian
Posted on by Vanessa Janek

Cosmology 101: The Present

A map of the CMB as captured by the Wilkinson Microwave Anisotropy Probe. Credit: WMAP team
A map of the Cosmic Microwave Background (CMB) as captured by the Wilkinson Microwave Anisotropy Probe. Credit: WMAP team

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Welcome back! Last time, we discussed the first few controversial and eventful moments following the birth of our cosmos. Looking around us today, we know that in the span of just a few billion years, the universe was transformed from that blistering amalgam of tiny elementary particles into a vast and organized expanse just teeming with large-scale structure. How does something like that happen?

Let’s recap. When we left off, the universe was a chaotic soup of simple matter and radiation. A photon couldn’t travel very far without bumping into and being absorbed by a charged particle, exciting it and later being emitted, just to go through the cycle again. After about three minutes, the ambient temperature had cooled to such an extent that these charged particles (protons and electrons) could begin to come together and form stable nuclei.

But, despite the falling temperature, it was still hot enough for these nuclei to start to combine into heavier elements. For the next few minutes, the universe cooked up various isotopes of hydrogen, helium and lithium nuclei in a process commonly known as big bang nucleosynthesis. As time went on and the universe expanded even further, these nuclei slowly captured surrounding electrons until neutral atoms dominated the landscape. Finally, after about 300,000 years, photons could travel freely across the universe without charged particles getting in their way. The cosmic microwave background radiation that astronomers observe today is actually the relic light from that very moment, stretched over time due to the expansion of the universe.

If you look at a picture of the CMB (above), you will see a pattern of differently colored patches that represent anisotropies in the background temperature of the cosmos. These temperature differences originally stemmed from tiny quantum fluctuations that were dramatically blown up in the very early universe. Over the next few hundred million years, the slightly overdense regions in the spacetime fabric attracted more and more matter (both baryonic – the kind that you and I are made of – and dark) under the influence of gravity. Some small regions eventually became so hot and dense that they were able to begin nuclear fusion in their cores; thus, in a delicate dance between external gravity and internal pressure, the first stars were born. Gravity then continued its pull, dragging clumps of stars into galaxies and later, clumps of galaxies into galaxy clusters. Some massive stars collapsed into black holes. Others grew so heavy and bloated that they exploded, spewing chunks of metal-rich debris in every direction. About 4.7 billion years ago, some of this material found its way into orbit around one unassuming main sequence star, creating planets of all sizes, shapes, and compositions – our Solar System!

Billions of years of geology and evolution later, here we are. And there the rest of the universe is. It’s a pretty striking story. But what’s next? And how do we know that all of this theory is even close to correct? Make sure to come back next time to find out!

Posted on by Nancy Atkinson

Absolutely Amazing: ISS, Discovery Transit Sun Near Active Sunspot Region

The International Space Station and a just-undocked space shuttle Discovery transit the surface of the Sun, appearing near an active spot region, 1166. Credit: Catalin Fus

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Amateur astronomer Catalin Fus from Poland has captured one of the most amazing images I’ve ever seen – and his timing was impeccable. On March 7th at 13:05:49 UTC, just after space shuttle Discovery had undocked from the International Space Station, the two ships flew in formation directly in front of the Sun, as seen from Fus’ location just outside of Krakow. With his solar-filtered telescope focused on active sunspot region 1166, he found there were a couple extra spots in his image – Discovery and the ISS. Given that this was Discovery’s final mission in space and final visit to the ISS, this image has historical significance, as well as just being absolutely fantastic. Keep in mind that transits like this last just over a half a second.

He used the following equipment:

Telescope : 102mm f6.3 GPU oilspaced apochromat
self-made Herschel Prism + Meade TeleXtender 2x 1.25”
Mount: Losmandy G11
Camera: Canon EOS 550D
1frame @ ISO 100, 1/1000s
With just a touch of post processing done in PixInsight and PS CS5

Cropped version of the ISS/Discovery/sunspont conjunction. Credit: Catalin Fus. Used by permission.

You can see more Fus’ handiwork at his website, www.catalinfus.ro. Our thanks to Catalin for allowing Universe Today to post his incredible image.

Posted on by Nancy Atkinson

New Color Image Shows Opportunity Rover from Orbit

Visible from Mars orbit are tracks, to the left, and the Opportunity rover itself, sitting on the edge of Santa Maria Crater. Credit: NASA/JPL/University of Arizona

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Another great shot by the HiRISE camera on the Mars Reconnaissance Orbiter: this one of the Opportunity rover sitting on the edge of Santa Maria Crater. The High Resolution Imaging Science Experiment took this image on March 1, 2011, and also visible are the tracks in the Martian soil that Oppy created as she made her way to the crater.

“Opportunity has been studying this relatively fresh 90-meter diameter crater to better understand how crater excavation occurred during the impact and how it has been modified by weathering and erosion since,” said Matt Golombeck, a research geologist at the Jet Propulsion Laboratory, and part of the rover team. “Note the surrounding bright blocks and rays of ejecta.”

You can see a non-annotated image here. March 1 on Earth is the 2,524th Martian day, or sol, of Opportunity’s work on Mars.

By the way, MRO celebrates its 5th anniversary of being in orbit of Mars on March 10. Wow, 5 years already? But its been 5 years of great images and discoveries, with wishes from all of us for many more!

Ken Kremer has put together a couple of collection of images that Opportunity has taken while at Santa Maria, some that he and others from Unmanned Spaceflight.com have processed and enhanced for sharper, colored views — this article contains several awesome panoramas, and here’s a collection of 3-D images.

Source: HiRISE website

Posted on by Anne Minard

‘Armada of Telescopes’ Captures Most Distant Galaxy Cluster Ever Seen

Hubble infrared image showing CL J1449+0856, the most distant mature cluster of galaxies found. Color data was added from ESO’s Very Large Telescope and the NAOJ’s Subaru Telescope. Credit: NASA, ESA, R. Gobat (Laboratoire AIM-Paris-Saclay, CEA/DSM-CNRS–)

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The galaxies above are among the oldest objects astronomers have ever laid eyes — er, telescopes — on, formed when the Universe was less than a quarter of its current age. In a new study out in the journal Astronomy & Astrophysics, a team of researchers has announced that they’ve used a fleet of the world’s most powerful telescopes to measure the distance from here to there.

And things look awfully familiar.

“The surprising thing is that when we look closely at this galaxy cluster it doesn’t look young — many of the galaxies have settled down and don’t resemble the usual star-forming galaxies seen in the early Universe,” said lead author Raphael Gobat of Université Paris Diderot in France.

The Very Large Telescope (VLT) at ESO's Cerro Paranal observing site in the Atacama Desert of Chile, consisting of four Unit Telescopes with main mirrors 8.2-m in diameter and four movable 1.8-m diameter Auxiliary Telescopes. The telescopes can work together, in groups of two or three, to form a giant interferometer, allowing astronomers to see details up to 25 times finer than with the individual telescopes. Credit: Iztok Boncina/ESO

Clusters of galaxies are the largest structures in the Universe that are held together by gravity. Astronomers expect these clusters to grow over time so that massive clusters would be rare in the early Universe. Although even more distant clusters have been seen, they appear to be young clusters in the process of formation, not settled mature systems.

The international team of astronomers used the powerful VIMOS and FORS2 instruments on ESO’s Very Large Telescope (VLT) to measure the distances to some of the blobs in a curious patch of very faint red objects first observed with the Spitzer space telescope. This grouping, named CL J1449+0856  for its position in the sky, had all the hallmarks of being a very remote cluster of galaxies. The results showed that we are indeed seeing a galaxy cluster as it was when the Universe was about three billion years old.

Once the team knew the distance to this very rare object, they looked carefully at the component galaxies using both Hubble and ground-based telescopes, including the VLT. They found evidence suggesting that most of the galaxies in the cluster were not forming stars, but were composed of stars that were already about one billion years old. This makes the cluster a mature object, similar in mass to the Virgo Cluster, the nearest rich galaxy cluster to the Milky Way.

Further evidence that this is a mature cluster comes from observations of X-rays coming from CL J1449+0856 made with ESA’s XMM-Newton space observatory. The cluster is giving off X-rays that must be coming from a very hot cloud of tenuous gas filling the space between the galaxies and concentrated towards the center of the cluster. This is another sign of a mature galaxy cluster, held firmly together by its own gravity, as very young clusters have not had time to trap hot gas in this way.

As Gobat concludes, “These new results support the idea that mature clusters existed when the Universe was less than one quarter of its current age. Such clusters are expected to be very rare according to current theory, and we have been very lucky to spot one. But if further observations find many more then this may mean that our understanding of the early Universe needs to be revised.”

Source: ESO press release. The research appears in a paper, “A mature cluster with X-ray emission at z = 2.07,” by R. Gobat et al., published in the journal Astronomy & Astrophysics. (see also arxiv). Lead author’s affiliation page: Université Paris Diderot.

Posted on by Ken Kremer

Endeavour Mated to Rockets for Last Flight Photo Album

Space Shuttle Endeavour in VAB for Final Lift and Mate to Rocket Boosters. Endeavour was attached for the last time to External fuel tank and Solid Rocket Boosters that will power her last ascent to space on the STS-134 mission in April 2011. Then she will be retired from active duty service and sit in a museum yet to be chosen. All the orbiters could be usefully flown for many more years but for lack of money from the US Federal Government. Credit: Ken Kremer

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For the final flight of Space Shuttle Endeavour, I was privileged to be one of the lucky few to be an eyewitness to how the orbiter was hoisted and attached for the last time to the External fuel tank and twin solid rocket boosters that will power her last ascent to space on the STS-134 mission . Thereafter she will be retired from active duty service.

“Lift and Mate” is the formal name for the nearly day and a half long intricate process to join Endeavour to the fuel tank and rocket boosters and took place after the orbiter was hauled inside the 52 story Vehicle Assembly Building atop a 76 wheeled transporter on Feb. 28.

Workers in the Vehicle Assembly Building (VAB) secure yellow metal sling to Endeavour prior to lift from the VAB transfer aisle into High Bay 3 on 1 March 2011. Credit: Ken Kremer

Lift and Mate is a jaw dropping and unforgettable experience because you see the orbiter suspended in mid air as though it was flying in space. While hanging in the air by thin cables, the 100 ton orbiter is reminiscent to me of what astronauts on the International Space Station surely see as the shuttle approaches for docking.

Following the shuttles rollover to the VAB on top on the transporter, technicians initially attached a large yellow, metal sling to Endeavour in the center area of the VAB – known as the transfer aisle.

Endeavour was then slowly and methodically hoisted on pulleys and chains into the vertical position. The tail came to rest just a few meters from the hard and unforgiving concrete floor. The orbiter was then lifted up to the VAB ceiling and carefully moved over walkways into High Bay 3. Media including myself watched this entire process in total awe from several different levels inside the VAB as Endeavour was lifted past us from just a few meters away.

The final step was to lower Endeavour into position for mating to the fuel tank and solid rocket boosters already awaiting her arrival.
Its hard to believe I was really an eyewitness to this majestic event and also sadly realize it will never happen again.

“The orbiter has a lot of life left in her,” said a top shuttle manager to me. “The shuttle could fly many more missions.”

Large yellow sling set to be attached to Endeavour. Credit: Ken Kremer

NASA will rollout Endeavour to Launch Pad 39 A on March 9 following the landing of Space Shuttle Discovery.

The STS-134 mission will be the 25th and final flight for shuttle Endeavour. Launch is set for April 19. Endeavour will haul the $2 Billion Alpha Magnetic Spectrometer (AMS) to orbit and attach it to the ISS. AMS will search for dark matter and seek to determine the origin of the universe.

Check out the majestic views of “Lift and Mate” for Space Shuttle Endeavour in my photo album herein

Final “Lift and Mate” of Space Shuttle Endeavour. Photos by Ken Kremer

Space Shuttle Endeavour in VAB for Lift and Mate. Credit: Ken Kremer
Overhead view of Space Shuttle Endeavour in VAB for Lift and Mate. Credit: Ken Kremer
Overhead view of Space Shuttle Endeavour in VAB for Lift and Mate from Level 16. Credit: Ken Kremer
Belly view of Space Shuttle Endeavour coated with thousands of heat shield tiles. Two rectangular attach points hold left and right side main separation bolts from ET Credit: Ken Kremer
Lifting Endeavour. Credit: Ken Kremer
Belly view of Space Shuttle Endeavour and heat shield tiles. Credit: Ken Kremer
Endeavour goes Vertical. Credit: Ken Kremer
Rotating Vertical Endeavour. Credit: Ken Kremer
Lowering Endeavour to Solid Rocket Boosters and External fuel tank inside VAB. Credit: Ken Kremer
Lowering Endeavour in High Bay 3 to SRBs and ET inside VAB. Credit: Ken Kremer
Lowering Endeavour to SRB’s and ET inside VAB. Credit: Ken Kremer
Lowering Endeavour to SRB’s and ET inside VAB. Credit: Ken Kremer
Endeavour disappears behind scaffolding while it is lowered to SRB’s and ET inside VAB. Credit: Ken Kremer
Endeavour disappears behind scaffolding while it is lowered to SRB’s and ET inside VAB. Tip of ET visible here above nose of Endeavour. Credit: Ken Kremer
Ken Kremer and Space Shuttle Endeavour in the VAB for Lift and Mate to Booster rocket
Posted on by Tammy Plotner

Capturing Thor’s Helmut

NGC 2359 - Credit: John Chumack

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It spans nearly 30 light years of space… and resides approximately 15,000 light-years from Earth. Its heartbeat is an extremely hot giant star thought to be in a brief, pre-supernova stage of evolution. Interactions with a nearby dense, warn and large molecular cloud are what may have contributed to its complex shape and curved bow-shock structure. Step back into mythology and see if you have what it takes to capture “Thor’s Helmut”…

Unlike many nebula, this unusual character is the product of the central Wolf-Rayet star, its stellar winds, and the surrounding interstellar matter. The powerful star emits a high velocity wind, pushing matter ahead of it. This process both compresses and expands its ring-like shell. As it grows, it collects even more gas and dust from the interstellar medium. But how many times and how many events?

“We have detected three different velocity components, and determined their spatial distribution and physical properties. The kinematics, morphology, mass and density are clearly stratified with respect to the W-R star.” says JR Rizzo (et al). “These features allow us to learn about the recent evolutionary history of HD 56925, because the multiple layers could be associated to several energetic events which have acted upon the surrounding circumstellar medium. Hence, a careful study of the different shockfronts contain clues in determining the present and past interaction of this evolved massive star with its surroundings.”

While most planetary nebulae contain old stars nearing the end of their lives, the central Wolf-Rayet star in NGC 2359 is very young. Its ultraviolet photons are the fueling source of the emission nebula. Wolf-Rayets are evolved, massive and extremely hot – up to ~50,000 K. Not only that, but their luminosity is incredible, too… up to 10L to the fifth or sixth power. Their surface composition is extremely exotic, being dominated by helium rather than hydrogen and the stars themselves are rare, simply because they are so short-lived. It was only three short decades ago that astronomers also realized that WRs suffered from heavy mass loss as well. Their ejecta bursts outward at speeds comparable to a nova. The whole process of formation simply isn’t clearly understood yet. The layers may be from differential rotation – but they could be the results of the exposed stellar core.

“The overall emission in the nebula is dominated by the overwhelming contribution of the H II region and is characteristic of photoionization processes. The embedded, photoevaporating cloud contributes enough mass over a dynamical lifetime to account for the shell mass of 5.0 solar mass.” says TE Jernigan. “In NGC 2359, imagery reveals variations in density, temperature, and ionization structure on scales ranging from the size of the nebula down to the seeing limit of approximately 2.1 seconds. The structure of the H II region can be understood in terms of a photoionized conical cavity protruding into the surrounding molecular cloud. The emission in the bubble region is characteristic of that produced in the incomplete cooling region behind a stellar-wind shock wave.”

No matter what explanation lay behind it, observing “Thor’s Helmut” is a pure pleasure. You’ll find it located about a fistwidth east-northeast of Sirius (07h 18m 30s, ?13° 13′ 48″). This Herschel object is a delightful 8th magnitude and well worth the effort!

And many thanks to John Chumack of Galactic Images for making the effort and sharing it with us!

Posted on by Jon Voisey

STEREO Looks at the Sun; Finds Planets

STEREO spacecraft. Credit: NASA

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The primary mission of the twin STEREO probes is to explore the 3-dimensional makeup of our Sun. Each craft carries a variety of instruments. One of them, the Heliospheric Imager (HI), doesn’t look directly at the Sun, but rather, explores a wide field near the Sun in order to explore the physics of coronal mass ejections (CMEs), in particular, ones aimed at the Earth. But while not focusing on solar ejections, the HI is free to make many other observations, including its first detection of an extrasolar planet.

As the Heliospheric Imager stares at the space between the Earth and Sun, it has made many novel observations. The device first opened its shutters in 2006 the instrument has observed the interaction of CMEs with the atmosphere of Venus, the stripping of a tail of a comet by a CME, atomic iron in a comet’s tail, and “the very faint optical emission associated with so-called Corotating Interaction Regions (CIRs) in interplanetary space, where fast-flowing Solar wind catches up with slower wind regions.”

The spacecraft allows for long periods of time to stare at patches of sky as the satellites precede and follow Earth in its orbit. The spacecraft is able to take pictures roughly every 40 minutes for almost 20 days in a row giving excellent coverage. As a result, the images taken have the potential to be used for detailed survey studies. Such information is useful for conducting variable star studies and a recent summary of findings from the mission reported the detection of 263 eclipsing variable stars, 122 of which were not previously classified as such.

Another type of variable star observed by the STEREO HI, was the cataclysmic sort, in particular, V 471 Tau. This red giant/white dwarf binary in the Hyades star cluster is a strong source of interest for stellar astrophysicists because the system is suspected to be a strong candidate for a type Ia supernova as the red giant dumps mass onto its high mass, white dwarf companion. The star system is extremely erratic in its light output and observations could help astronomers understand how such systems evolve.

Although planetary hunting is at the very edge of the capabilities of the HI’s limitations, eclipses caused by planet sized objects are feasible for many of the brighter stars in the field of view as dim as approximately 8th magnitude. Around one star, HD 213597, the STEREO team reported the detection of an object that seems too small to be a star based on the light curve alone. However, follow up studies will be necessary to pin down the object’s mass more accurately.

Posted on by Nancy Atkinson

STS-133 Crew Pays Tribute to Shuttle Discovery

The STS-133 crew sent down a video from orbit today where they each paid tribute to the legacy of space shuttle Discovery. My favorite line was from Nicole Stott: “I’m looking forward to bringing her home to the people who care for her the most, to the time when we are on the runway and can look back and still see her standing on her own gear, with her own proud wings holding her up before she goes back to that hanger for the last time.”