Universe Today

April 3, 2014April 26, 2016 by Ken Kremer

NASA Announces ‘Take the Plunge’ Contest – Guess when LADEE Hits the Moon – Soon!

You can enter NASA’s ‘Take the Plunge’ contest and guess LADEE’s impending lunar impact date, expected on or before April 21, 2014. Credit: NASA
Contest entry details below – deadline soon[/caption]

When will LADEE hit the Moon for its looming end of mission finale?

NASA’s resoundingly successful LADEE lunar dust exploring mission is nearly out of gas – and needs your help, now!

With its inevitable doom approaching, NASA needs you to summon your thoughts and is challenging you to participate in a ‘Take the Plunge’ contest – figuratively not literally – and guess LADEE’s impending impact date.

LADEE, which stand for Lunar Atmosphere and Dust Environment Explorer, will smack violently into the Moon and scatter into zillions of bits and pieces sometime in the next two and a half weeks, on or before about April 21.

But exactly when will it impact the lunar surface? NASA wants to hear your best guess!

The ‘Take the Plunge’ contest was announced by NASA today, April 4, at a media briefing.

For more information about the challenge and how to enter, visit: http://socialforms.nasa.gov/ladee

This dissolve animation compares the LRO image (geometrically corrected) of LADEE captured on Jan 14, 2014 with a computer-generated and labeled image of LADEE . LRO and LADEE are both NASA science spacecraft currently in orbit around the Moon. Credit: NASA/Goddard/Arizona State University

Between now and its inevitable doom, mission controllers will command LADEE to continue gathering groundbreaking science.

And it will do so at an even lower attitude that it orbits today by firing its orbit maneuvering thrusters tonight and this weekend.

The couch sized probe seeks to eek out every last smidgeon of data about the Moons ultra tenuous dust and atmospheric environment from an ultra low altitude just a few miles (km) above the pockmarked lunar surface.

But because the moon’s gravity field is so uneven, the probes thrusters must be frequently fired to keep it on course and prevent premature crashes.

“The moon’s gravity field is so lumpy, and the terrain is so highly variable with crater ridges and valleys that frequent maneuvers are required or the LADEE spacecraft will impact the moon’s surface,” said Butler Hine, LADEE project manager at Ames.

“Even if we perform all maneuvers perfectly, there’s still a chance LADEE could impact the moon sometime before April 21, which is when we expect LADEE’s orbit to naturally decay after using all the fuel onboard.”

LADEE will fly as low as fly approximately 1 to 2 miles (2 to 3 kilometers) above the surface.

Everyone of all ages is eligible to enter NASA’s “Take the Plunge: LADEE Impact Challenge.”

The submissions deadline is 3 p.m. PDT Friday, April 11.

NASA says that winners post impact. They will receive a commemorative, personalized certificate from the LADEE program via email.

Series of LADEE star tracker images features the lunar terrain. Credit: NASA Ames

Watch for my upcoming story on LADEE’s science accomplishments and what’s planned for her final days.

LADEE was launched on Sept. 6, 2013 from NASA Wallops in Virginia on a science mission to investigate the composition and properties of the Moon’s pristine and extremely tenuous atmosphere, or exosphere, and untangle the mysteries of its lofted lunar dust dating back to the Apollo Moon landing era.

Launch of NASA’s LADEE lunar orbiter on Friday night Sept. 6, at 11:27 p.m. EDT on the maiden flight of the Minotaur V rocket from NASA Wallops, Virginia, viewing site 2 miles away. Antares rocket launch pad at left. Credit: Ken Kremer/kenkremer.com

The science mission duration had initially been planned to last approximately 100 days and finish with a final impact on the Moon on about March 24th.

NASA granted LADEE a month long extension since the residual rocket fuel is more than anticipated due to the expertise of LADEE’s navigation engineers and the precision of the launch atop the Orbital Sciences Minotaur V rocket and orbital insertion.

Stay tuned here for Ken’s continuing LADEE, Chang’e-3, Orion, Orbital Sciences, SpaceX, commercial space, Mars rover and more planetary and human spaceflight news.

Learn more at Ken’s upcoming presentations at the NEAF astro/space convention, NY on April 12/13 and at Washington Crossing State Park, NJ on April 6.

Ken Kremer

Full scale model of NASA’s LADEE lunar orbiter on display at the free visitor center at NASA’s Wallops Flight Facility in Virginia. Credit: Ken Kremer/kenkremer.com

April 3, 2014December 23, 2015 by Nancy Atkinson

Cassini Spacecraft Confirms Subsurface Ocean on Enceladus

Jets of icy particles bursting from Saturn's moon Enceladus are shown in this Cassini image taken on November 2005. Credit: NASA/ESA/ASI.

Ever since the Cassini spacecraft first spied water vapor and ice spewing from fractures in Enceladus’ frozen surface in 2005, scientists have hypothesized that a large reservoir of water lies beneath that icy surface, possibly fueling the plumes. Now, gravity measurements gathered by Cassini have confirmed that this enticing moon of Saturn does in fact harbor a large subsurface ocean near its south pole.

“For the first time, we have used a geophysical method to determine the internal structure of Enceladus, and the data suggest that indeed there is a large, possibly regional ocean about 50 kilometers below the surface of the south pole,” says David Stevenson from Caltech, a coauthor on a paper on the finding, published in the current issue of the journal Science. “This then provides one possible story to explain why water is gushing out of these fractures we see at the south pole.”

Artist’s impression of the possible interior of Enceladus based on Cassini’s gravity investigation. The data suggest an ice outer shell and a low-density, rocky core with a regional water ocean sandwiched between at high southern latitudes. Cassini images were used to depict the surface geology in this artwork. The mission discovered plumes of ice and water vapour jetting from fractures – nicknamed ‘tiger stripes’ – at the moon’s south pole in 2005. Credit: NASA/JPL-Caltech.

On three separate flybys in 2010 and 2012, the spacecraft passed within 100 km of Enceladus, twice over the southern hemisphere and once over the northern hemisphere.

During the flybys, the gravitational tug altered a spacecraft’s flight path ever so slightly, changing its velocity by just 0.2–0.3 millimeters per second.

As small as these deviations were, they were detectable in the spacecraft’s radio signals as they were beamed back to Earth, providing a measurement of how the gravity of Enceladus varied along the spacecraft’s orbit. These measurements could then be used to infer the distribution of mass inside the moon.

For example, a higher-than-average gravity ‘anomaly’ might suggest the presence of a mountain, while a lower-than-average reading implies a mass deficit.

On Enceladus, the scientists measured a negative mass anomaly at the surface of the south pole, accompanied by a positive one some 30-40 km below.

“By analyzing the spacecraft’s motion in this way, and taking into account the topography of the moon we see with Cassini’s cameras, we are given a window into the internal structure of Enceladus,” said lead author Luciano Iess.

“This is really the only way to learn about internal structure from remote sensing,” Stevenson added.

The only way to get more precise measurements would be to put seismometers on Enceladus’s surface. And that’s not going to happen anytime soon.

Stevenson said the key feature in the gravity data was the negative mass anomaly at Enceladus’s south pole. This happens when there is less mass in a particular location than would be expected in the case of a uniform spherical body. Since there is a known depression in the surface of Enceladus’s south pole, the scientists expected to find a negative mass anomaly. However, the anomaly was quite a bit smaller than would be predicted by the depression alone.

“The perturbations in the spacecraft’s motion can be most simply explained by the moon having an asymmetric internal structure, such that an ice shell overlies liquid water at a depth of around 30–40 km in the southern hemisphere,” Iess said.

While the gravity data cannot rule out a global ocean, a regional sea extending from the south pole to 50 degrees S latitude is most consistent with the moon’s topography and high local temperatures observed around the fractures – called ‘tiger stripes’ at Enceladus south pole.

Many have said Enceladus is one of the best places in the Solar System to look for life. Noted scientist Carolyn Porco and Chris McKay have a recent paper out titled, “Follow the Plume: The Habitability of Enceladus,” where they say that since analysis of the plume by the Cassini mission indicates that the “steady plume derives from a subsurface liquid water reservoir that contains organic carbon, biologically available nitrogen, redox energy sources, and inorganic salts” that samples from the plume jetting out into space are accessible with a low-cost flyby mission. “No other world has such well-studied indications of habitable conditions.”

These latest findings by Cassini make a mission to Enceladus even more enticing.

Paper in Science (paywall) “The Gravity Field and Interior Structure of Enceladus.”

Sources: ESA, Caltech

April 3, 2014December 23, 2015 by David Dickinson

Night of the Red Planet: Mars Opposition 2014 Coming Soon!

Coming to you on April 8th courtesy of the Virtual Telescope!

Mars attacks and comes to a night sky near you this month, and the folks at the Virtual Telescope Project and Slooh are bringing it to you live and in color. Unlike most planets, “Mars viewing season” comes around only once about every two years. And while Mars is shining bright in the sky right now, the “official” event of Mars being closest to Earth happens next week on April 8^th, when the Red Planet reaches opposition and shines at magnitude -1.5 in the constellation Virgo.

We’ve written about the prospects and circumstances for viewing Mars this opposition season; now it’s time to watch it live. The webcast starts at 23:00 Universal Time (UT) or / 7:00 PM EDT on the night of Tuesday April 8^th, and will feature real-time images brought to you via robotic telescopes worldwide. Hosted by astrophysicist Gianluca Masi and run in conjunction with Astronomers Without Borders, this online observing session of Mars also occurs during Global Astronomy Month. Anyone who tuned in for their recent online Messier Marathon and live broadcasts of several recent Near-Earth Asteroids past our fair planet knows that they’re in for quite a treat!

Want more? Or simply want dual screen live views of “all Mars, all the time?” Our dependable friends over at Slooh will be chronicling the Mars opposition on the same night, starting at a slightly different bat-time at 02:00 UT (the morning of the 9^th) which is 10:00 PM EDT the evening of the 8^th. Slooh will be presenting a live feed from its automated telescopes based in the Canary Islands off of the coast of West Africa and will feature live commentary from hosts Paul Cox and astronomer and author of The Sun’s Heartbeat Bob Berman.

“Mars has held disproportionate focus for humans since ancient times,” Berman said in a recent press release. “It is neither the closest planet, nor the largest, nor the most detailed through telescopes. Nonetheless, it is the only planet in the universe that shows distinct and sometimes detailed surface features through our telescopes. It is also the most Earthlike body in the known universe, with oxygen bound into its soil and water contained in its ices. Therefore, during the brief two weeks when it comes near us every 26 months, it deserves the limelight.”

Indeed, Mars has captivated observers ever since Christiaan Huygens sketched the first blurry surface feature Syrtis Major back in 1659. Percival Lowell enthralled the public imagination with his sketches of what he thought were canals built by an intelligent and ancient civilization on the Red Planet, and astronomer David Peck Todd once proposed to signal said Martians via balloon aloft in 1909. The SETI Institute’s Seth Shostak noted in his book Confessions of an Alien Hunter that to the average person on the street in the early 20^th century, the idea that Mars was inhabited was a given.

Of course, the reality revealed to us by the early Mariner missions in the 1960s onwards paints a bleak picture of a cratered world with a tenuous atmosphere inhospitable to life as we know it.

Still, Mars is a real world, somewhere that rovers are rolling across and exploring even as we peer at it though the eyepiece this month. Six months prior to opposition also the best opportunity to send spacecraft to Mars, and later this year, NASA’s MAVEN and India’s Mars orbiter Mangalyaan both launched in late 2013 will complete the trip.

Mars approaches Earth during the month of April. Credit: Efrain Morales Rivera/Jaicoa Observatory/Aguadilla, Puerto Rico.

Observing the Red Planet through the eyepiece is easy. The most conspicuous feature is the white northern pole cap, currently tipped towards us. Orographic clouds have also been imaged by amateurs recently over the Hellas basin, and a planet wide dust storm could always crop up at any time. A Martian day is only 37 minutes longer than the Earth’s, meaning you’re only seeing Mars rotated by about 15 degrees of longitude if you observe it at the same time each night. At about 15” across, you could stack 120 Mars diameters as seen this week from Earth across a Full Moon. And no, Mars NEVER appears as big as a Full Moon as seen from the Earth, not this week, every August, or EVER, despite those pesky chain-emails from well meaning co-workers/friends/relatives who just know that you’re into that “space thing…”

All oppositions of Mars are not created equal. In fact, we’re coming off of a series of lackluster oppositions that’ll see Mars getting successively better until 2018, when it’ll nearly top the historic opposition of 2003. For ephemerides buffs, Mars reaches opposition — that is, it’s 180 degrees opposite to the Sun as reckoned in right ascension — on April 8^th at 21:00 UT/5:00 PM EDT. It is not quite, however, at its closest to us for 2014: it has still got 0.003 AU (465,000 kilometres, a little over the distance from the Earth to the Moon) and just over 5 days before its closest approach to Earth on the night of April 14^th/15^th, when a total eclipse of the Moon lies just nine degrees away. The reason opposition and the closest approach of Mars to Earth are not quite in sync is because the orbits of both planets are elliptical, and while Mars is currently moving towards perihelion, Earth is heading toward aphelion on July 4^th.

A photo-montage leading up to the 2003 opposition. Photos by author using a webcam turned planetcam.

Can’t wait until the 8^th? Universe Today hosts a Virtual Star Party every Sunday evening at 11:00 PM EDT / 03:00 UT on Google+ featuring telescopes and commentary by observers and astronomers worldwide. Weather willing, Mars should be a centerpiece object for the show this Sunday night on April 6^th.

Be sure to check out Mars at its best this week for 2014, either in a sky near you or online… hey, maybe we’ll be live casting the transit of Earth, the Moon and Phobos someday from Mars on the slopes of Elysium Mons on November 10^th, 2084:

Let’s see, hopefully they’ll have perfected that whole Futurama “head in a jar” thing by then…

Enjoy!

April 3, 2014December 23, 2015 by Elizabeth Howell

Watch Live: Next-Gen Environment Satellite Aims For Space

Artist's conception of Sentinel-1, an environment-monitoring satellite from the European Space Agency. Credit: ESA/ATG medialab

UPDATE, APRIL 4: The satellite safely made it into space! Watch the launch replay and successful satellite separation here.

Just in case you aren’t already in French Guiana, here’s your chance to watch a European environment radar satellite take a rocket ride. Tune into the webcast above to see Sentinel-1A’s launch. If the schedule holds, the launch will be at 5:02 p.m. EDT (9:02 p.m. UTC) on April 3, 2014. Watch live above!

ESA heralds Sentinel-1 as a “new era in Earth observation” because the satellite duo (yes, it will be eventually two satellites) will vastly improve their ability to send out information on natural disasters and quick-moving Earth observation events. Sentinel-1 will in fact be the first of a satellite series feeding into the same information system.

Once the second half of the duo launches in 2016, Sentinel-1 will have a wide swath of geographical coverage, could go to the same areas quickly, and would send data out quickly. Repeatable and rapid Earth observations will bring data quickly into the hands of the authorities who could make decisions about evacuations and other things.

This information will be fed into Copernicus, a new system that will co-ordinate all of the Sentinel satellites for users to gain information.

“The Sentinels will provide a unique set of observations, starting with the all-weather, day and night radar images from Sentinel-1 to be used for land and ocean services,” ESA stated in an explanation about Copernicus.

“Sentinel-2 will deliver high-resolution optical images for land services and Sentinel-3 will provide data for services relevant to the ocean and land. Sentinel-4 and Sentinel-5 will provide data for atmospheric composition monitoring from geostationary and polar orbits, respectively.”

And here are a few of the other applications ESA foresees it would be useful for: sea-ice measurements, looking for oil spills, tracking ships, flagging land with “motion risks” and also doing mapping for the forestry industry.

As far as the webcast, there’s a schedule of speeches and events beforehand at the European Space Agency’s space operations center in Darmstadt, Germany. Be sure to tune in a bit earlier at 3:30 p.m. EST (7:30 p.m. UTC) to see the ceremonies.

Source: European Space Agency

April 3, 2014April 26, 2016 by Nancy Atkinson

Norwegian Skydiver Almost Gets Hit by Falling Meteor — and Captures it on Film

A multiple frame picture of the rock falling, taken from a video taken during a skydive in 2012. Credit and copyright: Anders Helstrup, used by permission.

It sounds like a remarkable story, almost unbelievable: Anders Helstrup went skydiving nearly two years ago in Hedmark, Norway and while he didn’t realize it at the time, when he reviewed the footage taken by two cameras fixed to his helmet during the dive, he saw a rock plummet past him. He took it to experts and they realized he had captured a meteorite falling during its “dark flight” — when it has been slowed by atmospheric braking, and has cooled and is no longer luminous.

UPDATE: See our new article on this topic: Follow Up on Skydiving Meteorite: Crowdsourcing Concludes it Was Just a Rock

Respected Norwegian astrophysicist Pål Brekke confirmed to Universe Today that the story is true and the video is authentic. “I was part of the investigation – and kept secret for two years – in hope of finding the meteorite,” Brekke said via a conversation on Twitter.

Since the search for the meteorite has come up empty so far, Helstrup’s story and video has been released in an effort to recruit more people to look for the rock — and to confirm that this actually was a meteorite.

“It has been a little hard to keep it as a secret,” Helstrup told Universe Today via email, “but everyone has been loyal to the project and helped us out!”

Here’s the video:

The rock zooms by at about :15 in this video:

You can watch a slower version in the video below.

Helstrup has been searching with friends, family and volunteers after getting advice from experts from the Geological Museum in Oslo, Norwegian Space Centre and Norwegian meteor network, making painstaking efforts to pinpoint the location of where the meteorite fell.

“The meteorite has for sure some possible hiding spots,” Helstrup said. “There is a forest with lots of different places it can easily disappear. Even if there is several areas where it would be found easily, there is a river, some marshy spots and areas and lots of high grass. Therefore the best chance of a finding would be in springtime. But we have high hopes!”

Finding the rock would provide the definitive confirmation it really was a space rock that Helstrup captured on film. There’s been much debate about the veracity of both the video and the claim (read Phil Plait’s look at the evidence) but in fact, it is Helstrup who might be most skeptical this was a meteor. There are experts, however, who say there is no doubt.

“It can’t be anything else,” said geologist Hans Amundsen, quoted in the Norwegian publication NRK. “The shape is typical of meteorites – a fresh fracture surface on one side, while the other side is rounded.”

He added that the meteorite may have been part of a larger rock that had exploded perhaps 20 kilometers above Helstrup.

What if the rock would have hit Helstrup or his diving partner? Amundson said the rock would have cut him in half.

“Imagine a 5 kilo rock hitting you in the chest at 300 kilometers per hour,” Amundson says in the video. “That would have led to quite an accident investigation.”

This is unique because — if confirmed — this is the first time a meteor in dark flight has been captured on film.

“Fireballs entering the atmosphere have been filmed many times,” says Morten Bilet in the video. Bilet is a meteorite expert. “This is unique because it was filmed during its so called “dark flight” – after it has been burned out. That’s never been done before so this is something new and exciting.”

We’ve asked Helstrup to keep us posted on any developments in this story or if the meteorite is found.

You can read more about the story from NRK, and the Norwegian Space Center, and the Norwegian Meteorite Society.

April 3, 2014December 23, 2015 by Elizabeth Howell

NASA-Russia Breach Will Not Affect UrtheCast Cameras On Space Station, Company Says

One of the first pictures released from UrtheCast in April 2014 showed several hundred square miles around Moneague, Jamaica. Credit: UrtheCast

UrtheCast — the company aiming to bring high-definition pictures of Earth to the public — is among the exemptions after NASA severed most ties officially with Russia yesterday (April 2), the company said in a press release.

“It is business as usual for the company, as we continue the commissioning of our cameras on the International Space Station,” stated Wade Larson, UrtheCast President and chief operating officer.

“The ISS has long enjoyed a privileged position in international diplomacy and has survived unscathed during multiple international crises in recent years. In fact, we understand that the ISS has been nominated for this year’s Nobel Peace Prize. I think that says a lot.”

The news came around the same time that UrtheCast revealed its first pictures from its two cameras, which were installed by Russian spacewalkers in January following a failed attempt in December.

The new pictures reveal a few hundred square miles of Moneague, Jamaica and Santa Cruz de Mara, Venezuela, both taken on March 28.

“This is a pivotal moment for the company and for everyone who’s been a part of the vision that we set in motion in the fall of 2010. Our team has been working extremely hard to make certain that we reach this goal of democratizing a very powerful perspective on the planet,” stated Scott Larson, UrtheCast co-founder and chief executive officer.

The company is promising there will soon be a “near realtime” stream of Earth observations from the cameras’ perch on the International Space Station. Read more about the company’s plans in this past Universe Today story.

Following a leaked memo early yesterday, NASA released an official statement saying that it would sever most ties with Russia except for those related to International Space Station operations. The United States is among several countries condemning Russia’s decision to bring troops to Crimea a few weeks ago. The decision will likely affect several planetary science agreements with Russia, planetary scientist Barbara Cohen said on Twitter after the news was released.

April 3, 2014March 8, 2017 by Fraser Cain

Is Andromeda Drifting Towards Us?

Image of the Andromeda Galaxy, showing Messier 32 to the lower left, which is currently merging with Andromeda. Credit: Wikipedia Commons/Torben Hansen

In a Universe that’s expanding apart, isn’t it strange that Andromeda is actually drifting towards us? Dr. Thad Szabo from Cerritos College explains why this is happening.

“I’m Thad Szabo, and I teach astronomy and physics at Cerritos College.”

Is Andromeda drifting towards us?

“The reason that we see Andromeda moving toward us is because it’s nearby enough, and the Milky Way is massive enough and Andromeda is massive enough that they’re gravity is strong enough that there is not enough space between them that the space was able to expand and push them apart against the force of gravity. So if you take the Milky Way, all of its stars and all of its gas and dust, all of its dark matter, you’re looking at something that’s a trillion times the mass of the sun. You have the same for Andromeda, and they’re less than a mega parsec apart – to Andromeda, its about 2.2 billion light years. And so with that distance and that much mass, that’s close enough that gravity is drawing them together. Most galaxies, because they’re so distant, you do see them moving away due to the expansion of the universe.”

“But actually M81, which is about 12 million light years away, is also moving towards the Milky Way. It’s the most distant galaxy that doesn’t show red shift. So there’s enough gravity in this local group – I guess the local group is typically the Milky Way galaxy, the Andromeda galaxy, the Triangulum galaxy, and however many tens of dwarf galaxies that we’ve either discovered or haven’t discovered yet. But there’s also a bubble of about ten to twenty major size galaxies extending out to about fifteen million light years or so, and that’s kind of right on the border between where the expansion of the universe would drive things apart and where the gravity is strong enough to hold things together.”

April 3, 2014March 8, 2017 by Fraser Cain

Why Do Galaxies Have Arms?

Spiral galaxies get their name because of their beautiful spiral shape and iconic arms. But why do galaxies have these spiral shapes, and what causes the arms?

Galaxies are some of the most beautiful and inspiring structures in the Universe. As you know, they aren’t solid disks, they’re a gigantic spill of individual stars webbed together by gravity. There are a few rough fundamental shapes that a galaxy can have, and the bulk of these are some variation of a spiral. Each one with twisting arms of stars reaching tens of thousands of light years in every direction along a plane, out from a galactic core.

So what gives them this characteristic spiral shape? Earliest galaxies didn’t have clearly defined spiral arms. They were either two-armed or, had thick irregular chaotic woolly arms with star forming clumps. After 3.6 billion years, however, the chaos had settled down into the shapes we see today. But it took until the Universe was 8 billion years old for these modern multi-armed spirals, like the Milky Way or Andromeda to appear.

So where did they come from? These arms are in fact density waves passing through the galaxy, with stars moving in and out of the waves. The arms themselves aren’t permanent structures made of the same clumps of stars.

Imagine driving down a highway and people are slowing down to gape slack-jawed a crashed alien saucer. Cars will slow down as they reach the saucer and form a clump, and then the car in the lead of the clump will accelerate and proceed down the highway as other cars progress through the clump to take their place.

This is a great analogy for movement in a galaxy. As a density wave approaches, stars accelerate towards it. Then they slow down as they move away from it. Just like a comet falling into the gravity well of the Sun. And when the density wave moves through an area, it kicks off an era of star formation. So the material of the galaxy is being constantly stirred and new stars are born as a density wave makes its way through the galaxy.

Six spectacular spiral galaxies are seen in a clear new light in images from ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile. Credit: ESO

When you picture this, keep in mind that stars closer to the core of the galaxy orbit faster than the spiral arm, and the stars further out go more slowly. Our galaxy, the Milky Way takes about 240 million years to complete a full rotation. But we pass through a major spiral arm every 100 million years or so, remaining in the higher density region for about 10 million years. Astronomers have only recently figured out why these arms exist in the first place.

Originally, they suspected it might be like a garden sprinkler, with material fountaining out from the center of the galaxy, or channeled by magnetic fields. They also thought that the arms might be transient features. Appearing and disappearing over time. But new evidence and simulations show they’re long lasting, they believe the arms themselves form as a result of giant molecular clouds of hydrogen. These clouds initiate the arms and keep the shape sustained over billions of years.

What do you think? What’s your favorite spiral galaxy? Tell us in the comments below.

April 3, 2014December 23, 2015 by Bob King

Fly to Rosetta’s Comet with this New Interactive Visualization

Frame from the Rosetta Mission simulation shows the probe and comet when closest to the sun in late 2015. Credit: INOVE

Hang onto your space helmets. With a few moves of the mouse, you can now follow the European Rosetta mission to its target comet with this interactive 3-D simulator. Go ahead and give it a click – it’s live! The new simulator was created by INOVE Space Models, the same group that gave us the 3-D solar system and Comet ISON interactive models.

The embedded version gives you a taste, so be sure to also check out the full-screen version. You can either click play to watch the mission from start to finish or you can drop it at key points by selecting from list of 11 highlights on the left side of your screen. A tick-tock at the bottom of the screen helps reference the time and what the spacecraft is doing at that moment in the video.

To interact with the model, simply click the screen. The action stops, allowing you to zoom in and out by scrolling; to change orbital viewpoints hold down the mouse button and drag. So easy!

Simulator view of Rosetta's first Earth flyby / gravity assist in March 2005. The probe flew by Earth three times and Mars once to conserve fuel and send it beyond the asteroid belt to rendezvous with Comet Churyumov-Gerasimenko. Credit: INOVE — Simulator view of Rosetta’s first Earth flyby / gravity assist in March 2005. The probe flew by Earth three times and Mars once to conserve fuel and send it beyond the asteroid belt to rendezvous with Comet Churyumov-Gerasimenko. Credit: INOVE

I like the realism of the simulation, the attention paid to the planets’ variable spin rates and orbital periods and how well model illustrates the complicated maneuvers required to “fling” the probe to Comet Churyumov-Gerasimenko. And I do mean fling. Watching the video from a face-on solar system perspective I was struck by how Rosetta’s flight path resembled a spiral after repeated gravity assists by Mars and Earth.

*Rosetta heads toward Comet C-G after its final Earth flyby in this face-on view. Credit: INOVE*

Whether you’re a teacher or an armchair space enthusiast looking for an easy-to-understand, graphic way to find out how Rosetta will meet its target, I doubt you’ll find a more effective tool.

April 3, 2014December 23, 2015 by Elizabeth Howell

Three NASA Telescopes Begin Hunt For Earliest Galaxies

A grouping of galaxies, known as J0717 (center) is visible in this Spitzer Space Telescope image. Credit: NASA/JPL-Caltech/P. Capak (Caltech)

Talk about turning back time. Three NASA observatories — the Hubble Space Telescope, the Chandra X-Ray Observatory and the Spitzer Space Telescope — are all working together to look for the universe’s first galaxies. The project is called “Frontier Fields” and aims to examine these galaxies through a technique called gravitational lensing, which allows astronomers to peer at more distant objects when massive objects in front bend their light.

“Our overall science goal with the Frontier Fields is to understand how the first galaxies in the universe assembled,” stated Peter Capak, a research scientist with the NASA/JPL Spitzer Science Center at the California Institute of Technology and the Spitzer lead for the Frontier Fields.

“This pursuit is made possible by how massive galaxy clusters warp space around them, kind of like when you look through the bottom of a wine glass.”

Using the three observatories allows investigators to peer at the galaxies in different light wavelengths (namely, infrared for Spitzer, shorter infrared and optical for Hubble, and X-rays for Chandra). The teams also plan to learn more about how the foreground clusters influence the “warping” of the galaxies behind.

The Hubble and Spitzer telescopes are designed to locate where the galaxies are (and if they are indeed early galaxies) while Chandra can map out the X-ray emissions to better determine the galaxies’ masses. An early example of this project at work was examination of Abell 2744, which yielded a distant find: Abell2744 Y1, one of the earliest known galaxies, which was born about 650 million years after the Big Bang.

Source: California Institute Of Technology