Posted on by Fraser Cain

Weekly Space Hangout – May 3, 2012

Here’s the May 3, 2012 edition of the Weekly Space Hangout, where we were joined by our usual cast of space journalists, including Alan Boyle, Nicole Gugliucci, Ian O’Neill, Jason Major, Emily Lakdawalla and Fraser Cain. We were then joined by two new people, Amy Shira Teitel from Vintage Space and Sawyer Rosenstein from the Talking Space Podcast.

It was an action-packed episode talking about asteroid mining, SpaceX delays, Shuttle retirement, killer black holes, supermassive planets (aka brown dwarfs), Enceladus/Dione flybys, and a new mission to Jupiter.

Want to watch an episode live? We record the Weekly Space Hangout every Thursday at 10:00am PDT, 1:00pm EDT. The live show will appear in Fraser’s Google+ stream, or on our YouTube Channel. You can also watch it live over on Cosmoquest.org.

Posted on by Jason Major

ESA Turns On The JUICE For New Jupiter Mission

Galileo image of Ganymede, Jupiter's - and the Solar System's - largest moon. (Ted Stryk)

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The European Space Agency has given the go-ahead for an exciting mission to explore the icy moons of Jupiter, as well as the giant planet itself.

JUICE — JUpiter ICy moons Explorer — will consist of a solar-powered spacecraft that will spend 3.5 years within the Jovian system, investigating Ganymede, Europa and the upper atmosphere of Jupiter. Anticipated to launch in June 2022, JUICE would arrive at Jupiter in early 2030.

As its name implies, JUICE’s main targets are Jupiter’s largest icy moons — Ganymede and Europa — which are thought to have liquid oceans concealed beneath their frozen surfaces.

The largest moon in the Solar System, Ganymede is also thought to have a molten iron core generating a magnetic field much like Earth’s. The internal heat from this core may help keep Ganymede’s underground ocean liquid, but the dynamics of how it all works are not quite understood.

JUICE will also study the ice-coated Europa, whose cueball-smooth surface lined with cracks and jumbled mounds of frozen material seem to be sure indicators of a subsurface ocean, although how deep and how extensive is might be are still unknown — not to mention its composition and whether or not it could be hospitable to life.

The rust-colored cracks lining Europa's otherwise smooth surface hint at a subsurface ocean. (Ted Stryk)

“JUICE will give us better insight into how gas giants and their orbiting worlds form, and their potential for hosting life,” said Professor Alvaro Giménez Cañete, ESA’s Director of Science and Robotic Exploration.

The JUICE spacecraft was originally supposed to join a NASA mission dedicated to the investigation of Europa, but NASA deemed their proposed mission too costly and it was cancelled. According to Robert Pappalardo, study scientist for the Europa mission based at JPL, NASA may still supply some instruments for the spacecraft “assuming that the funding situation in the United States can bear it.”

Artist's rendering of JUICE at Jupiter. (ESA/AOES)

JUICE will also capture images of Jupiter’s moon Callisto and search for aurorae in the gas giant’s upper atmosphere, as well as measure the planet’s powerful magnetic field. Once arriving in 2030, it will spend at least three years exploring the Jovian worlds.

Read more in today’s news release from Nature, and stay tuned to ESA’s JUICE mission page here.

Recalibrated Galileo images © Ted Stryk. See more of Ted’s excellent work on his site Planetary Images From Then And Now.

Posted on by Ken Kremer

Outer Space – Mind Blowing Video from Jupiter and Saturn

Video Caption: This mesmerizing video unveils incredibly amazing sequences around Jupiter and Saturn from NASA’s Cassini and Voyager missions set to stirring music by “The Cinematic Orchestra -That Home (Instrumental)”. Credit: Sander van den Berg

Don’t hesitate 1 moment ! Look and listen to this mind blowing video of the Jupiter and Saturnian systems.

If you love the wonders of the hitherto unknown Universe unveiled before your eyes – and long to explore – feast your eyes on this short new video right now titled simply; “Outer Space”. Continue reading “Outer Space – Mind Blowing Video from Jupiter and Saturn”

Posted on by Nancy Atkinson

JUICE to Jupiter Could Be ESA’s Next Major Science Mission

Artist concept of JUICE, a Jupiter moons orbiter mission. Credit: ESA

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The Science Programme Committee of the European Space Agency has recommended that the next major space mission for ESA be an orbiter mission to the Jupiter system named JUICE, the JUpiter ICy moons Explorer. This mission would launch in about 2020 and explore potentially habitable moon around the gas giant, Callisto, Europa, and Ganymede.

This recommendation is not the final decision, but puts JUICE as a front-runner for when representatives of all 19 ESA member states meet to discuss the various mission candidates on May 2, 2012

Other missions being considered are ATHENA , the Advanced Telescope for High-ENergy Astrophysics (originally called IXO) – which would be the biggest X-ray telescope ever built — even though smaller in scope than the original IXO) and study the extremes of the Universe: from black holes to large-scale structure ; and NGO, the New Gravitational wave Observatory, a smaller version of LISA, a space-borne gravitational wave detector which would place a three satellites in orbit.

“This is a big blow to space based astrophysics,” wrote European science blogger Steinn Sigurdsson, who added that rumors are floating around that the NGO science team may be disbanded immediately, even though the new report issued by the Science Programme Committee is just a recommendation.

Planetary Society blogger Emily Lakdawalla also commented on the selection — if it is accepted — “represents a big win for planetary science and a big loss for space-based astrophysics in Europe. Which is, one can’t help but notice, opposite to what the currently-proposed NASA budget represents.”

Whatever mission is chosen for the next flagship science mission, ESA knows it will likely have to do it on their own.

In March 2011, NASA informed ESA that that it was highly unlikely that they could become a major partner in an “L” (large) mission for the 2020 timeframe.

“Given the resulting impossibility to continue with the mission concepts defined in the Assessment Phase, the Executive terminated the relative activities for EJSM-Laplace, IXO, and LISA, and informed the members of the three Science Study Teams of the termination of their mandate,” the new report says. “To preserve as much as possible the investment of the scientific community and of the Member States in the study activities of the L mission candidates, the Executive implemented a recovery action in the form of a fast-track re-formulation activity. The aim has been to ascertain if and which of the science goals of the L mission candidates could be implemented in the context of a programmatically feasible European-led, or potentially European-only mission.”

With NASA no longer in the mix, ESA knew they would have to descope their proposed missions, and with costs needing to be at least 20% less than originally planned. “Needless to say, missions within these constraints must be significantly less complex than the original L mission concepts selected in 2007,” the report says.

ESA’s science goals for the front-runner JUICE mission is to visit the Jupiter system concentrating on the characterization of three possible ocean-bearing worlds, Ganymede, Europa and Callisto as planetary objects and potential habitats and on the exploration of the Jupiter system considered as an archetype for gas giants in the solar system and elsewhere. The focus of JUICE is to characterize the conditions that may have led to the emergence of habitable environments among the Jupiter’s icy satellites.

Sources: Dynamics of Cats, Planetary Society blog,

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast – March 19-25, 2012

NGC 2539 - Credit: Palomar Observatory Courtesy of Caltech

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Greetings, fellow SkyWatchers! The week starts off with new Moon and the perfect opportunity to do a Messier Marathon. The planets continue to dazzle as we not only celebrate the Vernal Equinox, but the March Geminid meteor shower as well! If that doesn’t get your pulsar racing – nothing will. It’s time to get out your binoculars and telescopes and meet me in the backyard!

Monday, March 19 – Right now the Moon is between the Earth and the Sun, and you know what that means…New Moon! Tonight we’ll start in northern Puppis and collect three more Herschel studies as we begin at Alpha Monoceros and drop about four fingerwidths southeast to 19 Puppis.

NGC 2539 (Right Ascension: 8 : 10.7 – Declination: -12 : 50) averages around 6th magnitude and is a great catch for binoculars as an elongated hazy patch with 19 Puppis on the south side. Telescopes will begin resolution on its 65 compressed members, as well as split 19 Puppis – a wide triple. Shift about 5 degrees southwest and you find NGC 2479 (Right Ascension: 7 : 55.1 – Declination: -17 : 43) directly between two finderscope stars. At magnitude 9.6 it is telescopic only and will show as a smallish area of faint stars at low power. Head another degree or so southeast and you’ll encounter NGC 2509 (Right Ascension: 8 : 00.7 – Declination: -19 : 04) – a fairly large collection of around 40 stars that can be spotted in binoculars and small telescopes.

Tuesday, March 20 – Today is Vernal Equinox, one of the two times of the year that day and night become equal in length. From this point forward, the days will become longer – and our astronomy nights shorter! To the ancients, this was a time a renewal and planting – led by the goddess Eostre. As legend has it, she saved a bird whose wings were frozen from the winter’s cold, turning it into a hare which could also lay eggs. What a way to usher in the northern spring!

With the Moon still out of the picture, let’s finish our study of the Herschel objects in Puppis. Only three remain, and we’ll begin by dropping south-southeast of Rho and center the finder on a small collection of stars to locate NGC 2489 (Right Ascension: 7 : 56.2 – Declination: -30 : 04). At magnitude 7, this bright collection is worthy of binoculars, but only the small patch of stars in the center is the cluster. Under aperture and magnification you’ll find it to be a loose collection of around two dozen stars formed in interesting chains.

The next are a north-south oriented pair around 4 degrees due east of NGC 2489. You’ll find the northernmost – NGC 2571 (Right Ascension: 8 : 18.9 – Declination: -29 : 44) – at the northeast corner of a small finderscope or binocular triangle of faint stars. At magnitude 7, it will show as a fairly bright hazy spot with a few stars beginning to resolve with around 30 mixed magnitude members revealed to aperture. Less than a degree south is NGC 2567 (Right Ascension: 8 : 18.6 – Declination: -30 : 38). At around a half magnitude less in brightness, this rich open cluster has around 50 members to offer the larger telescope, which are arranged in loops and chains.

Congratulations on completing these challenging objects!

Are you up for another challenge? Then test your ability to judge magnitude as Mars has now dimmed to approximately -1.0. Does it look slightly different in size and brightness than it did a week or so ago? Keep watching!

Wednesday, March 21 – Take your telescopes or binoculars out tonight to look just north of Xi Puppis for a celebration of starlight known as M93 (Right Ascension: 7 : 44.6 – Declination: -23 : 52). Discovered in March of 1781 by Charles Messier, this bright open cluster is a rich concentration of various magnitudes that will simply explode in sprays of stellar fireworks in the eyepiece of a large telescope. Spanning 18 light-years of space and residing more than 3400 light-years away, it contains not only blue giants, but lovely golds as well. Jewels in the night…

Thursday, March 22 – Today in 1799 Friedrich Argelander was born. He was a compiler of star catalogues, studied variable stars and created the first international astronomical organization.

Tonight let’s celebrate no Moon and have a look at an object from an alternative catalog that was written by Lacaille, and which is about two fingerwidths south of Eta Canis Majoris.

Also known as Collinder 140, Lacaille’s 1751 catalog II.2 “nebulous star cluster” is a real beauty for binoculars and very low power in telescopes. More than 50% larger than the Full Moon, it contains around 30 stars and may be as far as 1000 light-years away. When re-cataloged by Collinder in 1931, its age was determined to be around 22 million years. While Lacaille noted it as nebulous, he was using a 15mm aperture reflector, and it is doubtful that he was able to fully resolve this splendid object. For telescope users, be sure to look for easy double Dunlop 47 in the same field.

Now, kick back and enjoy a spring evening with two meteor showers. In the northern hemisphere, look for the Camelopardalids. They have no definite peak, and a screaming fall rate of only one per hour. While that’s not much, at least they are the slowest meteors – entering our atmosphere at speeds of only 7 kilometers per second!

Far more interesting to both hemispheres will be the March Geminids which peak tonight. They were first discovered and recorded in 1973 and then confirmed in 1975. With a much faster fall rate of about 40 per hour, these slower than normal meteors will be fun to watch! When you see a bright streak, trace it back to its point of origin. Did you see a Camelopardalid, or a March Geminid?

Friday, March 23 – Today in 1840, the first photograph of the Moon was taken. The daguerreotype was exposed by American astronomer and medical doctor J. W. Draper. Draper’s fascination with chemical responses to light also led him to another first – a photo of the Orion Nebula.

Our target for tonight is an object that’s better suited for southern declinations – NGC 2451 (Right Ascension: 7 : 45.4 – Declination: -37 : 58). As both a Caldwell object (Collinder 161) and a southern skies binocular challenge, this colorful 2.8 magnitude cluster was probably discovered by Hodierna. Consisting of about 40 stars, its age is believed to be around 36 million years. It is very close to us at a distance of only 850 light-years. Take the time to closely study this object – for it is believed that due to the thinness of the galactic disk in this region, we are seeing two clusters superimposed on each other.

With the Moon out of the picture early, why not get caught up in a galaxy cluster study – Abell 426. Located just 2 degrees east of Algol in Perseus, this group of 233 galaxies spread over a region of several degrees of sky is easy enough to find – but difficult to observe. Spotting Abell galaxies in Perseus can be tough in smaller instruments, but those with large aperture scopes will find it worthy of time and attention.

At magnitude 11.6, NGC 1275 (Right Ascension: 3 : 19.8 – Declination: +41 : 31) is the brightest of the group and lies physically near the core of the cluster. Glimpsed in scopes as small as 150 mm aperture, NGC 1275 is a strong radio source and an active site of rapid star formation. Images of the galaxy show a strange blend of a perfect spiral being shattered by mottled turbulence. For this reason NGC 1275 is thought to be two galaxies in collision. Depending on seeing conditions and aperture, galaxy cluster Abell 426 may reveal anywhere from 10 to 24 small galaxies as faint as magnitude 15. The core of the cluster is more than 200 million light-years away, so it’s an achievement to spot even a few!

Saturday, March 24 – Today is the birthday of Walter Baade. Born in 1893, Baade was the first to resolve the Andromeda galaxy’s individual stars using the Hooker telescope during World War II blackout times, and he also developed the concept of stellar populations. He was the first to realize that there were two types of Cepheid variables, thereby refining the cosmic distance scale. He is also well known for discovering an area towards our galactic center which is relatively free of dust, now known as “Baade’s Window.”

Just after sunset, you really need to take a look out your western window for a really beautiful bit of scenery. As the sky darkens, look for the very tender crescent Moon lit with “Earthshine”. Above it you will see bright Jupiter. Above that you will see blazing Venus. And, if that’s not enough, just a little higher will bring you to the Pleiades! What a great way to start a weekend evening!

With the Moon so near the horizon, we have only a short time to view its features. Tonight let’s start with a central feature – Langrenus – and continue further south for crater Vendelinus. Spanning 92 by 100 miles and dropping 14,700 feet below the lunar surface, Vendelinus displays a partially dark floor with a west wall crest catching the brilliant light of an early sunrise. Notice also that its northeast wall is broken by a younger crater – Lame. Head’s up! It’s an Astronomical League challenge.

Once the Moon has set, revisit M46 in Puppis – along with its mysterious planetary nebula NGC 2438. Follow up with a visit to neighboring open cluster M47 – two degrees west-northwest. M47 may actually seem quite familiar to you already. Did you possibly encounter it when originally looking for M46? If so, then it’s also possible that you met up with 6.7 magnitude open cluster NGC 2423 (Right Ascension: 7 : 37.1 – Declination: -13 : 52), about a degree northeast of M47 and even dimmer 7.9 magnitude NGC 2414 (Right Ascension: 7 : 33.3 – Declination: -15 : 27 ) as well. That’s four open clusters and a planetary nebula all within four square arc-minutes of sky. That makes this a cluster of clusters!

Let’s return to study M47. Observers with binoculars or using a finderscope will notice how much brighter, and fewer, the stars of M47 are when compared to M46. This 12 light-year diameter compact cluster is only 1600 light-years away. Even as close as it is, not more than 50 member stars have been identified. M47 has about one tenth the stellar population of larger, denser, and three times more distant, M46.

Of historical interest, M47 was “discovered” three times: first by Giovanni Batista Hodierna in the mid-17th century, then by Charles Messier some 17 years later, and finally by William Herschel 14 years after that. How is it possible that such a bright and well-placed cluster needed “re-discovery?” Hodierna’s book of observations didn’t surface until 1984, and Messier gave the cluster’s declination the wrong sign, making its identification an enigma to later observers – because no such cluster could be found where Messier said it was!

Sunday, March 25 – Today in 1655, Titan – Saturn’s largest satellite – was discovered by Christian Huygens. He also discovered Saturn’s ring system during this same year. 350 years later, the probe named for Huygens stunned the world as it reached Titan and sent back information on this distant world. How about if we visit Saturn? You’ll find the creamy yellow planet located about a fistwidth northwest of bright, white Spica! Even a small telescope will reveal Titan, but remember… it orbits well outside the ring plane, so don’t mistake it for a background star! While you’re there, look closely around the ring edges for the smaller moons. A 4.5” telescope can easily show you three of them. How about the shadow the rings on the planet’s surface? Or how about the shadow of the planet on the rings? Is the Cassini division visible? If you have a larger telescope, look for other ring divisions as well. All are part and parcel of viewing incredible Saturn!

If you missed yesterday evening’s scenic line-up, don’t despair. Just after the Sun sets tonight – and above the western horizon – you’ll find the young Moon very closely paired with Jupiter. Keep traveling eastward (up) and you’ll encounter Venus. Continue east and the next stop is M45. Watch in the days ahead as the Moon sweeps by, continuing to provide us with a show! Need more? Then check out Leo and Mars! You’ll find a great triangulation of Regulus to the west, Mars to the east and Algieba to the north. If you didn’t know better, you’d almost swear the Lion swallowed the red planet.

Tonight let’s return to our previous studies of the Moon and revisit a challenging crater. Further south than Vendelinus, look for another large, mountain-walled plain named Furnerius, located not too far from the terminator. Although it has no central peak, its walls have been broken numerous times by many smaller impacts. Look at a rather large one just north of central on the crater floor. If skies are stable, power up and search for a rima extending from the northern edge. Keep in mind as you observe that our own Earth has been pummeled just as badly as its satellite.

On this day in 1951, 21 cm wavelength radiation from atomic hydrogen in the Milky Way was first detected. 1420 MHz H I studies continue to form the basis of a major part of modern radio astronomy. If you would like to have a look at a source of radio waves known as a pulsar, then aim your binoculars slightly more than a fistwidth east of bright Procyon. The first two bright stars you encounter will belong to the constellation of Hydrus and you will find pulsar CP0 834 just above the northernmost – Delta.

Unitl next week? May all your journeys be at light speed!

Posted on by Nancy Atkinson

Astrophoto: Conjunction Symmetry by Rick Ellis

Multiple images of the Venus-Jupiter conjuction on Mar. 13, 2012 from Toronto, Canada. Credit: Rick Ellis.

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It’s poetry in motion! Rick Ellis from Toronto, Canada created this 27 frame-composite of the conjunction between Venus and Jupiter on March 13, 2012, with 6 second exposures five minutes apart. Rick used a Canon A460, ISO 80.

Beautiful!

Check out Rick’s website for more poetry — seriously — and more images.

See our previous gallery of Venus-Jupiter conjunction images from around the world.

Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Posted on by Ken Kremer

Dawn gets Big Science Boost at Best Vesta Mapping Altitude

Vesta imaged by NASA’s Dawn Asteroid Orbiter. Dawn is currently at work at the Low Altitude Mapping Orbit (LAMO) acquiring new imagery and spectra of much higher resolution compared to these images acquired at higher altitudes and is also filling in gaps of surface data. The image from Dawn’s Framing Camera, at left, was taken on July 24 at a distance of 3,200 miles soon after achieving orbit around Vesta. The mosaic from Dawn’s Visible and infrared spectrometer (VIR), at right, was acquired from High-altitude mapping orbit (HAMO). Credit: NASA/ JPL-Caltech/ UCLA/ ASI/ INAF/ IAPS. Collage: Ken Kremer

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NASA’s Dawn mission is getting a whopping boost in science observing time at the closest orbit around Asteroid Vesta as the probe passes the midway point of its 1 year long survey of the colossal space rock. And the team informs Universe Today that the data so far have surpassed all expectations and they are very excited !

Dawn’s bonus study time amounts to an additional 40 days circling Vesta at the highest resolution altitude for scientific measurements. That translates to a more than 50 percent increase beyond the originally planned length of 70 days at what is dubbed the Low Altitude Mapping Orbit, or LAMO.

“We are truly thrilled to be able to spend more time observing Vesta from low altitude,” Dr. Marc Rayman told Universe Today in an exclusive interview. Rayman is Dawn’s Engineer at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

“It is very exciting indeed to obtain such a close-up look at a world that even a year ago was still just a fuzzy blob.”

The big extension for a once-in-a-lifetime shot at up close science was all enabled owing to the hard work of the international science team in diligently handling any anomalies along the pathway through interplanetary space and since Dawn achieved orbit in July 2011, as well as to the innovative engineering of the spacecraft’s design and its revolutionary ion propulsion system.

“This is a reflection of how well all of our work at Vesta has gone from the beginning of the approach phase in May 2011,” Rayman told me.

Simulated view of Vesta from Dawn in LAMO, low altitude mapping orbit - March, 6 2012
Credit: Gregory J. Whiffen, JPL

Dawn’s initially projected 10 week long science campaign at LAMO began on Dec. 12, 2011 at an average distance of 210 kilometers (130 miles) from the protoplanet and was expected to conclude on Feb. 20, 2012 under the original timeline. Thereafter it would start spiraling back out to the High Altitude Mapping Orbit, known as HAMO, approximately 680 kilometers above the surface.

“With the additional 40 days it means we are now scheduled to leave LAMO on April 4. That’s when we begin ion thrusting for the transfer to HAMO2,” Rayman stated.

And the observations to date at LAMO have already vastly surpassed all hopes – using all three of the onboard science instruments provided by the US, Germany and Italy.

“Dawn’s productivity certainly is exceeding what we had expected,” exclaimed Rayman.

“We have acquired more than 7500 LAMO pictures from the Framing Camera and more than 1 million LAMO VIR (Visible and Infrared) spectra which afford scientists a much more detailed view of Vesta than had been planned with the survey orbit and the high altitude mapping orbit (HAMO). It would have been really neat just to have acquired even only a few of these close-up observations, but we have a great bounty!”

“Roughly around half of Vesta’s surface has been imaged at LAMO.”

Dawn mosaic of Visible and Infrared spectrometer (VIR) data of Vesta
This mosaic shows the location of the data acquired by VIR (visible and infrared spectrometer) during the HAMO (high-altitude mapping orbit) phase of the Dawn mission from August to October 2011. Dawn is now making the same observations at the now extended LAMO (low-altitude mapping orbit) phase of the Dawn mission from December 2011 to April 2012. VIR can image Vesta in a number of different wavelengths of light, ranging from the visible to the infrared part of the electromagnetic spectrum. This mosaic shows the images taken at a wavelength of 550 nanometers, which is in the visible part of the electromagnetic spectrum. During HAMO VIR obtained more than 4.6 million spectra of Vesta. It is clear from this image that the VIR observations are widely distributed across Vesta, which results in a global view of the spectral properties of Vesta’s surface. This image shows Vesta’s southern hemisphere (lower part of the image) and equatorial regions (upper part of the image). NASA’s Dawn spacecraft obtained these VIR images with its visible and infrared spectrometer in September and October 2011. The distance to the surface of Vesta is around 700 kilometers (435 miles) and the average image resolution is 170 meters per pixel. Credit: NASA/ JPL-Caltech/ UCLA/ ASI/ INAF/ IAPS

The bonus time at LAMO will now be effectively used to help fill in the gaps in surface coverage utilizing all 3 science instruments. Therefore perhaps an additional 20% to 25% extra territory will be imaged at the highest possible resolution. Some of this will surely amount to enlarged new coverage and some will be overlapping with prior terrain, which also has enormous research benefits.

“There is real value even in seeing the same part of the surface multiple times, because the illumination may be different. In addition, it helps for building up stereo,” said Rayman.

Researchers will deduce further critical facts about Vesta’s topography, composition, interior, gravity and geologic features with the supplemental measurements.

Successive formation of impact craters on Vesta
This Dawn FC (framing camera) image shows two overlapping impact craters and was taken on Dec. 18,2011 during the LAMO (low-altitude mapping orbit) phase of the mission. The large crater is roughly 20 kilometers (12 miles) in diameter and the smaller crater is roughly 6 kilometers (4 miles) in diameter. The rims of the craters are both reasonably fresh but the larger crater must be older because the smaller crater cuts across the larger crater’s rim. As the smaller crater formed it destroyed a part of the rim of the pre-existing, larger crater. The larger crater’s interior is more densely cratered than the smaller crater, which also suggests that is it older. In the bottom of the image there is some material slumping from rim of the larger crater towards its center. This image with its framing camera on Dec. 18, 2011. This image was taken through the camera’s clear filter. The distance to the surface of Vesta is 260 kilometers (162 miles) and the image has a resolution of about 22 meters (82 feet) per pixel. Credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA

The foremost science goals at LAMO are collection of gamma ray and neutron measurements with the GRaND instrument – which focuses on determining the elemental abundances of Vesta – and collection of information about the structure of the gravitational field. Since GRaND can only operate effectively at low orbit, the extended duration at LAMO takes on further significance.

“Our focus is on acquiring the highest priority science. The pointing of the spacecraft is determined by our primary scientific objectives of collecting GRaND and gravity measurements.”

As Dawn continues orbiting every 4.3 hours around Vesta during LAMO, GRaND is recording measurements of the subatomic particles that emanate from the surface as a result of the continuous bombardment of cosmic rays and reveals the signatures of the elements down to a depth of about 1 meter.

“You can think of GRaND as taking a picture of Vesta but in extremely faint light. That is, the nuclear emissions it detects are extremely weak. So our long time in LAMO is devoted to making a very, very long exposure, albeit in gamma rays and neutrons and not in visible light,” explained Rayman.

Now with the prolonged mission at LAMO the team can gather even more data, amounting to thousands and thousands more pictures, hundreds of thousands of more VIR spectra and ultra long exposures by GRaND.

“HAMO investigations have already produced global coverage of Vesta’s gravity field,” said Sami Asmar, a Dawn co-investigator from JPL. Extended investigations at LAMO will likewise vastly improve the results from the gravity experiment.

Dawn Spacecraft Current Location and Trajectory - March, 6 2012. Credit: Gregory J. Whiffen, JPL

“We always carried 40 days of “margin,” said Rayman, “but no one who was knowledgeable about the myriad challenges of exploring this uncharted world expected we would be able to accomplish all the complicated activities before LAMO without needing to consume some of that margin. So although we recognized that we might get to spend some additional time in LAMO, we certainly did not anticipate it would be so much.”

“As it turned out, although we did have surprises the operations team managed to recover from all of them without using any of those 40 days.”

“This is a wonderful bonus for science,” Rayman concluded.

“We remain on schedule to depart Vesta in July 2012, as planned for the past several years.”

Dawn’s next target is Ceres, the largest asteroid in the main Asteroid Belt between Mars and Jupiter

Posted on by Jason Major

A Weekend Sky Show: Moon, Venus and Jupiter

Moon and Venus on Feb. 25, 2012. © Jason Major

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As promised by Nancy in a previous article on Universe Today, Venus was visible during the daylight hours this Saturday, very close to the crescent Moon. If you had clear weather you may have been able to catch a glimpse of the scene above, photographed from my location in north Texas at 6:35 p.m. local time.

Dim but visible, Venus is the “star” at lower left.

Later that same evening the show really went into full force as the Moon was illuminated by Earthshine in the western sky, with Venus ablaze and Jupiter making a bright appearance as well!

Nancy wrote on Feb. 24: If you don’t see Venus during the day, try to see Venus immediately at sunset; and right now, the Moon, Venus and Jupiter are lining up for triple conjunction at dusk, and with clear skies, it will be a great view that is almost impossible to miss!

A great view indeed! I grabbed a quick shot with my iPhone camera of the conjunction, and took the opportunity to point out the view to some neighbors as well.

Conjunction of the Moon, Venus and Jupiter on Feb. 25, 2012. (Jason Major)

One of the more dramatic planetary conjunctions I’ve seen, especially with the light from a fading sunset illuminating the stage.

Sometimes the best astronomy is the type you can see with your own eyes… and be able to easily share with others!

ADDED 2/26: Sunday evening brought some great views as well! Here’s a photo from around 6:45 pm on Feb. 26th:

Jupiter, the Moon and Venus on Feb. 26, 2012. © Jason Major

 

Posted on by Ken Kremer

Does Water Ice Lurk Beneath the Poles of Vesta ?

Viewing the South Pole of Vesta and Rhea Silvia Impact Basin. This image obtained by Dawn’s framing camera shows the south pole of the giant asteroid Vesta and the circular Rheasilvia impact basin which scientists believe originated by a collision with another asteroid early in the asteroid's history. The image was recorded from a distance of about 1,700 miles (2,700 kilometers). The image resolution is about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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The mysterious asteroid Vesta may well have more surprises in store. Despite past observations that Vesta would be nearly bone dry, newly published research indicates that about half of the giant asteroid is sufficiently cold and dark enough that water ice could theoretically exist below the battered surface.

Scientists working at NASA’s Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland have derived the first models of Vesta’s average global temperatures and illumination by the Sun based on data obtained from the Hubble Space Telescope.

“Near the north and south poles, the conditions appear to be favorable for water ice to exist beneath the surface,” says Timothy Stubbs of NASA’s Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland, Baltimore County. The research by Timothy Stubbs and Yongli Wang, of the Goddard Planetary Heliophysics Institute at the University of Maryland, was published in the January 2012 issue of the journal Icarus.

If any water lurks beneath Vesta, it would most likely exist at least 10 feet (3 meters) below the North and South poles because the models predict that the poles are the coldest regions on the giant asteroid and the equatorial regions are too warm.

Global Map of Average Surface Temperature of Vesta
This global map of average surface temperature shows the warmer equatorial zone of the giant asteroid Vesta is likely too warm to sustain water ice below the surface. But roughly half of Vesta is so cold and receives so little sunlight on average that water ice could have survived there for billions of years. The dividing lines (solid gray) are found at about 27 degrees north latitude and 27 degrees south latitude. This map, with temperatures given in kelvins, comes from the first published models of the average global temperature and illumination conditions on Vesta. Credit: NASA/GSFC/UMBC

If proven, the existence of water ice at Vesta would have vast implications for the formation and evolution of the tiny body and upend current theories.

The surface of Vesta is not cold enough for ice to survive all the time because unlike the Moon, it probably does not have any significant permanently shadowed craters where water ice could stay frozen on the surface indefinitely.

Even the huge 300 mile diameter (480-kilometer) crater at the South Pole is not a good candidate for water ice because Vesta is tilted 27 degrees on its axis, a bit more than Earth’s tilt of 23 degrees.

By contrast, the Moon is only tilted 1.5 degrees and possesses many permanently shadowed craters. NASA’s LCROSS impact mission proved that water ice exists inside permanently shadowed lunar craters.

New modeling shows that, under present conditions, Vesta's polar regions are cold enough (less than about 145 kelvins) to sustain water ice for billions of years, as this map of average surface temperature around the asteroid's south pole indicates.

The models predict that the average annual temperature around Vesta’s poles is below minus 200 degrees Fahrenheit (145 kelvins). Water ice is not stable above that temperature in the top 10 feet of Vestan soil, or regolith.

At the equator and in a band stretching to about 27 degrees north and south in latitude, the average annual temperature is about minus 190 degrees Fahrenheit (145 kelvins), which is too high for the ice to survive.

“On average, it’s colder at Vesta’s poles than near its equator, so in that sense, they are good places to sustain water ice,” says Stubbs in a NASA statement. “But they also see sunlight for long periods of time during the summer seasons, which isn’t so good for sustaining ice. So if water ice exists in those regions, it may be buried beneath a relatively deep layer of dry regolith.”

Vesta is the second most massive asteroid in the main Asteroid belt between Mars and Jupiter.

NASA’s Dawn Asteroid Orbiter is the very first mission to Vesta and achieved orbit in July 2011 for a 1 year long mission.

Dawn is currently circling Vesta at its lowest planned orbit. The three science instruments are snapping pictures and the spectrometers are collecting data on the elemental and mineralogical composition of Vesta.

The onboard GRaND spectrometer in particular could shed light on the question of whether water ice exists at Vesta.

So far no water has been detected, but the best data is yet to come.

In July 2012, Dawn fires up its ion thrusters and spirals out of orbit to begin the journey to Ceres, the largest asteroid of them all.

Ceres is believed to harbor huge caches of water, either as ice or in the form of oceans and is a potential habitat for life.

Posted on by Jason Major

Beneath the Surface: Seeing Jupiter’s Hidden Storms

Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach. (NASA/JPL-Caltech)


Launched on August 5, 2011, NASA’s Juno spacecraft will arrive at Jupiter in 2016 to study its magnetic field and atmosphere. Using its suite of science instruments Juno will peer inside the gas giant’s thick clouds, revealing hidden structures and powerful storms. To help people visualize what it means to see the invisible, JPL’s visual strategist Dan Goods created the exhibit above, titled Beneath the Surface. It’s an installation of lights, sound and fog effects that dramatically recreates what Juno will experience as it orbits Jupiter. By using their cell phone cameras, viewers can see lightning “storms” hidden beneath upper, opaque layers of “atmosphere”… in much the same way Juno will.

Goods explains: “Humans are only able to see a little, tiny sliver of what there is available in light. There’s gamma rays, microwaves, ultraviolet and infrared light also, and infrared is close enough to the visible part of the spectrum that cell phone cameras can pick it up. Cell phones normally produce more grainy photos at night because they don’t try to cut out the infrared light the way higher-end digital cameras do so in this case, the cell phone cameras are an advantage.” (Via the Pasadena Weekly.)

I had a chance to meet Dan Goods during a Tweetup event for the Juno launch at Kennedy Space Center. He’d brought a table that had magnetic elements set beneath a flat black surface, and by passing a handheld magnet over the table you could “detect” the different magnetic fields… in some cases rather strongly, even though they were all obviously invisible. It was an ingenious way that Juno’s abilities could be demonstrated in a “hands-on” manner.

Watch my video of the Juno launch from the KSC press site.

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Beneath the Surface takes that kind of demonstration to an entirely new level.

“I love to work with the world of things that are right in front of you but you just can’t see,” Goods said. “With Juno, there’s all this structure just under the surface of Jupiter, but humans can develop tools that help us understand things we’d never have seen before.”

The exhibit was installed at the Pasadena Museum of California Art until January 8. It will now travel to science museums around the country.

Video: watch how the exhibit was constructed.

Juno’s primary goal is to improve our understanding of Jupiter’s formation and evolution. The spacecraft will spend a year investigating the planet’s origins, interior structure, deep atmosphere and magnetosphere. Juno’s study of Jupiter will help us to understand the history of our own solar system and provide new insight into how planetary systems form and develop in our galaxy and beyond.

Explore the Juno mission more at http://missionjuno.swri.edu/.