Posted on by Nancy Atkinson

LRO Lets You Stand on the Rim of Aristarchus Crater

West wall of Aristarchus crater seen obliquely by the LROC NACs from an altitude of only 26 km. Scene is about 12 km wide at the base. Credit: NASA/GSFC/Arizona State University.

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Have you ever you looked up at the bright, cavernous Aristarchus Crater on the Moon through a telescope or binoculars and wondered what it would be like to stand on the rim and peer inside? Spectacular new views from the Lunar Reconnaissance Orbiter is almost as good as being there, and a new video lets you “rappel” down and take a closer look at the west side of the crater walls.

Full panoramic view of the west wall of Aristarchus crater revealing impact melt deposits, exposures of high reflectance anorthosite, streamers of pyroclastic ash, and blocks up to 100 meters in size. Full width of panorama is about 25 km. Credit: NASA/GSFC/Arizona State University.

LRO Camera Principal Investigator Mark Robinson describes the region around the crater, known as the Aristarchus plateau, as one of the most geologically diverse places on the Moon. “A mysterious raised flat plateau, a giant rille carved by enormous outpourings of lava, fields of explosive volcanic ash, and all surrounded by massive flood basalts,” Robinson wrote on the LROC website. “A relatively recent asteroid (or comet) slammed into this geologic wonderland, blowing a giant hole in the ground revealing a cross section of over 3,000 meters (9,800 ft) of geology. No wonder planners for the Apollo missions put this plateau high on its list of targets for human exploration.”

These new amazing images were acquired on November 10, 2011 as LRO passed only 26 km (16.2 miles) above the surface, which is about two times lower than normal, due to LRO’s current elliptical orbit. The spacecraft was slewed to the west for an oblique or “sideways” look at the crater, instead of looking straight down as LRO normally does, to provide this unique perspective on Aristarchus. For a sense of scale, Robinson said that altitude is only a little over twice as high as commercial jets fly above the Earth. This crater is only one-tenth the size of Earth’s Grand Canyon, but the views from up above are similarly spectacular.

The location of Aristarchus Crater. Credit: Wikipedia

Aristarchus crater is located on the southeast edge of the Aristarchus Plateau. This yawning crater is 40 km wide and 3.5 km deep. The edges appear scalloped, almost like it crater was strip-mined. Since the crater is relatively young, Aristarchus is one of the brightest regions on the Moon. Robinson says these bright rocks may be anorthositic like the highlands, or they may be a more silicic rock like granite — or both.

“Although granites have been found in Apollo rock samples, the formation of granite on the Moon is not well understood at this time – another reason why we need to get samples from this region,” he said.

A 'straight down' view of Aristarchus, Aristarchus crater.. Small white arrows indicate approximate corners of the NAC panorama. Vertical line on right shows LRO orbit ground track Credit: NASA/GSFC/Arizona State University.

From this ‘straight down’ view, you can see the bright ejecta, contrasted by darker areas, which reflects the compositional difference between the various rocks in the region.

On the floor of Aristarchus crater is a wide variety of lunar rocks and geologic processes.

“Diverse materials such as dark, multilayered mare basalts in the walls, bright crustal rocks in the central peak, impact melt, and even regional pyroclastic materials blanketing the crater are brought to the floor and accumulated through mass wasting, creating a bountiful trove of geologic materials,” Robinson said.

Who’s ready to go exploring?!

Click here to see the full-resolution panoramic view of Aristarchus Crater.

Source: LROC

Hat tip and inspiration from Stu Atkinson

Posted on by Paul Scott Anderson

ASU Researchers Propose Looking for Ancient Alien Artifacts on the Moon

The "Blair Cuspids" spires photographed by Lunar Orbiter 2 in 1966. Credit: NASA

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Two researchers at Arizona State University (ASU) have made a rather controversial proposal: have the public and other researchers study the high-resolution photographs of the Moon already being taken by the Lunar Reconnaissance Orbiter (LRO), to look for anomalies that may possibly be evidence of artifacts leftover from previous alien visitation. The theory is that if our solar system had been visited in the past, the Moon would have made an ideal base from which to study the Earth. The paper has just been recently published in the journal Acta Astronautica.

Professor Paul Davies and research technician Robert Wagner admit that the chances of success are very small, but argue that the endeavour would be worth the minimal investment required. The photographs are already being taken on a regular basis by LRO. Any interesting finds could be examined by others including imaging professionals. Shape-recognizing software could also be used to help discern any possible artificial artifacts from natural ones.

From the abstract:

The Search for Extraterrestrial Intelligence (SETI) has a low probability of success, but it would have a high impact if successful. Therefore it makes sense to widen the search as much as possible within the confines of the modest budget and limited resources currently available. To date, SETI has been dominated by the paradigm of seeking deliberately beamed radio messages.

However, indirect evidence for extraterrestrial intelligence could come from any incontrovertible signatures of non-human technology. Existing searchable databases from astronomy, biology, earth and planetary sciences all offer low-cost opportunities to seek a footprint of extraterrestrial technology. In this paper we take as a case study one particular new and rapidly-expanding database: the photographic mapping of the Moon’s surface by the Lunar Reconnaissance Orbiter (LRO) to 0.5 m resolution. Although there is only a tiny probability that alien technology would have left traces on the moon in the form of an artifact or surface modification of lunar features, this location has the virtue of being close, and of preserving traces for an immense duration.

Systematic scrutiny of the LRO photographic images is being routinely conducted anyway for planetary science purposes, and this program could readily be expanded and outsourced at little extra cost to accommodate SETI goals, after the fashion of the SETI@home and Galaxy Zoo projects.

Of course, it has been said by some that such artifacts have already been found and known about for decades but hidden from the public by NASA, et al. An entire cottage industry has grown around this idea. There are actually a handful of anomalies from various missions that would be interesting to see at much higher resolution via LRO, such as the well-known “Blair Cuspids” photographed by Lunar Orbiter 2 in 1966, although by far most unusual-looking objects are easily explained. It’s the same problem as with Mars; so many anomalies found by amateur observers are the product of pareidolia, lighting effects, image defects or even geology. Separating out any genuine anomalies from all of the noise would be a tedious and time-consuming task. On the other hand, we now have much better cameras in orbit around the Moon (and Mars) and more advanced photographic analysis techniques available.

Yes, the chances of finding anything are very small, maybe even nonexistent in the opinion of some, but if we have the images being taken anyway, and the willingness of some to study them, then why not? If nothing is found, no harm done. It something was found, well that’s another story entirely…

The abstract for the paper is here. (The paper itself costs $31.50 US to download).

Posted on by Ken Kremer

NASA’s Unprecedented Science Twins are GO to Orbit our Moon on New Year’s Eve

GRAIL probes uses precision formation-flying technique to map Lunar Gravity. The twin GRAIL spacecraft will map the moon's gravity field, as depicted in this artist's rendering. Radio signals traveling between the two spacecraft provide scientists the exact measurements required as well as flow of information not interrupted when the spacecraft are at the lunar farside, not seen from Earth. The result should be the most accurate gravity map of the moon ever made. The mission also will answer longstanding questions about Earth's moon, including the size of a possible inner core, and it should provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed. GRAIL is a part of NASA's Discovery Program. Credit: NASA/JPL-Caltech

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In less than three days, NASA will deliver a double barreled New Year’s package to our Moon when an unprecedented pair of science satellites fire up their critical braking thrusters for insertion into lunar orbit on New Year’s Eve and New Year’s Day.

NASA’s dynamic duo of GRAIL probes are “GO” for Lunar Orbit Insertion said the mission team at a briefing for reporters today, Dec. 28. GRAIL’s goal is to exquisitely map the moons interior from the gritty outer crust to the depths of the mysterious core with unparalled precision.

“GRAIL is a Journey to the Center of the Moon”, said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT) in Cambridge at the press briefing.

This newfound knowledge will fundamentally alter our understanding of how the moon and other rocky bodies in our solar system – including Earth – formed and evolved over 4.5 Billion years time.

After a three month voyage of more than 2.5 million miles (4 million kilometers) since launching from Florida on Sept. 10, 2011, NASA’s twin GRAIL spacecraft, dubbed Grail-A and GRAIL-B, are now on final approach and are rapidly closing in on the Moon following a trajectory that will hurl them low over the south pole and into an initially near polar elliptical lunar orbit lasting 11.5 hours.

GRAIL's trajectory to moon since Sept. 10, 2011 blastoff
Credit: NASA/JPL-Caltech

As of today, Dec. 28, GRAIL-A is 65,860 miles (106,000 kilometers) from the moon and closing at a speed of 745 mph (1,200 kph). GRAIL-B is 79,540 miles (128,000 kilometers) from the moon and closing at a speed of 763 mph (1,228 kph).

The lunar bound probes are formally named Gravity Recovery And Interior Laboratory (GRAIL) and each one is the size of a washing machine.

The long-duration trajectory was actually beneficial to the mission controllers and the science team because it permitted more time to assess the spacecraft’s health and check out the probes single science instrument – the Ultra Stable Oscillator – and allow it to equilibrate to a stable operating temperature long before it starts making the crucial science measurements.

NASA’s twin GRAIL A & B Moon mapping probes
The GRAIL satellites are now streaking to the Moon and their arrival for orbit insertion is just days away and hours apart on New Year’s Eve and New Year’s Day 2012. This picture shows how they looked, mounted side by side, during launch preparations inside the clean room at Astrotech Space Operations facility in Florida prior to blasting off for the Moon on Sept. 10, 2011 from Cape Canaveral, Florida. Credit: Ken Kremer

The duo will arrive 25 hours apart and be placed into orbit starting at 1:21 p.m. PST (4:21 p.m. EST) for GRAIL-A on Dec. 31, and 2:05 p.m. PST (5:05 p.m. EST) on Jan. 1 for GRAIL-B, said David Lehman, project manager for GRAIL at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

“The GRAIL A burn will last 40 minutes and the GRAIL-B burn will last 38 minutes. One hour after the burn we will know the results and make an announcement,” Lehman explained.

The thrusters must fire on time and for the full duration for the probes to achieve orbit. The braking maneuver is preprogrammed and done completely automatically.

Over the next few weeks, the altitude of the spacecraft will be gradually lowered to 34 miles (55 kilometers) into a near-polar, near-circular orbit with an orbital period of two hours. The science phase will then begin in March 2012.

“So far there have been over 100 missions to the Moon and hundreds of pounds of rock have been returned. But there is still a lot we don’t know about the Moon even after the Apollo lunar landings,” explained Zuber.

“We don’t know why the near side of the Moon is different from the far side. In fact we know more about Mars than the Moon.”

GRAIL’s science collection phase will last 82 days. The two spacecraft will transmit radio signals that will precisely measure the distance between them to within a few microns, less than the width of a human hair.

Artist concept of twin GRAIL spacecraft flying in tandem orbits around the moon to measure its gravity field in unprecedented detail. Credit: NASA/JPL

As they orbit in tandem, the moons gravity will change – increasing and decreasing due to the influence of both visible surface features such as mountains and craters and unknown concentrations of masses hidden beneath the lunar surface. This will cause the relative velocity and the distance between the probes to change.

The resulting data will be translated into a high-resolution map of the Moon’s gravitational field and also enable determinations of the moon’s inner composition.

The GRAIL mission may be extended for another 6 months if the solar powered probes survive a power draining and potentially deadly lunar eclipse due in June 2012.

Engineers would significantly lower the orbit to an altitude of barely 15 to 20 miles above the surface to gain even further insights into the lunar interior.

The twin probes are also equipped with 4 cameras each – named MoonKAM – that will be used by middle school students to photograph student selected targets.

The MoonKAM project is led Dr. Sally Ride, America’s first woman astronaut as a way to motivate kids to study math and science.

JPL manages the GRAIL mission for NASA.

Stay tuned for Universe Today updates amidst the News Year’s festivities.

Blastoff of twin GRAIL A and B lunar gravity mapping spacecraft on a Delta II Heavy rocket on Sept. 10 from Pad 17B Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT. Credit: Ken Kremer

Read continuing features about GRAIL by Ken Kremer here:
Student Alert: GRAIL Naming Contest – Essay Deadline November 11
GRAIL Lunar Blastoff Gallery
GRAIL Twins Awesome Launch Videos – A Journey to the Center of the Moon
NASA launches Twin Lunar Probes to Unravel Moons Core
GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

Posted on by Jon Voisey

Echoes From η Carinae’s Great Eruption

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During the mid 1800’s, the well known star η Carinae underwent an enormous eruption becoming for a time, the second brightest star in the sky. Although astronomers at the time did not yet have the technology to study one of the largest eruptions in recent history in depth, astronomers from the Space Telescope Science Institute recently discovered that light echoes are just now reaching us. This discovery allows astronomers to use modern instruments to study η Carinae as it was between 1838 and 1858 when it underwent its Great Eruption.

V838 Mon (Credit: NASA, European Space Agency and Howard Bond (STScI))
Light echoes have been made famous in recent years by the dramatic example of V838 Monocerotis. While V838 Mon looks like an expanding shell of gas, what is actually depicted is light reflecting off shells of gas and dust that was thrown off earlier in the star’s life. The extra distance the light had to travel to strike the shell, before being reflected towards observers on Earth, means that the light arrives later. In the case of η Carinae, nearly 170 years later!

The reflected light has its properties changed by the motion of the material off which it reflects. In particular, the light shows a notable blueshift, telling astronomers that the material itself is traveling 210 km/sec. This observation fits with theoretical predictions of eruptions similar to the type η Carinae is thought to have undergone. However, the light echo has also highlighted some discrepancies between expectation and observation.

Typically, η Carinae’s eruption is classified as a “supernova impostor”. This title is fitting since the eruptions create a large change in the overall brightness. However, although these events may release 10% of the total energy of a typical supernova or more, the star remains intact. The main model to explain such eruptions is that a sudden increase in the star’s energy output causes some of the outer layers to be blown off in an opaque wind. This shell of material is so thick, that it gives a large increase in the effective surface area from which light is emitted, thereby increasing the overall brightness.

However, for this to happen, models predict that the temperature of the star prior to the eruption needs to be at least 7,000 K. Analyzing the reflected light from the eruption places the temperature of η Carinae at the time of the eruption at a much lower 5,000 K. This would suggest that the favored model for such events is incorrect and that another model, involving an energetic blast was (a mini-supernova), may be the true culprit, at least in η Carinae’s case.

Yet this observation is somewhat at odds with observations made in the years following the eruption. As spectrography came into use, astronomers in 1870 visually noticed emission lines in the star’s spectrum which is more typical in hotter stars. In 1890, η Carinae had a smaller eruption and a photographic spectrum put the temperature around 6,000 K. While this may not accurately reflect the case of the Great Eruption, it is still puzzling how the star’s temperature could change so quickly and may also indicate that the favored model of the opaque-wind model is a better fit for later times or the smaller eruption, which would suggest two different mechanisms causing similar results in the same object on short timescales.

Either way, η Carinae is a marvelous object. The team has also identified several other areas in the shell surrounding the star which appear to be brightening and undergoing their own echoes which the team promises to continue to observe which would allow them to verify their findings.

Posted on by Mike Simonsen

Supernova Alphabet Soup

SN 2011fe aka PTF11kly Image credit: Wikipedia

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The International Astronomical Union (IAU) is the sole body responsible for the official naming of astronomical objects. So if you have a problem with the way things in the Universe are named, you now know where to send your email and letters of protest.

Before we get into this, a quick grammar note. When we discuss more than one supernova, they are called supernovae (super- no- vee), not supernovas. The same holds true for more than one nova. They are novae (no- vee). Please don’t write and ask me about Novas. Those are old Chevrolets, not stars.

Fortunately, the naming convention used for supernovae is pretty simple and straightforward.

The name is formed by combining the prefix SN, for supernova, the year of discovery and a one- or two-letter designation. The first 26 supernovae of the year get an upper case letter from A to Z (SN 1987A). After that, we start over with pairs of lower-case letters are used, starting with aa, ab, and so on (SN 2005ap).

Of course there are exceptions, there are always exceptions. That’s one of the things about astronomical nomenclature that is maddening, but I digress…

Four important historical supernovae are known simply by the year they occurred- SN 1006, SN 1054, SN 1572 (more commonly referred to as Tycho’s Nova), and SN 1604 (also known as Kepler’s Star).

One reason I’m bringing this subject up now is that we are ending the year, so we are approaching the time where we reset the naming schema for 2012 and the first supernova of the new year will get named SN 2012A. With the annual number of discoveries rising each year to well over 500, it is always a bit surprising how long it takes for that first one of the year to get named. So each year we hold an unofficial contest to see who will discover the first SN of the new year.

One of the reasons it usually doesn’t occur on the first day of the year is that supernova discoveries have to be officially confirmed spectroscopically before they get an official IAU designation. When someone discovers a possible supernova it gets reported to the IAU and then listed on the CBAT Transient Objects Confirmation Page. If it is a possible SN it gets a temporary designation of PSN (possible supernova) followed by its coordinates (PSN J01560719+1738468).

Only after someone has taken a spectrum confirming it is a supernova does it get a name with the year and letter combination. This can take several days, so it is unlikely a SN discovered on January 1 will be named until later in the week or the second week of the month. If it were discovered on December 23rd and confirmed on the 1st of January it would still get a name from the previous year.

This time lag will not be acceptable in the near future, with surveys like LSST coming on line. Astronomers will want immediate notification of discoveries of all types of transient objects including supernovae, so what has happened is new groups searching for SNe have begun to make up their own names.

The Catalina Real Time Survey is one such group. They are discovering dozens of possible supernovae that don’t always get official IAU designations. Their discoveries are all named CSS (Catalina Sky Survey) followed by the date in yymmdd format and then the rough coordinates, like this CSS111227:104742+021815. Crazy, huh?

ROTSE, the Robotic Optical Transient Search Experiment, also discoveries SNe and gives them their own designation in the form of ROTSE3 (the third iteration of this experiment) followed by coordinates, such as ROTSE3 J133033.0-313427.

And there is the Palomar Transient Factory which names its discoveries with the prefix PTF of course, such as PTF11kly, the nearest supernovae in decades, visible with small telescopes in M101. This SN eventually received an IAU designation, SN 2011fe, but that just created more confusion, since now it is known variously by both names in the literature.

Somehow managing to keep it all together amidst the confusion, David Bishop maintains the Latest Supernova Website where you can see discovery images and keep track of your favorite supernovae and related news. There is an excellent article about David and how his website evolved from simple beginnings.

So if you’re asking WTF? about the latest SNe the on the WWW the URL that will lead you through the ABC’s is definitely http://www.rochesterastronomy.org/supernova.html.

Got that? Good, there will be a quiz later…

Posted on by Nancy Atkinson

Our Picks of Best Space and Astronomy Images from 2011

First Ever Portrait of the International Space Station and docked Shuttle Endeavour from Soyuz capsule. This image of the International Space Station and the docked Space Shuttle Endeavour, flying at an altitude of 220 miles was taken by Expedition 27 crew member Paolo Nespoli from the Soyuz TMA-20 following its undocking on May 23, 2011. It is the first-ever image of a space shuttle docked to the International Space Station. Endeavour at left. European ATV cargo carrier at right. Credit: NASA/Paolo Nespoli

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2011 was a picturesque year! The year brought us new discoveries, a new supernova, the end of an era in human spaceflight, and much more. Here’s a look back at some of the best images we’ve posted on Universe Today in 2011, listed in no particular order:

Above, is one of the first-ever images of a space shuttle docked to the International Space Station. The images were taken by ESA astronaut Paolo Nespoli on May 23, 2011 through a window inside the Soyuz TMA-20 vehicle as he and two crewmates were departing the ISS for their return trip to Earth. See the entire gallery of images of this event here.


Astrophoto: Supernova PTF11kly in M101 by Rick Johnson
Supernova PTF11kly in M101. Credit: Rick Johnson

A new supernova showed up in 2011 in the Pinwheel galaxy, and skywatchers around the world tried to capture it. Amateur astronomer Rick Johnson submitted this image for our new “Astrophoto” feature this year on Universe Today. Called the SN PTF11kly, the new Type Ia supernova was spotted by Caltech’s Palomar Transient Factory (PTF) survey in the M101, and is located 21 million light years away. You can see the supernova marked in the southern part of the galaxy.

Atlantis launches one last time on July 8, 2011. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

2011 saw the end of an era: the space shuttle program is now history. Universe Today photographer Alan Walters captured this stunning view of the last shuttle launch ever. Read our articles about the final launch and landing of the space shuttle era.

A portion of the Lagoon nebula imaged by the Gemini South telescope with the Gemini Multi-Object Spectrograph. Credit: Julia I. Arias and Rodolfo H. Barbá Departamento de Física, Universidad de La Serena (Chile), and ICATE-CONICET (Argentina).

A gorgeous new look at the “Southern Cliff” in the Lagoon Nebula from the Gemini South Observatory.

Saturns moons and rings, in color. Credit: NASA / JPL / SSI. Edited by Jason Major. Click for larger version.

The Cassini spacecraft continues to crank out spectacular images, and this stunning image of a “flash mob” of moons strung along Saturn’s rings is just an example.

ATV2 (Johannes Kepler) as it departs the ISS against the backdrop of Earth. Credit: NASA/Ron Garan

Real image or from a movie? The ATV-2 Johannes Kepler looks like an X-Wing fighter from Star Wars as it departed from the International Space Station.

A new image from the HiRISE camera on the Mars Reconnaissance Orbiter shows an ethereal landscape near Mars north pole. Credit: NASA/HiRISE team

Incredible landscapes are specialties of the HiRISE camera on the Mars Reconnaissance Orbiter, and this observation shows dune gullies laced with beautiful swirls of tracks left by dust devils. Just like on Earth, dust devils move across the Martian surface and expose the underlying darker material, creating a striking view.

A new image from ESO of the reflection nebula Messier 78. Credit: ESO and Igor Chekalin

Here’s a “Hidden Treasure” from the European Southern Observatory, from the astrophotography competition where amateurs create images from unused ESO data. In this new image of Messier 78, brilliant starlight ricochets off dust particles in the nebula, illuminating it with scattered blue light and creating what is called a reflection nebula.

Series of transits taken on May 20, 22 and 23, 2011 from different areas of France, showing variations of orientation of the ISS with Endeavour docked. On May 23, the ISS passes besides a sunspot which is larger than the Earth. Credit: Thierry Legault

This series of images is just an example of the great work by award-winning French astrophotographer Thierry Legault. During shuttle Endeavour’s final mission, Legault traveled through Germany, France and Spain to find clear skies and good seeing to capture the shuttle’s voyage to the International Space Station. See more incredible images here.

The 'Rock Garden' at the rim of Endeavour Crater on Mars as seen by the Opportunity rover. Credit: NASA/JPL/Caltech, color by Stu Atkinson

The Opportunity rover is now exploring Endeavour Crater and this color view of shows a stunning landscape on Mars. This view of a Red Planet “rock garden” is the colorized handiwork of Stu Atkinson, a member of Unmanned Spaceflight and author of the Road to Endeavour blog. This is actually an ejecta field of rocks thrown about after the impact that created this huge crater, and has been an exciting region for the MER scientists to explore.

Dense filaments of gas in the IC5146 interstellar cloud. This image was taken by ESA’s Herschel space observatory at infrared wavelengths 70, 250 and 500 microns. Stars are forming along these filaments. Credits: ESA/Herschel/SPIRE/PACS/D. Arzoumanian (CEA Saclay) for the “Gould Belt survey” Key Programme Consortium.

Its true there is no sound in empty interstellar space, but the Herschel space observatory has observed the cosmic equivalent of sonic booms. Filaments like this have been sighted before by other infrared satellites, but they have never been seen clearly enough to have their widths measure.

A huge and spectacular prominence eruption on the Sun, June 7, 2011. Credit: NASA/Solar Dynamics Observatory

On June 7, 2011 an amazingly massive and spectacular event took place on the Sun: a huge prominence eruption, marked by a solar flare and release of energetic particles. It was an event that was heretofore unseen on the Sun, but the Solar Dynamics Observatory saw it all.

A view of a recent aurora from the ISS. Credit: NASA

With the Sun’s activities ramping up, we saw more aurorae. What better place to see them than from the International Space Station? This view taken by astroanut Mike Fossum shows a stunning aurora, with two Russian vehicles docked to the station in the foreground.

The star cluster NGC 2100 in the Large Magellanic Cloud. Credit: ESO

A brilliant cluster of stars in the Large Magellanic Cloud, open cluster NGC 2100 shines brightly, competing with the nearby Tarantula Nebula for bragging rights in this image from ESO’s New Technology Telescope (NTT).

Martian Vista from Opportunity nearing Endeavour Crater on Sol 2678 - August 2011 Large ejecta blocks from the nearby, small Odyssey crater are visible in the middle, foreground and are Opportunity’s next science target in this photo mosaic taken 2 martian days ago on Sol 2678 (Aug. 6). Opportunity is now less than 400 feet from the foothills of Endeavour Crater and will soon make first landfall at Spirit Point - off to the left. At Endeavour, Opportunity will investigate the oldest minerals deposits she has ever visited from billions of years ago and which may hold clues to environments that were potentially habitable for microbial life. This photo mosaic shows portions of the discontinuous crater rim – Cape Tribulation at right. Mosaic Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Kenneth Kremer

Universe Today’s Ken Kremer helped bring this stunning image of the hills around Endeavour Crater to light, as the Opportunity Rover headed towards the crater in August.

Astrophoto: Moon Covers Venus by Kevin Jung
Moon Covers Venus. Credit: Kevin Jung

Another amateur astrophoto shows an occultation of Venus by the Moon, taken by Kevin Jung.

X-ray Image of Tycho's Supernova Remnant. (NASA/CXC/Rutgers/K.Eriksen et al.)

The Chandra X-Ray Observatory took a brand new, deep look inside the Tycho Supernova Remnant, providing a nearly three-dimensional view of the iconic space object.

Comet Lovejoy by Barry Armstead
Comet Lovejoy. Image Credit: Barry Armstead

And just the past several days southern skywatchers have been treated to the beautiful sights of Comet Lovejoy — which was also seen from the International Space Station. Go take a look!

These are just a sampling of the great images we’ve seen in 2011. Here’s to more great views in 2012!

Posted on by Nancy Atkinson

As Seen From Space: Volcanic Eruption Creates New Island in the Red Sea

The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this high-resolution, natural-color images on December 23, 2011 showing an island being formed in the Red Sea. Credit: NASA

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Looking for some new lake-front property? Here’s the newest available on the planet. Volcanic activity in the Red Sea that started in mid-December has created what looks like a new island. The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured a high-resolution, natural-color image on December 23, 2011 showing an apparent island where previously there was none. Here, a thick plume of volcanic ash still rises from the new island.

See below for an image from 2007 of the same region.

Satellite image of the same region from October 24, 2007. Credit: NASA

According to the NASA Earth Observatory website, the volcanic activity occurred along the Zubair Group, a collection of small islands off the west coast of Yemen. The islands poke above the sea surface, rising from a shield volcano. This region is part of the Red Sea Rift where the African and Arabian tectonic plates pull apart and new ocean crust regularly forms.

According to news reports, fishermen witnessed lava fountains reaching up to 30 meters (90 feet) tall on December 19.

Source: NASA Earth Observatory

Posted on by Ray Sanders

Dr. Alan Stern Answers Your Questions!

Dr. Alan Stern preparing for a high-altitude test flight in A two-seater, NASA WB-57 aircraft. Photo Credit: SOuthwest Research Institute.

[/caption]Some of you may know, we recently launched a new “Ask” feature here at Universe Today. Our inaugural launch features Dr. Alan Stern, Principal Investigator for the New Horizons mission to Pluto and the Kuiper Belt. We collected your questions in our initial post and passed them along to Dr. Stern who graciously took the time to answer them.

Here are the questions picked by you, the readers, and Dr. Stern’s responses. We’d like to thank our readers for making this kick-off a success, as well as Dr. Stern for his participation.


1.) Many sci-fi authors have dreamed of putting some sort of telescope on the surface of Pluto to take advantage of the relative darkness and extreme cold encountered on this distant dwarf planet. How feasible would it be, judging from what we’re learning from the New Horizons expedition, to actually land a spacecraft, or a telescope, on Pluto’s surface? If such a telescope where deployed, how much more effective, if at all, could it be than an instrument like the JWST?

Alan Stern:“Space astronomy has revolutionized the way we look at the universe and is fundamental to modern astrophysics.” There are benefits to getting telescopes out of the atmosphere, and even benefits to getting out of Earth orbit, as in the case of Kepler and someday maybe JWST.

With regard to taking advantage of Pluto’s cold temperature – we’ve gotten really good at cooling down space telescopes. “There would be a benefit to placing a radio telescope on the far side of the Moon, but there’s no real practical reasons to place a telescope on Pluto—particularly given the cost of getting there, other than it being cool.”

2.) Kuiper objects differentiate strongly in color suggesting compositional or perhaps formation differences. Interestingly the color distribution correlates with the two different cold and hot Kuiper populations. Assuming the spectral analysis capability of New Horizon works for identifying the follow up Kuiper objects beyond Pluto-Charon, and given the putative possibility of choosing between several such targets, what type of target would the mission aim for? Would it try to cover as much diversity of objects as possible or is there a certain class of objects that could be important to concentrate on?

A.S: “We have to find Kuiper belt objects within our spacecraft’s fuel supply.” Stern elaborated, stating, “Predictions from our computer models tell us to expect to be able to have perhaps six possible candidates, to choose from, but so far we’ve just begun to search for these and though we’re finding KBOs, none we’ve found are yet are within the fuel supply.”

Stern also added, “Keep in mind our search for candidates isn’t easy – these are 27th magnitude objects which are roughly 50,000 times fainter than Pluto. What we’ll use to select between candidates once we have them are color, orbits, moons, rotational speeds – basically what combination of properties give us the most science for our fuel budget. The longer we wait after the Pluto flyby in July 2015 to make a decision, the more fuel will be consumed, so the “sweet spot” would be to have preliminary candidates in early 2015.”
(UT Note: New Horizons will perform its Pluto flyby in mid-2015 ).

3.) Given the limited funds available, Which do you recommend (Europa or Enceladus) as a suitable target for a mission in the 2025 time-frame in terms of value for money, scientific return, and practicality, and what kind of mission do you propose (lander vs. orbiter) ?

A.S: “Every scientist has their own judgment of what would make a good outer system flagship mission, or the best world to perform a series of missions that would equal a flagship mission.” Dr. Stern’s opinion is to explore Titan first, with Enceladus as a secondary target of that mission and Europa last, stating “Titan is the belle of the ball”, citing Titan’s active liquid cycle and thick atmosphere. Stern also added that he believes a mission to Titan would provide the most science per budget dollar.

4.) Four of the craft escaping the Solar System – Pioneers 10 & 11 and Voyagers 1 & 2 – have on board some sort of “message” to any possible extraterrestrials in the unlikely event they find it. Why was not some sort of message like that included on New Horizons, which may be the last (in our lifetimes) craft to also escape the Solar System?

A.S “There are several mementos onboard New Horizons, but no Voyager-like message.” Dr. Stern discussed a promise he made to his team that New Horizons would not be canceled and that he wanted his team focused on the science of the mission. Stern also pointed out that the process of deciding what to place on the Voyager plaques became mired in political correctness, (should the humans have been clothed? What cultures and races should be represented, etc.)

By separating the “icing from the cake”. Stern and his team have been able to concentrate on their main objective—to execute the New Horizons mission for about twenty cents on the dollar, as compared to the Voyager missions. Stern concluded with, “I’m proud that we got this done and that New Horizons is operating perfectly now way out there between Uranus and Neptune and flying almost a million kilometers per day toward the Pluto system.”

5.) Are any present or foreseeable technologies being considered for exploring the depths of our four “gas giant” planets?

A.S “There are no serious proposals to put a probe into one of the giant planets now, or even any call for such in the recent decadal survey for planetary missions. Keep in mind, though, that the Juno mission (now en route to Jupiter ) will use powerful remote sensing techniques to probe Jupiter from orbit around it to greater depths than the Galileo probe (which actually entered Jupiter’s atmosphere).”

6.) Why was it considered “urgent” to get to Pluto before the atmosphere refroze?

A.S “We have three “Group 1″ objectives for New Horizons. Map the surface, map the composition, and assay the atmosphere.” Stern referred to the objectives as a “three legged stool” in that no one objective could be omitted and still justify the mission, adding “so we need to accomplish that.. we need to get there before the atmosphere collapses”. Stern also referred to Pluto’s atmosphere as “very different from any other planet yet studied”, hence its inclusion as one of the three “Group 1” objectives.

7.) The Dawn mission to Vesta has shown us a body that was much less round than expected. Do you think it is possible that New Horizons will surprise us about Pluto, to the same degree? Please compare the expectations of the New Horizons fly by, to the early images of Vesta from Dawn.

A.S “With New Horizons being the first mission to Pluto, we will be surprised—after all, we’re always surprised on first reconnaissance flybys”. Stern added, “With Mariner 10, we discovered Mercury was all core, with Voyager we discovered volcanos and geysers across the outer solar system, and of course we were surprised when craters and river valleys were discovered by early Mars probes.”

Regarding Pluto, Stern stated “Pluto is the first discovered and soon to be reconnoitered of the most plentiful class of planets, while I’m not big on making predictions, I will say that what we will find will certainly be, well, wonderful.”

9.) Can new horizons now take more detailed photos of Pluto than HST? If not, when does it get close enough?

A.S “Great question! We actually thought about that a lot when designing New Horizons. One of our instruments, LORRI (Long-Range Reconnaissance Imager – http://pluto.jhuapl.edu/spacecraft/sciencePay.html) will provide us with views better than HST around April of 2015, and we expect to have about twenty weeks (10 weeks before, 10 weeks after the Pluto flyby) when we “own” the Pluto system — and I can guarantee the best images we hope to make should be as good as Landsat images of Earth!”

That wraps up our interview with Dr. Alan Stern. Once again, we at Universe Today would like to thank Dr. Stern for his gracious participation. If you’d like to learn more about the New Horizons mission to Pluto and The Kuiper Belt, visit: http://pluto.jhuapl.edu/index.php

Next month, we’ll be having an “Ask an Astronaut” feature with Mike Fossum, Commander of Expedition 29 on the International Space Station. Stay tuned!