Posted on by Nancy Atkinson

No, NASA is Not Predicting We’ll be Destroyed by Aliens

Movie poster from 'Aliens Attack," via getfilm.co.uk

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There were some interesting, if not shocking headlines this week regarding a study supposedly put out by NASA, with the articles saying that aliens might come and destroy Earth because of our global warming problems. Headlines such as:

Aliens Could Attack Earth to End Global Warming, NASA Frets (Fox News)

Global Warming Could Provoke Alien Attack: NASA (International Business Times)

NASA: Aliens might destroy us because of our gases, (CNET)

and this one, which started the whole thing:

Aliens may destroy humanity to protect other civilizations, say scientists (The Guardian — The subheadline for this article originally said it was a NASA report, but has since been amended)

While the report is real, and one of the authors was a NASA intern, NASA in no way sponsored or endorsed the article, which was basically an enjoyable thought-experiment, and was titled: “Would Contact with Extraterrestrials Benefit or Harm Humanity? A Scenario Analysis.”

(Available as pdf here.)

By comparing the title of the paper to the splashy headlines, as you can imagine, most of the news articles don’t accurately describe the paper’s content and conclusions — over-blowing just a tad the part about alien invasions — and the headlines portray NASA as being behind the paper and the research. But NASA didn’t really have a thing to do with the very speculative, if not fun paper.

After receiving some razzing from Keith Cowing at NASAWatch about how NASA just quietly allows the tabloids to determine the space agency’s public image, NASA used their social media presence to try and rectify the misconceptions. This morning @NASA twittered: Yes, @drudge & @guardiannews are mistaken about an “alien” report. It’s not NASA research. Ask the report’s author http://go.nasa.gov/nRI8Lf

Here’s the abstract from the paper: “While humanity has not yet observed any extraterrestrial intelligence (ETI), contact with ETI remains possible. Contact could occur through a broad range of scenarios that have varying consequences for humanity. However, many discussions of this question assume that contact will follow a particular scenario that derives from the hopes and fears of the author. In this paper, we analyze a broad range of contact scenarios in terms of whether contact with ETI would benefit or harm humanity. This type of broad analysis can help us prepare for actual contact with ETI even if the details of contact do not fully resemble any specific scenario.”

The paper was written by Seth Baum, Jacob Haqq-Misra, and Shawn Domagal-Goldman. Domagal-Goldman is a post-doc student working at NASA. Probably flustered, bewildered and a bit embarrassed, he wrote on NASA’s PaleBlue blog today to try and explain how this all got out of hand:

“So here’s the thing. This isn’t a “NASA report.” It’s not work funded by NASA, nor is it work supported by NASA in other ways. It was just a fun paper written by a few friends, one of whom happens to have a NASA affiliation.

A while ago, a couple good friends of mine (Seth Baum and Jacob Haqq-Misra) approached me about a paper they were writing, and asked if I wanted to join them on it. The paper was a review of all the different proposed situations for contact with an alien civilization. I didn’t think this was particularly important. After all, I consider the likelihood of contact with an alien civilization to be low. It certainly wasn’t urgent, as I don’t expect this to happen anytime soon. But… it sounded like fun and I decided to join in on it. So we wrote the paper, but I have to admit that Seth and Jacob put in the vast majority of the work on it. One of the scenarios we considered in the review was the possibility that an alien civilization would contact us because they were concerned about the exponential growth of our civilization, as evidenced by climate change. This isn’t an entirely new idea; remember, this was a review effort. Indeed, Keanu Reaves recently played a similar alien in the movie “The Day the Earth Stood Still.” There were lots of other ideas we reviewed, but this was probably the most provocative.

Well, the paper came out a couple months ago. Today, for some reason, The Guardian picked it up, publishing an article about it with the following title: “Aliens may destroy humanity to protect other civilizations, say scientist: Rising greenhouse emissions may tip off aliens that we are a rapidly expanding threat, warns a report for NASA.” That then was picked up by The Drudge Report, with this headline:

“NASA REPORT: Aliens may destroy humanity to protect other civilizations…”

UH OH. Now that is a bit problematic.

So here’s the deal, folks. Yes, I work at NASA. It’s also true that I work at NASA Headquarters. But I am not a civil servant… just a lowly postdoc. More importantly, this paper has nothing to do with my work there. I wasn’t funded for it, nor did I spend any of my time at work or any resources provided to me by NASA to participate in this effort. There are at least a hundred more important and urgent things to be done on any given work day than speculate on the different scenarios for contact with alien civilizations… However, in my free time (what precious little I have), I didn’t mind working on stuff like this every once in a while. Why? Well, because I’m a geek and stuff like this is fun to think about. Unfortunately, there is not enough time for fun. Indeed, I felt guilty at times because this has led to a lack of effort on my part in my interactions with Seth and Jacob. Beyond adding some comments here or there, I did very little for the paper.

But I do admit to making a horrible mistake. It was an honest one, and a naive one… but it was a mistake nonetheless. I should not have listed my affiliation as “NASA Headquarters.” I did so because that is my current academic affiliation. But when I did so I did not realize the full implications that has. I’m deeply sorry for that, but it was a mistake born out of carelessness and inexperience and nothing more. I will do what I can to rectify this, including distributing this post to the Guardian, Drudge, and NASA Watch. Please help me spread this post to the other places you may see the article inaccurately attributed to NASA.

One last thing: I stand by the analysis in the paper. Is such a scenario likely? I don’t think so. But it’s one of a myriad of possible (albeit unlikely) scenarios, and the point of the paper was to review them. But remember – and this is key – it’s me standing for the paper… not the full weight of the National Aeronautics and Space Administration. For anything I have done to mis-convey that to those covering this story, to the public, or to the fine employees of NASA, I apologize.”

Posted on by Ken Kremer

GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad

GRAIL Lunar Twins hoisted to top of Launch Pad 17B at Cape Canaveral. NASA's twin Gravity Recovery and Interior Laboratory (GRAIL) spacecraft are lifted to the top of their launch pad at Space Launch Complex 17B at Cape Canaveral Air Force Station in Florida and were mated to their Delta II Heavy Booster Rocket. They are wrapped in plastic to prevent contamination outside the clean room. Launch is scheduled for Sept. 8. Credit: NASA/Kim Shiflett

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With blastoff just 2 ½ weeks away, NASA’s GRAIL lunar twins completed a major milestone towards launch today (Aug. 18) when they were mated to the top of the Delta II Heavy rocket that will boost them to the moon. Launch is slated for Sept. 8 at 8:37 a.m. EDT.

This morning the tightly wrapped $496 Million duo took their last trip on Earth before beginning their nearly four month journey to the Moon. GRAIL A & GRAIL B were carefully transported 15 miles (25 km) from the clean room processing facility at the Astrotech Space Operation’s payload processing facility in Titusville, Fla to Space Launch Complex 17B (SLC-17B) at Cape Canaveral Air Force Station in Florida.

“The GRAIL spacecraft transportation convoy to SLC-17B departed Astrotech at 11:55 p.m. EDT on Wednesday, Aug. 17, “ said Tim Dunn, NASA’s Delta II Launch Director in an interview with Universe Today. “The spacecraft, inside the handling can, arrived at the launch pad, SLC-17B, at 4:00 a.m. this morning.”

“The spacecraft was then hoisted by the Mobile Service Tower crane onto the Delta II launch vehicle and the spacecraft mate was complete at 9:30 a.m.”

Crane lifts GRAIL A & B to the top of the Mobile Service Tower on Aug. 18. The probes are wrapped in protective plastic sheeting inside the handling can. Credit: NASA/Kim Shiflett

Technicians joined the nearly identical and side by side mounted spacecraft onto the top of the guidance section adapter of the Delta’s second stage. The Delta II was built by United Launch Alliance (ULA).

“Tomorrow, the GRAIL spacecraft team will perform functional testing on both the GRAIL A and GRAIL B spacecraft,” Dunn told me.

“The next major milestone will be performance of the Integrated Systems Test (IST) on Monday, (8/22/11).

“Today’s spacecraft mate operation was flawlessly executed by the combined ULA and NASA Delta II Team,” said Dunn.

These tests will confirm that the spacecraft is healthy after the fueling and transport operations. After further reviews of the rocket and spacecraft systems the GRAIL team will install the payload fairing around the lunar probes.

NASA’s twin GRAIL Science Probes ready for Lunar Expedition
GRAIL B (left) and GRAIL A (right) spacecraft are mounted side by side on top of a payload adapter inside the clean room at Astrotech Space Operations facility. The spacecraft await lunar launch on Sept. 8, 2011. Credit: Ken Kremer

NASA’s dynamic duo will orbit the moon to determine the structure of the lunar interior from crust to core and to advance understanding of the thermal evolution of the moon.

“We are about to finish one chapter in the GRAIL story and open another,” said Maria Zuber, GRAIL’s principal investigator, based at the Massachusetts Institute of Technology in Cambridge in a statement. “Let me assure you this one is a real page-turner. GRAIL will rewrite the book on the formation of the moon and the beginning of us.”

The GRAIL launch will be the last for a Delta II in Florida.

GRAIL A & B lunar twins arrive at Pad 17B. Credit: NASA/Kim Shiflett

Technicians hoist GRAIL A & B lunar twins inside the handling can at Pad 17B. Credit: NASA/Kim Shiflett

Read my prior features about GRAIL
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

Posted on by Tammy Plotner

Cosmic Collisions Could Eject Habitable Planets

One of 42 new proplyds discovered in the Orion Nebula, 177-341E is one of the bright proplyds that lies relatively close to the nebula’s brightest star, Theta 1 Orionis C. The tadpole-shaped tail is actually a jet of matter flowing away from the excited cusp. Credit:NASA/ESA and L. Ricci (ESO)

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When it comes to solar systems, chances are good that we’re a lot more special than we thought. According to a German-British team led by Professor Pavel Kroupa of the University of Bonn, our orderly neighborhood of varied planet sizes quietly orbiting in a nearly circular path isn’t a standard affair. Their new models show that habitable planets might just get ejected in a violent scenario where forming solar systems mean highly inclined orbits where hot Jupiters rule.

Some 4600 million years ago, our local planetary system was surmised to have evolved from a blanket of dust surrounding a rather ordinary star. Its planets orbited the same direction as the solar spin and lined up neatly on a plane fairly close to the solar equator. We were good little children… But maybe other systems aren’t so hospitable. There could be systems where the planets cruise around in the opposite direction of their host star’s spin – and have highly inclined orbits. What could cause one protoplanetary disk to take on quiet properties while another is more radical? Try a cosmic crash.

This new study focuses on the theory of a protoplanetary disk colliding with another cloud of material… not unrealistic thinking since most stars form within a cluster. The results could mean the inclusion of up to thirty times the mass of Jupiter. This added “weight” of extra gas and dust could add a tilt to a forming system. Team member Dr Ingo Thies, also of the University of Bonn, has carried out computer simulations to test the new idea. What he has found is that adding extra material can not only incline a forming disk, but cause a reverse spin as well. It may even speed up the planetary formation, leaving the rogues in retrograde orbits. This inhospitable scenario means that smaller planets get ejected systematically, leaving only hot Jupiters to hug in close to the parent star. Thankfully our path was a bit less disturbing.

Says Dr Thies: “Like most stars, the Sun formed in a cluster, so probably did encounter another cloud of gas and dust soon after it formed. Fortunately for us, this was a gentle collision, so the effect on the disk that eventually became the planets was relatively benign. If things had been different, an unstable planetary system may have formed around the Sun, the Earth might have been ejected from the Solar System and none of us would be here to talk about it.”

Professor Kroupa sees the model as a big step forward. “We may be on the cusp of solving the mystery of why some planetary systems are tilted so much and lack places where life could thrive. The model helps to explain why our Solar System looks the way it does, with the Earth in a stable orbit and larger planets further out. Our work should help other scientists refine their search for life elsewhere in the Universe.”

Original News Source: Royal Astronomical Society News.

Posted on by Tammy Plotner

Rewriting Lunar History

NASA Science News Lunar Image Credt: Sylvain Weiller

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We thought we knew everything there was to know about our Moon, but new investigations into its volcanic origins are causing scientists to take another look at how our nearest astronomical neighbor formed – and its age. If you like a little lunacy in your life, then step inside and read more…

A team of scientists led by Carnegie’s Erik Hauri have been busy studying seven tiny Apollo 17 return samples with a a state-of-the-art NanoSIMS 50L ion microprobe. These little pieces of lunar “evidence” are fragments of lunar magma which contain crystals called “melt inclusions”. High in titanium content, these crystals were once a part of volcanic glass beads ejected in explosive volcanic eruptions. The cool part is these melt inclusions coughed up from the lunar depths eons ago yielded a discovery – the magma trapped within crystals show a hundred times more water than once believed.

“In contrast to most volcanic deposits, the melt inclusions are encased in crystals that prevent the escape of water and other volatiles during eruption. These samples provide the best window we have to the amount of water in the interior of the Moon,” said James Van Orman of Case Western Reserve University, a member of the science team. The paper’s authors are Hauri; Thomas Weinreich, Alberto Saal and Malcolm Rutherford from Brown University; and Van Orman.

As meteorite fans well know, water content is everything and the inner Solar System was nearly devoid of it and other volatile elements during early formation. Past lunar studies show an even lower content, supporting the giant impactor theory – a theory which could very well need to be reconsidered. New findings also point to the need for more sample returns from other Solar System bodies as well.

“Water plays a critical role in determining the tectonic behavior of planetary surfaces, the melting point of planetary interiors, and the location and eruptive style of planetary volcanoes,” said Hauri, a geochemist with Carnegie’s Department of Terrestrial Magnetism (DTM). “We can conceive of no sample type that would be more important to return to Earth than these volcanic glass samples ejected by explosive volcanism, which have been mapped not only on the Moon but throughout the inner Solar System.”

But this isn’t a first for Saal. Three years ago the same team reported the first evidence for the presence of water in lunar volcanic glasses. Using modeling, they were able to theorize how much water was contained within the magma before eruption. From those results, Weinreich, a Brown University undergraduate, found the melt inclusions. This permitted the team to measure the pre-eruption concentration of water in the magma and estimate the amount of water in the Moon’s interior.

“The bottom line,” said Saal, “is that in 2008, we said the primitive water content in the lunar magmas should be similar to the water content in lavas coming from the Earth’s depleted upper mantle. Now, we have proven that is indeed the case.”

Of course, this could mean changing scientific thought on where lunar pole ice deposits originated, too. Current theory suggests they are the product of comets and meteoroid impacts – but perhaps they also could be magma related. It’s a fascinating study which could also help us to understand the properties of other planetary bodies.

But the magma doesn’t stop there…

According to new research from a team that includes Carnegie’s Richard Carlson and former-Carnegie fellow Maud Boyet, magma samples might be revealing a younger Moon, too. Building on the giant impactor theory, samples of a rock type called ferroan anorthosite, or FAN, are being examined. Believed to be the oldest of the Moon’s crustal rocks, FAN could be as old as 4.36 billion years – a figure much younger than previous lunar estimates. Using isotopes of the elements lead and neodymium, the team analyzed the samples for consistent ages from multiple isotope dating techniques.

“The extraordinarily young age of this lunar sample either means that the Moon solidified significantly later than previous estimates, or that we need to change our entire understanding of the Moon’s geochemical history,” Carlson said.

What does all this mean? Thanks to our understanding of the oldest terrestrial minerals, such as zircons from western Australia, we can derive the Moon’s crust may have evolved at the same time as Earth’s… a time which could date back to a giant impact. “The Earth’s Moon is the archetypical example of this type of differentiation.” says the team. “Evidence for a lunar magma ocean is derived largely from the widespread distribution, compositional and mineralogical characteristics, and ancient ages inferred for the ferroan anorthosite (FAN) suite of lunar crustal rocks.”

The next time you observe the Moon, remember… she’s a bit younger than you thought!

Original News Source: Carnegie Science News and Science Daily.

Posted on by Nancy Atkinson

Enhanced Technique for Tracking Solar Storms All the Way From Sun to Earth

Heliophysicists announced today that new data processing techniques have enabled them to track solar storms from their origin in the Sun’s fiery corona all the way to impact with the Earth in unprecedented detail. “For the first time we’ve been able to image a coronal mass ejection all the way through its entire life cycle, from inside the solar corona until it reaches Earth,” said Craig DeForest, speaking at a NASA press briefing. DeForest is the lead author paper published in the Astrophysical Journal.
Continue reading “Enhanced Technique for Tracking Solar Storms All the Way From Sun to Earth”

Posted on by Jason Major

What Lies Beneath

Collapse pit on Mars reveals opening to an underground cave

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What would make a great home for a giant Martian ant lion? I’d have to say this pit, imaged by the HiRISE camera aboard the Mars Reconnaissance Orbiter!

Earlier this year a crater was spotted with a dark spot at its center. When the team took a closer look with the high-resolution camera they saw that the spot is actually a 35-meter (115-foot) -wide skylight that opens into an underground cavern. The cavern is most likely a section of an empty lava tube, leftovers from ancient Martian volcanic activity.

Detail of the skylight

Based on the shadows it’s estimated that the pit is about 20 meters (65 feet) deep. But, how much of that is material piled up on the floor of the cavern from the surrounding crater itself? And what caused the crater to form in the first place? These are questions that remain to be answered.

The HiRISE image itself is false-color, the hues denoting the texture and composition of the surface material and not the actual color as would be seen in visible light.

As far as a giant Martian ant lion… well, unless there are some giant Martian ants around for it to snack on, I’m going to assume there’s nobody home!

Image credit: NASA / JPL / University of Arizona.

Posted on by Nancy Atkinson

Q&A with Brian Cox, part 3: ‘Wonders’ and Popularizing Science

Brian Cox, during the filming of one of his television series. Image courtesy Brian Cox.

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Professor Brian Cox is the Chair in Particle Physics at the University of Manchester, and works on the ATLAS experiment (A Toroidal LHC ApparatuS) at the Large Hadron Collider at CERN. But he’s also active in the popularization of science, specifically with his new television series and companion book, Wonders of the Universe. Universe Today had the chance to talk with Cox, and on Tuesday he told us about the recent advances in particle physics, and on Wednesday we asked him about his favorite space missions and his hopes for the future of science. Today, Cox tells us about his role in sharing science with the public, and talks about his new book and filming the television series.

For a chance to win a copy of the “Wonders of the Universe” book, see our contest post.

Universe Today: You’ve been really busy, with writing books, filming two television series and DVDs. Do you have time to do research in particle physics as well?

Brian Cox: Well, I must say I’ve been a bit restricted over the past couple of years in how much research I’ve done. I’m still attached to the experiment at CERN, but it’s just one of those things! In many ways it’s a regret because I would love to be there full time at the moment because it is so genuinely exciting. We’re making serious progress and we’re going to discover something like the Higgs particle, I would guess, within the next 12 months.

But then again, you can’t do everything and it’s a common regret amongst academics, actually, that that as they get older, they get taken away from the cutting-edge of research if they’re not careful! But I suppose it is not a bad way to be taken away from the cutting edge, to make TV programs and push this agenda that I have to make science more relevant and popular.

UT : Absolutely! Outreach and educating the public is very important, especially in the area of research you are in. I would guess a majority of the general public are not exceptionally well-versed in particle physics.

Cox: Well, Carl Sagan is a great hero of mine and he used to say it is really about teaching people the scientific method – or actually providing the understanding and appreciation of what science is. We look at these questions, such as what happened just after the Universe began, or why the particles in the Universe have mass – they are very esoteric questions.

But the fact that we’ve been able build some reasonable theories about the how old universe is — and we have a number 13.73 ± 0.12 billion years old, quite a precise number — so the question of showing how you get to those quite remarkable conclusions is very important. When you look at what we might call more socially-important subjects – for example how to respond to global warming, or what should be our policy for vaccinating the population against disease, or how should we produce energy in the future, and if you understand what the scientific method is and that it is apolitical and a-religious and it is a-everything and there is no agenda there, and is just pure way of looking of universe, that’s the important thing for society to understand.

UT : Please tell us about your new book, “Wonders of the Universe.”

“Wonders of the Universe” is a book about the television series. Traditionally these books are quite ‘coffee table,’ image-heavy books. The filming of the series took longer than we anticipated, so actually the book got written relatively quickly because I had time to sit down and really just write about the physics. Although it is tied with the television series, it does go quite a lot deeper in many areas. I’m quite pleased about that. So it’s more than just snapshots of my view of the physics of the TV series.

I should say also, some parts of it are in the form of a diary of what it was like filming the TV series. There are always some things you do and places you go that have quite an impact on you. And I tend to take a lot of pictures so many of the photographs in the book are mine. So, it is written on two levels: It is a much deeper view of the physics of the television series, but secondly it is a diary of the experience of filming the series and going to those places.

(Editor’s note, Cox is also just finishing a book on quantum mechanics, so look for that in the near future)

Brian Cox, while filming a BBC series in the Sahara. Image courtesy Brian Cox

UT : What were some of your best experiences while filming ‘Wonders?’

Cox: One thing that, well, I wouldn’t say enjoyed filming, because it was quite nerve-wracking – but something that really worked was the prison demolition sequence in Rio. We used it as an analog for a collapsing star, a star at the end of its life that has run out of fuel and it collapses under its own gravity. It does that in a matter of seconds, on the same timescale as a building collapses when you detonate it.

Wandering around a building that is full of live dynamite and explosives is not very relaxing! It was all wired up and ready to go. But when we blew it up, and I thought it really worked well, and I enjoyed it a lot, actually as a television piece.

The ambition of the series is to try and get away from using too many graphics, if possible. You obviously have to use some graphics because we are talking about quite esoteric concepts, but we tried to put these things ‘on Earth’, by using real physical things to talk about the processes. What we did, we went inwards into the prison and at each layer we said, here’s where the hydrogen fuses to helium, and here’s the shell where helium goes to carbon and oxygen, and another shell all the way down to iron at the center of the stars. That’s the way stars are built, so we used this layered prison to illustrate that and then collapse it. That’s a good example of what the ambition of the series was.

UT : You’ve been called a rock star in the physics and astronomy field but in actuality you did play in a rock band before returning to science. What prompted that shift in your career?

Cox: I always wanted to be a physicist or astronomer from as far back as I can remember, that was always my thing when I was growing up. I got distracted when I was in my teens, or interested I should say, in music and being in a band. The opportunity came to join a band that was formed by an ex-member of Thin Lizard, a big rock band in the UK, and the States as well, so I did that. We made two albums; we toured with lots of people. That band split up and I went to university and then joined another band as a side line, and that band got successful as well. That was two accidents, really! It was a temporary detour rather than a switch, because I always wanted to do physics.

UT : Thanks for taking the time to talk with us on Universe Today – we appreciate all the work you do in making science more accessible so everyone can better appreciate and understand how it impacts our lives.

Cox: Thank you, I appreciate it!

Find out more about Brian Cox at his website, Apollo’s Children

Posted on by Ken Kremer

3 D Alien Snowman Graces Vesta

3D Snowman craters and Vesta’s Equatorial Region from Dawn. This anaglyph image of Vesta's equator with the crater feature named “snowman” (center, right) was put together from two clear filter images, taken on July 24, 2011 by the framing camera instrument aboard NASA's Dawn spacecraft. The anaglyph image shows hills, troughs, ridges and steep craters. The framing camera has a resolution of about 524 yards (480 meters) per pixel. Use red-green (or red-blue) glasses to view in 3-D (left eye: red; right eye: green [or blue]). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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An alien ‘Snowman’ on an alien World.

The ‘Snowman’ is a string of three craters and is among the most strange and prominent features discovered on a newly unveiled world in our solar system – the giant asteroid Vesta. It reminded team members of the jolly wintertime figure – hence its name – and is a major stand out in the 3 D image above and more snapshots below.

Until a few weeks ago, we had no idea the ‘Snowman’ even existed or what the rest of Vesta’s surface actually looked like. That is until NASA’s Dawn spacecraft approached close enough and entered orbit around Vesta on July 16 and photographed the Snowman – and other fascinating Vestan landforms.

“Each observation of Vesta is producing incredible views more exciting than the last”, says Dawn’s Chief Engineer, Dr. Marc Rayman of the Jet Propulsion Laboratory. “Every image revealed new and exotic landscapes. Vesta is unlike any other place humankind’s robotic ambassadors have visited.”

‘Snowman’ craters on Vesta. What is the origin of the ‘Snowman’?
The science team is working to determine how the ‘Snowman’ formed. This set of three craters is nicknamed ‘Snowman” and is located in the northern hemisphere of Vesta. NASA’s Dawn spacecraft obtained this image with its framing camera on August 6, 2011. This image was taken through the framing camera’s clear filter aboard the spacecraft. The framing camera has a resolution of about 280 yards (260 meters). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The Snowman is located in the pockmarked northern hemisphere of Vesta – see the full frame image below. The largest of the three craters is some 70 km in diameter. Altogether the trio spans roughly 120 km in length. See Image at Left

“Craters, Craters, Craters Everywhere” – that’s one thing we can now say for sure about Vesta.

And soon we’ll known a lot more about the mineralogical composition of the craters and Vesta because spectral data is now pouring in from Dawn’s spectrometers.

After being captured by Vesta, the probe “used its ion propulsion system to spiral around Vesta, gradually descending to its present altitude of 2700 kilometers (1700 miles),” says Chief Engineer Rayman. “As of Aug.11, Dawn is in its survey orbit around Vesta.”

Dawn has now begun its official science campaign. Each orbit currently last 3 days.

Dawn’s scientific Principal Investigator, Prof. Chris Russell of UCLA, fondly calls Vesta the smallest terrestrial Planet !

I asked Russell for some insight into the Snowman and how it might have formed. He outlined a few possibilities in an exclusive interview with Universe Today.

“Since there are craters, craters, craters everywhere on Vesta it is always possible that these craters struck Vesta in a nearly straight line but many years apart,” Russell replied.

“On the other hand when we see ‘coincidences’ like this, we are suspicious that it is really not a coincidence at all but that an asteroid that was a gravitational agglomerate [sometimes called a rubble pile] struck Vesta.”

“As the loosely glued together material entered Vesta’s gravity field it broke apart with the parts moving on slightly different paths. Three big pieces landed close together and made adjacent craters.”

So, which scenario is it ?

“Our science team is trying to figure this out,” Russell told me.

“They are examining the rims of the three craters to see if the rims are equally degraded, suggesting they are of similar age. They will try to see if the ejecta blankets interacted or fell separately”

“The survey data are great but maybe we will have to wait until the high altitude mapping orbit [HAMO] to get higher resolution data on the rim degradation.”

Dawn will descend to the HAMO mapping orbit in September.

Close-up View of 'Snowman' craters.
This image of the set of three craters informally nicknamed ‘Snowman’ was taken by Dawn’s framing camera on July 24, 2011 after the probe entered Vesta’s orbit. Snowman is located in the northern hemisphere of Vesta. The image was taken from a distance of about of about 3,200 miles (5,200 kilometers). The framing camera was provided by Germany. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Russell and the Dawn team are elated with the fabulous results so far, some of which have been a total surprise.

How old is the Snowman ?

“We date the age of the surface by counting the number of craters on it as a function of size and compare with a model that predicts the number of craters as a function of size and as a function of time from the present,” Russell responded.

“However this does not tell us the age of a crater. If the crater destroyed all small craters in its bowland and left a smooth layer [melt] then the small crater counts would be reset at the impact.”

“Then you could deduce the age from the crater counts. You can also check the degradation of the rim but that is not as quantitative as the small crater counts in the larger crater. The team is doing these checks but they may have to defer the final answer until they obtain the much higher resolution HAMO data,” said Russell.

Besides images, the Dawn team is also collecting spectral data as Dawn flies overhead.

“The team is mapping the surface with VIR- the Visible and Infrared Mapping Spectrometer – and will have mineral data shortly !”, Russell told me.

At the moment there is a wealth of new science data arriving from space and new missions from NASA’s Planetary Science Division are liftoff soon. Juno just launched to Jupiter, GRAIL is heading to the launch pad and lunar orbit and the Curiosity Mars Science Laboratory (MSL) is undergoing final preflight testing for blastoff to the Red Planet.

Russell had these words of encouragement to say to his fellow space explorers;

“Dawn wishes GRAIL and MSL successful launches and hopes its sister missions join her in the exploration of our solar system very shortly.”

“This year has been and continues to be a great one for Planetary Science,” Russell concluded.

Detailed 'Snowman' Crater
Dawn obtained this image with its framing camera on August 6, 2011. This image was taken through the camera’s clear filter. The camera has a resolution of about 260 meters per pixel. This image shows a detailed view of three craters, informally nicknamed 'Snowman' by the camera’s team members. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dawn snaps First Full-Frame Image of Asteroid Vesta – Snowman at Left
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body. The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The framing cameras were built by the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, and the German Aerospace Center (DLR) Institute of Planetary Research, Berlin. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Read my prior features about Dawn
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Tammy Plotner

The Lyman-Alpha Blob That Ate The Universe…

Observations from ESO’s Very Large Telescope have shed light on the power source of a rare vast cloud of glowing gas in the early Universe. The observations show for the first time that this giant “Lyman-alpha blob” — one of the largest single objects known — must be powered by galaxies embedded within it. The results appear in the 18 August issue of the journal Nature. Credit: ESO

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It’s called a Lyman-alpha blob and it’s one of the largest known single objects in the Universe. It first made its presence known in the year 2000 and we know it’s located some 11.5 billion light years away. What will really get your attention is the size. LAB-1 has a diameter of about 300,000 light-years across!

Utilizing ESO’s Very Large Telescope (VLT), a team of astronomers were checking out areas of the early Universe where matter was the most dense – home to huge and very luminous rare structures called Lyman-alpha blobs. While there wasn’t anything in particular they were looking for, what they captured was something unique… evidence of polarization.

“We have shown for the first time that the glow of this enigmatic object is scattered light from brilliant galaxies hidden within, rather than the gas throughout the cloud itself shining.” explains Matthew Hayes (University of Toulouse, France), lead author of the paper.

These super-sized clouds of hydrogen gas stagger the imagination with their sheer dimensions. Some reach diameters of a few hundred thousand light-years – large enough to enfold the Milky Way three times over – and are as luminous as the most powerful galaxy we can observe. Since Lyman-alpha blobs are located so far away, we can only see them as they were when the Universe was a few billion years old, but they have a lot to teach us about their origins. Some theories suggest they shine when cool gas is pulled in by the blob’s powerful gravity and heated. Other conjectures are they are illuminated from within – lit by extreme star-forming events, supernovae or hungry black holes swallowing matter.

Thanks to these recent studies, the latest idea is the illumination comes from embedded galaxies. How do astronomers know this? By measuring whether the light from the blob was polarized. By measuring the physical processes that produced the light with sensitive equipment, researchers can gain insight from scattering or reflecting properties. However, the task hasn’t been easy considering the great distance of Lyman-alpha blobs.

“These observations couldn’t have been done without the VLT and its FORS instrument. We clearly needed two things: a telescope with at least an eight-metre mirror to collect enough light, and a camera capable of measuring the polarisation of light. Not many observatories in the world offer this combination.” adds Claudia Scarlata (University of Minnesota, USA), co-author of the paper.

According to ESO, the team observed their target for about 15 hours with the Very Large Telescope, and the light from the Lyman-alpha blob LAB-1 showed a centralized ring of polarization – but no central polarized spot. “This effect is almost impossible to produce if light simply comes from the gas falling into the blob under gravity, but it is just what is expected if the light originally comes from galaxies embedded in the central region, before being scattered by the gas. The astronomers now plan to look at more of these objects to see if the results obtained for LAB-1 are true of other blobs.”

Before they find us…

Original Story Source: ESO Science News Release.

Posted on by Nancy Atkinson

Win A Copy of Brian Cox’s New Book, “Wonders of the Universe”

This week we’ve been talking with Professor Brian Cox about physics, space exploration and the future. He also talks about all those things in his two television series, Wonders of the Solar System and Wonders of the Universe. Cox has written a companion book to Wonders of the Universe, and thanks to HarperCollins, Universe Today has four copies to give away to our readers! Just send us an email with “Brian Cox Book” in the subject line. Fraser will randomly choose four winners from the emails we receive. The contest ends at 12:00 GMT on Monday, August 22, 2011. This contest is limited to people living in North America and Europe.

For more information or to purchase the book see Amazon UK, Amazon US, or HarperCollins.

Above, see a sample of the television series.