Out in Space, Back in Time: Images from the Hubble Space Telescope

December 15, 2012 – February 10, 2013
Recurring weekly on Sunday, Wednesday, Thursday, Friday, Saturday
Event Times: Wednesdays – Sundays, 11 a.m. – 5 p.m.
Event Admission: $3; $2 seniors & youth; $8 families; Free on Wednesdays & to staff, students, children, faculty

Location: University of Oregon Museum of Natural and Cultural History
Address: 1680 E 15th Ave, Eugene, OR 97403
Phone: 541.346.5083
The Hubble Telescope takes amazingly clear pictures of objects beyond Earth—from our close neighbors in space to the distant Rose Galaxies. Discover the universe in this exhibit of photographs.

Updated Theory: A Huge Chunk Of Earth, Blasted Away In A Collision, Is Now The Moon

By Rebecca BoylePosted 10.17.2012 at 3:02 pm

New simulations of a crash between Earth and a protoplanetary sister long ago could have produced a moon that’s chemically similar to our planet, according to a new analysis. It bolsters a theory that the moon is part of Earth, and it helps settle a question about how this could be physically possible.

Since around the time of the Apollo missions, lunar scientists have theorized that our moon formed after a horrendous collision between Earth and another world, which sheared off part of this planet. But all the while, there’s been a major disconnect with reality and the satisfying theoretical explanation of this concept. If that’s what happened, then the moon should be primarily composed of material from the collider, which would have been reincarnated as our natural satellite. Theoretical models and computer simulations of this catastrophic impact say the moon would be about 20 to 40 percent Earth parts and 60 to 80 percent non-Earth parts.

But the moon and the Earth have identical isotopes of key elements, proving the moon was made from Earth’s mantle. A host of theories have tried to explain this, even one suggesting that Earth generated its own internal thermonuclear reaction and blew itself apart.

Some scientists have suggested that Earth and moon material mixed together, so the Earth also contains some foreign matter. But very recent studies cast doubt on this, too. There was another problem in that Earth-sized planets should have been spinning faster than this one did, if that model is correct. Matija Ćuk and colleagues at the SETI Institute started over, and envisioned a very fast-spinning Earth colliding with a smaller-than-Mars planet, nicknamed Theia.

In their computer simulations, which you can see in part below, it all works out. The moon can form from mostly Earth material, and a faster-spinning proto-Earth can lose some angular momentum thanks to tidal interactions with the sun, explaining its slower-than-expected speed.

In this animation, Earth and Theia are represented by the agglomerations of particles. Earth is spinning super-fast–its day is only 2.3 hours long. Theia, which has about half the mass of Mars, careens toward Earth at 44,740 MPH. It penetrates all the way to Earth’s core and excavates a massive hole in our planet, throwing material out in the process. Theia is mostly vaporized, along with part of our planet, and the iron from its core merges with Earth’s core.

Some material escapes Earth and forms a huge disk around it. The disk has almost no iron, but is made mostly of Earthly material. This would explain the moon’s composition, which very neatly matches that of Earth.

To test this hypothesis, a separate group of researchers ran further simulations with slower-moving impactors that were a little larger. This also produces a moon with the same chemical makeup as Earth’s mantle, they found. Taken together, the results suggest that our moon-formation theories may be spot on.


Thanks to Logan Ellis for sending this my way…

Hubble spots spiral galaxy that shouldn’t exist

Astronomers using the Hubble Space Telescope have discovered the oldest known spiral galaxy, a 10.7-billion-year-old anomaly that by all rights shouldn’t exist. The galaxy was present in the early universe, about 3 billion years after the Big Bang, at a time when galaxies were still forming and normally looked clumpy and irregular. “The vast majority of old galaxies look like train wrecks,” said UCLA astronomer Alice E. Shapley, one of the discoverers of the unusual spiral galaxy. “Our first thought was, why is this one so different, and so beautiful?”

A team headed by astronomer David R. Law of the University of Toronto, a former graduate student at UCLA, used the Hubble to observe more than 300 distant galaxies and study their properties. One of the galaxies, named BX442, appeared unusual, and the team used the W. M. Keck Observatory in Hawaii to study it further. At first, the astronomers thought that it was an illusion of a spiral galaxy caused by the accidental alignment of two galaxies in the images. But studies of spectra from more than 3,600 locations in and around the galaxy revealed that it is, indeed, a rotating spiral galaxy, they reported in the journal Nature.

In fact, it is a so-called grand design spiral galaxy, which has prominent, well-formed spiral arms. “The fact that this galaxy exists is astounding,” Law said. “Current wisdom holds that such grand design spiral galaxies didn’t exist at such an early time in the history of the universe.”

The reason this one does exist may be the companion dwarf galaxy that appears to be merging with it. Computer simulations by co-author Charlotte Christensen of the University of Arizona suggest that such a merger could produce the spiral pattern observed. The calculations also suggest, however, that the merger would be rapid and that the spiral would disappear after a relatively brief 100 million years. Apparently, astronomers just happen to be looking at BX442 at the right time.



Copyright © 2012, Los Angeles Times

New Telescope Optics Can Directly View Exoplanets By Hiding Interfering Starlight

By Rebecca Boyle
June 11th, 2012

Sifting Starlight These two images show HD 157728, a nearby star 1.5 times larger than the sun. The star is centered in both images, and its light has been mostly removed by an adaptive optics system and coronagraph belonging to Project 1640, which uses new technology on the Palomar Observatory’s 200-inch Hale telescope to spot planets.

For now, the thousands of potential exoplanets discovered in the past two years are little more than curvy dips on a graph. Astronomers using the Kepler Space Telescope pick them out by examining the way they blot out their own stars’ light as they move through their orbits. But if astronomers could block out the stars themselves, they may be able to see the planets directly. A new adaptive optics system on the storied Palomar Observatory just started doing that — it’s the first of its kind capable of spotting planets outside our solar system.

The new system is called Project 1640, and it creates dark holes around stars that may harbor planets. It removes the blinding glare of starlight so astronomers can see the exoplanets. This is extremely hard to do, said Charles Beichman, executive director of the NASA Exoplanet Science Institute at Caltech. “Imagine trying to see a firefly whirling around a searchlight more than a thousand miles away,” he said in a statement.

Coronagraphs are used to block out starlight so scientists can see what lurks around the stars. But even when you block the brightest light, about half of it can still fuzz up an image, creating speckles and background light that will interfere with images of potential planets. To address this speckly starlight, Project 1640 uses the world’s most advanced adaptive optics system, and four separate instruments on Palomar’s 200-inch Hale telescope that image the infrared light generated by young, warm planets orbiting stars.

Beta Pictoris: This image of the star Beta Pictoris shows a huge planet orbiting the star. The pale blue dots at the center are the planet, shown in two orbital configurations. The black disk is where the star would be; it’s blocked by a coronagraph. But more starlight is visible at the sides, which could potentially be outshining other, smaller planets in this solar system. A new adaptive optics system can remove this shine, too, unveiling new worlds around distant stars.

Its adaptive optics system can make more than 7 million active mirror deformations per second, with a precision level better than one nanometer. Its wave front sensor, which detects the atmosphere-caused deformations of light hitting the telescope, is also sensitive to a nanometer. As the system detects perturbations in the light waves coming into the telescope, it continually adjusts and deforms to block out the light as effectively as possible.

The system can resolve objects 1 million to 10 million times fainter than the object at the center of the image, which is usually the star. With that level of sensitivity, astronomers may be able to see planets.

Now that it’s up and running, as of late June, astronomers have embarked on a three-year survey of hot young stars. The planets they will detect with this method will probably be large hot Jupiters, and so unlikely to contain life — but their moons potentially could. In any event, it’s likely to be yet another major player in the planet-hunting business.

A Fifth Moon For Pluto!

By Phil Plait

Astronomers have just announced that tiny Pluto has a fifth moon! It was discovered using the Hubble Space Telescope:

You can see it in that image (click to enhadesenate) in the green circle. Pluto was targeted by HST for several observations in late June and early July, and P5 – also called S/2012 (134340), the moon’s designation until it gets a proper name – was seen moving around the tiny world. This image is from July 7.

As moons go, it isn’t much: it’s probably only about 10 – 25 kilometers (6 – 15 miles) across, making it one of the smallest moons detected in the entire solar system. That’s actually pretty amazing, given Pluto was 4.7 billion km away (2.8 billion miles) when these images were taken!

Pluto was observed in part to look for more moons. In 2015, the New Horizons probe will zip past Pluto, and scientists want to know as much about the system as they can before it gets there. The odds are low of them hitting any of those moons – space is big, and the moons and spacecraft are small – but a) better safe than sorry, and 2) if there are more targets to observe we want to know now so they can be added to the itinerary!

Observations like this are good for discovering moons and getting their locations, but size is a different matter. Literally. We know how far away the moon is, and how bright, but it’s far too small to directly get the size. Its diameter has to be estimated by assuming how reflective the surface is. If it’s dark like coal, it has to be bigger to be so bright, and if it’s shiny like ice, it’s smaller. That’s why we don’t know P5′s size to even within a factor of 2! But once New Horizons zips past, it may be able to nail down the size far better.

The first moon of Pluto, Charon, was discovered in 1978. Nix and Hydra were found using Hubble in 2006, and the fourth moon just last year, in 2011.

As for the argument about Pluto being a planet or not, this will no doubt provide grist for the mill. However, number of moons does not a planet make; Mercury and Venus have none and they’re planets. Mars has twice as many as Earth does, but it’s not twice the planet! And many very small asteroids have moons, too.
My feelings about this are on record: the word “planet” is not and can not be defined; it’s a concept, not a definition. It’s like the word “continent”: it’s more of an idea than something you can rigidly define. There is no sharp border that you can use to divide objects into planet and not planet.

So I actually don’t care if you call Pluto a planet or not. It is what it is: a very cool object, perhaps the biggest in the Kuiper Belt of frozen icy comet-like bodies past Neptune. It’s an oddity, since it’s so bright, and yes, has so many moons.

And it’s absolutely worthy of study, no matter what you call it.

Seen for the First Time: Starless Galaxies

Colin Lecher
June 11th, 2012

Dark Galaxies The illuminating quasar is circled in red. The dark galaxies are in blue. Royal Astronomical Society

Galaxy-building theory says there are stars and there are stage hands. The bright, shining galaxies filled with stars, the theory goes, took star-building gas from somewhere else, but we couldn’t find exactly where the help came from. Now astronomers have likely found that source; starless “dark galaxies” that fed others early in the history of the universe have been seen.

The European Southern Observatory’s Very Large Telescope was able to catch a glimpse of the galaxies for the first time as they were being illuminated by a quasar. Since the galaxies are bad at forming stars on their own, they’re difficult to see without a light source like a quasar, which shines UV light and can cause a fluorescent glow in the starless galaxies. Their existence has been hinted at before, but this marks the first direct look.

Some estimations were also offered by researchers on the properties of these galaxies. The mass of their gas is about 1 billion times that of the Sun’s, and they’re about 100 times less conducive to star-forming than similar neighbors.

The find also validates progressive rock band King Crimson’s early scientific predictions.

A nearby star may have more planets than we do!

By Phil Plait

HD 10180 is a star that’s nearly the Sun’s twin: it’s very close in mass, temperature, brightness, and even chemical content of our friendly neighborhood star. But in this case of stellar sibling rivalry, HD 10180 may have the upper hand: a new analysis of observations of the star indicate it may have nine planets!

In a new report accepted for publication in the journal Astronomy and Astrophysics, an astronomer re-analyzed data of the star taken with the High Accuracy Radial Velocity Planet Searcher (HARPS), an exquisitely high-precision camera mounted on a 3.6 meter telescope in Chile. HARPS has been observing HD 10180 for years; the star is a mere 130 light years away, making it bright and easy to study. The observations look to see if the star exhibits a periodic shift in its light: a Doppler shift as planets circle it, tugging it one way and another.

Six clear Doppler shift signals were found in the original analysis: six planets, five of which have masses ranging from 12 – 25 times that of the Earth (making them more like Neptune than our own comfortable planet), and a sixth that was bigger yet, 65 times Earth’s mass (more like Saturn than Neptune). These planets orbit HD 10180 with periods of 5 – 2000 days. A seventh possible planet was detected, but the data weren’t strong enough to make a solid claim.

The new analysis looks at the old data in a different way, examining it using different statistical methods. Not only are the six planets seen in the new results, but the seventh is confirmed, as well as finding two additional planets in the data. If this result pans out, that means HD 10180 has nine planets, more than our solar system does!

The three additional planets have masses of 1.3, 1.9, and 5.1 times that of Earth, and orbit the star with periods (think of that as the planets’ years) of 1.2, 10, and 68 days, respectively.

Those first two are pretty firmly in the Earth-mass range, what astronomers call “super Earths”. However, Earth-like they ain’t: they’d be cooked by the star. The first is only 3 million km (less than 2 million miles) from HD 10180, and the second barely any cooler at about 14 million km (8 million miles). This is much closer to the star than Mercury is to the Sun, and remember HD 10180 is very much like the Sun. If those planets are rocky, their surfaces are hot enough to melt tin, zinc, and on that inner planet, maybe even iron.

So yeah, not exactly a fun place to visit.

An added bonus is that the analysis looked at how stable the orbits are over time. Not all orbits are stable; if two planets occupy certain orbits then they can tug on each other enough over time to make the orbits unstable. It’s like pumping your legs on a swing; do it with the right timing and you can change your swing. In this case, the analysis showed the orbits are stable over time. That doesn’t prove the planets exist, but it does add confidence to the analysis.

And if this does all turn out to be correct, it’s amazing! We’ve been detecting planets around other stars for a while now, including those in multiple systems. But those generally have four planets or fewer; even finding six planets around HD 10180 would be a record. With three more, this would put HD 10180 firmly ahead of every other system detected.

Heck, it beats us. Mind you, no matter where you fall in the Pluto planetary club membership debate, these objects are all more massive even than Earth, so they are most assuredly planets.

Even though this system is very alien to ours, with far more massive planets packed more tightly around their star, most of them cooked to boiling, it’s still a very, very encouraging result. 15 years ago we didn’t know of any other planets orbiting other stars. Now we know of hundreds, with thousands more candidates. And many of these are parts of systems, planetary families a bit like our own. We used to wonder if our solar system was the only one like it in the Universe; unique among the stars.

And now we know the answer: No. And that’s a pretty cool thing to know.

Could One of These Worlds Be E.T.’s Home?

by Gregory Mone

Of the more than 700 planets discovered outside our solar system, none yet fit the description alien hunters dream about: an Earth-like planet in an Earth-like orbit around a sunlike star. But some scientists want to broaden the parameters of their search. In November a team led by Washington State University astrobiologist Dirk Schulze-Makuch devised the Planetary Habitability Index, or PHI, a scoring system for distant worlds that measures their suitability for any kind of life, not merely life as we know it. “We can’t go after only the Earth model of life,” he says. “You really want to be open-minded.”

Courtesy Habitability Laboratory at UPR Arecibo; Courtesy NASA (3)

Under Schulze-Makuch’s criteria, a faraway world racks up points if it has a solid surface and an atmosphere, which act together to support chemical reactions and deflect damaging radiation. Liquid water is not a prerequisite for a high score: A planet with liquids on the surface receives more points than a dry world, but the presence of water confers no additional advantage. “If you didn’t know that water worked on Earth,” Schulze-Makuch says, “you might think methanol would work much better for life.”

The PHI scores of bodies within the solar system reflect Schulze-Makuch’s hypothesis that the most Earth-like places are not necessarily the friendliest for life. Earth gets a near-perfect score of 0.96 on the 0 to 1 scale (it just has less available energy now than it did when life originated 4 billion years ago). But second place goes to Saturn’s moon Titan (0.64), which hosts vast lakes of liquid hydrocarbons but has surface temperatures of –300 degrees Fahrenheit. Mars, the target of more than a dozen robotic missions to hunt for signs of microbial life, comes in third at 0.59.

None of the planets yet found outside our solar system score particularly well. Gliese 581d, a rocky world nestling a cool, dim star, nets a rating of 0.43. Kepler-22b, the most Earth-like planet NASA’s Kepler space telescope has found so far, gets a similar score. However, Schulze-Makuch emphasizes that the numbers are subject to change. Astronomers have been able to determine the surface and atmospheric composition of only a few exoplanets, so for most planets the data are incomplete. Future telescopes that are powerful enough to probe these worlds, such as NASA’s proposed Terrestrial Planet Finder, should make the PHI much more useful.