New Telescope Optics Can Directly View Exoplanets By Hiding Interfering Starlight

By Rebecca Boyle
June 11th, 2012
popsci.com

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

popsci.com
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
04.05.2012

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.

Private company does indeed plan to mine asteroids… and I think they can do it!

By Phil Plait – an astronomer, lecturer, author, and the creator of Bad Astronomy

Planetary Resources, Inc. is not your average startup: its mission is to investigate and eventually mine asteroids in space!

Last week, the company issued a somewhat cryptic announcement saying they “will overlay two critical sectors – space exploration and natural resources – to add trillions of dollars to the global GDP”. I predicted this meant they wanted to mine asteroids, and yes, I will toot my own horn: I was right. They’re holding a press conference Tuesday morning to officially announce they’re going asteroid hunting.

The company had a pretty fierce amount of credibility right off the bat, with several ex-NASA engineers, an astronaut, and planetary scientists involved, as well as the backing of not one but several billionaires, including a few from Google… not to mention James Cameron. The co-founders of Planetary Resources are Peter Diamandis — he created the highly-successful X-Prize Foundation, to give cash awards to incremental accomplishments that will help achieve technological breakthroughs, including those for space travel — and Eric Anderson, X-Prize board member and Chairman of the Board of the Space Spaceflight Federation.

These are very, very heavy hitters. Clearly, they’re not screwing around.

So what’s the deal?

——————————————————————————–

Step 1

I spoke with Planetary Resources President and Chief Engineer Chris Lewicki on the phone Monday. He has an excellent pedigree: Lewicki was Flight Director for the NASA’s Spirit and Opportunity Mars rover missions, and also Mission Manager for the Mars Phoenix lander surface operations. So when he says he’s confident the company can and will succeed, I’m willing to listen.

“This is an attempt to make a permanent foothold in space,” he said. “We’re going to enable this piece of human exploration and the settlement of space, and develop the resources that are out there.”

The plan structure is reminiscent of that of Apollo: have a big goal in mind, but make sure the steps along the way are practical.

The key point is that their plan is not to simply mine precious metals and make millions or billions of dollars– though that’s a long-range goal. If that were the only goal, it would cost too much, be too difficult, and probably not be attainable.

Instead, they’ll make a series of calculated smaller missions that will grow in size and scope. The first is to make a series of small space telescopes to observe and characterize asteroids. Lewicki said the first of these is the Arkyd 101, a 22 cm (9″) telescope in low-Earth orbit that will be aboard a tiny spacecraft just 40 x 40 cm (16″) in size. It can hitch a ride with other satellites being placed in orbit, sharing launch costs and saving money (an idea that will come up again and again in their plans). This telescope will be used both to look for and observe known Near-Earth asteroids, and can also be pointed down to Earth for remote sensing operations.

I’ll note Lewicki said they expect to launch the first of these telescopes by the end of next year, 2013. They’re already building them (what’s referred to as “cutting metal”). They could launch on already-existing rockets — an Atlas or Delta, for example, Europe’s Ariane, India’s GSLV, or Space X’s Falcon 9.

After that, once they’re flight-tested, more of these small spacecraft can be launched equipped with rocket motors. If they hitch a ride with a satellite destined for a 40,000 km (24,000 mile) geosynchronous orbit, the motor can be used to take the telescope — now a space probe — out of Earth orbit and set on course for a pre-determined asteroid destination. Technical bit: orbital velocity at geosync is about 3 km/sec, so only about an additional 1 km/sec is needed to send a probe away from Earth, easily within the capability of a small motor attached to a light-weight probe.

Many asteroids pass close to the Earth with a low enough velocity that one of these probes could reach them. Heck, some are easier to reach in that sense than the Moon! Any asteroid-directed probe can be equipped with sensors to make detailed observations, including composition. It could even be designed to land on the asteroid and return samples back to Earth, or leave when the observations are complete and head off to observe more asteroids up close and personal.

——————————————————————————–

Step 2

Once a suitable asteroid is found, the idea is not to mine it right away for precious metals to return to Earth, Lewicki told me, but instead to tap it for volatiles — materials with low boiling points such as water, oxygen, nitrogen, and so on, which also happen to be critical supplies for use in space.

The idea behind this is to gather these materials up and create in situ space supply depots. Water is very heavy and incompressible, so it’s very difficult to launch from Earth into space (Lewicki quoted a current price of roughly $20,000 per liter to get water into space). But water should be abundant on some asteroids, locked up in minerals or even as ice, and in theory it shouldn’t be difficult to collect it and create a depot. Future astronauts can then use these supplies to enable longer stays in space — the depots could be put in Earthbound trajectories for astronauts, or could be placed in strategic orbits for future crewed missions to asteroids. Lewicki didn’t say specifically, but these supplies could be sold to NASA — Planetary Resources would make quite a bit money while saving NASA quite a bit. Win-win.

The details of exactly how they’ll collect these resources and store them may be revealed in the press conference Tuesday. If I can, I’ll ask.

——————————————————————————–

Step 3

The last step is to actually get the precious minerals from the asteroids and bring them to Earth. The exact setup for this isn’t clear at this time — again, the press conference should reveal that — but for the moment it may not really need to be. There are several options. One way would be to launch equipment to a distant asteroid already explored previously by a souped-up Arkyd. Another might be to use the small spacecraft to bring a smallish asteroid near the Earth — a study of this was just released, in fact [Note: two of the authors on that study were from Planetary Resources, including Lewicki]. A rock could be brought into an orbit around the Moon (that’s easiest to do in terms of fuel) where it could then be mined. Or it could be both: a small operation could start work while the asteroid is being towed to Earth, getting a few years head start.

——————————————————————————–

Step 4: Profit???

I asked Lewicki specifically about how this will make money. Some asteroids may be rich in precious metals — some may hold tens or even hundreds of billions of dollars in platinum-group metals — but it will cost billions and take many years, most likely, to mine them before any samples can be returned. Why not just do it here on Earth? In other words, what’s the incentive for profit for the investors? This is probably the idea over which most people are skeptical, including several people I know active in the asteroid science community.

I have to admit, Lewicki’s answer surprised me. “The investors aren’t making decisions based on a business plan or a return on investment,” he told me. “They’re basing their decisions on our vision.”

On further reflection, I realized this made sense. Not every wealthy investor pumps money into a project in order to make more… at least right away. Elon Musk, for example, has spent hundreds of millions of his own fortune on his company Space X. Amazon’s founder Jeff Bezos is doing likewise for his own space company, Blue Origin. Examples abound. And it’ll be years before either turns a respectable profit, but that’s not what motivates Musk and Bezos to do this. They want to explore space.

The vision of Planetary Resources is in their name: they want to make sure there are available resources in place to ensure a permanent future in space. And it’s not just physical resources with which they’re concerned. Their missions will support not just mining asteroids for volatiles and metals, but also to extend our understanding of asteroids and hopefully increase our ability to deflect one should it be headed our way.

This again was a topic I discussed with Lewicki specifically. He agreed with my proposition that all three topics — science, deflection, and resource use — are tied together. After all, we need to understand asteroids scientifically if we want to use them or prevent them from hitting us. We can use them for depots to establish better exploration of them, and sometime in the future we may need to deflect one to prevent all this from being a moot point anyway.

——————————————————————————–

My opinion on all this

The beauty of being me (among other things) is that I don’t always have to be objective. So I’ll say this: I love this idea. Love it.

Mind you, that’s different than saying I think they can do it. But, in theory at least, I think they can. Their step-wise plan makes sense to me, and they don’t need huge rockets and huge money to get things started. By the time operations ramp up to something truly ambitious they should already have in place the pieces necessary for it, including the track record. In other words, by the time they’re ready to mine an asteroid, they’ll have in place all the infrastructure needed to actually do it. I still want to see some engineering plans and a timeline, but in general what I’ve heard sounds good.

My biggest initial skepticism would be the investors — with no hope of profit for years, would they really stick with it?

But look at the investors: Film maker James Cameron. Google executives Larry Page & Eric Schmidt, and Google investor K. Ram Shriram. Software pioneer Charles Simonyi. Ross Perot, Jr. These are all billionaires, some of them adventurers, and all of them have proven to have patience in developing new ventures. I don’t think they’ll turn tail and run at the first setback.

Lewicki said much the same thing. “I was a harsh skeptic at first, but [when the company founders Peter Diamandis and Eric Anderson] approached me we talked about a plan on how to create a company and pursue this.” Soon after, he came to the conclusion this was a logical plan and the group was capable of doing it. In the press release, he said, “Not only is our mission to expand the world’s resource base, but we want to expand people’s access to, and understanding of, our planet and solar system by developing capable and cost-efficient systems.”

That sounds like a great idea to me. And I am strongly of the opinion that private industry is the way to make that happen. The Saturn V was incredible, but not terribly cost effective; that wasn’t its point. And when NASA tried to make a cost-effective machine, they came up with the Space Shuttle, which was terribly expensive, inefficient, and — let’s face it — dangerous. The government is good for a lot of things, but political machinations can really impede innovation when it comes to making things easier and less costly. As many people involved with NASA used to joke: “Faster, better, cheaper: pick two.”

I still strongly support NASA, of course; don’t get me wrong. It should still do what it does best: the things private industry can’t, like breaking new ground. That’s what NASA has been doing in space for 50 years, and now that paved way is being taken up by private companies. I think it’s just that combination of government support and private innovation that will get us to the stars. And for now, just for now, you know what?

Getting to the asteroids will do just fine.

Stunning vortex appears on Saturn’s moon, puzzles scientists

By Mike Wehner, Tecca

NASA’s Cassini orbiter has already taken some stunning photos of Saturn and its moons, but the latest snapshot from the multi-billion-dollar mission might be its most impressive yet. After swinging down to the southern hemisphere of Titan — Saturn’s largest moon — the high-powered orbiter captured images of a massive vortex forming at its pole, and scientists can only guess as to why it’s suddenly appeared.

The massive collection of swirling gas has gathered at Titan’s south pole, which measures approximately 3,200 miles across. The whirlwind has never before been spotted, and it remains unclear how long it has been forming. Cassini — which first arrived near Saturn in 2004 (and shot the stunning images below) — had been orbiting the moon too far north to have captured it, until now.

Photo of Titan against backdrop of Saturn

Prior to this discovery, the probe spotted images of a large “hood” on Titan’s north pole, which researchers believe is the result of cell convection — a process where dense air sinks towards the surface, pushing air at its edges upwards to create clouds. As Titan’s seasons change, scientists believe that the same mechanism may be at work at the moon’s southern pole, but they can’t be sure.

Cassini photo of Saturn

A single year on Titan lasts approximately 30 Earth years, making the study of each season a lengthy endeavor. The planet is composed of rock, water ice, and methane, making for some weather formations not typically seen here on Earth. The gigantic, swirling anomaly — which is spinning at four times the speed of the rest of the moon — appears to be yet another interesting characteristic of Saturn’s most interesting satellite.

High-contrast photo of Saturn from Cassini probe