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Scientists Seek Your Help to Photograph Another Sun's "Pale Blue Dot"

A simulation of the “pale blue dot”—an Earth-like planet—Project Blue hopes to capture orbiting a star in Alpha Centauri. The color could be attributed to the presence of a substantial atmosphere that allows liquid water to exist on the planet’s surface. Image credit: Jared Males.

 
In 1990, the Voyager I spacecraft took a mosaic of images known as the “family portrait”―a view of the solar system from a distance of 6 billion kilometers. In the image, Earth is captured as a single pixel later immortalized by Carl Sagan, who put the affairs of our “pale blue dot,” as he called it, into perspective:

On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there—on a mote of dust, suspended in a sunbeam.

The past 26 years have yielded astonishing and wonderful revelations about the cosmos, including proof of the existence of exoplanets―worlds orbiting other stars―with many of them in “habitable zones” around their suns, areas where it’s not too hot and not too cold. These are planets, in other words, that might support life.

For all the artistic renditions, however, and the hypotheses of what such worlds might be like, the totality of our images of those planets exist mostly as waveform graphs, with a scattering of thermal images of gas giants analogous to Jupiter. No rocky world in a habitable zone has ever been imaged directly. Their stars are billions of times brighter than they are, and there is no hardware in space able to “turn off” the light of the star without turning off the habitable-zone planet.

Project Blue intends to change that. It is an effort by a group of scientists, engineers, and space organizations to launch a small telescope into space with the singular goal of directly imaging in visible light (i.e. the light we see with our own eyes) an Earth-like planet around one or more of the stars of Alpha Centauri, and to do so using private funds. Not only might the mission redefine humanity’s place in the universe, but it might also redefine how planetary science missions are funded, launched, and operated.

THE NULL RESULT

Since the 1990s, astronomers have been rigorously engaged in the study of Alpha Centauri, the closest star system to our own, and people have been talking about imaging planets around nearby stars for nearly as long. The Project Blue team, comprised of some of the best minds in the field, came together this summer to work through and settle on the different technical concepts that have long been considered necessary for this sort of mission. A perennial roadblock has been funding—it's simply been too expensive to mount this sort of mission. That roadblock has finally given way.

Even when it was too expensive to attempt the imaging of a habitable exoplanet in Alpha Centauri, however, it was still a good bet. The Project Blue team has chosen to focus on the binary stars Alpha Centauri A and B. The stars are close to our solar system, relatively speaking, which means a space telescope needs only a half-meter mirror. Because the system contains two stars, there is promising potential for discovery. In fact, the Kepler space observatory already discovered a planet around Alpha Centauri B in 2012, though it could not be described as habitable: Its orbit is just 6 million kilometers from its star. (Just this summer, Kepler spotted a planet orbiting Proxima Centauri, a smaller, dimmer star that is closest to our Sun. It, too, has a tight orbit.) 

As for finding a habitable world, imagine you flip two coins. The possible results are: both coins turning up heads; one turning up heads, the other turning up tails; or both turning up tails. If you’re betting on heads, those are great odds. Consider further that in our own solar system, there are three planets in the habitable zone: Venus, Earth, and Mars. (Obviously, only one of the trio is a habitable blue dot.) Suddenly the likelihood of Project Blue successfully photographing something seems a lot higher.

To capture the image, Project Blue will launch a space telescope the size of a small washing machine, equipped with a coronagraph and deformable mirror. A coronagraph can "turn off" the light of the alien suns. That light is focused by the mirror. Because the twin stars in Alpha Centauri are so much like our own Sun, astronomers know where to look to find their habitable zones, and where planets have to be in those zones to host liquid water. Therein lies the key difference between NASA space telescopes and the one to be launched by Project Blue: NASA has to design its telescopes to service hundreds of targets. Project Blue has only one, and a precise target area within the system. If a NASA telescope fails to find something, it moves on to the next thing. If Project Blue fails to find its target, the mission is over.

NASA has passed over this sort of mission in the past because of this "null result"―the possibility of two tails turning up from our coin toss. Peer review panels normally look for a larger context for scientific impact, and however likely it is that habitable planets orbit one of these stars, what would it mean for exoplanets in general if no such planets exist? Very little. It wouldn't tell us anything at all about how common or rare Earth-like planets are around other stars in the galaxy.

This isn't to say there hasn't been excitement for a mission like this. "Excitement" is an understatement. Directly imaging an Earth-like world is a holy grail of exoplanet study.

KICKSTARTING THEIR WAY TO SPACE (AT FIRST) 

The era of commercial space has arrived, and the logical next step is to bring space science into the fold. Such barriers as spacecraft control and access to space are now surmountable thanks to companies like SpaceX, the private company helmed by Elon Musk that is pioneering reusable rockets, and that presently launches orbital payloads and resupplies the International Space Station (with designs to launch astronauts in 2019 and put humans on Mars in the next decade).

“It's a great time to be moving on a project like this using private funding,” Jon Morse, the CEO of BoldlyGo and one of the leaders of Project Blue, tells mental_floss. “It leverages what NASA has been investing in exoplanet research, along with pulling together the technologies and capabilities that commercial space has been developing, which has really brought a lot of the cost down.”

Project Blue is taking a three-pronged approach to raising funds for the mission. The first $1 million will be raised on Kickstarter, in a campaign that begins today. This is analogous to the way NASA funds “Phase A” studies, in which a small percentage of a mission’s cost is provided for scientists to develop a preliminary design. A methodical NASA-like approach to mission development is no accident. Before Jon Morse ran BoldlyGo, he was the director of the Astrophysics division of NASA’s Science Mission Directorate.

Crowdfunding this phase of Project Blue has the added benefit of raising the mission's profile. If nothing else, the public can be invested, literally, in the mission’s success. Afterward, the mission leadership will engage private investors directly to raise another $24 million. Since its announcement last month, the project has been inundated with requests from companies to help provide such things as onboard computing and spacecraft control. “We could not conceive of doing this even a few years ago,” says Morse.

And NASA, while not strictly necessary for mission success, will not be excluded from this endeavor. Project Blue has also approached the agency to establish a Space Act Agreement, in which it will provide modest resources in exchange for a minority role in the mission. NASA has such an agreement with SpaceX. No money is exchanged, but NASA field centers—its facilities around the country—partner with SpaceX to provide expertise and institutional knowledge. For Project Blue, this might mean the use of test facilities, and NASA personnel assigned to the project. This is also analogous to NASA’s participation in certain international missions, where there is no exchange of funds, but in exchange for a small role, NASA provides certain technologies or technical support.

TARGET 2020

The Project Blue team believes it can get the science payload built and integrated into a spacecraft in roughly three years—four on the outside. “We have a pretty good idea of what to do to get the spacecraft built,” says Morse. “Look for it by the end of the decade. It won’t be earlier than late 2019―maybe 2020―to launch. This is a lean-and-mean assessment that’s based on our experience with other payloads that have been developed."

And its effects on commercial and public-private partnerships for science missions would be tectonic. Capturing an image of a "pale blue dot" around one of the Alpha Centauri stars “would be a really compelling scientific result that we think would rival some of the most momentous discoveries in science and space exploration,” says Morse. It would also enable study beyond an imaged habitable world. Scientists could extract from the light wavelengths evidence of things like elements in the atmosphere, water, and perhaps extrapolate signs of life by way of such processes as photosynthesis on the planet's surface.

That our own pale blue dot exists is something of a miracle. So much could have gone wrong, and might yet still. So little keeps the light of civilization flickering. We dream of other blue dots, and write stories, poems, and scholarly research to that effect, but to see it? To know with certainty that it’s there, and that it might too hold the dreams of a species? This recasts the question, “Why are we here?” as something parochial—albeit globally so. Suddenly, “we” encompasses so much more, and “here” so much less. And though Carl Sagan said this about our own dot, he might as well have been saying this about another: “The Earth is a very small stage in a vast cosmic arena ... Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.”

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10 Astonishing Things You Should Know About the Milky Way
Anne Dirkse, Flickr // CC BY-SA 2.0
Anne Dirkse, Flickr // CC BY-SA 2.0

Our little star and the tiny planets that circle it are part of a galaxy called the Milky Way. Its name comes from the Greek galaxias kyklos ("milky circle") and Latin via lactea ("milky road"). Find a remote area in a national park, miles from the nearest street light, and you'll see exactly why the name makes sense and what all the fuss is about. Above is not a sky of black, but a luminous sea of whites, blues, greens, and tans. Here are a few things you might not know about our spiraling home in the universe.

1. THE MILKY WAY IS GIGANTIC.

The Milky Way galaxy is about 1,000,000,000,000,000,000 kilometers (about 621,371,000,000,000,000 miles) across. Even traveling at the speed of light, it would still take you well over 100,000 years to go from one end of the galaxy to the other. So it's big. Not quite as big as space itself, which is "vastly, hugely, mind-bogglingly big," as Douglas Adams wrote, but respectably large. And that's just one galaxy. Consider how many galaxies there are in the universe: One recent estimate says 2 trillion.

2. IT'S JAM-PACKED WITH CELESTIAL STUFF.

artist's illustration of the milky way galaxy and its center
An artist's concept of the Milky Way and the supermassive black hole Sagittarius A* at its core.
ESA–C. Carreau

The Milky Way is a barred spiral galaxy composed of an estimated 300 billion stars, along with dust, gas, and celestial phenomena such as nebulae, all of which orbits around a hub of sorts called the Galactic Center, with a supermassive black hole called Sagittarius A* (pronounced "A-star") at its core. The bar refers to the characteristic arrangement of stars at the interior of the galaxy, with interstellar gas essentially being channeled inward to feed an interstellar nursery. There are four spiral arms of the galaxy, with the Sun residing on the inner part of a minor arm called Orion. We're located in the boondocks of the Milky Way, but that is OK. There is definitely life here, but everywhere else is a question mark. For all we know, this might be the galactic Paris.

3. FOR A SPIRAL GALAXY, IT'S PRETTY TYPICAL …

If you looked at all the spiral galaxies in the local volume of the universe, the Milky Way wouldn't stand out as being much different than any other. "As galaxies go, the Milky Way is pretty ordinary for its type," Steve Majewski, a professor of astronomy at the University of Virginia and the principal investigator on the Apache Point Observatory Galactic Evolution Experiment (APOGEE), tells Mental Floss. "It's got a pretty regular form. It's got its usual complement of star clusters around it. It's got a supermassive black hole in the center, which most galaxies seem to indicate they have. From that point of view, the Milky Way is a pretty run-of-the-mill spiral galaxy."

4. …AND YET IT STANDS OUT AMONG ALL GALAXIES.

On the other hand, he tells Mental Floss, spiral galaxies in general tend to be larger than most other types of galaxies. "If you did a census of all the galaxies in the universe, the Milky Way would seem rather unusual because it is very big, our type being one of the biggest kinds of galaxies that there are in the universe." From a human perspective, the most important thing about the Milky Way is that it definitely managed to produce life. If they exist, the creatures in Andromeda, the galaxy next door (see #9), probably feel the same way about their own.

5. FIGURING OUT ITS STRUCTURE FROM THE INSIDE IS A CHALLENGE.


John McSporran, Flickr // CC BY 2.0

We have a very close-up view of the phenomena and forces at work in the Milky Way because we live inside of it, but that internal perspective places astronomers at a disadvantage when it comes to determining a galactic pattern. "We have a nice view of the Andromeda galaxy because we can see the whole thing laid out in front of us," Majewski says. "We don't have that opportunity in the Milky Way."

To figure out its structure, astronomers have to think like band members during a football halftime show. Though spectators in the stands can easily see the letters and shapes being made on the field by the marchers, the band can't see the shapes they are making. Rather, they can only work together in some coordinated way, moving to make these patterns and motions on the field. So it is with telescopes and stars.

6. INTERSTELLAR DUST BLOCKS OUR VIEW OF SOME PARTS OF THE GALAXY.

Interstellar dust further stymies astronomers. "That dust blocks our light, our view of the more distant parts of the Milky Way," Majewski says. "There are areas of the galaxy that are relatively obscured from view because they are behind huge columns of dust that we can't see through in the optical wavelengths that our eyes work in." To ameliorate this problem, astronomers sometimes work in longer wavelengths such as radio or infrared, which lessen the effects of the dust.

7. THE MILKY WAY SPINS, BUT ITS SPEED DOESN'T ADD UP …

Astronomers can make pretty reasonable estimates of the mass of the galaxy by the amount of light they can see. They can count the galaxy's stars and calculate how much those stars should weigh. They can account for all the dust in the galaxy and all of the gas. And when they tally the mass of everything they can see, they find that it is far short of what is needed to account for the gravity that causes the Milky Way to spin.

In short, our Sun is about two-thirds of the way from the center of the galaxy, and astronomers know that it goes around the galaxy at about 144 miles per second. "If you calculate it based on the amount of matter interior to the orbit of the Sun, how fast we should be going around, the number you should get is around 150 or 160 kilometers [93–99 miles] per second," Majewski says. "Further out, the stars are rotating even faster than they should if you just account for what we call luminous matter. Clearly there is some other substance in the Milky Way exerting a gravitational effect. We call it dark matter."

8. … AND WE BLAME DARK MATTER FOR THAT.

Dark matter is a big problem in galactic studies. "In the Milky Way, we study it by looking at the orbits of stars and star clusters and satellite galaxies, and then trying to figure out how much mass do we need interior to the orbit of that thing to get it moving at the speed that we can measure," Majewski says. "And so by doing this kind of analysis for objects at different radii across the galaxy, we actually have a fairly good idea of the distribution of the dark matter in the Milky Way—and yet we still have no idea what the dark matter is."

9. THE MILKY WAY IS ON A COLLISION COURSE WITH ANDROMEDA. BUT DON'T PANIC.

andromeda galaxy
The Andromeda galaxy
ESA/Hubble & NASA

Sometime in the next 4 or 5 billion years, the Milky Way and Andromeda galaxies will smash into each other. The two galaxies are about the same size and have about the same number of stars, but there is no cause for alarm. "Even though there are 300 billion stars in our galaxy and a comparable number, or maybe more, in Andromeda, when they collide together, not a single star is expected to hit another star. The space between stars is that vast," Majewski says.

10. WE'RE THROWING EVERYTHING WE HAVE AT STUDYING IT.

There are countless spacecraft and telescopes studying the Milky Way. Most famous is the Hubble Space Telescope, while other space telescopes such as Chandra, Spitzer, and Kepler are also returning data to help astronomers unlock the mysteries of our swirling patch of stars. The next landmark telescope in development is NASA's James Webb Space Telescope. It should finally launch in 2019. Meanwhile, such ambitious projects as APOGEE are working out the structure and evolution of our spiral home by doing "galactic archaeology." APOGEE is a survey of the Milky Way using spectroscopy, measuring the chemical compositions of hundreds of thousands of stars across the galaxy in great detail. The properties of stars around us are fossil evidence of their formation, which, when combined with their ages, helps astronomers understand the timeline and evolution of the galaxy we call home. 

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Mysterious 'Hypatia Stone' Is Like Nothing Else in Our Solar System
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In 1996, Egyptian geologist Aly Barakat discovered a tiny, one-ounce stone in the eastern Sahara. Ever since, scientists have been trying to figure out where exactly the mysterious pebble originated. As Popular Mechanics reports, it probably wasn't anywhere near Earth. A new study in Geochimica et Cosmochimica Acta finds that the micro-compounds in the rock don't match anything we've ever found in our solar system.

Scientists have known for several years that the fragment, known as the Hypatia stone, was extraterrestrial in origin. But this new study finds that it's even weirder than we thought. Led by University of Johannesburg geologists, the research team performed mineral analyses on the microdiamond-studded rock that showed that it is made of matter that predates the existence of our Sun or any of the planets in the solar system. And, its chemical composition doesn't resemble anything we've found on Earth or in comets or meteorites we have studied.

Lead researcher Jan Kramers told Popular Mechanics that the rock was likely created in the early solar nebula, a giant cloud of homogenous interstellar dust from which the Sun and its planets formed. While some of the basic materials in the pebble are found on Earth—carbon, aluminum, iron, silicon—they exist in wildly different ratios than materials we've seen before. Researchers believe the rock's microscopic diamonds were created by the shock of the impact with Earth's atmosphere or crust.

"When Hypatia was first found to be extraterrestrial, it was a sensation, but these latest results are opening up even bigger questions about its origins," as study co-author Marco Andreoli said in a press release.

The study suggests the early solar nebula may not have been as homogenous as we thought. "If Hypatia itself is not presolar, [some of its chemical] features indicate that the solar nebula wasn't the same kind of dust everywhere—which starts tugging at the generally accepted view of the formation of our solar system," Kramer said.

The researchers plan to further probe the rock's origins, hopefully solving some of the puzzles this study has presented.

[h/t Popular Mechanics]

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