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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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Scott Butner, Flickr // CC BY-NC-ND 2.0
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Space
Look Up! The Lyrid Meteor Shower Arrives Saturday Night
Scott Butner, Flickr // CC BY-NC-ND 2.0
Scott Butner, Flickr // CC BY-NC-ND 2.0

There is a thin line between Saturday night and Sunday morning, but this weekend, look up and you might see several of them. Between 11:59 p.m. on April 21 and dawn on Sunday, April 22, the Lyrid meteor shower will peak over the Northern Hemisphere. Make some time for the celestial show and you'll see a shooting star streaking across the night sky every few minutes. Here is everything you need to know.

WHAT IS THE LYRID METEOR SHOWER?

Every 415.5 years, the comet Thatcher circles the Sun in a highly eccentric orbit shaped almost like a cat's eye. At its farthest from the Sun, it's billions of miles from Pluto; at its nearest, it swings between the Earth and Mars. (The last time it was near the Earth was in 1861, and it won't be that close again until 2280.) That's quite a journey, and more pressingly, quite a variation in temperature. The closer it gets to the Sun, the more debris it sheds. That debris is what you're seeing when you see a meteor shower: dust-sized particles slamming into the Earth's atmosphere at tens of thousands of miles per hour. In a competition between the two, the Earth is going to win, and "shooting stars" are the result of energy released as the particles are vaporized.

The comet was spotted on April 4, 1861 by A.E. Thatcher, an amateur skywatcher in New York City, earning him kudos from the noted astronomer Sir John Herschel. Clues to the comet's discovery are in its astronomical designation, C/1861 G1. The "C" means it's a long-period comet with an orbit of more than 200 years; "G" stands for the first half of April, and the "1" indicates it was the first comet discovered in that timeframe.

Sightings of the Lyrid meteor shower—named after Lyra, the constellation it appears to originate from—are much older; the first record dates to 7th-century BCE China.

HOW CAN I SEE IT?

Saturday night marks a first quarter Moon (visually half the Moon), which by midnight will have set below the horizon, so it won't wash out the night sky. That's great news—you can expect to see 20 meteors per hour. You're going to need to get away from local light pollution and find truly dark skies, and to completely avoid smartphones, flashlights, car headlights, or dome lights. The goal is to let your eyes adjust totally to the darkness: Find your viewing area, lay out your blanket, lay down, look up, and wait. In an hour, you'll be able to see the night sky with great—and if you've never done this before, surprising—clarity. Don't touch the smartphone or you'll undo all your hard ocular work.

Where is the nearest dark sky to where you live? You can find out on the Dark Site Finder map. And because the shower peaks on a Saturday night, your local astronomy club is very likely going to have an event to celebrate the Lyrids. Looking for a local club? Sky & Telescope has you covered.

WHAT ELSE IS GOING ON UP THERE?

You don't need a telescope to see a meteor shower, but if you bring one, aim it south to find Jupiter. It's the bright, unblinking spot in the sky. With a telescope, you should be able to make out its stripes. Those five stars surrounding it are the constellation Libra. You'll notice also four tiny points of light nearby. Those are the Galilean moons: Io, Europa, Ganymede, and Callisto. When Galileo discovered those moons in 1610, he was able to prove the Copernican model of heliocentricity: that the Earth goes around the Sun.

THERE'S BAD WEATHER HERE! WHAT DO I DO?

First: Don't panic. The shower peaks on the early morning of the 22nd. But it doesn't end that day. You can try again on the 23rd and 24th, though the numbers of meteors will likely diminish. The Lyrids will be back next year, and the year after, and so on. But if you are eager for another show, on May 6, the Eta Aquariids will be at their strongest. The night sky always delivers.

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Space
New NASA Satellite Called TESS Could Discover Thousands of New Planets

Since NASA’s Kepler spacecraft launched in 2009, the space agency has found and confirmed a whopping 2343 new planets. Of those, 30 are considered to be situated in a “habitable zone,” an area in which a planet’s surface could theoretically contain water.

A new satellite, set to launch today, is expected to find thousands more planets outside of our solar system, known as exoplanets. TESS, short for the Transiting Exoplanet Survey Satellite, is NASA’s latest effort to plumb the depths and darkness of outer space in search of other Earth-like planets—including those that could potentially support life.

TESS is slated to complete a two-year survey of the “solar neighborhood,” a general region which comprises more than 200,000 of the brightest nearby stars. To find these outlier planets, NASA scientists will be keeping an eye out for temporary changes in brightness, which indicate that a planet is blocking its host star.

According to Martin Still, the program scientist working on the TESS mission, the launch comes “with certainty” that TESS will find many nearby exoplanets. "We expect to find a whole range of planet sizes, between planets the size of Mercury or even the Moon—our Moon—to planets the same size as Jupiter and everything in between,” Still said in a NASA interview.

While the Kepler mission was considered a major success, NASA noted that most of the planets it recorded are those that orbit faint, faraway stars, making it difficult to conduct follow-up observations. The stars that TESS plans to survey will be 30 to 100 times brighter than those observed by its predecessor. This allows for newly detected planets and their atmospheres to be characterized more easily.

“Before Kepler launched, we didn't know for sure if Earth-sized planets existed,” Elisa V. Quintana, a NASA astrophysicist, told Reddit. “Kepler was a statistical survey that looked at a small patch of sky for four years and taught us that Earths are everywhere. TESS is building on Kepler in the sense that TESS wants to find more small planets but ones that orbit nearby, bright stars. These types of planets that are close to us are much more easy to study, and we can measure their masses from telescopes here on Earth.”

The most common categories of exoplanets are Earth- and Super Earth–sized masses—the latter of which are larger than Earth but smaller than Uranus and Neptune.

TESS is scheduled to launch from the Cape Canaveral Air Force Station in Florida on a SpaceX Falcon 9 rocket at 6:32pm EDT today.

For more information about TESS, check out this video from NASA.

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