Posted on by Shannon Hall

Help a Universe Today Writer Share Stories About Our Search For Earth-like Planets

An array of Earth-like planets. Image Credit: NASA

Since 1995, astronomers have detected thousands of worlds orbiting nearby stars, sparking a race to find the one that most resembles Earth. The discovery of habitable exoplanets and even extraterrestrial life is often referred to as the Holy Grail of science. So with the gold rush of exoplanet discoveries these days, it’s pretty tempting in news articles to lose readers in a fantastical narrative.

This month I’m launching a project on Beacon — a new independent platform for journalism — that will go behind the sensational headlines covering the search for Earth 2.0.

But I can’t do it without your help. In order to commit to writing about this on a regular basis, I need to raise $4,000 from subscribers who are willing to support my work over this month. Don’t worry, subscriptions are available for only $5 per month. This will supply the funding necessary to write for six months.

By Kepler’s definition, to be Earth-like a planet must be both Earth-size (less than 1.25 times Earth’s radius and less than twice Earth’s mass) and must circle its host star within the habitable zone: the band where liquid water can exist.

Image Credit: xkcd
Image Credit: xkcd

This simple, and yet variant, definition is a crucial starting point. But one glance at our Solar System (namely Venus and Mars) demonstrates that just because a planet is Earth-like doesn’t mean it’s an Earth twin.

So even if we do find Earth-like planets, we still don’t have the ability to know if they’re water worlds with luscious green planets and civilizations peering back at us.

But should we scale our definition of Earth-like planets up or down? Examples in the Solar System suggest that we should scale it down. Maybe planets located nearer to the center of the habitable zone are more congenial to life.

But can we base our definition on a single example — even if it’s the only example we know — alone? Theoretical astronomers suggest the picture is much more complicated. Life might arise on larger worlds, ones up to three times as massive as Earth, because they’re more likely to have an atmosphere due to more volcanic activity. Or life might arise on older worlds, where there’s simply more time for life to evolve.

It’s a crucial debate in astronomy research today, and it’s one that the media needs to handle with care. I am proud to be a part of Universe Today’s team, bringing readers up-to-date with the on goings in our local Universe. And Beacon will allow me to spend even more time, focusing on such a critical topic.

For each article, I will gather news, opinions and commentary from astronomers in the field. Not only do I have training as an astronomer, but my graduate school research focused on detecting exoplanet atmospheres from ground-based telescopes. With this deep-rooted understanding of the field at hand, I am able to parse complex information by directly reading peer-reviewed journal articles and interviewing astronomers I’ve met through my previous research.

But I really do need your help. Subscriptions are available for only $5 per month, and there are special rewards — such as gorgeous astronomy photos printed on canvas and gift subscriptions for friends — for people who subscribe at higher levels. You can directly subscribe here.

But here’s the best part: when you subscribe to my work, you’ll get access not only to all the stories I write, but the work of over 100 additional writers, based all over the world. This month Beacon is launching a series of astronomy projects, including one by Universe Today writer Elizabeth Howell.

Please help me write about our exciting search for Earth-like planets.

Posted on by Shannon Hall

First Exoplanet Discovered Beyond the “Snow Line”

This artist's conception shows the Uranus-sized exoplanet Kepler-421b, which orbits an orange, type K star about 1,000 light-years from Earth. Kepler-421b is the transiting exoplanet with the longest known year, circling its star once every 704 days. It is located beyond the "snow line" – the dividing line between rocky and gaseous planets – and might have formed in place rather than migrating from a different orbit. David A. Aguilar (CfA)

Data from NASA’s crippled Kepler space telescope has unleashed a windfall of hot Jupiters — sizzling gas giants that circle their host star within days — and only a handful of Earth-like planets. A quick analysis might make it seem as though hot Jupiters are far more common than their smaller and more distant counterparts.

But in large surveys, astronomers have to be careful of the observational biases introduced into their data. Kepler, for example, mainly finds broiling furnace worlds close to their host stars. These are easier to spot than small exoplanets that take hundreds of days to transit.

New data, however, shows a transiting exoplanet, Kepler-421b, with the longest known year, clocking in at 704 days.

“Finding Kepler-421b was a stroke of luck,” said lead author David Kipping from the Harvard-Smithsonian Center for Astrophysics in a press release. “The farther a planet is from its star, the less likely it is to transit the star from Earth’s point of view. It has to line up just right.”

Kepler-416b's folded light curve. Image Credit:
Kepler-421b’s folded light curve. Blue points are data from the first transit observed, and red points are the second transit.  Image Credit: Kipping et al.

Kepler-421b is roughly 4 times Earth’s girth and at least 60 times Earth’s mass. It circles its host star at about 1.2 times the distance from the Earth to the Sun. But because its host star is much smaller than our Sun, this places its orbit beyond the snow line — the dividing line between rocky and gas planets.

On Earth, snow lines typically form at high elevations where falling temperatures turn atmospheric moisture to snow. Similarly, in planetary systems, snow lines are thought to form in the distant, colder reaches of the stars’ disk.

Depending on the distance from the star, however, other more exotic molecules — such as carbon dioxide, methane, and carbon monoxide — can freeze and turn to snow. This forms a frost on dust grains: the building blocks of planets and comets.

“The snow line is a crucial distance in planet formation theory. We think all gas giants must have formed beyond this distance,” said Kipping.

The fact that this gas giant is still beyond this distance, roughly 4 billion years after formation, suggests that it’s the first non-migrating gas giant in a transiting system found.

Astronomers currently think gas giants form by small rocky cores that glom together until the body is massive enough to accrete a gaseous envelope. As they grow, they migrate inward, sometimes moving as close to their host star as Mercury is to the Sun.

Kepler-421b may be the first exoplanet discovered to have formed in situ. But further observations, especially those of its atmosphere, will help shed light on its formation history. Unfortunately given its long year, it won’t transit again until February, 2016.

The research has been accepted for publication in The Astrophysical Journal and is available online.

Posted on by Shannon Hall

Distant Stellar Atmospheres Shed Light on How Jupiter-like Planets Form

Interior of Jupiter. Image Credit: NASA / R. J. Hall

It’s likely that Jupiter-like planets’ origins root back to either the rapid collapse of a dense cloud or small rocky cores that glom together until the body is massive enough to accrete a gaseous envelope.

Although these two competing theories are both viable, astronomers have, for the first time, seen the latter “core accretion” theory in action. By studying the exoplanet’s host star they’ve shed light on the composition of the planet’s rocky core.

“Our results show that the formation of giant planets, as well as terrestrial planets like our own Earth, leaves subtle signatures in stellar atmospheres”, said lead author and PhD student Marcelo Tucci Maia from University of São Paulo, Brazil, in a press release.

Maia and colleagues pointed the 3.5-meter Canada-France-Hawaii Telescope toward the constellation Cygnus, in order to take a closer look at two Sun-like stars in the distant 16 Cyg triple-star system. Both stars, having formed together from the same gaseous disk over 10 billion years ago and having reached the same mass, are nearly solar twins.

But only one star, 16 Cygni B, hosts a giant planet. By decomposing the light from the two stars into their wavelengths and looking at the difference between the two stars, the team was able to detect signatures left from the planet formation process on 16 Cygni B.

It’s the perfect laboratory to study the formation of giant planets.

Difference in chemical composition between the stars 16 Cyg A and 16 Cyg B, versus the condensation temperature of the elements in the proto-planetary nebula. If the stars had identical chemical compositions then the difference (A-B) would be zero. The star 16 Cyg A is richer in all elements relative to star 16 Cyg B. In other words, star 16 Cyg B, the host star of a giant planet, is deficient in all chemical elements, especially in the refractory elements (those with high condensation temperatures and that form dust grains more easily), suggesting evidence of a rocky core in the giant planet 16 Cyg Bb. Credits: M. Tucci Maia, J. Meléndez, I. Ramírez.
Difference in chemical composition between the stars 16 Cyg A and 16 Cyg B, versus the condensation temperature of the elements in the proto-planetary nebula. Image Credit: M. Tucci Maia, J. Meléndez, I. Ramírez.

Maia and colleagues found that the star 16 Cygni A is enhanced in all chemical elements relative to 16 Cygni B. Hence, the metals removed from 16 Cygni B were most likely removed from the protoplanetary disk in order to form the planet.

On top of the overall deficiency in all elements, 16 Cygni B has an added deficiency in the refractory elements — those with high condensation temperatures that form dust grains more easily — such as iron, aluminum, nickel, magnesium, scandium, and silicon. This helps verify what astronomers have expected all along: rocky cores are rich in refractory elements.

The team was able to decipher that these missing elements likely created a rocky core with a mass of about 1.5 to 6 Earth masses, which is similar to the estimate of Jupiter’s core.

“16 Cyg is a remarkable system, but certainly not unique,” said coauthor Ivan Ramírez from the University of Texas. “It is special because it is nearby; however, there are many other binary stars with twin components on which this experiment could be performed. This could help us find planet-host stars in binaries in a much more straightforward manner compared to all other planet-finding techniques we have available today.”

The results were accepted for publication in The Astrophysical Journal Letters and are available online.

Posted on by Brian Koberlein

Is Our Solar System Weird?

This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right).
This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right). Image Credit: IAU/M. Kornmesser/N. Risinger (skysurvey.org)

Is our Solar System normal? Or is it weird? How does the Solar System fit within the strange star systems we’ve discovered in the Milky Way so far?

With all the beautiful images that come down the pipe from Hubble, our Solar System has been left with celestial body image questions rivaling that of your average teenager. They’re questions we’re all familiar with. Is my posture crooked? Do I look pasty? Are my arms too long? Is it supposed to bulge out like this in the middle? Some of my larger asteroids are slightly asymmetrical. Can everyone tell? And of course the toughest question of all… Am I normal?

The idea that stars are suns with planets orbiting them dates back to early human history. This was generally accompanied by the idea that other planetary systems would be much like our own. It’s only in the last few decades that we’ve had real evidence of planets around other stars, known as exoplanets. The first extrasolar planet was discovered around a pulsar in 1992 and the first “hot jupiter” was discovered in 1995.

Most of the known exoplanets have been discovered by the amazing Kepler spacecraft. Kepler uses the transit method, observing stars over long periods of time to see if they dim as a planet passes in front of the star. Since then, astronomers have found more than 1700 exoplanets, and 460 stars are known to have multiple planets. Most of these stellar systems are around main sequence stars, just like the Sun. Leaving us with plenty of systems for comparison.

Artist's impression of the solar system showing the inner planets (Mercury to Mars), the outer planets (Jupiter to Neptune) and beyond. Credit: NASA
Artist’s impression of the solar system showing the inner planets (Mercury to Mars), the outer planets (Jupiter to Neptune) and beyond. Credit: NASA

So, is our Solar System normal? Planets in a stellar system tend to have roughly circular orbits, just like our Solar system. They have a range of larger and smaller planets, just like ours. Most of the known systems are even around G-type stars. Just like ours.….and we are even starting to find Earth-size planets in the habitable zones of their stars. JUST LIKE OURS!

Not so fast…Other stellar systems don’t seem to have the division of small rocky planets closer to the star and larger gas planets farther away. In fact, large Jupiter-type planets are generally found close to the star. This makes our solar system rather unusual.

Computer simulations of early planetary formation shows that large planets tend to move inward toward their star as they form, due to its interaction with the material of the protoplanetary disk. This would imply that large planets are often close to the star, which is what we observe. Large planets in our own system are unusually distant from the Sun because of a gravitational dance between Jupiter and Saturn that happened when our Solar System was young.

55 Cancri. Image credit: NASA/JPL
55 Cancri. Image credit: NASA/JPL

Although our Solar System is slightly unusual, there are some planetary systems that are downright quirky. There are planetary systems where the orbits are tilted at radically different angles, like Kepler 56, and a sci-fi favorite, the planets that orbit two stars like Kepler 16 and 34. There is even a planet so close to its star that its year lasts only 18 hours, known 55 Cancri e.

And so, the Kepler telescope has presented us with a wealth of exoplanets, that we can compare our beautiful Solar System to. Future telescopes such as Gaia, which was launched in 2013, TESS and PLATO slated for launch in 2017 and 2024 will likely discover even more. Perhaps even discovering the holy grail of exoplanets, a habitable planet with life…

And the who knows, maybe we’ll find another planet… just like ours.

What say you? Where should we go looking for habitable worlds in this big bad universe of ours? Tell us in the comments.

And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!

Posted on by Shannon Hall

NameExoWorlds, an IAU Worldwide Contest to Name Alien Planets, Continues Controversy

This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right).
This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right). Image Credit: IAU/M. Kornmesser/N. Risinger (skysurvey.org)

The International Astronomical Union has unveiled a worldwide contest, NameExoWorlds, which gives the public a role in naming planets and their host stars beyond the solar system.

It’s the latest chapter in a years-long controversy over how celestial objects, including exoplanets, are classified and named.

Although the IAU has presided over the long process of naming astronomical objects for nearly a century, until last year they didn’t feel the need to include exoplanets on this long list.

As late as March 2013, the IAU’s official word on naming exoplanets was: “The IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge.” Since there was seemingly going to be so many exoplanets, the IAU saw it too difficult to name them all.

Other organizations, however, such as the SETI institute and the space company Uwingu leapt at the opportunity to engage the public in providing names for exoplanets. Their endeavors have been widely popular with the general public, but generated discussion about how ‘official’ the names would be.

The IAU issued a later statement in April 2014 (which Universe Today covered with vigor) and claimed that these two campaigns had no bearing on the official naming process. By August 2014, the IAU had introduced new rules for naming exoplanets, drastically changing their stance and surprising many.

Now in partnership with Zooniverse, a citizen-science organization, the IAU has drawn up a list of 305 well-characterized exoplanets in 206 solar systems. Starting in September, astronomy organizations can register for the opportunity to select planets for naming.

In October, the IAU plans to ask the registered organizations to vote for the 20 to 30 worlds on the list that they want to name. The exact number will depend on the number of registered groups. In December, those groups can propose names for the worlds that get the most votes. Groups can only propose names in accordance with the following set of rules. A name must be:

—   16 characters or less in length

—   Preferably one word

—   Pronounceable (in some language)

—   Non-offensive

—   Not too similar to an existing name of an astronomical object

Starting in March 2015, the list of proposed names will be put up to an Internet vote. The winners will be validated by the IAU, and announced during a ceremony at the IAU General Assembly in Honolulu in August 2015.

The popular name for a given exoplanet won’t replace the scientific name. But it will carry the IAU seal of approval.

Astronomer Alan Stern, principal investigator of the New Horizons mission to Pluto and CEO of Uwingu told Universe Today’s Senior Editor, Nancy Atkinson, that he was not surprised by the IAU’s new statement. “To my eye though, it’s just more IAU elitism, they can’t seem to get out of their elitist rut thinking they own the Universe.”

“Uwingu’s model is in our view far superior — people can directly name planets around other stars, with no one having to approve the choices,” Stern continued. “With 100 billion plus planets in the galaxy, why bother with committees of elites telling people what they do and don’t approve of?”

If nothing else, the controversy has sparked multiple venues to name exoplanets and more importantly learn about these alien worlds.

Posted on by Nancy Atkinson

Join the Live Discussion: The Hunt for Other Worlds Heats Up

Artist’s impression of a massive asteroid belt in orbit around a star. Earth's water may not have all come from asteroids and comets, so maybe that's true for exoplanets. Credit: NASA-JPL / Caltech / T. Pyle (SSC)
Artist’s impression of a massive asteroid belt in orbit around a star. Earth's water may not have all come from asteroids and comets, so maybe that's true for exoplanets. Credit: NASA-JPL / Caltech / T. Pyle (SSC)

As readers of Universe Today know, exoplanets are one of the hottest topics in astronomy today. In just the past six months, astronomers have announced the discovery of more than 700 planets orbiting other stars, bringing the total to more than 1700. These discoveries include the first Earth-size planet found in what’s called the habitable zone of a star, where liquid water could exist; the oldest known planet that could support life; and the first rocky “mega-Earth,” a planet that’s much like Earth except that it’s 17 times more massive.

On July 9, at 19:00 UTC (3 pm EDT, 12:00 pm PDT), three exoplanet hunters will come together discuss the discovery boom, consider the next steps in the hunt for habitable worlds, and debate whether we’re likely to find alien life in the next decade.

You can watch live (or watch the webcast later) below:

The panel includes MIT’s Zachory Berta-Thompson, Stanford’s Bruce Macintosh and Université de Montréal’s Marie-Eve Naud) will come together discuss the recent discovery boom, consider the next steps in the hunt for habitable worlds, and ponder the odds of finding life on another planet. The discussion will be moderated by journalist Kelen Tuttle.

To submit questions ahead of time or during the webcast, send an email to [email protected] or post on Twitter with hashtag #KavliLive. You can find additional information about the webcast and the Kavli Foundation here.

Posted on by Nancy Atkinson

Nearby Super-Earth is Best Habitable Candidate So Far, Astronomers Say

An artistic representation of Gliese 832 c against a stellar nebula background. A new paper says Gliese 832 might be home to another planet similar to this, but in the habitable zone. Credit: Planetary Habitability Laboratory at the University of Puerto Rico, Arecibo, NASA/Hubble, Stellarium.
An artistic representation of Gliese 832 c against a stellar nebula background. A new paper says Gliese 832 might be home to another planet similar to this, but in the habitable zone. Credit: Planetary Habitability Laboratory at the University of Puerto Rico, Arecibo, NASA/Hubble, Stellarium.

On a clear night, you might be able to spot the red dwarf star Gliese 832 through a backyard telescope, as it is just 16 light years away. Today, astronomers announced the discovery of super-Earth planet orbiting this nearby star and say it might be the best candidate yet for habitable world.

Gliese 832c was spotted by an international team of astronomers, led by Robert A. Wittenmyer from UNSW Australia. They used high-precision radial-velocity data from HARPS-TERRA, the Planet Finder Spectrograph and the UCLES echelle spectrograph. This star is already known to have one additional planet, a cold Jupiter-like planet, Gliese 832 b, discovered in 2009.

Orbital analysis of Gliese 832 c, a potentially habitable world around the nearby red-dwarf star Gliese 832. Gliese 832 c orbits near the inner edge of the conservative habitable zone. Its average equilibrium temperature (253 K) is similar to Earth (255 K) but with large shifts (up to 25K) due to its high eccentricity (assuming a similar 0.3 albedo). Credit: Planetary Habitability Laboratory.
Orbital analysis of Gliese 832 c, a potentially habitable world around the nearby red-dwarf star Gliese 832. Gliese 832 c orbits near the inner edge of the conservative habitable zone. Its average equilibrium temperature (253 K) is similar to Earth (255 K) but with large shifts (up to 25K) due to its high eccentricity (assuming a similar 0.3 albedo). Credit: Planetary Habitability Laboratory.

Since red dwarf stars shine dimly, the habitable zones around these stars would be very close in. Gliese 832c complies with an orbital period of 36 days (it’s orbital companion Gliese 832 b orbits the star in 9.4 years.)

The newly found super-Earth has a mass at least five times that of Earth’s and the astronomers estimate it receives about the same average energy as Earth does from the Sun. “The planet might have Earth-like temperatures, albeit with large seasonal shifts, given a similar terrestrial atmosphere,” says a press release from the Planetary Habitability Laboratory. “A denser atmosphere, something expected for Super-Earths, could easily make this planet too hot for life and a ‘Super-Venus’ instead.”

Using the Earth Similarity Index (ESI) — a measure of how physically similar a planetary mass object is to Earth, where 1 equals the same qualities as Earth — Gliese 832 c has an ESI of 0.81. This is comparable to Gliese 667C c (ESI = 0.84) and Kepler-62 e (ESI = 0.83).

“This makes Gliese 832c one of the top three most Earth-like planets according to the ESI (i.e. with respect to Earth’s stellar flux and mass) and the closest one to Earth of all three, a prime object for follow-up observations. However, other unknowns such as the bulk composition and atmosphere of the planet could make this world quite different to Earth and non-habitable.”

Artistic representation of the potentially habitable exoplanet Gliese 832 c as compared with Earth. Gliese 832 c is represented here as a temperate world covered in clouds. The relative size of the planet in the figure assumes a rocky composition but could be larger for a ice/gas composition. Credit: Planetary Habitability Laboratory.
Artistic representation of the potentially habitable exoplanet Gliese 832 c as compared with Earth. Gliese 832 c is represented here as a temperate world covered in clouds. The relative size of the planet in the figure assumes a rocky composition but could be larger for a ice/gas composition. Credit: Planetary Habitability Laboratory.

In their paper, Wittenmyer and his colleagues noted that while Solar Systems like our own appear — so far — to be rare, the Gliese 832 system is like a scaled-down version of our own Solar System, with an inner potentially Earth-like planet and an outer Jupiter-like giant planet. They added that the giant outer planet may have played a similar dynamical role in the Gliese 832 system to that played by Jupiter in our Solar System.

Certainly, astronomers will be attempting to observe this system further to see if any additional planets can be found.

If you’re interested in trying to see this star, here’s our guide on red dwarf stars that are visible in backyard telescopes.

Posted on by Shannon Hall

A New Mantra: Follow the Methane — May Advance Search for Extraterrestrial Life

Extrasolar planet HD189733b rises from behind its star. Is there methane on this planet? Image Credit: ESA

The search for life is largely limited to the search for water. We look for exoplanets at the correct distances from their stars for water to flow freely on their surfaces, and even scan radiofrequencies in the “water hole” between the 1,420 MHz emission line of neutral hydrogen and the 1,666 MHz hydroxyl line.

When it comes to extraterrestrial life, our mantra has always been to “follow the water.” But now, it seems, astronomers are turning their eyes away from water and toward methane — the simplest organic molecule, also widely accepted to be a sign of potential life.

Astronomers at the University College London (UCL) and the University of New South Wales have created a powerful new methane-based tool to detect extraterrestrial life, more accurately than ever before.

In recent years, more consideration has been given to the possibility that life could develop in other mediums besides water. One of the most interesting possibilities is liquid methane, inspired by the icy moon Titan, where water is as solid as rock and liquid methane runs through the river valleys and into the polar lakes. Titan even has a methane cycle.

Astronomers can detect methane on distant exoplanets by looking at their so-called transmission spectrum. When a planet transits, the star’s light passes through a thin layer of the planet’s atmosphere, which absorbs certain wavelengths of the light. Once the starlight reaches Earth it will be imprinted with the chemical fingerprints of the atmosphere’s composition.

But there’s always been one problem. Astronomers have to match transmission spectra to spectra collected in the laboratory or determined on a supercomputer. And “current models of methane are incomplete, leading to a severe underestimation of methane levels on planets,” said co-author Jonathan Tennyson from UCL in a press release.

So Sergei Yurchenko, Tennyson and colleagues set out to develop a new spectrum for methane. They used supercomputers to calculate about 10 billion lines — 2,000 times bigger than any previous study. And they probed much higher temperatures. The new model may be used to detect the molecule at temperatures above that of Earth, up to 1,500 K.

“We are thrilled to have used this technology to significantly advance beyond previous models available for researchers studying potential life on astronomical objects, and we are eager to see what our new spectrum helps them discover,” said Yurchenko.

The tool has already successfully reproduced the way in which methane absorbs light in brown dwarfs, and helped correct our previous measurements of exoplanets. For example, Yurchenko and colleagues found that the hot Jupiter, HD 189733b, a well-studied exoplanet 63 light-years from Earth, might have 20 times more methane than previously thought.

The paper has been published in the Proceedings of the National Academy of Sciences and may be viewed here.

Posted on by Susie Murph

Carnival of Space #357

Carnival of Space. Image by Jason Major.
Carnival of Space. Image by Jason Major.

Welcome, come in to the 357th Carnival of Space! The carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. I’m Susie Murph, part of the team at Universe Today and now, on to this week’s stories!

We’re going to start off with a double blast from the past, courtesy of CosmoQuest! This week, they’re featuring Stuart Robbins’s blog post from January 13, 2012, titled “Perspective on the Apollo 15 Landing Site.” He explores the region of the Moon that is the current home of the MoonMappers images that YOU are still mapping and exploring today – the Apollo 15 landing site area. It’s a neat place and we can study a lot of things there. Due to a quirk of optics and angles, you can even imagine you’re flying towards it.

Next, we stay with Cosmoquest’s Moon Mappers as they highlight the interesting discovery that the groundbreaking Soviet Lunakhod 2 lunar rover traveled farther than earlier estimated on it’s mission in 1972. Visit MoonMappers at Cosmoquest for more great stories!

Moving through history, we travel over to io9’s Space blog for a history of the American Space Shuttle disasters is a grim reminder of the danger of space travel. Just released is Major Malfunction, a documentary on the two Shuttle catastrophes. Major malfunction is an understatement for the destruction of Space Shuttle Challenger moments after launch in 1986, and the loss of Space Shuttle Columbia during re-entry in 2003.

Next at io9, we visit Mars to view the magnificent Draa, which are ancient landforms created from waves of sand. Check out the article and it’s images here.

We also have another article from io9, which new astronaut Reid Wiseman recounts his first adventurous days in space.

Now we’ll jump over for some gorgeous views from the Chandra X-Ray Observatory! One of their new images is a glorious view of the Whirlpool spiral galaxy which radiates with fantastic points of x-ray light. These image is breath-taking!

Want more gorgeous images? Visit Brownspaceman.com to see his discussion of the Tulip Nebula, which is a composite image which also maps the emissions from this incredible nebula.

Next, we head over to the Meridani Journalfor coverage of a major find in the search for exoplanets. A new world which is more than twice as large as Earth and about 17 times heavier has been discovered, a sort of “mega-Earth” as some have referred to it.

The NextBigFuture Blog lives up to it’s name by bringing us two interesting stories from Elon Musk and his company SpaceX. First, he points out that the key is reusability. Musk said the crewed Dragon is designed to land softly back on Earth and be rapidly turned around for another flight — possibly on the same day. Spacex is aiming for 10 flights without any significant refurbishment for the Dragon v2. The thing that will have to be refurbished is the main heat shield. Further improved heat shield materials [later versions of PICA-X] would mean Spacex could aim for 100 reusable flights.

We then head over to the Urban Astronomer, where recent observations of a very near pair of brown dwarf objects has led to something new: We’re watching the weather on stars themselves!

Finally, we return to Universe Today for some interesting potential missions. First, the B612 Foundation’s privately-funded Sentinel mission, once launched and placed in orbit around the Sun in 2018, will hunt for near-Earth asteroids down to about 140 meters in size using the most advanced infrared imaging technology, without government red tape to hamper the mission. Next, the NASA Innovative Advanced Concepts office announced a dozen far-flung drawing-board proposals that have received $100,000 in Phase 1 funding for the next 9-12 months, one of which is a balloon for exploring Titan. We’re looking forward to hearing about these projects and many others in the coming years.

That’s it for this week’s Carnival! See you all next time!

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.