Holy Planets, Batman

The Google Doodle celebrating the TRAPPIST-1 system announcement on 22 February 2017

Hopefully you've already heard about today's announcement during a NASA press conference about the confirmation of discovery of 7 Earth-sized planets around the star TRAPPIST-1, three of which are in that star system's Goldilocks Zone for liquid water. This star system is only 39 lightyears away from Earth (coincidentally, that's 12 parsecs, so just within one good Kessel Run if you have the right ship). 39 lightyears is practically down the street in the context of our galaxy (which spans over 100,000 lightyears from one end to the other). This announcement isn't only exciting, but it also comes with a lot of implications for astrobiology. We have the capabilities right now to start observing these planets closely to look for signs of biosignatures in their atmosphere and that will only get better in the coming years (especially when the James Webb Space Telescope goes into operation). I'm still in the process of crunching out my Ph.D. dissertation, so I can't write up all of my thoughts about this incredible announcement right now, but definitely stay tuned to the exoplanet and planetary science community to see what more we can learn in the coming years about these world so close to our own. 

Credit: JPL/NASA

Answering the Question "Are We Alone?"

 A TEDx Talk by Shawn Domagal-Goldman

Shawn Domagal-Goldman may be one of the hippest of our current generation of astrobiologists. I've heard him speak several times and have found his manner of speaking profound and enjoyable. Domagal-Goldman's work has focused on global geochemistry of terrestrial worlds, including the Earth, as well as on how we can characterize extrasolar planets from afar to learn more about their surface conditions and possibilities for supporting biology. Here's a video of Domagal-Goldman's talk from TEDxMidAtlantic 2015 where he considers how NASA is currently going about answering the all-important question "Are We Alone?":

Pluto might not behave like a planet, but it's still pretty cool

NASA/JHUAPL/SwRI

"If you slid Pluto to where Earth is right now, heat from the sun would evaporate that ice, and it would grow a tail. Now that's no kind of behavior for a planet." 

-Neil deGrasse Tyson

It may be true that Pluto is nothing like the Terrestrial or Jovian planets, but it's still an intriguing little world. The New Horizons mission has taught us so much more about Pluto than we ever knew before and has made Pluto an object of extreme interest once again. Even if it's not a planet, Pluto is still pretty awesome!

Voyaging, for Almost Four Decades

This beautiful image was produced by NASA to commemorate the anniversary of the Voyager spacecraft, which were launched in August and September of 1977. 

We'll soon be closing on 40 years since the launch of Voyagers 1 and 2. These missions have done so much for planetary science and are still alive, continuing to send data back to us about the space environment along their travels. They may last as much as another 5 or 10 years before they run so low on power that all of their instruments shut down. 

Even after the Voyagers have shut down their instruments and died, they will still travel; out there amongst the stars, the furthest reach of humanity, they will continue on.

Jupiter, King of Worlds

Jupiter is the king of the planets of our solar system. Jupiter is almost 26,000 times more massive than the Moon and 318 times more massive than Earth! Even though Jupiter is still less than one tenth of one percent as massive as the Sun, the king of our worlds is over 2.5 times greater in mass than the rest of all of the planets in the solar system combined (unless there really is a Planet IX out there, which would only change that number a little bit; a quick back-of-the-envelope calculation tells me that if Planet IX is there and is 10 times the mass of the Earth, then Jupiter would be about 2.3 times more massive than all the other planets combined)!

Jupiter is a behemoth of planetary mass in our solar system. Here you can see the relative masses of the 8 planets. (image from Das steinerne Herz on Wikipedia)

Jupiter was one of the five planets beyond Earth known by many ancient peoples. Jupiter's apparent point of light in the night's sky was associated with the god Marduk by the ancient Babylonians, while ancient Chinese beliefs personified Jupiter as the Fu Star (Fuxing), association the bright light of Jupiter with prosperity. It was from the ancient Romans that Jupiter gained the name we use for it. Jupiter in Roman mythology is the king of the gods, just as Zeus was the king of the gods in Greek mythology. We even came to name one of the days of our weeks after Jupiter (though in English, our word for that day (Thursday) has derived from the Germanic mythologies and the god Thor).

It was Galileo's discovery of four of the moons of Jupiter in 1610 and his writing of them that nearly caused the Catholic Church to murder Galileo (the idea that there could be moons orbiting other planets was certainly considered blasphemy against the church at that time). Below you can see a page from the Sidereus Nuncius ("Starry Messenger"; Galileo's 1610 book on his astronomical observations), where Galileo drew Jupiter and the moons he had discovered:

Although Galileo's discoveries of Jupiter's moons propelled astronomy and our understanding of the universe forward, it was Giovanni Cassini who first drew pictures of the features on Jupiter that he could observe with his telescope. For instance, below are some images from Cassini where he first shows what we believe was the discovery of the Great Red Spot (or, at least, discovery of a spot which may have preceded the Great Red Spot by over a century).

Perhaps one of the coolest of the earliest drawings of Jupiter came in 1880, and can be found in the collections of astronomer and artist E.L. Trouvelot. His drawing of Jupiter was created during an observation on November 1st of 1880, and clearly shows the Great Red Spot:

These early observations and drawings must have sent people's minds racing with wonderment at what those features on the king of worlds could be. However, once we started incorporating photographic imaging with observational astronomy and, especially, started sending spacecraft to explore the other worlds we started constraining what it was we were seeing on Jupiter (while also raising lots of more questions!). 

The Pioneer 10 spacecraft was the first extension of humanity to fly by Jupiter back in 1973. Here's one of the images taken during that encounter with the giant world. Pioneer 10 was the first spacecraft to measure the radiation and magnetic fields surrounding Jupiter. It was also the first to take images of the moons of Jupiter up-close. Pioneer 10 passed within 81,000 miles of the cloudtops of Jupiter on it's flyby over 40 years ago.

Jupiter has since had several other spacecraft go zooming by, most of which at least took pictures if not full-on collecting data and targeting Jupiter and its moons for observation; for instance, check out this table I stole from Wikipedia on spacecraft that have flown by along with the dates of closest approach and the minimum distance from Jupiter at that time:

-----Spacecraft-----	Closest -----Approach------	-----Distance-----
Pioneer 10	December 3, 1973	130,000 km
Pioneer 11	December 4, 1974	34,000 km
Voyager 1	March 5, 1979	349,000 km
Voyager 2	July 9, 1979	570,000 km
Ulysses	February 8, 1992	408,894 km
	February 4, 2004	120,000,000 km
Cassini	December 30, 2000	10,000,000 km
New Horizons	February 28, 2007	2,304,535 km

The only spacecraft so far to be sent into orbit of Jupiter was the Galileo Spacecraft, which operated in the Jovian system for over 8 years (from its arrival in December of 1995 until we crashed it into Jupiter (something we like to call "de-orbiting") in September of 2003). Galileo was used to study Jupiter's atmosphere and rings and to image and study the volcanoes on Io. Galileo discovered that Ganymede has its own, very strong magnetic field and really gave us most of the best data from which we have concluded that there is likely a deep subsurface ocean on Europa. The Galileo spacecraft really unlocked Jupiter and set the grounds for future spacecraft to visit that giant world.

An artist's concept of the Galileo spacecraft at Jupiter, with Io's volcanoes erupting nearby

Of the upcoming missions to Jupiter, one of them is actually going to get there very soon. The Juno spacecraft (see image to the left for a digital image of the spacecraft) is a NASA mission to Jupiter which was launched in August of 2011 and will arrive at Jupiter on July 4th of this year. Juno, named after the wife of Jupiter who was able to see through his clouds, will study Jupiter's composition, magnetic and gravitational fields, and will study the various processes within the Jovian atmosphere.

Following Juno, there are two missions in the works for studying the icy moons of Jupiter. JUICE (the Jupiter Icy Moon Explorer) is an ESA mission slated for launch in 2022. JUICE is designed to study primarily Ganymede and Callisto, though it should also fly by Europa a couple of times as well. A NASA mission set for launch on the early 2020s (likely 2022, as of now) is also in the works. The mission is currently called the Europa Multiple-Flyby Mission, though that name will surely change when the mission is more fully developed. This mission will focus on studying Europa. It will tell us about the surface processes and composition of Europa, will tell us a bit about the internal geology and composition of this moon, and, most importantly for astrobiology, will seek to determine the existence of Europa's ocean and determine what it can about the composition and possible surface-interactions of this ocean. 

Though JUICE and the Europa Multiple-Flyby Mission will target the icy moons of Jupiter, they will teach us a lot about the Jovian system in general (like how Jupiter's magnetic field and the chaotic whipping of particles through that field effect the moons of Jupiter). Taken along with Juno, the next couple of decades of research on Jupiter should be highly revealing, telling us a lot about the king of the planets but also helping us to uncover new mysteries and new questions about this behemoth in our solar system. 

In closing out this post, here is a quote about Jupiter, the god, from Ovid:

"Jupiter, from on high, smiles at the perjuries of lovers."

When it comes to the "perjuries of lovers" on Earth, Jupiter the planet, just as Jupiter the god, most certainly has no interest in our shortcomings. Though there is a beautiful history to consider in astrology, and Jupiter most certainly has played a prominent role there, the real test of time for Jupiter has revealed this king of our planets to be a massive and active monster of nature, though also beautiful in its presentation of itself to the universe.

Jupiter Drawing, from Kelvin Ma at Wikipedia

Phobos on My Phone

This pic of the Martian moon Phobos is rockin' on the background of my phone today. I recently downloaded the NASA App, which allows you to set up your phone to display a new picture very day from Astronomy Picture of the Day (APOD). The app also let's you download cool ringtones and notification sound-clips that are made of up of sounds from space (rockets launching, the sounds of the planets, and sonified transit data from Kepler light curves). Definitely get this app on your phone. Then you will also be able to rock sweet images, like this one of little Phobos, every single day.

There is no sound in space (or is there?)

(You can pickup some threads with this picture here)

In space, no one can hear you scream! That's what the tagline from the film Alien taught a generation of folks. Well, at least it taught some part of a generation. Well, maybe it only slightly hinted at an idea for a minimal fraction of some part of a generation. Or something like that. 

Too many times we've gone to the movies to see yet another sci-fi adventure with spaceships blasting each other with phasers and lasers and things that go "boom", all making lots of noises that some sound technicians likely spent hours in a studio putting together. And, most of the time it seems, these films get space completely wrong. 

Humans cannot hear in the vacuum of space. We can't. Since sound waves need a medium through which to travel and space generally offers nothing of the sort, there will be no propagation of sound from space battles, Star Destroyers traveling past you, or your fellow astronaut screaming from inside their space suit as they drift away from the ship after forgetting to attach their tether (unless, of course, they're screaming into their radio communication system).

Check out this vid from Coma Niddy at Sci Code on Space Myths

Star Trek, Star Wars, Battlestar Galactica, and more: the sounds of the spaceships and space battles and other spacey stuff in most of our television and films seem to show an utter lack of understanding on the part of the populace general. Even if filmmakers know that there shouldn't be sounds in space, it seems like most of them pander to the ignorance of the people by adding sounds to space. There are some who get it right, though. The cult sensation Firefly was well-known for presenting the lack of sound waves in space. 2001: A Space Odyssey, Gravity, and a few others also present the silence of space to the audience.

But hold on now, you might be thinking. Slow your roll, Cosmo Boy. Perhaps you've heard that NASA has recordings of some sounds from space. So what's up with that?

Just because sound waves don't generally propagate through space doesn't mean there's nothing for us to hear out there. For instance, several spacecraft (including the Voyager, Injun, and Hawkeye spacecraft) have had instruments capable of detecting the interactions of various particles with the ionospheres and magnetospheres of planets as well as the solar wind. The electromagnetic interactions spread over a large range of vibrations, but a lot of them are in the 20-20,000 Hz range in which we humans hear. NASA has released lots of these sound data sets online, including files primed for ringtones and notification sounds. Here's a video compilation of some of these sounds from our solar system (definitely awesome!):



Pretty cool, huh?!

Well, guess what? There's more.

As if listening to the interactions of the planets with the space environment weren't awesome enough, we can also take data from many our observations of the universe and convert those data into sound files. This is done through a process called sonification. For instance, we can take the Kepler light curves of stars and convert those light curves into sounds, allowing us to listen to the data. We can listen to the variations in the stars and we can even listen to the dips in the light curves as exoplanets transit in front of the stars. 

Sounds that are produced in this way aren't anything you would naturally hear, but they're still pretty awesome. For instance, this video presents a chorus of sounds produced through the sonification of light curves:



That's some eerie stuff. We can use sonification to convert all kinds of data into sounds, but listening to the processes occurring so far away in some way seems haunting and yet inspiring. Pod Academy recorded an episode called The Sounds of Space back in 2012 which can give you a fuller description of some of the cool stuff that what we can listen to from our observations of space. It's definitely worth a listen.

So even though no one can hear you scream in space, and even though all those spaceships going "pew pew pew" with their lasers and phasers and such in science fiction movies is a bunch of silliness (even if it does sound cool), there are some awesome things that we can really hear from our observations of space, either actual interactions of matter that cause vibrations in our hearing range or from data that we've converted to sounds. 

If you'd like to hear some more, I have another post to accompany this one that includes several embedded videos with the sounds from some of the worlds of our solar system.

(Image from PRX)

The Sounds of the Planets

Below are some awesome videos that have sounds recorded from various spacecraft that let us listen to some of the interactions of matter and energy in our solar system. You can find these audio files and more from NASA's website for space sounds.

Earth

Jupiter

Io

Saturn

Uranus

Neptune

Beyond Our Solar System's Plutonian Shore: Whither Pluto After New Horizons?

An artist's conception of New Horizons passing Pluto and its satellites (NASA)

It has definitely been a big year for one little world in our solar system. 

The flyby of Pluto by the New Horizons spacecraft on July 14th of this year has spawned renewed interests in the king of the Kuiper Belt, lord of the dwarf planets. 

From reigniting the discussions over Pluto's designation as a dwarf planet to revealing that the surface of Pluto holds geological mysteries for us to explore, New Horizons has been an amazing success. As the spacecraft continues on its mission and leaves Pluto behind, many of us wonder what might come next for the 17th largest object in our solar system.

This image has probably been the widest shared image from the New Horizons mission thus far (NASA)

Pluto has long fascinated many of us. Since the accidental discovery of Pluto by Clyde Tombaugh in 1930 (he was definitely looking for a planet, but it's very lucky he actually found Pluto) and its being named for the god of the underworld in Roman mythology by an eleven year-old girl, Pluto has made many of us wonder about what lies beyond the planets in our solar system and has inspired storytellers of all sorts to question what remote regions of star systems might be like. 

H.P. Lovecraft included Pluto in his fictional mythologies of the "ancient evil ones", it's believed by many that Disney named their famous cartoon dog after Pluto, Doctor Who visited Pluto in a fictional future, and in the Mass Effect video-game universe Charon, Pluto's largest moon, is the locale where an alien device for faster-than-light travel is discovered. In fact, there have been a large number of science fiction stories that have included mention of Pluto. Part of the allure of Pluto for storytelling has been the uncertainty about what kind of world it is.

We've often talked about Pluto as being a frozen world touched only by the dimmest light from the Sun; a little, icy ball enshrouded in mystery. But, thanks to the New Horizons mission, we now know so much more about Pluto: we know that there are icy mountains on Pluto that rise as high as 3.5 km above the surface, there are variations in the composition of surface ices (most notably causing the "heart" on Pluto; see above image), and that the moons of Pluto have their own surprises in store.

Also, it's great to know that scientists from the New Horizons team have been naming the features on Pluto after various science fiction and fantasy stories as well as from the history of exploration. There are the Cthulhu Regio, Vader Crater, Sputnik Planum, Viking Terra, and Uhuru and Spock Craters, just to name a few. 

Some of the surface features of Pluto

New Horizons' mission is continuing on now that the spacecraft has screamed past Pluto. The current plan for New Horizons is to try to fly by some other Kuiper Belt Objects (KBOs) before continuing on and away. Much like the Pioneer 10 and 11 and Voyager 1 and 2 spacecraft, New Horizons will continue sailing away from us, leaving our solar system behind in the decades and centuries to come. It will have long-since lost the capability of communicating with us or even operating, but maybe thousands or millions of years from now it will bump into some alien spacecraft and present a mystery to whoever finds it.

I used to think that New Horizons was going fast enough to overtake Voyager 1 at some point in the near future, but it turns out that New Horizons will never catch up with Voyager 1. This means that Voyager 1 will continue to be the furthest stretch of humanity in the universe for quite some time to come.

"Goodbye Pluto!" A look back from New Horizons (NASA)

Now that New Horizons has left the Plutonian system, a lot of people have wondered what else lies in store for Pluto?

Of course, there's the still the debate as to whether or not Pluto should be called a planet. You may know that Pluto is currently classified as a dwarf planet due to a vote amongst the International Astronomical Union (IAU) back in 2006. This decision caused a lot of public backlash, mostly for sentimental reasons. A lot of people felt like Pluto had always been a planet in their lifetimes so it should stay that way (of course, that's not how science works). There are certainly some good scientific reasons to call Pluto a planet, but, as many people point out, if we call Pluto a planet, then there are a lot of other worlds in the solar system that we'll have to call planets as well. These other worlds are also currently known as dwarf planets, and include the likes of Makemake and Eris (it was really the discovery of Eris that became the impetus for reclassifying Pluto). 

I personally tend to be on the fence about calling Pluto a planet. It most certainly shouldn't be classified along with the terrestrial worlds, like Venus and Earth, and definitely doesn't fit with the gas giants, like Jupiter and Uranus. Yet, the word planet hails from the Greek for "wandering star" (aster planetes) and that original concept could be fit to just about any body in the solar system. Also, to change the classification of Pluto required finding a definition of "planet" that fit the other eight large worlds, but would cut out Pluto and other dwarf planets and moons. That's what led the IAU to come up with their three requirements for a "planethood":

1. A planet is in orbit around the Sun

2. A planet has sufficient mass to assume hydrostatic equilibrium (a nearly round shape)

3. A planet has cleared its orbital neighborhood

The first part takes care of moons that orbit around other bodies, but also fails to include exoplanets (which do not orbit our Sun!). The second part makes a planet anything that is massive enough to draw itself roughly into a spherical shape, which fits with the planets and the dwarf planets, but leaves out many of the smaller asteroids and some moons. Finally, the third part is where they got Pluto. Pluto is a member of the Kuiper Belt and has not "cleared its neighborhood" of other bodies. Pluto is also weird in a lot of other ways (for instance, it's orbital plane is nothing close to that of the eight planets in the solar system), but there are many of us who still love Pluto, regardless of what it's called. 

It seems to many of us that what we choose to call Pluto should be based on science. There are several other dwarf planets and smaller bodies that were once considered planets (including Vesta, Juno, Ceres, and Pallas), so the idea that Pluto should be a planet because it was once a planet makes little to no sense. If we make Pluto a planet, then that means we have many other planets as well (which is not necessarily a problem, but does bother some people). Of course, there is also the potential that we could abandon "planet" as a scientific word and find something else, leaving the word "planet" to be something of a public matter. I suppose the debate over Pluto's status will continue on. How long that debate will last and what its outcomes will be, who knows...

As for what comes next for Pluto: there are no current missions in the works that will visit Pluto. We've learned a lot from New Horizons and will continue learning more as the data stream in over the next 15 months. However, although we'll have gained a lot more knowledge about Pluto, there will surely be many more mysteries to ponder. I would love to see a future where we could afford to send missions to the outer solar system more often, but, for now, we have to hope that there might be another mission to Pluto within our lifetimes.

If you'd like to know more about Pluto and the New Horizons mission, the video below has a lot of great information. It was released before the New Horizons flyby, but still serves as a fantastic resource for interested people:

Also, if you'd like to know more about the New Horizons flyby of Pluto, Space.com posted a Complete Coverage article for following the news as it was coming up online.

An image from New Horizons shows a mountain range of ice on Pluto (NASA)

As I close out this post, I leave these questions for you: 

-What comes next for Pluto? 

-Would you like to see another mission to Pluto? A lander this time, maybe? 

-Where do you stand on Pluto's status as a dwarf planet? 

-Finally, if you could name some of the new features on Pluto after science fiction and fantasy or famous exploration stories, which names would you choose and why?

This image shows what appear to be swirling ices of different compositions on Pluto (NASA)

The "Not Planets" World

The image below was created by Kristoffer Åberg (Örebro Astronomi) and shows a map of the Earth with country borders which is overlain with the land areas of the largest worlds in our solar system that are not planets. Check it out:

Kepler-452b: One of the newest discovered kids on the block may be similar to our Earth

An artist's concept of what Kepler-452b might look like from orbit (NASA Ames/JPL-Caltech/T. Pyle)

We've now confirmed the existence of nearly 2,000 exoplanets in our neighborhood of the galaxy. There are still another three thousand or so possible finds that are awaiting confirmation, but there's a good chance many of them will turn out to be real planets as well. We still estimate maybe 160 billion (or more) planets exist in our galaxy alone (averaging 1.6 planets per star). These numbers are incredible, especially for those of us who remember a time when we had not yet confirmed the existence of planets around other stars. 

Most of the worlds we have confirmed were first detected by the Kepler space telescope. Kepler was launched and entered service in 2009, immediately getting to the work of hunting for alien worlds. The mission had a highly successful lifetime of 3.5 years and was even granted a mission extension, but then, in 2013, a second of four of the reaction wheels within the spacecraft had broken (the reaction wheels are what allow such spacecraft to orient themselves in space without the need for fuel). Since that time, an ingenious repurposing of the spacecraft for a new planet-hunting mission called "Second Light" (a.k.a. K2) has been undertaken. Second Light has been operating since early 2014 and has been slowly building upon the list of potential exoplanets out there.

From all of the worlds discovered through Kepler's original mission and the Second Light mission, none has been as exciting for the general public as one that was just announced this past week. On July 23rd, researchers announced 521 more planet candidates, including 11 worlds that are close in their size and orbital distances from their stars as is our own Earth. One of those eleven is a world currently known as Kepler-452b. This exoplanet orbits a G2 star (one that is in the same spectral class as our Sun), it has an orbit that is similar in size to the Earth's (Kepler-452b's year is only 20 days longer), and this alien world is only about 1.6 times larger than the Earth. The following infographic from Space.com gives some fantastic details on what we've recently discovered about this exoworld:

The discovery of another world very similar to our own Earth is very suggestive that we are on the right path to discovering extraterrestrial life. Since my birth, we've now determined that there are billions of planets in our galaxy and we now know that some of them, like Kepler-452b, are very similar to our homeworld in their size and orbit (and some even orbit similar stars!). With current improvements in telescope technology and the development of exoplanet atmosphere research, it seems more and more like it really is only a matter of time before we start seeing abundant evidence for worlds that are habitable. Following that, how long might it be before the first detections of biosignature gases on exoplanets? If life is abundant in our universe, then it seems like we are only around the corner from finally determining whether we are alone in the vast cosmos.

Kepler-452b excites many people because of how similar it is to our world. Might there be a geophysical processes occurring on that world that are similar to ours? Might there be plate tectonics, continents, oceans...

We have a tendency to think that we need to find worlds like our own to find life (though this may not truly be the case), and that's why Kepler-452b is so exciting. I'm glad to know that so many people in the general public have been excited by this new finding. It might be that Kepler-452b is another Venus (a hothouse world devastated by a runaway greenhouse), or maybe the surface of Kepler-452b is simply a barren wasteland. Yet it's fun to imagine some of the more intriguing possibilities. 

Maybe Kepler-452b has a surface covered in microbial mats that generate large amounts of gases that are far from equilibrium with the atmosphere. Maybe that world has gigantic creatures like walking trees, dinosaurs, or giant floating blobs. Maybe there are intelligent beings on that world that have also discovered math and science and who have orbiting space telescopes that are peering out into their galactic neighborhood. Maybe, if that's the case, then just maybe they're also holding exciting press conferences to share their findings of new exoplanets around other stars. Maybe they've even had a meeting to discuss this new planet that is just like theirs in it's orbit around a similar star. Maybe that planet is just a bit smaller. Does it also have life?

An artist's illustration of a possible surface of newfound planet Kepler-452b (SETI Institute/Danielle Futselaar)

The Blue Marble: The importance of seeing our world in its entirety

This image of the Earth was taken by the crew of Apollo 17 on their trip to the Moon on the 7th of December, 1972. It is one of the most famous images in recorded history and has come to be known as The Blue Marble. 

Not only is the image significant as it was taken by the last human beings to travel to the Moon (something that will hopefully soon change), but The Blue Marble is one of the first images that captured our world as a whole, without any of the borders we've been told to imagine between nations and cultures. The image shows the place of birth of every human being who has ever lived. The Blue Marble shows land, sea, clouds, vegetation, and ice. Just like the Earthrise and Pale Blue Dot images, The Blue Marble gives us pause to reflect upon our connections to one another and to the rest of our biosphere. Seeing our world as a whole set amongst the background black of space should remind us that we're all in this crazy thing called life together and that our world is only one amongst what we now know to be a very great many.

Seeing the World We've Made

All is Fair in Love and War, by Bugspray609

Any thoughtful person who takes the time to regard the known history of our species must assuredly, at least sometimes, take some pause when considering the dichotomy of how well and how bad we have treated each other. For all of the beauty we have created in our music and art and literature and architecture, we have have created just as much destruction and pain through our acts of selfishness and fear. I think any person who seeks a better life in this world for everyone has to admit to and understand the atrocities that have occurred in human history while working to stop such atrocities from occurring again (whether through direct or indirect means).

In the 1937 preface to his science-fiction story, "Star Maker", Olaf Stapledon wrote of the direct and indirect approaches to overcoming the crises of human suffering while commenting on the foreseen terror of the rise of fascism in Europe. He pointed out the importance developing the "self-critical self-consciousness of the human species" (something I see as the capability for us to review our actions and work to improve the world for future generations by improving our actions). Although written over three decades before The Blue Marble image was produced, Stapledon had the foresight to point out the potential importance of seeing our world as a whole:

"...Perhaps the attempt to see our turbulent world against a background of stars may, after all, increase, not lessen, the significance of the present human crisis. It may also strengthen our charity to one another."

Stapledon even attempted a guess in Star Maker at what the Earth may look like from space:

"...The sheer beauty of our planet surprised me. It was a huge pearl, set in spangled ebony. It was nacrous, it was an opal. No, it was far more lovely than any jewel. Its patterned colouring was more subtle, more ethereal. It displayed the delicacy and brilliance, the intricacy and harmony of a live thing. Strange that in my remoteness I seemed to feel, as never before, the vital presence of Earth as of a creature alive but tranced and obscurely yearning to wake."

Olaf Stapledon couldn't have known it at the time of that writing, but the first official image taken of the Earth from space would be collected from a weapon of war, a V-2 rocket, less than a decade after the writing of Star Maker.

Earth from Space 

Taken from a V-2 Rocket in 1946, this is the first picture of Earth from space

Since the atmosphere of the Earth doesn't actually have a perfectly defined edge or separation that can tell you when you're still on Earth or when you're in space, a border called the Kármán Line was agreed upon for this purpose at 100 km above the surface of the planet. Theodore von Kármán, the namesake for the Kármán Line, was the first person to realize that it is around this altitude that the gases of the atmosphere become too rarified for aeronautical flight. As such, it's also this altitude that separates the study of aeronautics from the study of astronautics.

The first image of Earth taken by a camera that had passed the Kármán Line was taken on the 24th of October in 1946. This camera was riding along with a V-2 rocket, a weapon of war that was the progenitor of the rockets that took the first American astronauts into space and which took the first people to the Moon. It's somewhat ironic that one of the arguably most important pictures in history, one which has the power to captivate our wonder and to show us that we really are all in this together, was captured from an implement of death and destruction.

You can find more information about the first picture of Earth from space in this article from Air & Space Magazine.

Capturing the Blue Marble

There have been lots of pictures taken of the entirety of the Earth from spacecraft since that first one in 1946, but The Blue Marble remains as the first full shot of our world fully lit by the sun. 

Still, there are a lot of other great images from spacecraft of the Earth that have been released. Here, for example, are satellite composite images of Earth released by NASA in 2001 and 2002:

Composite images of the Earth from space, developed by NASA

Another fantastic image of our world is one known as The Blue Marble 2012. In the first week after its release, the Flickr page for the image garnered over 3 million views and now stands at almost 6 million views total. It's a fantastic composite image of our world that was taken from the Suomi NPP satellite:

The Blue Marble and similar images are testaments to our technological and scientific progress as a species. I think everyone should take a moment, at least once in their goings about in their daily lives, to consider the importance of seeing our world as a whole. 

Capturing images and videos of our Earth gives us a chance to look at our entire biosphere as though it is one living entity. Just as all humans are composed of human cells and cells of microorganisms that work together in one large system, our world can be viewed as one entity with one biosphere composed of many trillions of trillions of organisms that all function together as one whole (think: Gaia Hypothesis). It's especially intriguing to watch video, like the ISS Ustream Live Feed, that shows some of the dynamic processes on Earth that can be seen from space.

There's no knowing yet if biology is itself a cosmological imperative or if maybe life as we know it on our little Blue Marble is just the happenstance of chemistry and physics in one place and in one time. Many of us think the former is more likely, especially given the vastness of our universe and the myriad worlds we now know to exist outside of our own, yet we won't know more without further exploration. 

When I see The Blue Marble, it reminds me that all of our technological and cultural advancement over the last two hundred thousand years may just be the beginning of our advancement as a cosmologically conscious species. The Blue Marble, as an image, couldn't have been taken without our first taking those minuscule steps into space. If we continue working together to advance ourselves, technologically and philosophically, then maybe one day The Blue Marble will be an icon for how we first took to the heavens to know more about our world and its place in the cosmos.

Update (10 June 2015):

For more information about the importance of seeing our world from space, check out this article published in Space Policy in 2010 by my friend, Sanjoy Som. He discusses the importance of The Blue Marble and has proposed that we create a world flag with The Blue Marble at its center to support future exploration for all of our species and all of our biosphere. If you're interested in getting involved in spreading the word about The Blue Marble, check out One Flag in Space as well.

Venus is a Hot Planet. Oh, and the Temperature at the Surface is also Pretty High

False-color image of Venus' clouds taken by the Venus Express spacecraft

 Mother of Rome, delight of Gods and men,

   Dear Venus that beneath the gliding stars

  Makest to teem the many-voyaged main

      And fruitful lands—for all of living things

        Through thee alone are evermore conceived

-Lucretius, On the Nature of Things (1st century BCE); 

translation by William Ellery Leonard

Venus. I've long argued that, of all the planets and all the worlds in our solar system outside of Earth, Venus is the most likely to have once had life. Stress the "once" there, for sure. Where Venus may have once had a biosphere, it's now a world obscured by clouds, overriding a dense atmosphere, and the surface is hotter than a pizza oven. Seriously, the surface of Venus is over 863^o Fahrenheit! That's a scorcher for sure.

I'm not going to just drop a lot of facts about Venus on you (you can find such stuff on the NASA and Wikipedia pages for Venus), though I definitely recommend watching this short SciShow video on what it's like on Venus:

Venus definitely hasn't been getting the press it deserves of late. So much of our solar system exploration in the public mindset has been focused on Mars and Europa. Although I adore Mars and icy worlds like Europa are important for my graduate research, Venus is too close and too interesting for us to not get excited about that planet's history. That said, something has just popped up recently: the HAVOC (the High Altitude Venus Operational Concept) mission concept design has recent;y made its way around the interwebs. HAVOC, a concept that was developed by NASA's Space Mission Analysis Branch, is an idea of the possible future human exploration of Venus by using high-altitude balloons (thinking long-term, something like the Cloud City of Bespin but here in our own solar system). If you're into the future of human space exploration, Venus, or even the freaggin' awesome idea of exploring other worlds in balloons, then check out this video from NASA:



Pretty cool, huh?! I'd gladly volunteer to be an early explorer in a cloud city on Venus.  

But why would we want to build a cloud city on Venus? What would be the return? I recently gave a guest lecture for a friend's class at Front Range Community College. We ended the class in a large discussion about the costs and benefits of sending humans to Mars. One student highly questioned the pay-off for human exploration, especially since any reward for exploration (outside of the satisfaction of our human curiosity and urge to explore) must be long-term (i.e. technology and resource development) or seems untenable (e.g. expanding our Earth's biosphere to avoid potential full-scale extinction). I've heard these arguments before and, although I will always argue the opposite in favor of human exploration and colonization of space, we must consider the costs and benefits at all steps in our endeavors. 

Sending humans to Venus (especially building cloud cities) would obviously be expensive, but Venus is too intriguing to be left alone. Outside of the long term payoffs of exploration, like building new technologies and preparing for a future as residents of the entire solar system, I think we have a lot to learn from Venus. For instance:
   

• Venus is very similar to Earth and it can teach us about global climate on a planetary scale.

• Planets with runaway greenhouses and hostile surfaces like our Venus may be quite common in the universe, so Venus may be a good testbed for our future studies of such exoplanets.

• Venus has a storied history in human culture and understanding. Once known as the Morning and/or Evening Star, Venus is the brightest object in our night's sky after the Sun and the Moon (barring supernovae and meteors).

• Venus may have once been home to an alien biosphere. This is something I've been suggesting for a long time. Due to the similarities between Earth and Venus, I find it likely that Venus had the best shot in the early solar system of also forming life (far more than Mars). But, who mourns for life on Venus? This concept is not often discussed, since many people believe that any signs of such ancient Venusian are no longer remnant. Still, as the cosmobiologist, I'm intrigued by Venus and I want to see humans go there to explore. 

Venus is definitely a hot planet. But don't take my word for it: check out this music video on the "Hot Planet" from Distant Vantage Media Labs

Need some more information about our exploration of Venus? Check out this list of all of the spacecraft that we have sent to Venus.

Also, check out this related blog post from my friend, Julia DeMarines, at Pale Blue Blog on Astrobiology Magazine.