The Moon Of Lakes And Rivers - Saturn’s Moon Titan

Gretchen: On the International Space Station, you have astronauts from the US and from other English speaking countries and you have cosmonauts from Russia. And obviously it’s very important to get your communication right if you’re on a tiny metal box circling the Earth or going somewhere. You don’t want to have a miscommunication there because you could end up floating in space in the wrong way. And so one of the things that they do on the ISS – so first of all every astronaut and cosmonaut needs to be bilingual in English and Russian because those are the languages of space. Lauren: Yep. Wait, the language of space are English and Russian? I’m sorry, I just said ‘yep’ and I didn’t really think about it, so that’s a fact is it? Gretchen: I mean, pretty much, yeah, if you go on astronaut training recruitment forums, which I have gone on to research this episode… Lauren: You’re got to have a backup job, Gretchen. Gretchen: I don’t think I’m going to become an astronaut, but I would like to do astronaut linguistics. And one of the things these forums say, is, you need to know stuff about math and engineering and, like, how to fly planes and so on. But they also say, you either have to arrive knowing English and Russian or they put you through an intensive language training course. But then when they’re up in space, one of the things that they do is have the English native speakers speak Russian and the Russian speakers speak English. Because the idea is, if you speak your native language, maybe you’re speaking too fast or maybe you’re not sure if the other person’s really understanding you. Whereas if you both speak the language you’re not as fluent in, then you arrive at a level where where people can be sure that the other person’s understanding. And by now, there’s kind of this hybrid English-Russian language that’s developed. Not a full-fledged language but kind of a- Lauren: Space Creole! Gretchen: Yeah, a Space Pidgin that the astronauts use to speak with each other! I don’t know if anyone’s written a grammar of it, but I really want to see a grammar of Space Pidgin.

Excerpt from Episode 1 of Lingthusiasm: Speaking a single language won’t bring about world peace. Listen to the full episode, read the transcript, or check out the show notes. (via lingthusiasm)

Here’s a great example of the kinds of experiments astronauts perform on the International Space Station, just like I talked about in Episode 19! I absolutely want to high-five whoever called is ISS-CREAM.

From Frozen Antarctica to the Cold Vacuum of Space

A new experiment that will collect tiny charged particles known as galactic cosmic rays will soon be added to the International Space Station. The Cosmic Ray Energetics And Mass for the International Space Station payload, nicknamed ISS-CREAM, will soon be installed in its new home on the Station’s Japanese Experiment Module Exposed Facility. ISS-CREAM will help scientists understand more about galactic cosmic rays and the processes that produce them.

Wait, what are cosmic rays?

Cosmic rays are pieces of atoms that move through space at nearly the speed of light. Galactic cosmic rays come from beyond our solar system. 

They provide us with direct samples of matter from distant places in our galaxy.

Why do these things go so fast?

Galactic cosmic rays have been sped up by extreme processes. When massive stars die, they explode as supernovas. The explosion’s blast wave expands into space along with a cloud of debris. 

Particles caught up in this blast wave can bounce around in it and slowly pick up speed. Eventually they move so fast they can escape the blast wave and race away as a cosmic ray.

Where can we catch cosmic rays?

Cosmic rays are constantly zipping through space at these super-fast speeds, running into whatever is in their path – including Earth.  

But Earth’s atmosphere is a great shield, protecting us from 99.9 percent of the radiation coming from space, including most cosmic rays.  This is good news for life on Earth, but bad news for scientists studying cosmic rays.  

So… how do you deal with that?

Because Earth has such an effective shield against cosmic rays, the best place for scientists to study them is above our atmosphere – in space.  Since the 1920s, scientists have tried to get their instruments as close to space as possible. One of the simplest ways to do this is to send these instruments up on balloons the size of football stadiums. These balloons are so large because they have to be able to both lift their own weight and that of their cargo, which can be heavier than a car. Scientific balloons fly to 120,000 feet or more above the ground – that’s at least three times higher than you might fly in a commercial airplane!  

Credit: Isaac Mognet (Pennsylvania State University)

Earlier versions of ISS-CREAM’s instruments were launched on these giant balloons from McMurdo Station in Antarctica seven times, starting in 2004, for a total of 191 days near the top of the atmosphere.  Each of these flights helped the team test their hardware and work towards sending a cutting-edge cosmic ray detector into space!  

How is going to space different than flying balloons?

Balloon flights allowed the team to collect a lot of cosmic rays, but even at 120,000 feet, a lot of the particles are still blocked. Scientists at the University of Maryland, College Park, who operate ISS-CREAM, expect to get about 10 times as much data from their new home on the International Space Station. 

That’s because it will be both above the atmosphere and fly far longer than is possible with a balloon. As you might imagine, there are large differences between flying something on a balloon and launching it into space. The science instruments and other systems had to be changed so ISS-CREAM could safely launch on a rocket and work in space.

What will ISS-CREAM do?

While on the space station, ISS-CREAM will collect millions of cosmic rays – electrons, protons and atomic nuclei representing the elements found in the solar system. These results will help us understand why cosmic rays reach the wicked-fast speeds they do and, most important, what limits those speeds.

ISS-CREAM launches to the International Space Station aboard the latest SpaceX Dragon spacecraft, targeted to launch August 14. Want to learn more about ISS-CREAM and some of our scientific balloons? Check out our recent feature, NASA’s Scientific Balloon Program Reaches New Heights.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Ep. 23 Quasars and Blazars - HD and the Void

Hear an overview of two of the major types of active galaxies: quasars and blazars! I discuss the history of the study of quasars as well as where we're going with future studies of these extragalactic objects.

When I was in Ireland in 2013, I kept seeing signs for ‘quasar.’ I finally learned that it’s the European way of saying laser tag. It has nothing to do with quasars, which are a specific type of a specific type of galaxy. Listen to this week’s (pretty short) podcast on two types of active galaxies: quasars and blazars.

Below the cut, I have the transcript, sources, music credits, and timeline of people I talked about! If you have suggestions for topics I could cover, please send me a Tumblr message or tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me. Please subscribe on iTunes, rate my podcast and maybe review it, and tell friends if you think they’d like to hear it!

(My thoughts on the next episode are the SOFIA observatory, Chuck Yaeger, or the great Stephen Hawking. The next episode will go up April 2nd.)

Glossary

active galaxy or active galactic nucleus- a galaxy with a small core of emission embedded at the center. This core is typically very variable and very bright compared to the rest of the galaxy. These galaxies emit much more energy than they should; this excess energy is found in the infrared, radio, UV, and X-ray regions of the electromagnetic spectrum.

blazar - a subcategory of active galaxy, it is an extremely bright, distant object, powered by a black hole, which emits massive amounts of energy. It is distinct from a quasar because it is even brighter.

extragalactic objects - objects outside our Milky Way galaxy.

interferometry - a group of techniques to extract information from superimposing electromagnetic waves to create interference. In radio astronomy, this is done by using a wide spread of receivers to look at the same distant object, then bringing that data together with a correlator that can create a larger, clearer picture than an individual radio telescope alone could.

lunar occultations - when stars pass behind the Moon. This is the basis for a method of determining and mapping star positions.

quasar - a subcategory of active galaxy, it is an extremely bright, distant object, powered by a black hole, which emits massive amounts of energy. It is distinct from a blazar because it is less-bright. The name is a contraction of “quasi-stellar radio source” (which is not necessarily true of all quasars—90% are radio-quiet).

torus - a donut shape.

Script/Transcript

Timeline

Walter Baade, German (1893-1960)

Rudolph Minkowski, German-American (1895-1976)

Fritz Zwicky, Swiss (1898-1974)

Gordon Stanley, New Zealander (1921-2001)

John Bolton, English-Australian (1922-1993)

Owen Bruce Slee, Australian (1924-2016)

Allan Rex Sandage, American (1926-2010)

Cyril Hazard, English (1928- )

Maartin Schmidt, Dutch (1929- )

Hong-Yee Chiu, American (1932- )

Stephen Hawking, English (1942 -2018)

Jedidah Isler

Sources

Active Galaxies via NASA (Dec 2016)

Galaxy shapes via Cornell University (April 2000)

Galaxies and Black Holes by David Merritt, published on NED by Caltech and NASA

Cyril Hazard via University of Pittsburgh

The Discovery of Quasars and its Aftermath via Journal of Astronomical History and Heritage (2014)

“Characteristically, Fritz Zwicky (1898–1974; Figure 11) immediately pointed out that ‘All of the five quasi-stellar galaxies described individually by Sandage (1965) evidently belong to the subclass of compact galaxies with pure emission spectra previously discovered and described by the present writer. (Zwicky, 1965: 1293).’ A few years later, Zwicky was less circumspect and wrote: ‘In spite of all these facts being known to him in 1964, Sandage attempted one of the most astounding feats of plagiarism by announcing the existence of a major new component of the Universe: the quasi-stellar galaxies ... Sandage‘s earthshaking discovery consisted in nothing more than renaming compact galaxies, calling them ‘interlopers‘ and quasistellar galaxies, thus playing the interloper himself. (Zwicky and Zwicky, 1971: xix)’”

Lunar occultations via Sky and Telescope

Quasars and Blazars by Matthew Whiting (a chapter in his thesis, What made the quasar blush? Emission mechanisms in optically-red quasars) via the Australia Telescope National Facility (2000)

Jedidah Isler on quasars and blazars via TED Talks (March 2015)

Quasar definition via Space.com (Feb 2018)

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: ‘Into The White’ by Pixies off their album Wave of Mutilation.

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

A new LEGO set honors the women of NASA—and it looks pretty awesome

"The set clearly touched and inspired many."

Oh my gosh this is incredibly exciting! Imagine combining them with a Star Wars LEGO set...

Physicists Have Figured Out Where The Sun's Plasma Jets Come From

Things are heating up.

After over a century of observations and several theories, scientists may have finally nailed the origin of the high-speed plasma blasting through the Sun’s atmosphere several times a day. Using a state-of-the-art computer simulation, researchers have developed a detailed model of these plasma jets, called spicules.

The new findings answer some of the bigger questions in solar physics, including how these plasma jets form and why the Sun’s outer atmosphere is far hotter than the surface.

“This is the first model that has been able to reproduce all the features observed in spicules,” Juan Martinez-Sykora, lead author and astrophysicist at the Bay Area Environmental Research Institute in California, told ScienceAlert.

Continue Reading.

115th Anniversary of the Antikythera Mechanism's Discovery

Today's Google Doodle

On this date in 1902, Greek archaeologist Valerios Stais sifted through some artifacts from a shipwreck at Antikythera. The wrecked Roman cargo ship was discovered two years earlier, but Stais was the first to notice an intriguing bit of bronze among the treasures. It looked like it might be a gear or wheel. That corroded chunk of metal turned out to be part of the Antikythera Mechanism, an ancient analog astronomical computer.

The Antikythera Mechanism tracked planetary positions, predicted lunar and solar eclipses, and even signaled the next Olympic Games. It was probably also used for mapping and navigation. A dial on the front combines zodiacal and solar calendars, while dials on the back capture celestial cycles. Computer models based on 3-D tomography have revealed more than 30 sophisticated gears, housed in a wooden and bronze case the size of a shoebox.  

Cassini prepares for final orbital “Grand Finale” at Saturn.

Erik Wernquist, the same filmmaker who created 2014’s “Wanderers” and a stunning New Horizons promotional film in 2015, has created a new video highlighting NASA’s Cassini mission’s final days at Saturn. The Cassini spacecraft will begin its final series of orbits to cap a 13-year groundbreaking science mission known as the Grand Finale. For the first time ever in Cassini’s time at Saturn, the spacecraft will fly in between the planet’s rings and atmosphere. No spacecraft has ever before flown in this region of any of the solar system’s ringed planets. After 20 orbits, Cassini will dive into Saturn’s upper atmosphere September 15 where it will be destroyed. In 2008, mission managers explored a range of End of Mission scenarios that would protect Saturn’s moon’s from Earthly contaminants before ultimately deciding on atmospheric reentry. Cassini began her End of Mission manoeuvres on November 26, 2016, when it began the first of 20 ring-grazing orbits. A close flyby of Titan April 22 will alter the spacecraft’s trajectory to begin the first of 23 orbits in the Grand Finale, which will begin April 26.

Cassini launched from Earth on October 20, 1997, and entered Saturn orbit July 1, 2004. 16 days later, the European-built Huygens probe attached to the spacecraft landed on Titan, becoming the first probe to land in the outer solar system. Originally scheduled for a four-year mission ending in 2008, Cassini received two mission extensions in 2008 and 2010, with the latter ending in 2017. With the spacecraft’s fuel reserves low, the Cassini team decided to end the mission. P/C: JPL/Erik Wernquist

Ep. 5 Star Classifications Part 1: Leavitt and Variable Stars - HD and the Void

First in a two-part series about stars and how we classify them. Variables are a very specific kind of star that have a regular variation in brightness, like a heartbeat. They were first categorized and analyzed by Henrietta Swan Leavitt at the tu...

Stars are too distant to really peer at and they have all that radiation and heat and blinding light and such so it’s doubtful that we will ever be able to prod the Sun, but astronomers can certainly classify what stars we’ve been able to observe! This is the first part of a two-part series on star classification systems. This podcast focuses on variable stars, how they were discovered, the awesome women who started developing the basis of a major star classification system, and what variable stars did for our understanding of the universe. 

There is a lot of technical talk and I did my best to make it comprehensible but you can absolutely hit me up with questions if you have them! I’m also on Twitter at @HDandtheVoid if you’d rather ask me there. And go ahead and check out the podcast on iTunes, rate it or review it if you’d like, and subscribe! I’ll always post all the extras here on tumblr but iTunes might be more convenient for downloading and podcast apps and all that good stuff.

Below the cut is some elaboration on the episode itself, including my sources, music credits, a BIG glossary, a quote on women and emotional labor that really hits home for me, and a transcript. I mention a couple of books and quote a couple people in this episode so if you want to see that written down, those sources are there as well. Let me know what you think of this episode, let me know what you think I should research next*, tell me a fun space fact… anything’s helpful! 

*(The June 19th podcast is already set, it’s going to be part 2 on star classifications, but in July I could start talking about things like spectroscopy, planets, dark matter, or I have a book in at the library on longitude.)

Glossary:

arcsecond - an infinitesimal measurement of a degree; in 1 degree there are 3,600 arcseconds.

cosmic distance measurements: light-years - a way to imagine distance scales on an astronomical level; the distance light can travel in one year, or about 6 trillion miles. parsecs - a measurement of distance on an astronomical scale; the distance to a star that shifts by one arcsecond from one side of Earth’s orbit to the other. It’s more common than using light-years when discussing deep space astronomy. One parsec is about 19 trillion miles (30 trillion kilometers), a bit over 3 light-years.

magnitude - the measurement of a star’s brightness as seen from earth. The brighter it is, the lower its magnitude value; the Sun has an apparent magnitude of -27.

Malmquist Bias - the stars that are visible in a cluster are the brightest ones. Astronomers rely on them to compute average luminosity, but the fact that they’re the brightest ones inevitably skews the results.

parallax - the apparent shift of an object when viewed through two different lines of sight.

radial velocity - the speed at which a star is moving away from or towards Earth.

standard candle - a kind of celestial object that has a known luminosity due to some characteristic that the entire class of objects possesses.

stellar photometry - measuring and recording the magnitude of stars.

triangulation - a technique to measure the distance of an object by observing it from two different locations, knowing the distance between both observation locations and measuring the angle at which the distant object moves (its parallax angle).

variable stars: variable stars - stars that change brightness. Reasons for the brightness changes vary, and certain types of variable stars can be used to determine relative distance. They are either intrinsic (when a change in brightness is caused by a star’s own physical changes, like pulsation or eruption) or extrinsic (when the variance has an external cause, such as an eclipse of one star by another or stellar rotation). Cepheid variables - variable stars with a period between 1 and 70 days, with light variations from 0.1 to 2 magnitudes. They’re massive, with a high luminosity and are usually classified between F and G or K. They obey the period-luminosity relationship and played a major part in calculating distances to far-away galaxies as well as helping to determine the age of the Universe. eclipsing binaries - binary systems of stars where the components regularly eclipse one another, causing an apparent decrease in the brightness of the system. irregular variables - variable stars, typically red giants, without a measurable period to their luminosity. Long Period Variables - LPVs have periods ranging from 30 to 1,000 days. They’re red giants or supergiants, typically classified M, R, C, or N. There are subclasses, too: Mira, which have light variations of more than 2.5 magnitudes and are the future evolution of our own star, the Sun; and semiregular, which have some regular periods and some irregular light variation and have light variations less than 2.5 magnitudes. RR Lyrae - variable stars with a period of 0.05 to 1.2 days and a light variation between 0.3 and 2 magnitudes. They’re older and smaller than Cepheids, and are white giant stars typically classified as A. RV Tauri - variable stars that have periods between 30 and 150 days, light variation up to 3 magnitudes, and possible cycle variations that can be hundreds or thousands of days long. They’re yellow supergiants classified between G and K.

cataclysmic variables: dwarf nova - a close binary system of a red dwarf, a white dwarf, and an accretion disk around the white dwarf. They brighten by 2 to 6 magnitudes depending on the stability of the disk, which loses material to the white dwarf. nova - a close binary system of a white dwarf and a secondary star that’s a little cooler than the Sun. The system brightens 7 to 16 magnitudes in 1 to 100 days, and then the star fades slowly to the initial brightness over a period of several years or decades. At maximum brightness, it’s similar to an A or F giant star. Recurrent novae are similar to this category of variable but have several outbursts during their recorded history. R Coronae Borealis - an eruptive variable, a supergiant star that is hydrogen-poor and carbon-rich and spends most of its time at maximum light, fading as much as 9 magnitudes at irregular intervals. Most often classified between F and K or R. supernova - a massive star that explodes with a magnitude increase of 20 or more. Supernovae have led us to realize that the expansion of the Universe is accelerating. symbiotic stars -  close binary systems of a red giant and a hot blue star. They have nova-like outbursts up to 3 magnitudes.

Script/Transcript

Sources:

What stars are made of via NASA

Stars, Cepheid Variable by T. Lloyd Evans via the California Institute of Technology aka CalTech

Variable stars via the Australia Telescope National Facility

American Association of Variable Star Observers website. I used a couple of pages from this one but the whole organization is kinda on the nose.

Stellar magnitude via EarthSky

A star magnitude scale via Harvard

Harvard Observatory’s Astronomical Photographic Plate Collection, which has a history of the collection and the women computers.

Definitions and differences for parsecs and light-years, and a description of parallax and triangulation via EarthSky

Standard candle breakdowns via some magical wonderful person with the best accessible online science book project I have ever encountered. Mad props to whoever is doing this, it’s a noble cause.

Info on Walter Baade via the Online Archives of California

A very math-y breakdown of the Malmquist Bias in the article “Observational Selection Bias Affecting the Determination of the Extragalactic Distance Scale” by P. Teerikorpi, published 1997

Johnson, George. Miss Leavitt’s Stars. Atlas Books: NY, 2005.

Henrietta Swan Leavitt quote: “It is worthy of notice [that] the brighter variables have the longer periods” (38).

“If a theory or observation seemed to suggest that we, the observers, happen to occupy an exalted place in the heavens, then it was probably wrong” (110)

Edwin Hubble quote: “With increasing distance, our knowledge fades, and fades rapidly. Eventually, we reach the dim boundary—the utmost limits of our telescopes. There, we measure shadows, and search among ghostly errors of measurements for landmarks that are scarcely more substantial” (130)

Pickover, Clifford A. “Leavitt’s Luminosity Law.” Archimedes to Hawking: Laws of Science and the Great Minds Behind Them. Oxford UP: NY, 2008. 475.

Soba, Dava. The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars. Viking: New York, 2016.

From Claire Messud’s The Woman Upstairs (I haven’t read the book, I just collect quotes, so this isn’t me endorsing the book; I know nothing about it except this paragraph): “I’m a good girl, I’m a nice girl, I’m a straight-A, strait-laced, good daughter, good career girl, and I never stole anybody’s boyfriend and I never ran out on a girlfriend, and I put up with my parents’ shit and my brother’s shit, and I’m not a girl anyhow, I’m over forty fucking years old, and I’m good at my job and I’m great with kids and I held my mother’s hand when she died, after four years of holding her hand while she was dying and I speak to my father every day on the telephone–every day, mind you, and what kind of weather do you have on your side of the river, because here it’s pretty gray and a bit muggy too? It was supposed to say ‘Great Artist’ on my tombstone, but if I died right now it would say ‘such a good teacher/daughter/friend’ instead; and what I really want to shout, and want in big letters on that grave, too, is FUCK YOU ALL.”

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: 'River Man’ by Nick Drake off his album Five Leaves Left.

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught