Fillthevoid-with-space - Fill The Void With... SPACE

Ep. 8 Planets - HD and the Void

Eight planets in the solar system or nine? I go into depth with nine because I grew up with Pluto. The first five planets are visible to the naked eye but how did we find Uranus, Neptune, and Pluto? What are we doing to still learn about our close...

Earth is a super special world. It has life on it, and getting conditions just right so that life will survive is an incredibly difficult task. Other planets and other moons in our solar system may look like they could have life on them, but it just didn’t happen.

Life on other planets is for a different episode, though. In this one, I’m talking about what we can see on our close neighbors, the eight (maybe seven?) planets in our solar system. Learn how they were discovered, what naming conventions we use for them and their moons, how to differentiate between them, and what probes we’ve sent out to learn more about them. Also enjoy snippets from the lovely orchestral suite written for each planet by Gustav Holst! It’s the longest episode so far but I promise it’s worth it.

There’s a timeline below the cut in addition to the other resources because hooboy did I mention a lot of people. I may also put together a timeline of probes... But that’s for another podcast. Maybe the next podcast! Let me know what you think I should research by messaging me here, tweeting at me at @HDandtheVoid, or asking me to my face if you know me in real life. And please check out the podcast on iTunes, rate it or review it if you’d like, subscribe, and maybe tell your friends about it if you think they’d like to listen! Also below the cut are my sources, music credits, vocab list, and the transcript. I mention a book, a play, a poem, and a few works of art, and I quote an astronomy book in this episode so if you want to see that written down, those sources are there as well.

(My thoughts for the next episode were spectroscopy, auroras, or probes through the ages. Let me know by the 21st and I’ll have the next podcast up by July 31!)

Glossary:

auroras - a light display that occurs when a magnetosphere is sufficiently disturbed by solar wind that charged particles scatter into the upper atmosphere and lose their energy.

magnetosphere - an invisible barrier that surrounds a celestial objet. It is often generated by the movement of the liquid metal core of the object. Around a planet, it deflects high-energy, charged particles called cosmic rays that can either come from the Sun or, less often, from interstellar space.

prograde - when a planet spins from east to west.

retrograde - when a planet spins from west to east.

sol - a unit of time measuring one Martian day, or 24 Earth-hours and 40 Earth-minutes. The immediately previous Martian day is called yestersol.

transit of Mercury/Venus - when a planet passes in front of the Sun.

Script/Transcript

Timeline of people mentioned

Nicolaus Copernicus, Polish (1473-1543)

Tycho Brahe, Danish (1541-1601)

Galileo Galilei, Italian (1564-1642)

Johannes Kepler, German (1571-1630)

Simon Marius, German (1573-1625)

Pierre Gassendi, French (1592-1655)

Giovanni Cassini (also known as Jean-Dominique Cassini), Italian/French (1625-1712)

Christiaan Huygens, Dutch (1629-1695)

William Herschel, German/English (1738-1822)

Johann Elert Bode, German (1747-1826)

Caroline Herschel, German/English (1750-1848)

Johann Franz Encke, German (1791-1865)

John Herschel, English (1792-1871)

William Lassell, English (1799-1880)

Urbain Le Verrier, French (1811-1877)

Johann Galle, German (1812-1910)

John Couch Adams, English (1819-1892)

Edouard Roche, French (1820-1883)

Heinrich Louis d’Arrest, German (1822-1875)

Asaph Hall III, American (1829-1907)

James Clark Maxwell, Scottish (1831-1879)

Giovanni Schiaparelli, Italian (1835-1910)

Percival Lowell, American (1855-1916)

Eugène Antoniadi (also known as Eugenios Antoniadis), Greek (1870-1944)

Gerard Kuiper, Dutch/American (1905-1973)

Clyde Tombaugh (1906-1997)

Sources:

Who discovered each planet via Cornell University

The mathematical discovery of Neptune and Pluto via University of St. Andrews, where my mom’s boyfriend’s son graduated last year! Mad props, Henry!

Holst’s The Planets via the Utah Symphony

More on Holst’s suite, including music files

Chronology of solar system discovery

MESSENGER information via John Hopkins University Applied Physics Laboratory

Auroras via NASA’s Themis mission

Magnetospheres via NASA, which has a tumblr! You should follow it! Good stuff.

Curiosity rover via NASA

‘Canali on Mars’ debacle via NASA

Mariner 9 via NASA

Origin of ‘yestersol’ and Martian day-length via A Way With Words

Richard Bram: “Superlatives are inadequate; words fail. Look. Think. Be in awe.”

Images of Mars through the years via The Telegraph

Mars-One mission to colonize Mars

Names of all the planet’s moons and their significance in mythology, last updated in 2013 and questionably reliable but from what I know of mythology—and I do know more than most—it’s not too far off.

Table of moons of various planets

Jupiter via NASA

Jupiter moon name facts via NASA

The Galilean Moons of Jupiter via University of Colorado at Boulder

Saturn’s moons via Phys.org

Cassini mission website

Saturn overview via NASA

Saturn’s moon Titan via NASA

Ethane via PubChem

Methane via EPA

Neptune’s moons via Space.com

What is Pluto via NASA

Pluto Overview via NASA

“Dwarf planets may provide the best evidence about the origins of our solar system.”

New Horizons mission via NASA

Pluto and our designations for planets are mentioned very briefly in this Oatmeal comic. I liked it.

Sobel, Dava. The Planets. Viking: NY, 2005.

“But tides raised by the Sun in the planet’s molten middle gradually damped Mercury’s rotation down to its present slow gait” (34).

“Light and heat always hit Mercury dead on, while the north and south poles, which receive no direct sunlight, remain relatively frigid at all times” (35).

“Venusian clouds comprise large and small droplets of real vitriol—sulfuric acid along with caustic compounds of chlorine and fluorine. They precipitate a constant acid rain, called virga, that evaporates in Venus’ hot, arid air before it has a chance to strike the ground” (61).

“…Neptune, where the voices of a female choir, sequestered in a room offstage, are made to fade out at the finale (with no sacrifice in pitch) by the slow, silent closing of a door” (165).

Holst: “Saturn brings not only physical decay but also a vision of fulfillment” (165).

“They occupy a nearby region of perpetual fragmentation known as the Roche zone, named for the nineteenth-century French astronomer Edouard Roche, who formulated the safe distances for planetary satellites” (172).

“It's near twin, Neptune, reveals a more complex beauty in subtle stripes and spots of royal to navy blue, azure, turquoise, and aquamarine” (200).

“This outlying population offered Pluto a new identity—if not the last planet, then the first citizen of a distant teeming shore” (214).

Van Gogh, Vincent. Starry Night (June 1889). 

—. Road with Cypress and Star (May 1890). 

—. White House at Night (June 1890). 

Shakespeare, William. A Midsummer Night’s Dream (1605).

Pope, Alexander. “The Rape of the Lock” (1712). (It’s a mock-epic satiric poem about stealing a lock of hair, not physical rape)

Duane, Diane. Wizards at War. Harcourt Trade Publishers: San Diego CA, 2005.

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

Filler Music: The Planets (1918) by Gustav Holst, performed by the London Symphony Orchestra in 2003.

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

Ep. 21 Radio Astronomy and RQZs - HD and the Void

Be brave in the face of an extremely technical episode where I tackle radio astronomy! Astronomers collect radio waves to map distant objects. To do their work they need a level of quiet that's hard to find without some help from Radio Frequency I...

I’ve gotten some feedback that episodes can be too technical. Unfortunately, that feedback came too late to save you from this week’s episode, which requires me to summarize the electromagnetic spectrum, radio astronomy, a concept called interferometry, and government regulations to talk about the topic that originally started me on this path: radio quiet zones. Please, bear with me! Pardon my mess! It was all very interesting stuff, I couldn’t resist digging into it.

Below the cut are my sources, music credits, a vocab list, a timeline of the astronomers I mention, and the transcript of this episode. I’ve bolded those sources I mention in the podcast, including the podcast that started me on this topic: The Adventure Zone! Please let me know what you think I should research next by messaging me here, tweeting at me at @HDandtheVoid, or asking me to my face if you know me. I’d love it if you would subscribe on iTunes, rate my humble little podcast and maybe review it, and tell friends if you think they’d like to hear it!

(My thoughts on the next episode are SOFIA, which you need to listen to find out what it stands for, or the pilot Chuck Yaeger. The next episode will go up February 26th.)

Glossary

aperture synthesis - the process of collecting electromagnetic radiation from a variety of separate, small telescopes and then combining this data to recreate the image at a higher resolution than would be possible with a single telescope.

frequency - the number of times a wave oscillates up and down per second.

hertz - the number of times an electromagnetic wave cycles per second. One cycle per second is 1 hertz.

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.

radiation - energy that travels and spreads out as it goes.

Script/Transcript

Timeline

Joseph-Louis Lagrange, French (1736-1813)

Armand-Hippolyte-Louis Fizeau, French (1819-1896)

Edward W. Morley, American (1838-1923)

Albert A. Michelson, American (1852-1931)

Sir Martin Ryle, British (1918-1984)

Bernard Yarnton Mills, Australian (1920-2011)

Derek Vonberg, British (1922-2015)

Antony Hewish, British (1924- )

Sources

Electromagnetic spectrum via NASA

Observatories across the EM spectrum via NASA

Fermi satellite via NASA

The Neil Gehrels Swift Observatory via NASA

NuSTAR via Caltech

NuSTAR via NASA

Chandra X-Ray Observatory via Harvard

The Galaxy Evolution Explorer (GALEX) via Caltech

Kepler satellite via NASA

Hubble Space Telescope via NASA

Spitzer satellite via Caltech

Stratospheric Observatory for Infrared Astronomy (SOFIA)

Planck satellite via ESA

Spekt-R Radioastron from Russia

High Energy Stereoscopic System (HESS)

W. M. Keck Observatory on Mauna Kea

South Africa Large Telescope (SALT) in Namibia

The Combined Array for Research in Millimeter-Wave Astronomy (CARMA) via Caltech

CARMA public page (decommissioned)

Very Large Array (VLA) via NRAO

Space radio telescope (1997) via NRAO

Highly Advanced Laboratory for Communications and Astronomy (HALCA) via NASA

A timeline of the history of radio interferometry via University of Groningen (Netherlands)

Interferometers via the LIGO Laboratory

Michelson-Morley Experiment via University of Virginia

Astronomical Interferometry via Magdalena Ridge Observatory

Interferometry via XKCD

How Radio Works via How Stuff Works

Radio Spectrum Allocation via the Federal Communications Commission

Interferometry via the European Space Observatory

National Radio Quiet Zone via National Radio Astronomy Observatory

“minimize possible harmful interference to the National Radio Astronomy Observatory (NRAO) in Green Bank, WV and the radio receiving facilities for the United States Navy in Sugar Grove, WV.”

National Radio Quiet Zone via CNN

“Tucked in the Allegheny Mountains, researchers are listening to exploding galaxies at the edge of the universe – a signal that is so faint, it’s about a billionth of a billionth of a millionth of a watt.”

The Quiet Zone: Where mobile phones are banned via BBC News (May 2015)

Enter The Quiet Zone: Where Cell Service, Wi-Fi Are Banned via NPR (Oct 2013)

Green Bank Observatory in West Virginia, USA

Karen O’Neil: “The types of energies we look at are less than the energy of a single snowflake falling on the Earth.”

Characteristics of radio quiet zones via International Telecommunication Union (Sept 2012)

“transmissions below 15 GHz are restricted within a certain radius around the Arecibo Observatory, located in Puerto Rico. Since no observations are carried out, nor are any expected to be carried out above that frequency in the future, no restrictions are needed on higher frequency transmissions. The reverse is not necessarily true, however. For example, some restrictions may be imposed on transmissions below 30 GHz in the neighbourhood of the large international ALMA observatory even though it is not expected to ever observe below that frequency, due to its susceptibility to interference at these lower frequencies in the signal path.”

“It is important to emphasize that a RQZ does not imply a complete absence of radio transmissions. The existence of, and coexistence with, a range of man-made devices will always be necessary. A RQZ may include options for notification of other users and for negotiation in mitigating interference. On the other hand, a RQZ does not consist entirely of mitigating techniques implemented by the radio astronomy facility; some level of control on externally-generated interference is intrinsic to a RQZ.

A RQZ is therefore a buffer zone that allows for the implementation of mechanisms to protect radio astronomy observations at a facility within the zone from detrimental radio frequency interference, through effective mitigation strategies and regulation of radio frequency transmitters.”

ALMA Observatory website

The Scientific Committee on Frequency Allocations for Radio Astronomy (IUCAF) website

Google Map of worldwide radio quiet zones (Aug 2016)

ITU-R Recommendations of Particular Importance to Radio Astronomy by A. Richard Thompson

“the necessity of maintaining the shielded zone of the Moon as an area of great potential for observations by the radio astronomy service and by passive space research, and consequently of maintaining it as free as possible from transmissions.”

The Adventure Zone: Amnesty setup episode via Maximum Fun

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

Filler Music: ‘Junkyard Chandelier’ by Radical Face aka Ben Cooper, who primarily releases music as Radical Face but also has at least three other bands or band names he’s working with/has released music as.

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

Ep. 32 Black Holes - HD and the Void

I have mentioned black holes in previous episodes, but now feels like the right time to talk about them in their very own episode! I also discuss the new photos of the supermassive black hole in the galaxy Messier 87 and the telescope that was nee...

New Zealand was lovely, but I already touched on what I’d be tempted to talk about with my Southern Stars episode. A person I interviewed as a potential new housemate gave me the idea for this episode because the joy of outer space is truly everywhere and anywhere. The field of astrogeology was not something I had heard of before, though I had indirectly heard of Eugene Shoemaker. I knew the comet Shoemaker-Levy 9 was named after him (and Carolyn Shoemaker, his wife). It turns out he basically founded the modern field of astrogeology! So I talk about him for quite a while, too.

Below the cut are the glossary, transcript, sources, and music credits. Send me any topic suggestions via Tumblr message (you don’t need an account to do this, just submit as anonymous). You can also tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me in real life. Subscribe on iTunes to get the new episodes of my semi-monthly podcast, and please please please rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!

(The next episode is definitely going to be on famous comets, and I’m hoping to publish that episode in May.)

Glossary

active galaxy - 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.

black hole -  a region of spacetime where a great deal of mass and energy have been compressed into a relatively small space. Black holes exert such strong gravitational effects that no mass or energy, not even light, can escape from inside them. There are supermassive black holes in galaxies that contribute to the development and life cycle of galaxies.

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.

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.

Messier object - a deep-sky object included on a list of 103-110 deep-sky objects made by Charles Messier and his colleagues in the 18th century in an attempt to prevent fuzzy, bright objects from being confused with comets.

torus - a donut shape.

quasar - a distant, massive celestial object that emits extremely large amounts of energy. These star-like objects may reflect a stage in the evolution of some galaxies.

Script/Transcript

Sources

Black Holes, explained via National Geographic

What Is a Black Hole? via NASA

Black Holes via NASA

Black Hole via Swinburne University of Technology

Darkness Visible, Finally: Astronomers Capture First Ever Image of a Black Hole via the New York Times (April 2019)

Event Horizon Telescope

Astronomers Capture First Image of a Black Hole via ESO (April 2019)

How They Took the First Picture of a Black Hole via New York Times (April 2019)

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

Filler Music: ‘Flame On Flame (A Slow Dirge)’ by Kishi Bashi off his album Sonderlust

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

Does Mars Have Rings? Not Right Now, But Maybe One Day

NASA - Mars Science Laboratory (MSL) patch. March 20, 2017 As children, we learned about our solar system’s planets by certain characteristics – Jupiter is the largest, Saturn has rings, Mercury is closest to the sun. Mars is red, but it’s possible that one of our closest neighbors also had rings at one point and may have them again someday. That’s the theory put forth by NASA-funded scientists at Purdue University, Lafayette, Indiana, whose findings were published in the journal Nature Geoscience. David Minton and Andrew Hesselbrock developed a model that suggests that debris that was pushed into space from an asteroid or other body slamming into Mars around 4.3 billion years ago alternates between becoming a planetary ring and clumping together to form a moon. One theory suggests that Mars’ large North Polar Basin or Borealis Basin – which covers about 40 percent of the planet in its northern hemisphere – was created by that impact, sending debris into space. “That large impact would have blasted enough material off the surface of Mars to form a ring,” Hesselbrock said. Hesselbrock and Minton’s model suggests that as the ring formed, and the debris slowly moved away from the Red Planet and spread out, it began to clump and eventually formed a moon. Over time, Mars’ gravitational pull would have pulled that moon toward the planet until it reached the Roche limit, the distance within which a planet’s tidal forces will break apart a celestial body that is held together only by gravity.

Image above: The image from NASA’s Curiosity Mars rover shows one of Mars’ two moons, Phobos, passing directly in front of the other, Deimos, in 2013. New research suggests the moons consolidated long ago from dust rings around the planet and, in the distant future, may disintegrate into new rings. Image Credits: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ. Phobos, one of Mars’ moons, is getting closer to the planet. According to the model, Phobos will break apart upon reaching the Roche limit, and become a set of rings in roughly 70 million years. Depending on where the Roche limit is, Minton and Hesselbrock believe this cycle may have repeated between three and seven times over billions of years. Each time a moon broke apart and reformed from the resulting ring, its successor moon would be five times smaller than the last, according to the model, and debris would have rained down on the planet, possibly explaining enigmatic sedimentary deposits found near Mars’ equator. “You could have had kilometer-thick piles of moon sediment raining down on Mars in the early parts of the planet’s history, and there are enigmatic sedimentary deposits on Mars with no explanation as to how they got there,” Minton said. “And now it’s possible to study that material.” Other theories suggest that the impact with Mars that created the North Polar Basin led to the formation of Phobos 4.3 billion years ago, but Minton said it’s unlikely the moon could have lasted all that time. Also, Phobos would have had to form far from Mars and would have had to cross through the resonance of Deimos, the outer of Mars’ two moons. Resonance occurs when two moons exert gravitational influence on each other in a repeated periodic basis, as major moons of Jupiter do. By passing through its resonance, Phobos would have altered Deimos’ orbit. But Deimos’ orbit is within one degree of Mars’ equator, suggesting Phobos has had no effect on Deimos. “Not much has happened to Deimos’ orbit since it formed,” Minton said. “Phobos passing through these resonances would have changed that.” “This research highlights even more ways that major impacts can affect a planetary body,” said Richard Zurek of NASA’s Jet Propulsion Laboratory, Pasadena, California. He is the project scientist for NASA’s Mars Reconnaissance Orbiter, whose gravity mapping provided support for the hypothesis that the northern lowlands were formed by a massive impact. Minton and Hesselbrock will now focus their work on either the dynamics of the first set of rings that formed or the materials that have rained down on Mars from disintegration of moons. Curiosity is part of NASA’s ongoing Mars research and preparation for a human mission to Mars in the 2030s. Caltech manages JPL, and JPL manages the Curiosity mission for NASA’s Science Mission Directorate in Washington. For more about Curiosity, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ For more information about NASA missions investigating Mars, visit: https://mars.nasa.gov/ Image (mentioned), Text, Credits: NASA/Laurie Cantillo/Dwayne Brown/JPL/Guy Webster/Purdue University/Steve Tally/Emil Venere/Writer: Brian Wallheimer. Best regards, Orbiter.ch Full article

I love this comic a lot! You can read it all online to make sure you want to buy it, and then you should buy it because it’s extremely excellent. It’s about preservation in space and also love and found families! And it’s absolutely beautiful. I met Tillie while she was in my town signing her comic Spinning (also excellent) and she drew one of the fish spaceships for me and she was so kind even though I am terrible at smalltalk. Check her comic out!

OH MY! Here’s the cover for ON A SUNBEAM the graphic novel. Coming out this fall!!!! 

The Birth of a New Star. IRAS 14568-6304

via reddit

Heads up, this is tomorrow night! I hope it's clear where I am to see it but considering I'm in the Pacific Northwest, I don't have super high hopes. Get a look if you can, though! Rare to see a blue moon that's actually red :)

A Total Lunar Eclipse is Coming: 10 Things to Know

If you were captivated by August’s total solar eclipse, there’s another sky show to look forward to on Jan. 31: a total lunar eclipse!

Below are 10 things to know about this astronomical event, including where to see it, why it turns the Moon into a deep red color and more…

1. First things first. What’s the difference between solar and lunar eclipses? We’ve got the quick and easy explanation in this video:

2. Location, location, location. What you see will depend on where you are. The total lunar eclipse will favor the western U.S., Alaska, Hawaii, and British Columbia on Jan. 31. Australia and the Pacific Ocean are also well placed to see a major portion of the eclipse, if not all of it.

3. Color play. So, why does the Moon turn red during a lunar eclipse? Here’s your answer:

4. Scientists, stand by. What science can be done during a lunar eclipse? Find out HERE. 

5. Show and tell. What would Earth look like from the Moon during a lunar eclipse? See for yourself with this artist’s concept HERE. 

6. Ask me anything. Mark your calendars to learn more about the Moon during our our Reddit AMA happening Monday, Jan. 29, from 3-4 pm EST/12-1 pm PST.

7. Social cues. Make sure to follow @NASAMoon and @LRO_NASA for all of the latest Moon news leading up to the eclipse and beyond.

8. Watch year-round. Can’t get enough of observing the Moon? Make a DIY Moon Phases Calendar and Calculator that will keep all of the dates and times for the year’s moon phases right at your fingertips HERE.

Then, jot down notes and record your own illustrations of the Moon with a Moon observation journal, available to download and print from moon.nasa.gov.

9. Lesson learned. For educators, pique your students’ curiosities about the lunar eclipse with this Teachable Moment HERE.

10. Coming attraction. There will be one more lunar eclipse this year on July 27, 2018. But you might need your passport—it will only be visible from central Africa and central Asia. The next lunar eclipse that can be seen all over the U.S. will be on Jan. 21, 2019. It won’t be a blue moon, but it will be a supermoon.

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

Andromeda [x]

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Comet That Took a Century to Confirm Passes by Earth

NASA Goddard Space Flight Center logo. March 31, 2017 On April 1, 2017, comet 41P will pass closer than it normally does to Earth, giving observers with binoculars or a telescope a special viewing opportunity. Comet hunters in the Northern Hemisphere should look for it near the constellations Draco and Ursa Major, which the Big Dipper is part of. Whether a comet will put on a good show for observers is notoriously difficult to predict, but 41P has a history of outbursts, and put on quite a display in 1973. If the comet experiences similar outbursts this time, there’s a chance it could become bright enough to see with the naked eye. The comet is expected to reach perihelion, or its closest approach to the sun, on April 12.

Image above: In this image taken March 24, 2017, comet 41P/Tuttle-Giacobini-Kresák is shown moving through a field of faint galaxies in the bowl of the Big Dipper. On April 1, the comet will pass by Earth at a distance of about 13 million miles (0.14 astronomical units), or 55 times the distance from Earth to the moon; that is a much closer approach than usual for this Jupiter-family comet. Image Credits: image copyright Chris Schur, used with permission. Officially named 41P/Tuttle-Giacobini-Kresák to honor its three discoverers, the comet is being playfully called the April Fool’s Day comet on this pass. Discovery credit goes first to Horace Tuttle, who spotted the comet in 1858. According to the Cometography website, 41P was recognized at the time as a periodic comet — one that orbits the sun — but astronomers initially were uncertain how long the comet needed to make the trip. The comet was rediscovered in 1907 by Michael Giacobini but not immediately linked to the object seen in 1858. Later, the astronomer Andrew Crommelin determined that the two observations had been of the same object and predicted that the comet would return in 1928 and 1934, according to the Cometography entry for the comet. However, the object was not seen then and was considered lost. In 1951, L’ubor Kresák discovered it again and tied it to the earlier observations. A member of the Jupiter family of comets, 41P makes a trip around the sun every 5.4 years, coming relatively close to Earth on some of those trips. On this approach, the comet will pass our planet at a distance of about 13 million miles (0.14 astronomical units), or about 55 times the distance from Earth to the moon. This is the comet’s closest approach to Earth in more than 50 years and perhaps more than a century. For scientists, 41P’s visit is an opportunity to fill in details about the comet’s composition, coma and nucleus.

Image above: An artist’s illustration of a group of comet enthusiasts. Image Credits: NASA’s Goddard Space Flight Center. “An important aspect of Jupiter-family comets is that fewer of them have been studied, especially in terms of the composition of ices in their nuclei, compared with comets from the Oort cloud,” said Michael DiSanti of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. He and his team will be observing 41P on April 1 using NASA’s Infrared Telescope Facility in Hawaii. Astronomers will try to determine characteristics such as how quickly 41P’s nucleus rotates, which provides clues about how structurally sound the nucleus is, and whether any changes can be documented in the coma and tail. Observers also will look for outbursts, which are an indication of how active a comet is. By cataloging the subtle, and sometimes not-so-subtle, differences among comets, researchers can construct a family tree and trace the history of how and where these objects formed as the solar system was taking shape. “Comets are remnants from the early solar system,” said DiSanti. “Each comet that comes into the neighborhood of Earth gives us a chance to add to our understanding of the events that led to the formation of our own planet.” Related links: Comets: http://www.nasa.gov/comets Goddard Space Flight Center: https://www.nasa.gov/centers/goddard/home/index.html Images (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Elizabeth Zubritsky/Rob Garner. Greetings, Orbiter.ch Full article

Ep. 16 Voyager Golden Record - HD and the Void

Full disclosure: this is a kissing story. A kissing story about the ultimate mixtape and alien communication plan, sent out in 1977 and now in interstellar space. Hear about the Voyager Golden Record and the people who put it together as a compila...

The process of making an audio and visual compilation to explain Earth and humanity to an alien species is an incredible undertaking, and Carl Sagan undertook it in 1977. The resulting record from his little team was sent out with the Voyager 1 and 2 probes and is now in interstellar space, but there was also a more personal result of this project. Learn about Sagan and his third wife’s meet-cute and also hear what is actually out there in the stars, conveying the best humanity had to offer in the 70s. 

Below the cut are my sources, music credits, a vocab list, and the transcript of this episode. Vote on what you think I should research next by messaging me here, tweeting at me at @HDandtheVoid, or asking me to my face if you know me in real life. And please subscribe to the podcast on iTunes, rate it and maybe review it, and tell friends if you think they’d like to listen!

(My thoughts on the next episode are space race history, the transit of Venus, Edmond Halley, or Dark Sky Preserves. Next episode will be up on December 4th.)

Glossary

electroencephalography (EEG) - a recording that displays brainwave activity by measuring the electrical impulses of neurons firing in the brain

heliosheath - the outer region of the heliosphere. It is just beyond termination shock, the point where solar wind abruptly slows down and becomes denser and hotter as it presses outward against the approaching wind in interstellar space.

heliosphere - a huge wind sock-shaped bubble that extends beyond Pluto’s orbit and contains our solar system, solar wind, and the entire solar magnetic field.

Transcript

Sources

Drunk History episode transcript

Golden record via NASA

Carl Sagan via Smithsonian Magazine, March 2014

Carl Sagan via Biography.com

Carl Sagan via National Geographic

The Voyager project love story via NASA

Ann Druyen: “We know that EEG patterns register some changes in thought. Would it be possible, I wondered, for a highly advanced technology of several million years from now to actually decipher human thoughts?"

Ann Druyen: "a mental itinerary of the ideas and individuals of history whose memory I hoped to perpetuate."

Ann Druyen: "My feelings as a 27-year-old woman, madly fallen in love, they're on that record. It's forever. It'll be true 100 million years from now. For me, Voyager is a kind of joy so powerful, it robs you of your fear of death."

Arthur C. Clarke: "Please leave me alone; let me go on to the stars."

How 8-track tapes work via 8 Track Heaven

How vinyl records work via The Guardian, June 2010

Golden record via Smithsonian Magazine, April 2012

Golden record via the JPL at NASA

Golden record retrospective by Timothy Ferris via The New Yorker, August 2017

Voyager Golden Record - Greetings In 55 Languages via YouTube

The 116 images NASA wants aliens to see via YouTube

The Voyagers documentary by Penny Lane via Brain Pickings

Ann Druyen: “Carl and I knew we were the beneficiaries of chance, that pure chance could be so kind that we could find one another in the vastness of space and the immensity of time. We knew that every moment should be cherished as the precious and unlikely coincidence that it was.”

Article on Sagan’s divorce from Linda Salzman Sagan via People, December 1980

Article on Sagan’s divorce from Linda Salzman Sagan via The Cornell Daily Sun, March 1981

Voyager record available on Soundcloud via Cosmos Magazine

Golden record now available for purchase via The Atlantic, August 2017

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

Filler Music:  ‘Dark Was The Night, Cold Was The Ground’ by Blind Willie Johnson (1897-1945) off the album Dark Was The Night ‘Carl Sagan’ by Loch Lomond off their album Paper The Walls

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