Glossary

Astronaut tweets

I found a bizarre open-access, peer-review journal of STEM research. It was hard for me to find anything that pertained to astronomy or any of the stellar studies, but I did find a couple categories I could investigate: 

Astrobiology

Astronomical Sciences

Spectroscopy (I didn’t see any astronomical spectroscopy stuff but who knows)

Just looking at the articles popping up suggests that it would take some serious digging to find anything (and I would certainly have to work on my keyword optimization techniques because typing ‘space’ into the search bar got me nothing relevant to my interests), but it’s a new potential resource! And for anyone who wants to find a way to publish in STEM fields, maybe it’s something worth checking out?

Ep. 4 Henges and Archaeoastronomy - HD and the Void

Henges are only one type of astronomical tracking and observation monument. Other kinds include using big rocks that already exist and then building something close enough to observe its interaction with the Sun; building an observatory or a big p...

Henges! What the heck are they? And why is the word for studying them (and various monuments around the world that serve a similar purpose) so friggin long? Archaeoastronomy? What even is that? I got quite a few requests for this one so hopefully I did it justice... in my own special, somewhat contrary way.

Below the cut is some elaboration on the episode itself, including my sources, music credits, a glossary, some Google Maps images of the locations I talk about, and a transcript (not an exact record of this episode, but it’s the loose, fairly conversational script I was working with). 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 too. I’m also on Twitter at @HDandtheVoid.

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 at this point!

*(My thoughts were planets or star classifications. Give me some feedback by May 25th so I can start working on it! The next episode will be on June 5th.)

Glossary:

archaeoastronomy - the study of the astronomical practices, celestial lore, mythologies, religions, and world-views of all ancient cultures. The anthropology of astronomy.

equinox - twice a year, in the spring (vernal equinox) and fall (autumnal equinox), the 23.5-degree tilt of the Earth’s axis and Earth’s orbit around the sun combine in such a way that the axis is inclined neither away from nor toward the sun. The day and night are of equal length.

henge - a prehistoric monument consisting of a circle of stone or wooden uprights.

kiva - a room used for rituals and political meetings for many Southwest American Indian tribes.

petroglyph - rock carvings made by pecking directly on the rock surface using a stone chisel and a hammerstone. The desert varnish on the surface of the rock is chipped off, exposing the lighter rock underneath.

solstice - twice a year, in the summer (Midsummer) and winter (Midwinter), the 23.5-degree tilt of the Earth’s axis and Earth’s orbit around the sun mean that the axis is inclined away from or toward the sun. In Midsummer, the day is longest; in Midwinter, the day is shortest.

Script/Transcript (I do tend to embellish in the moment of recording so it’s not exact, but all the facts are there and I can’t know a fact and not talk about it so trust me, all you’re missing is probably another swear word or two)

Chaco Canyon, New Mexico, United States of America

Chichen Itza, Yucutan, Mexico

Stonehenge, Salisbury, England

Newgrange, County Meath, Republic of Ireland

Sources:

The definition of ‘henge’

A slightly more exciting definition of ‘henge,’ with pictures

Classifications of henges in the British Isles

The definition of a petroglyph, with pictures

A 3-minute video about solstices and equinoxes that has images of Chichen Itza and Stonehenge as well as Macchu Picchu, via National Geographic

Another explanation of the equinoxes and solstices; no video, though

The great Stonehenge Purchase!

More on the great Stonehenge Purchase!

Neil deGrasse Tyson writes about Manhattanhenge

Find your own city’s henge!

Burl, Aubrey. The Stone Circles of Britain, Ireland, and Brittany. Yale UP: New Haven, CT, 2000. Located on Google Books.

Crouper, Heather and Nigel Henbest. The History of Astronomy. Firefly Books: Buffalo, NY, 2007.

Clive Ruggles quote: “Generally people in indigenous cultures in the past tried to make sense of the cosmos—of the world around them—by drawing links between things; things in the sky, things around them in the landscape, and social things too—all mixed in” (14).

G.B. Cornucopia quote: “One of the Chacoan people’s tools was certainly astronomy, and they were interested in astronomy because anyone living in this harsh environment who does not understand their environment will not survive” (11).

Ed Krupp quote: “Usually monumental architecture isn’t dedicated to observing the sky. It’s a way that people express how they feel at home in the universe; but also how they control the universe” (21).

Glowacki, Donna M. Living and Leaving: A Social History of Regional Depopulation in Thirteenth-Century Mesa Verde. U of AZ P: Tucson, AZ, 2015. Located on Google Books.

McCluskey, S. C.  “Historical Archaeoastronomy: The Hopi Example.”  Archaeoastronomy in the New World.  Ed. A. F. Aveni.  London: Cambridge UP, 1982 (31-58).

McCluskey quote: “began watching when the sun ‘went in’ near the cultural center and motel on Second Mesa” (38).

Williamson, R. A. et al.  “Anasazi Solar Observatories.”  Native American Astronomy.  Ed. A. F. Aveni.  Austin: U Texas P, 1977 (203-218).

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

Filler Music: ‘Leaves’ by Patients 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. 20 Challenger - HD and the Void

January 28th was the anniversary of the Challenger space shuttle disaster, and while I do discuss what happened, I talk more about the American space shuttle program and what the repercussions of this disaster were for NASA as an agency. I have cl...

I had to skip last week to finish an article on STEM but it got me a really awesome intro to a very serious episode. Learn this week about 1) Sally Ride (a bit, just like the highlight reel on her) 2) NASA’s space shuttle program 3) the Challenger disaster that occurred January 28, 1986. It was the anniversary of this tragedy yesterday and I wanted to learn more about it and why it happened and what, ultimately, came out of that difficult time in the space shuttle program. 

I have a quick and easy way for you to cut out listening to the actual recap of the disaster if you don’t want to hear about it and just want to hear the fun space shuttle facts and the changes that NASA undertook in learning from Challenger’s destruction. Below the cut are my sources, music credits, a vocab list, and the transcript of this episode. I’ve bolded those sources I mention in the podcast, and I do have a trigger warning for the actual, live-coverage footage of the Challenger disaster. 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 (especially since I seem to have so many problems this month with consistent timing), 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 national radio quiet zones, or I could go into the transit of Venus. The next episode will go up February 12th.)

Glossary

gimbaled - moveable. In a gimbaled thrust system for rockets, the exhaust  nozzel of the rocket can be swiveled from side to side, which changes the direction of that thrust relative to rocket’s center of gravity.

pitch - in flight, this is rotation around the side-to-side axis. If the object’s nose points upwards or downwards, this is changing its pitch.

roll - in flight, this is rotation around the front-to-back axis. If the object’s wings spin from horizontal to vertical, it’s rolling.

yaw - in flight, this is rotation around the vertical axis. If the pilot turns the object so they can see more to the left or to the right, with no change in the horizon’s position, this is changing its yaw.

Script/Transcript

Sources

Sally Ride (for K-4) via NASA

Sally Ride bio via NASA

Sally Ride via the Smithsonian National Air and Space Museum

Sally Ride and her sexuality via Slates blog ‘Outward’ (May 2014)

Sexual Orientation Discrimination Policy via NASA

“Employees should expect to find a diversity of sexual orientations at NASA. In the past, it was common practice to fire or to refuse to hire suspected homosexuals in the Federal workplace. Employees have been physically threatened, verbally abused, and subjected to hostile working conditions. Laws and policies have changed, and all NASA employees need to be aware of their responsibility to prevent this form of discrimination and to ensure that lesbian, gay, bisexual, and transgender (LGBT) individuals are an accepted and valued part of the diverse NASA workforce.”

Space shuttle era via NASA

1983-1986: The Missions and History of Space Shuttle Challenger via NASA Spaceflight

Space shuttle process via NASA (archived)

Space shuttle components via NASA

Gimbaled thrust via NASA

Roll, Pitch, and Yaw via the Smithsonian National Air and Space Museum

Typical shuttle mission via NASA

Challenger via Space.com (Nov 2017)

Challenger disaster via History.com — contains an autoplay video

Challenger disaster live on CNN via YouTube (Jan 2011)—tw: destruction occurs at timecode 1:35

Challenger myths debunked via National Geographic (Jan 2016)

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

Filler Music: ‘Repent’ by Dreamend off their album And So I Ate Myself, Bite By Bite, which has cover art that scared the hell out of me when my friend gave it to me because I was on painkillers for a shattered radial head. Really good band, though.

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

This is so sweet! What a nice way to spend a Saturday night.

Make Sure You Observe the Moon on October 20

On Saturday, October 20, NASA will host the ninth annual International Observe the Moon Night. One day each year, everyone on Earth is invited to observe and learn about the Moon together, and to celebrate the cultural and personal connections we all have with our nearest celestial neighbor.

There are a number of ways to celebrate. You can attend an event, host your own, or just look up! Here are 10 of our favorite ways to observe the Moon:

1. Look up

Image credit: NASA’s Scientific Visualization Studio/Ernie Wright

The simplest way to observe the Moon is simply to look up. The Moon is the brightest object in our night sky, the second brightest in our daytime sky and can be seen from all around the world — from the remote and dark Atacama Desert in Chile to the brightly lit streets of Tokyo. On October 20, the near side of the Moon, or the side facing Earth, will be about 80 percent illuminated, rising in the early evening.

See the Moon phase on October 20 or any other day of the year!

2. Peer through a telescope or binoculars

The Moon and Venus are great targets for binoculars. Image Credit: NASA/Bill Dunford

With some magnification help, you will be able to focus in on specific features on the Moon, like the Sea of Tranquility or the bright Copernicus Crater. Download our Moon maps for some guided observing on Saturday.

3. Photograph the Moon

Image credit: NASA/GSFC/ASU

Our Lunar Reconnaissance Orbiter (LRO) has taken more than 20 million images of the Moon, mapping it in stunning detail. You can see featured, captioned images on LRO’s camera website, like the one of Montes Carpatus seen here. And, of course, you can take your own photos from Earth. Check out our tips on photographing the Moon!

4. Take a virtual field trip

Image credit: NASA/JPL-Caltech

Plan a lunar hike with Moontrek. Moontrek is an interactive Moon map made using NASA data from our lunar spacecraft. Fly anywhere you’d like on the Moon, calculate the distance or the elevation of a mountain to plan your lunar hike, or layer attributes of the lunar surface and temperature. If you have a virtual reality headset, you can experience Moontrek in 3D.

5. Touch the topography

Image credit: NASA GSFC/Jacob Richardson

Observe the Moon through touch! If you have access to a 3D printer, you can peruse our library of 3D models and lunar landscapes. This model of the Apollo 11 landing site created by NASA scientist Jacob Richardson, is derived from LRO’s topographic data. Near the center, you can actually feel a tiny dot where astronauts Neil Armstrong and Buzz Aldrin left the Lunar Descent Module.

6. Make Moon art

Image credit: LPI/Andy Shaner

Enjoy artwork of the Moon and create your own! For messy fun, lunar crater paintings demonstrate how the lunar surface changes due to consistent meteorite impacts.

7. Relax on your couch

Image credit: NASA’s Scientific Visualization Studio/Ernie Wright

There are many movies that feature our nearest neighbor, from A Voyage to the Moon by George Melies, to Apollo 13, to the newly released First Man. You can also spend your evening with our lunar playlist on YouTube or this video gallery, learning about the Moon’s role in eclipses, looking at the Moon phases from the far side, and seeing the latest science portrayed in super high resolution. You’ll impress all of your friends with your knowledge of supermoons.

8. Listen to the Moon

Video credit: NASA’s Scientific Visualization Studio/Ernie Wright

Make a playlist of Moon songs. For inspiration, check out this list of lunar tunes. We also recommend LRO’s official music video, The Moon and More, featuring Javier Colon, season 1 winner of NBC’s “The Voice.” Or you can just watch this video featuring “Clair de Lune,” by French composer Claude Debussy, over and over.

9. See the Moon through the eyes of a spacecraft

Image credit: NASA/GSFC/MIT

Visible light is just one tool that we use to explore our universe. Our spacecraft contain many different types of instruments to analyze the Moon’s composition and environment. Review the Moon’s gravity field with data from the GRAIL spacecraft or decipher the maze of this slope map from the laser altimeter onboard LRO. This collection from LRO features images of the Moon’s temperature and topography. You can learn more about our different missions to explore the Moon here.

10. Continue your observations throughout the year

Image credit: NASA’s Scientific Visualization Studio/Ernie Wright

An important part of observing the Moon is to see how it changes over time. International Observe the Moon Night is the perfect time to start a Moon journal. See how the shape of the Moon changes over the course of a month, and keep track of where and what time it rises and sets. Observe the Moon all year long with these tools and techniques!

However you choose to celebrate International Observe the Moon Night, we want to hear about it! Register your participation and share your experiences on social media with #ObserveTheMoon or on our Facebook page. Happy observing!

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

Margaret Hamilton is a computer scientist and mathematician. She was the lead software engineer for Project Apollo.  Her work prevented an abort of the Apollo 11 moon landing. She’s also credited for coining the term “software engineer." 

Stars Born in Winds from Supermassive Black Holes

ESO - European Southern Observatory logo. 27 March 2017 ESO’s VLT spots brand-new type of star formation

Artist’s impression of stars born in winds from supermassive black holes

Observations using ESO’s Very Large Telescope have revealed stars forming within powerful outflows of material blasted out from supermassive black holes at the cores of galaxies. These are the first confirmed observations of stars forming in this kind of extreme environment. The discovery has many consequences for understanding galaxy properties and evolution. The results are published in the journal Nature. A UK-led group of European astronomers used the MUSE and X-shooter instruments on the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile to study an ongoing collision between two galaxies, known collectively as IRAS F23128-5919, that lie around 600 million light-years from Earth. The group observed the colossal winds of material — or outflows — that originate near the supermassive black hole at the heart of the pair’s southern galaxy, and have found the first clear evidence that stars are being born within them [1]. Such galactic outflows are driven by the huge energy output from the active and turbulent centres of galaxies. Supermassive black holes lurk in the cores of most galaxies, and when they gobble up matter they also heat the surrounding gas and expel it from the host galaxy in powerful, dense winds [2]. “Astronomers have thought for a while that conditions within these outflows could be right for star formation, but no one has seen it actually happening as it’s a very difficult observation,” comments team leader Roberto Maiolino from the University of Cambridge. “Our results are exciting because they show unambiguously that stars are being created inside these outflows.”

Artist’s impression of stars born in winds from supermassive black holes

The group set out to study stars in the outflow directly, as well as the gas that surrounds them. By using two of the world-leading VLT spectroscopic instruments, MUSE and X-shooter, they could carry out a very detailed study of the properties of the emitted light to determine its source. Radiation from young stars is known to cause nearby gas clouds to glow in a particular way. The extreme sensitivity of X-shooter allowed the team to rule out other possible causes of this illumination, including gas shocks or the active nucleus of the galaxy. The group then made an unmistakable direct detection of an infant stellar population in the outflow [3]. These stars are thought to be less than a few tens of millions of years old, and preliminary analysis suggests that they are hotter and brighter than stars formed in less extreme environments such as the galactic disc. As further evidence, the astronomers also determined the motion and velocity of these stars. The light from most of the region’s stars indicates that they are travelling at very large velocities away from the galaxy centre — as would make sense for objects caught in a stream of fast-moving material. Co-author Helen Russell (Institute of Astronomy, Cambridge, UK) expands: “The stars that form in the wind close to the galaxy centre might slow down and even start heading back inwards, but the stars that form further out in the flow experience less deceleration and can even fly off out of the galaxy altogether.” The discovery provides new and exciting information that could better our understanding of some astrophysics, including how certain galaxies obtain their shapes [4]; how intergalactic space becomes enriched with heavy elements [5]; and even from where unexplained cosmic infrared background radiation may arise [6]. Maiolino is excited for the future: “If star formation is really occurring in most galactic outflows, as some theories predict, then this would provide a completely new scenario for our understanding of galaxy evolution.” Notes: [1] Stars are forming in the outflows at a very rapid rate; the astronomers say that stars totalling around 30 times the mass of the Sun are being created every year. This accounts for over a quarter of the total star formation in the entire merging galaxy system. [2] The expulsion of gas through galactic outflows leads to a gas-poor environment within the galaxy, which could be why some galaxies cease forming new stars as they age. Although these outflows are most likely to be driven by massive central black holes, it is also possible that the winds are powered by supernovae in a starburst nucleus undergoing vigorous star formation. [3] This was achieved through the detection of signatures characteristic of young stellar populations and with a velocity pattern consistent with that expected from stars formed at high velocity in the outflow. [4] Spiral galaxies have an obvious disc structure, with a distended bulge of stars in the centre and surrounded by a diffuse cloud of stars called a halo. Elliptical galaxies are composed mostly of these spheroidal components. Outflow stars that are ejected from the main disc could give rise to these galactic features. [5] How the space between galaxies — the intergalactic medium — becomes enriched with heavy elements is still an open issue, but outflow stars could provide an answer. If they are jettisoned out of the galaxy and then explode as supernovae, the heavy elements they contain could be released into this medium. [6] Cosmic-infrared background radiation, similar to the more famous cosmic microwave background, is a faint glow in the infrared part of the spectrum that appears to come from all directions in space. Its origin in the near-infrared bands, however, has never been satisfactorily ascertained. A population of outflow stars shot out into intergalactic space may contribute to this light. More information: This research was presented in a paper entitled “Star formation in a galactic outflow” by Maiolino et al., to appear in the journal Nature on 27 March 2017. The team is composed of R. Maiolino (Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), H.R. Russell (Institute of Astronomy, Cambridge, UK), A.C. Fabian (Institute of Astronomy, Cambridge, UK), S. Carniani (Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), R. Gallagher (Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), S. Cazzoli (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), S. Arribas (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), F. Belfiore ((Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), E. Bellocchi (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), L. Colina  (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), G. Cresci (Osservatorio Astrofisico di Arcetri, Firenze, Italy), W. Ishibashi (Universität Zürich, Zürich, Switzerland), A. Marconi (Università di Firenze, Italy; Osservatorio Astrofisico di Arcetri, Firenze, Italy), F. Mannucci (Osservatorio Astrofisico di Arcetri, Firenze, Italy), E. Oliva (Osservatorio Astrofisico di Arcetri, Firenze, Italy), and E. Sturm (Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany). ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”. Links: ESOcast 101 Light: Stars found in black hole blasts http://www.eso.org/public/videos/eso1710a/ Research paper in Nature: http://www.eso.org/public/archives/releases/sciencepapers/eso1710/eso1710a.pdf Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/ ESO’s Very Large Telescope (VLT): http://www.eso.org/public/teles-instr/paranal-observatory/vlt/ MUSE instrument: http://www.eso.org/public/teles-instr/paranal-observatory/vlt/vlt-instr/muse/ X-shooter instrument: http://www.eso.org/public/teles-instr/vlt/vlt-instr/x-shooter/ Image, Video, Text, Credits: ESO/Richard Hook/Cavendish Laboratory, Kavli Institute for Cosmology University of Cambridge/Roberto Maiolino/M. Kornmesser. Best regards, Orbiter.ch Full article

Ep. 26 Transits and Oppositions - HD and the Void

It's a history-heavy episode this week! Hear about the transits of Mercury and Venus, and learn what they have in common with the oppositions of planets like Mars, Jupiter, and Saturn—they're like eclipses, but with planets instead of the Moon.

The inner planets and the outer planets all look like stars from Earth. They are strange stars that move in strange ways, but their appearance depends on how they relate to observers on Earth. They are also affected by their position in relation to the Sun. Planets experience eclipses as well when the Sun, Earth, and planet are all aligned; in the inner planets, this is called a transit, and this has been a source of vast information about the solar system and the planets’ places in that system. In the outer planets, this eclipsing is called opposition. You get to hear about both in this week’s podcast!

Below the cut, I have the glossary, transcript, timeline of astronomers, sources, and music credits. I take topic suggestions from Tumblr messages, or you can 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 Chuck Yeager, Edmond Halley, Stephen Hawking and his theories, or famous comets. The next episode will go up later in June!)

Glossary

aphelion - a planet’s most distant position from the Sun

black drop effect - an optical illusion where a planet nearing the edge of the Sun appears to be connected to the Sun’s edge by a black teardrop.

conjunction - when the Earth, Sun, and another planet in the solar system are aligned so that Earth and the planet are on opposite sides of the Sun.

node - the point where another planet’s orbit crosses the plane of Earth’s orbit. The planets’ orbits are tilted at slightly different angles from each other; for example, Mercury’s orbit is inclined 7 degrees compared to Earth’s orbit. Because Mercury orbits the Sun once every 88 days, it crosses Earth’s orbit every 44 days at these nodes.

opposition - when one of the outer planets crosses the plane of Earth’s orbit opposite the Sun.

perihelion - a planet’s closest position to the Sun

retrograde - the apparent motion of a planet in a direction opposite to that of other bodies within its system, as observed from a particular vantage point.

syzygy - the straight line between three celestial bodies, usually the Sun to the Earth to another planetary body.

transit - when one of the inner planets crosses between the plane of Earth’s orbit and the Sun.

Script/Transcript

Timeline

Bernhard Walther, German (1430-1504)

Johannes Regiomontanus, German (1436-1476)

Willibald Pirckheimer, German (1470-1530)

Nicolaus Copernicus, Polish (1473-1543)

Georg Rheticus, Austrian (1514-1574)

Johannes Kepler, German (1571-1630)

Pierre Gassendi, French (1592-1655)

Johannes Hevelius, Polish (1611-1687)

Jeremiah Horrocks, English (1618-1641)

Edmond Halley, English (1656-1742)

Leonhard Euler, Swiss (1707-1783)

Alexandre Guy Pingré, French (1711-1796)

César-François Cassini de Thury, French (1714-1784)

Maximilian Hell, Hungarian (1720-1792)

Jean-Baptiste Chappe d’Auteroche, French (1722-1769)

James Cook, English (1728-1779)

Charles Mason, English (1728-1786)

Jeremiah Dixon, English (1733-1779)

János Sajnovics, Hungarian (1733-1785)

Thomas Hornsby, English (1733-1810)

Charles Green, English (1734-1771)

Joseph Jérôme Lefrançois de Lalande, French (1732-1807)

Jean Guillaume Wallot, French/German (1743-1794)

Christian VII of Denmark, Danish (1749-1808)

Sources

Mercury Solar Transit (image) via NASA

Mercury Transit of the Sun: Why Is It So Rare? via Space.com (May 2016)

The 2016 Transit of Mercury via NASA

Before the Transit of Mercury: forgotten forerunners of an astronomical revolution via The Guardian (May 2016)

Catalog of Venus Transits via NASA’s Fred Espenak

Mars Opposition via NASA

Mars brighter in 2018 than since 2003 via EarthSky (May 2018)

Opposition of Superior Planets via Hong Kong Observatory

Saturn at Opposition via NASA

Earth between sun and Saturn late June via EarthSky (Jun 2018 [not possible because I’m releasing this podcast in May 2018 but okay])

Uranus at opposition via EarthSky (Oct 2017)

Earth passing between Neptune and sun via EarthSky (Sept 2018 [not possible because I’m releasing this podcast in May 2018 but okay])

Anderson, Mark. The Day the World Discovered the Sun. Da Capo Press: Philadelphia, 2012.

“Visionaries like Edmund Halley had in 1716, for instance, argued that the Venus transit could enable science to trace out a map of the solar system accurate to 99.8 percent or better” (191).

Wulf, Andrea. Chasing Venus: The Race to Measure the Heavens. Alfred A. Knopf: New York, 2012.

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

Filler Music: ‘Cannonballs’ by Hey Marseilles off their album To Travels and Trunks.

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

How much of a daily threat is "Space junk"?

Good question, as this is a serious issue and one which we must monitor constantly in order to avoid harmful impacts on the International Space Station with objects in space.  For example, the US Space Command in Colorado is monitoring all objects bigger than a few inches in order to assess any potential impact with the Space Station.  We categorize the chance of impact and if there is a high probability, we will actually use thrusters to slightly change the position of the Space Station to avoid the impact.  If it is something that we are unable to avoid, we will have the astronauts shelter in place in their spacecrafts and in case of a catastrophic impact, they will return to Earth.

pretty space words

aphelion - the point in the orbit of a planet, asteroid, or comet at which it is farthest from the Sun. astral - relating to or resembling the stars. caldera - a large volcanic crater, especially one formed by a major eruption leading to the collapse of the mouth of the volcano. celestial - positioned in or relating to the sky, or outer space as observed in astronomy. constellation - a group of stars forming a recognizable pattern. cosmos - the universe seen as a well-ordered whole. equinox - the time or date at which the sun crosses the celestial equator, when day and night are of equal length. faculae - bright patches that are visible on the Sun’s surface. lunation - the interval of a complete lunar cycle, between one new Moon and the next. interstellar - occurring or situated between stars. nebula - a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter. perihelion - the point in the orbit of a planet, asteroid, or comet at which it is closest to the Sun. synodic - relating to or involving the conjunction of stars, planets, or other celestial objects.