You May Recognize The Seventh Picture In The Slideshow--it’s My Profile Picture Here. Happy Birthday

Ep. 22 African-American Astrophiles - HD and the Void

As Black History Month 2018 wraps up, learn about some of the African-American men and women who have contributed to space research and exploration! 7 astronomers and 9 astronauts shine in this episode, which spans from the 1700s to modern-day folks.

February is Black History Month, and it’s been the perfect excuse to research all of the African-American people who have contributed to space research and exploration! I talk about seven astronomers and nine astronauts who have delved into outer space because it was just so dang amazing, nothing could stop them from learning about it; astrophiles, if you will. Space-lovers.

Below the cut, I have the transcript, sources, music credits, and timeline of people I talked about! Maybe you have something you want to hear me talk about that’s related to space. I’m kind of set for topics for the next few months but I’ll take suggestions here 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 humble 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, the transit of Venus, or quasars and blasars. The next episode will go up March 19th, unfortunately; I have a work retreat the day I’d usually post and I don’t trust the wifi out there. See you then!)

Script/Transcript

Timeline

Benjamin Banneker, American (1731-1806)

Dorothy Vaughan, American (1910-2008)

Katherine Johnson, American (1918- )

Mary Jackson, American (1921-2005)

Ed Dwight, American (1933- )

Robert Henry Lawrence, American (1935-1967)

Doctor Arthur Bertram Cuthbert Walker II, American (1936-2001)

Frederick Gregory, American (1941- )

Guion "Guy" Bluford, American (1942- )

Doctor Ronald E. McNair, American (1950-1986)

Ilan Ramon, Israeli, American (1954-2003)

Doctor Bernard Harris, Jr., American (1956- )

Doctor Mae Jemison, American (1956- )

Neil DeGrasse Tyson, American (1958- )

Michael P. Anderson, American (1959-2003)

Leland Melvin, American (1964- )

Doctor Beth A. Brown, American (1969-2008)

Sources

African Americans in Astronomy and Space via ThoughtCo (Mar 2017)

Benjamin Banneker via Encyclopedia Britannica

Benjamin Banneker via PBS

Benjamin Banneker via America’s Library

Benjamin Banneker via Brookhaven National Laboratory

Hidden Figures (2016)

Katherine Johnson via NASA

Mary Jackson via NASA

Dorothy Vaughan via NASA

Doctor Arthur Bertram Cuthbert Walker II via Encyclopedia Britannica

Doctor Arthur Bertram Cuthbert Walker II obituary via the American Astronomical Society

Ed Dwight via The History Makers

Robert Henry Lawrence via Black Past

Robert Henry Lawrence via PBS

Robert Henry Lawrence via Hill Air Force Base

Guion "Guy" Bluford via Space.com (Feb 2017)

Guion Bluford: “I mean, I laughed and giggled all the way up. It was such a fun ride.” 

Guion "Guy" Bluford via NASA

Guion "Guy" Bluford via Encyclopedia Britannica

Doctor Ronald E. McNair via NASA

Doctor Ronald E. McNair via Black Past

Doctor Ronald E. McNair via New Jersey Institute of Technology

Frederick “Fred” Gregory via NASA

Frederick “Fred” Gregory via Black Past

The Harris Foundation website

“empower individuals, in particular minorities and others who are economically and/or socially disadvantaged, to recognize their potential and pursue their dreams.”

Doctor Mae Jemison via NASA

Doctor Mae Jemison via NASA

Doctor Mae Jemison via the U.S. National Library of Medicine

Mae Jemison: “I followed the Gemini, the Mercury, and the Apollo programs, I had books about them and I always assumed I would go into space. Not necessarily as an astronaut; I thought because we were on the moon when I was 11 or 12 years old, that we would be going to Mars—I'd be going to work on Mars as a scientist. And that's despite the fact that there were no women, and it was all white males—and in fact, I thought that was one of the dumbest things in the world, because I used to always worry, believe it or not as a little girl, I was like: What would aliens think of humans? You know, these are the only humans?”

Michael P. Anderson via NASA

Michael P. Anderson via Black Past

Ilan Ramon via NASA

Leland Melvin via Space.com (Nov 2017)

Leland Melvin as Makers Men via Space.com (May 2017)

Leland Melvin via NASA

Leland Melvin via Pioneer Works

Doctor Beth A. Brown via the American Physical Society

Doctor Beth A. Brown via the American Astronomical Society

Doctor Beth A. Brown via NASA

Neil DeGrasse Tyson via Hayden Planetarium

Neil DeGrasse Tyson via the New Yorker

StarTalk Radio via Apple Podcasts

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

Filler Music: ‘Dorothy Dandridge Eyes (feat. Esperanza Spalding)’ by Janelle Monáe off her album The Electric Lady.

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

Ep. 28 Tidal Forces - HD and the Void

Tidal forces are not only the cause of ocean tides, but affect how satellites orbit objects in space, and they can even tear some objects apart under their extreme stresses. Learn about types of tides on Earth and in our solar system.

This episode’s been a long time coming because the topic’s come up before. I originally conceived of this podcast as a way for me to learn about space things I’d always taken for granted, and truly, there is nothing closer to home that I’ve just agreed to believe than the statement that the tides are affected by the Moon. What? How? Why? All these questions and some I didn’t even realize I had will be answered in this episode on tidal forces!

Below the cut are my standard glossary, transcript, sources, and music credits. Send me any topic suggestions via Tumblr message (you don’t need an account for it!). You can also tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me. Subscribe on iTunes to get the new episodes of my maybe now monthly-updated podcast (we’ll see how the weeks unfold), and please please please rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!

(My thoughts on the next episode are Stephen Hawking and his theories, or famous comets. The next episode will go up in September—ideally, September 10th!)

Glossary

barycenter - the common center of mass between two objects that allows them to orbit.

Roche limit - the distance in which a celestial body will disintegrate because of a second celestial body's tidal forces exceeding the first body's gravitational self-attraction, or the force that’s holding it together. Within the Roche limit, orbiting material disperses and forms rings, like how Saturn’s rings are within the Roche zone; outside the limit, material tends to coalesce.

spaghettification - when extreme tidal forces pull an object apart in space.

tidal force - an apparent force (sometimes also called the differential force) that stretches a body towards another, more gravitationally-strong body’s center of mass. This can cause such diverse phenomena as tides, tidal locking, breaking celestial bodies apart to form ring systems within a Roche limit, and in extreme cases, spaghettification. It arises because the gravitational force exerted on one body by another is not constant across its parts: the nearest side is attracted more strongly than the farthest side.

Types of ocean tides:

diurnal tide - a daily tidal cycle with only one high and low tide each lunar day, and a period of a little over 24 hours.

meteorological tide - a tidal change due to weather patterns. Wind, or unusually high or low barometric pressure causes variations between the actual sea level and its predicted height.

mixed tide - a daily tidal cycle with two high and low tides that differ in their peaks. This difference in height between successive high or low tides is called the diurnal inequality. They have a period of 12 hours and 25 minutes.

neap tide - a type of bi-monthly tidal cycle that occurs when the Sun, Earth, and Moon are positioned at a 90-degree angle, so the tidal forces of the Sun are acting against the tidal forces of the Moon. During a neap tide, the difference between high tide and low tide is the least extreme.

semidiurnal tide - a daily tidal cycle with two nearly equal high tides and low tides every lunar day. They have a period of 12 hours and 25 minutes.

spring tide - a type of bi-monthly tidal cycle that occurs when the Sun, Earth, and Moon line up so that the gravitational forces of Sun and Moon are working together to form a large tidal bulge. During a spring tide, the difference between high tide and low tide is at its maximum.

tidal locking - when long-term interaction between two co-orbiting astronomical bodies causes at least one of the bodies to rotate in such a way that one face of the body is always pointed at the body it’s orbiting. This is also called gravitational locking or captured rotation. An example is that the same side of the Moon always faces the Earth, and its synchronous rotation means that it takes just as long to rotate around its own axis as it does to revolve around the Earth.

Script/Transcript

Sources

Tidal Cycles in Tides Explained via beltoforian.de

“a tide is a distortion in the shape of one body induced by the gravitational pull of another nearby object.”

Meteorological effects on tides via the New Zealand Government website

Tides and Water Levels via the National Oceanic and Atmospheric Administration (NOAA)

Tides by R. Nave, my dude, my guy, my friend and yours, of Georgia State University

The Tidal Force by Neil deGrasse Tyson via Hayden Planetarium (Nov 1995)

“A mild increase in distance between two objects can make a large difference in the strength of the tidal force. For example, if the Moon were just twice its current distance from us, then its tidal force on Earth would decrease by a factor of eight. At its current average distance of 240,000 miles from Earth, the Moon manages to create sizable atmospheric, oceanic, and crustal tides by attracting the part of Earth nearest the Moon more strongly than the part of Earth that is farthest. (The Sun is so far away that in spite of its generally strong gravity, its tidal force on Earth amounts to less than half that of the Moon.) The oceans respond most visibly in being stretched toward the direction of the Moon.” 

“When Earth's rotation slows down until it exactly matches the orbital period of the Moon, then Earth will no longer be rotating within its oceanic tidal bulge and the Earth-Moon system will have achieved a double tidal lock. In what sounds like an undiscovered wrestling hold, double tidal locks are energetically favorable (like a ball coming to rest at the bottom of a hill), and are thus common in the universe.”

Forget “Earth-Like”—We’ll First Find Aliens on Eyeball Planets via Nautilus (Feb 2015)

High Tide on Io! via NASA (Mar 2012)

Tidal forces and spaghettification via NASA handout

Spaghettification via Cosmic Funnies

Single atoms feel tidal force via Physics World (May 2017)

Robbins, Tom. Still Life with Woodpecker. Bantam Books: New York, 1980.

“Being four times larger than the moon, the earth appeared to dominate. Caught in the earth’s gravitational web, the moon moved around the earth and could never get away. Yet, as any half-awake materialist well knows, that which you hold holds you.”

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

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

Background Music: ‘Sad Business’ 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.

Filler Music: ‘It’s Getting Boring by the Sea’ by Blood Red Shoes off their album Box of Secrets

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

This is an article from last year, but still very exciting news! I wonder how far it’s progressed since?

Voyager 1's thrusters fired up for first time since 1980

NASA scientists are able to fire up a set of thrusters on Voyager 1 for the first time since 1980, allowing the spacecraft to orient itself in interstellar space, 13 billion miles from Earth.

The venerable Voyager 1 spacecraft.  Still impressing after all these years. 

Hahaha, right after I start out a podcast talking about how we’ll never poke the Sun, it turns out we’re sending a probe to do just that!

Solar System: Things to Know This Week

Mark your calendars for summer 2018: That’s when we’re launching a spacecraft to touch the sun. 

In honor of our first-ever mission to the heart of the solar system, this week we’re delving into the life and times of this powerful yellow dwarf star.

1. Meet Parker 

Parker Solar Probe, our first mission to go to the sun, is named after Eugene Parker, an American astrophysicist who first theorized that the sun constantly sends out a flow of particles and energy called the solar wind. This historic mission will explore one of the last regions of the solar system to be visited by a spacecraft and help scientists unlock answers to questions they’ve been pondering for more than five decades.

2. Extra SPF, Please 

Parker Solar Probe will swoop within 4 million miles of the sun’s surface, facing heat and radiation like no spacecraft before it. The mission will provide new data on solar activity to help us better understand our home star and its activity - information that can improve forecasts of major space-weather events that could impact life on Earth.

3. Majorly Massive 

The sun is the center of our solar system and makes up 99.8 percent of the mass of the entire solar system. If the sun were as tall as a typical front door, Earth would be about the size of a nickel.

4. Different Spin 

Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun spins once about every 25 days, but at its poles the sun rotates once on its axis every 36 Earth days.

5. Can’t Stand on It

The sun is a star and a star doesn’t have a solid surface. Rather, it’s a ball of ionized gas 92.1% hydrogen (H2) and 7.8% helium (He) held together by its own gravity.

6. Center of Attention 

The sun isn’t a planet, so it doesn’t have any moons. But, the sun is orbited by eight planets, at least five dwarf planets, tens of thousands of asteroids, and hundreds of thousands to trillions of comets and icy bodies.

7. It’s Hot in There 

And we mean really, really hot. The temperature at the sun’s core is about 27 million degrees Fahrenheit. However, its atmosphere, the corona, can reach temperatures of 3 million degrees. (That’s as if it got hotter the farther away you got from a fire, instead of cooler!) Parker Solar Probe will help scientists solve the mystery of why the corona’s temperature is so much higher than the surface.

8. Travel Conditions

The sun influences the entire solar system, so studying it helps us better understand the space weather that our astronauts and spacecraft travel through.

9. Life on the Sun? 

Better to admire from afar. Thanks to its hot, energetic mix of gases and plasma, the sun can’t be home to living things. However, we can thank the sun for making life on Earth possible by providing the warmth and energy that supply Earth’s food chain.

10. Chance of a Lifetime 

Last but not least, don’t forget that the first total solar eclipse to sweep across the U.S. from coast-to-coast since 1918 is happening on August 21, 2017. Our toolkit has you need to know to about it. 

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

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

Yes, sure its fun to see a lady spin around like that, but I had one of my friends ask me - “Where do you even use this mate?”

Here’s one application that I know very well off.

Spin Stabilization

If you have ever seen a rocket launch, you might know that sometimes the rockets are given a spin while launching. This is known as spin stabilization.

Basically, the rotational inertia of the rotating body will stabilize the rocket against any disturbances and help maintain its intended heading.

The same principle is used in rifling of firearms as well. **

YoYo DeSpin

Okay, now there is the question how to “De-spin” the rocket:

Well, you do what the lady does: stretch out your arms and you will slow down !

The rocket has weights connected to a cable that stretch out and almost immediately the rocket slows down. This maneuver is known as the YoYo DeSpin. ( Damn good name ! )

All thanks to the conservation of angular momentum !

Have a good one !

* Another method to stabilization : 3-axis stabilization

** Bullets spin stabilization - post

** Source rocket launch video

Star Discovered in Closest Known Orbit Around Likely Black Hole

NASA - Chandra X-ray Observatory patch. Astronomers have found evidence for a star that whips around a black hole about twice an hour. This may be the tightest orbital dance ever witnessed for a likely black hole and a companion star.

Image above: Artist’s illustration of a star found in the closest orbit known around a black hole in the globular cluster named 47 Tucanae. Image Credits: X-ray: NASA/CXC/University of Alberta/A.Bahramian et al.; Illustration: NASA/CXC/M.Weiss. This discovery was made using NASA’s Chandra X-ray Observatory as well as NASA’s NuSTAR and CSIRO’s Australia Telescope Compact Array (ATCA). The close-in stellar couple – known as a binary – is located in the globular cluster 47 Tucanae, a dense cluster of stars in our galaxy about 14,800 light years from Earth. While astronomers have observed this binary for many years, it wasn’t until 2015 that radio observations with the ATCA revealed the pair likely contains a black hole pulling material from a companion star called a white dwarf, a low-mass star that has exhausted most or all of its nuclear fuel. New Chandra data of this system, known as X9, show that it changes in X-ray brightness in the same manner every 28 minutes, which is likely the length of time it takes the companion star to make one complete orbit around the black hole. Chandra data also shows evidence for large amounts of oxygen in the system, a characteristic feature of white dwarfs. A strong case can, therefore, be made that the companion star is a white dwarf, which would then be orbiting the black hole at only about 2.5 times the separation between the Earth and the Moon. “This white dwarf is so close to the black hole that material is being pulled away from the star and dumped onto a disk of matter around the black hole before falling in,” said first author Arash Bahramian of the University of Alberta in Edmonton, Canada, and Michigan State University in East Lansing. “Luckily for this star, we don’t think it will follow this path into oblivion, but instead will stay in orbit.”

 Although the white dwarf does not appear to be in danger of falling in or being torn apart by the black hole, its fate is uncertain.

Chandra X-ray Observatory. Image Credits: NASA/CXC

“Eventually so much matter may be pulled away from the white dwarf that it ends up only having the mass of a planet,” said co-author Craig Heinke, also of the University of Alberta. “If it keeps losing mass, the white dwarf may completely evaporate.”

 How did the black hole get such a close companion? One possibility is that the black hole smashed into a red giant star, and then gas from the outer regions of the star was ejected from the binary. The remaining core of the red giant would form into a white dwarf, which becomes a binary companion to the black hole. The orbit of the binary would then have shrunk as gravitational waves were emitted, until the black hole started pulling material from the white dwarf. The gravitational waves currently being produced by the binary have a frequency that is too low to be detected with Laser Interferometer Gravitational-Wave Observatory, LIGO, that has recently detected gravitational waves from merging black holes. Sources like X9 could potentially be detected with future gravitational wave observatories in space. An alternative explanation for the observations is that the white dwarf is partnered with a neutron star, rather than a black hole. In this scenario, the neutron star spins faster as it pulls material from a companion star via a disk, a process that can lead to the neutron star spinning around its axis thousands of times every second. A few such objects, called transitional millisecond pulsars, have been observed near the end of this spinning up phase. The authors do not favor this possibility as transitional millisecond pulsars have properties not seen in X9, such as extreme variability at X-ray and radio wavelengths. However, they cannot disprove this explanation.
 “We’re going to watch this binary closely in the future, since we know little about how such an extreme system should behave”, said co-author Vlad Tudor of Curtin University and the International Centre for Radio Astronomy Research in Perth, Australia. “We’re also going to keep studying globular clusters in our galaxy to see if more evidence for very tight black hole binaries can be found.”

 A paper describing these results was recently accepted for publication in the Monthly Notices of the Royal Astronomical Society and is available online: https://arxiv.org/abs/1702.02167 NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations. Read More from NASA’s Chandra X-ray Observatory: http://chandra.harvard.edu/photo/2017/47tuc/ For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra Images (mentioned), Text, Credits: NASA/Lee Mohon/Marshall Space Flight Center/Molly Porter/Chandra X-ray Center/Megan Watzke. Greetings, Orbiter.ch Full article

HD and the Void by HD on Apple Podcasts

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Haaaaaay I’m on iTunes now! Slightly more convenient to download maybe!

Cost per kg for human spaceflight

via reddit

Scott Kelly just tweeted this photo of the Moon, Venus, Jupiter and Earth as seen from the International Space Station

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TODAY IN HISTORY: The first-ever color image of Mars, taken by NASA’s Viking 1 lander on July 21, 1976. (San Diego Air & Space Museum)