Exploring the Heavens – Week 1

On Tuesday 3 May I attended the first week of my new course on astronomy at Sydney Observatory. The course is titled ‘Exploring the Heavens’ and is led by Dr Paul Payne. The structure of the course is as follows:

  1. History of Astronomy
  2. Celestial rhythms
  3. The solar system
  4. The stars
  5. Telescopes

So the course started with Dr Payne’s two hour version of the history of astronomy in the Sydney Observatory 3D theatre. Some of the main figures covered included:

  • Aristotle (384 – 322 BC)
  • Claudius Ptolemy (~140 BC)
  • Nicolas Copernicus (1473 – 1543)
  • Tycho Brahe (1546 – 1601)
  • Johannes Kepler (1571 – 1630)
  • Giordano Bruno (1547 – 1600)
  • Galileo Galilee (1564 – 1642)
  • Isaac Newton (1642 – 1727)
  • Edmund Halley (1656 – 1742)
  • Charles Messier (1730 – 1817)
  • William Herschel (1738 – 1822)
  • James Bradley (1693 – 1762)
  • Friedrich Bessel (1784 – 1846)
  • John Adams (1819 – 1892)
  • Jean Le Verrier (1811 – 1877)
  • Albert Einstein (1879 – 1955)

Dr Payne kept the pace moving pretty quickly to cover all of these historical and important figures and more about the ancient Greeks, Romans, Babylonians, Renaissance as well as advancements in mathematics, engineering and technology.

Dr Payne also used his homemade 3D graphics to help demonstrate certain themes and concepts, including retrograde motion of planets, constellations and the movement of the moon and planets from Earth’s point of view. The graphics were great and they certainly enhanced the presentation putting us firmly in the cosmic realms.

I was surprised at how important astrology was in ancient times and how seriously it was taken to predict future events. People were also very superstitous and heavenly objects played an important role in how people lived their lives, including Roman emperors. It is also amazing at how much people knew about the solar system hundreds and thousands of years ago without even the aid of a telescope.

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As well as learning about the history of astronomy Dr Payne gave us a tour of the night sky on what was a beautiful and clear evening in Sydney. Some of the notable objects we spotted were: Mars, Jupiter, Alpha Centauri, Sirius, Betelgeuse, as well as some notable constellations.

Jupiter-planet

The final part of the evening involved us moving to the south dome of the observatory to use the telescope to view the night sky. We were lucky enough that the sky was clear from clouds and we were treated to an amazing view of Jupiter and the Galilean moons Ganymede, Io, Europa and Callisto.

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Image of the telescope in the south dome of Sydney Observatory.

This telescope is the oldest working one in Australia and was built in 1874 by Hugo Schroder in Hamburg, Germany. An interesting article about the telescope can be found here.

This was actually my first time looking through a telescope and the view did not disappoint. I was amazed by how clear Jupiter appeared, being able to clearly identify its white zones and brown belts, both of which are cloud systems with winds that blow in opposite directions. The Galilean moons, although tiny, were very bright and also so clear to see. This is exactly what I had been hoping to see and has just added more fuel to my growing love for astronomy.

Looking forward to week 2!

Introduction to Solar Systems Astronomy Design Project

Earth’s twin: No oxygen, no water, scorching temperatures and a runaway greenhouse effect. What else do we know about our closest neighbour, Venus?

Arizona State University’s AST111

Introduction to Solar System Astronomy

Design Project evidence

Learning objective

Describe the origins, structure, contents, and evolution of our solar system.

Project goal

“Venus favours the bold” – Ovid

Describe the planet Venus, how it became so hot and examine the scientific impact resulting from the many missions to Venus, otherwise known as Freya’s planet.

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Image courtesy of http://www.space.com/images/i/000/044/599/original/venus-surface-magellan-spacecraft.jpg

Venus fact file

  • Second planet from the Sun, 67 million miles apart (0.72 AU)
  • Second brightest object in the night sky, behind the Moon. Venus’ clouds are highly reflective, making it shine bright in the night sky
  • Named after the Roman Goddess of love and beauty
  • Has no moons or rings
  • Spins very slowly in a clockwise direction (retrograde rotation), backwards to the other planets in the solar system. Backwards spin is probably due to a cosmic collision early in its history
  • Venus is very nearly a perfect sphere, thanks slow rotation!
  • 80% size of Earth, similar mass and both rocky worlds
  • Hottest world in our system, 480 degrees celsius on the surface, hot enough to melt lead
  • Runaway greenhouse effect. It is thought Venus used to have oceans but due to extra heat from the Sun these oceans evaporated and the water vapour trapped more heat in the atmosphere warming the planet further, trapping more heat until the oceans were no more
  • Has a cratered and volcanic surface
  • 1 year on Venus is equal to 225 Earth days, and 1 day on Venus lasts 243 Earth days – making a day last longer than a year on Venus
  • Atmosphere consists mainly of carbon dioxide (~96%), Nitrogen (~4%)
  • More than 40 spacecraft have explored Venus

Venus in culture

The Venus de Milo is ancient Greek statue created between 130 and 100 BC. It depicts Aphrodite, the Greek goddess of love and beauty, known as Venus to the Romans. It is on permanent display at the Louvre in Paris.

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Men are from Mars, Women are from Venus. This book published in 1992 has sold over 50 million copies around the world. It states that common relationship problems between men and women are a result of fundamental psychological differences between the sexes because they are from ‘different planets’.

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Beyond Apollo – Barry M. Malzberg. A novel about a 2 man mission to Venus which is aborted and when the mission returns to Earth the captain is missing and the other man cannot explain what happened to him. The novel tries to get to the bottom of this mystery and overall it represents humanity’s incompetence at the enormity of space exploration. The book is listed as in development on IMDb so look out for a motion picture soon. (http://www.imdb.com/title/tt2403823/?ref_=fn_al_tt_1)

beyond apollo

For a twin planet, Venus is very different to Earth

4 billion years ago Venus was thought to be a lot like Earth, with evidence pointing towards Venus supporting bodies of water (H2O), perhaps even oceans. However, 4 billion years ago the Sun was less powerful that it is today and was only 70% as bright. Over time as the Sun became much hotter any bodies of water on Venus evaporated and water vapour was driven into the atmosphere, causing major greenhouse changes. Water vapour can trap heat, acting as a blanket around a body. At the top of the Venus atmosphere water molecules were split into hydrogen (H) and oxygen (O), under the full intensity of sunlight and ultraviolet rays. Much of the hydrogen (H) escaped into space whilst the oxygen (O) combined with carbon to form carbon dioxide (CO2), a great absorber of heat. Oxygen also bound with sulphur (S) and created sulphur dioxide (SO2) which created droplets of sulphuric acid (H2SO4). Could this runaway greenhouse effect ever happen here on Earth?

Venus atmosphere

The Venus atmosphere is extremely dense and hot. It is mainly composed of carbon dioxide with clouds of sulphuric acid, which gives Venus its yellow colour. It does rain sulphuric acid, but drops never reach the surface due to the extreme heat. The thick atmosphere traps heat and the tremendous amount of carbon dioxide adds to the runaway greenhouse effect on the planet. The weight of the thick, dense atmosphere creates enormous pressure on the surface of 90 times heavier than standing on the surface of Earth. The equivalent pressure on Earth is about 1 km beneath the surface of an ocean. The atmosphere is slowly being stripped away by the solar wind, a million tonne per second stream of material coming from the Sun. About 300 kg of the atmosphere is being lost every day from Venus.

Internal structure

Venus has an iron core approx. 3000 km in radius. This is similar to all terrestrial planets because of the effects of gravity, causing heavier material to sink to the middle of the planet whilst lighter material floated to the top. Venus does not have a magnetic field as it rotates too slowly.

InteriorOfVenus

Image courtesy http://astronomy.nmsu.edu/tharriso/ast105/InteriorOfVenus.png

Missions to Freya

Over 40 missions have explored Venus. The first craft to land on the surface was Venera 7 and was actually the first craft to land on another planet, after 15 failed missions. This Soviet mission in 1970 successfully landed on the surface and was able to send back 23 minutes worth of data, including a surface temperature reading of 475 degrees celsius and a pressure reading of 90. Not a very pleasant place to be!

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Image courtesy http://solarsystem.nasa.gov/missions/venera_07/galleries

There is presently an active Venus mission called Akatsuki. The goal of the mission is to study weather patterns, confirm the presence of lightning in thick clouds and search for signs of active volcanism. This mission suffered a huge blow early on in its mission when thrusters failed to fire and the craft ended up on a journey around the Sun rather than Venus. Over the next five years JAXA (the Japanese Space Agency) tested the various thrusters and came up with a strategy to fix the craft and send it back to Venus. To do this they dumped fuel from the broken thrusters and used the secondary control thrusters to orient the probe towards Venus. This happened in December of 2015 and the probe entered the orbit of Venus as originally planned.

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Image courtesy http://solarsystem.nasa.gov/galleries/space-tourism-posters

Magellan – mapping the surface of Venus. Launched in 1989 by NASA, the Magellan deep space orbiter was designed to map the surface of Venus down to a resolution of 120 to 300 metres. On 15 September 1990 the craft began to send high resolution radar images of the surface  clearly showing signs of vulcanism, tectonic movement, surface winds, lava channels and pancake shaped domes. During its first cycle it mapped 83.7% of the surface returning 1200 GB of data, an incredible amount at that time. After the second cycle it had mapped 96% of the surface and the third mapped 98%. Contact with the probe was lost on 12 October 1994 after it had plunged into the atmosphere to collect further aerodynamic data.

Magellan findings:

  • 85% of the surface is covered with volcanic flows
  • Complete lack of water
  • Extremely slow erosion process
  • Surface features persist for hundreds of millions of years

ESA goes express to Venus in 2005! The ESA sent the Venus Express to Venus in 2005 with the primary goal of studying the atmosphere. This was the ESA’s first mission to Venus and it was named Express due to the quick time the mission took to prepare and execute.

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Image courtesy http://www.esa.int/spaceinimages/Images/2007/11/Artist_s_concept_of_lightning_on_Venus

The magnetometer (MAG) on board ESA’s Venus Express detected wave signals that show evidence of lightning in the atmosphere.

Major achievements of Venus Express include:

  • Discovery of a shape-shifting southern solar vortex. It can take almost any shape indicating complex weather patterns due to centre of vortex being offset to geographical pole
  • Evidence of recent volcanism, perhaps in the last few thousand to ten thousand years

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Double volcano on Venus. Image courtesy http://astronomy.nmsu.edu/tharriso/ast105/Ast105week08.html

A ten-fold increase in sulphur dioxide in the atmosphere has led scientists to question whether volcanos are still active today.

  • Venus’ rotation is slowing down, found by comparing data collected by the Magellan mission. Features monitored by Express could only be lined up with Magellan if the length of a day on Venus is on average 6.5 minutes longer than when Magellan tracked the same features
  • Discovery of a cold area 125 km above the surface where snow or ice could exist. The temperature of -175 degrees celsius means the carbon dioxide can freeze
  • Detection of a thin ozone layer approx. 90 to 120 km above the surface, far higher than on Earth where ozone exists at 15 to 50 km above the surface
  • Water loss due to splitting of water molecules in upper atmosphere by ultraviolet radiation from the Sun. The process creates two hydrogen atoms and one oxygen atom which are carried into space by the solar wind. Venus does not generate a magnetic field which can protect its atmosphere from the solar wind
  • Discovered mean wind speed of 400 km/h, an increase of 100 km/h over the 8 year mission

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Pancake domes on Venus. Image courtesy http://astronomy.nmsu.edu/tharriso/ast105/Ast105week08.html

Images from the surface – Venera 13. On 1 March 1982 Venera 13, a Soviet mission, set down on the surface of Venus and began relaying data back to Earth. It was able to transmit data for 127 minutes, far longer than the expected 32 minutes before the craft was crushed and melted by the extreme pressure and heat on the surface of Venus. It successfully relayed the first colour pictures of the surface of Venus, something previous missions had failed to do. It sent 8 panoramas showing fields of orange-brown rocks and loose soil. Soil analysis showed soil similar to terrestrial leucitic basalt with high potassium content.

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Image above shows Venus surface.

Future Venus missions?

1. The clockwork Venus rover. The solution to Venus landers not lasting longer than 2 hours could be a clockwork lander with no electronics. To send messages back home it would record data on a phonograph and then loft it on a balloon to rendezvous with a spacecraft overhead. (https://www.newscientist.com/article/mg23030693-600-our-top-5-wacky-nasa-missions-that-might-just-happen/)

The phonograph is a machine invented by Thomas Edison in 1877. It is a machine for recording sound on tinfoil coated cylinders. It has 2 needles, one for recording and one for playback. It is incredible to think that over one-hundred year old technology could be used to explore the solar system today.

2. Can sound help us detect ‘earthquakes’ on Venus? (http://www.astrobio.net/topic/solar-system/venus/can-sound-help-us-detect-earthquakes-on-venus/)

Researchers are planning to deploy an array of balloons in the atmosphere of Venus that could detect seismic activity on the surface using sound. A team of experts at the Keck Institute for Space Studies began thinking of ways to use infrasonic observations to get a better look at the geological dynamics of Venus. If we can get a better idea of the seismic activity on the planet this can tell us more about the history of the planet and its interior.

Escape velocity of Venus

During the course the mathematical labs have not been my strongest area, but I have learnt so much from attempting the challenges, something I really enjoyed doing. I would like to finish with a math problem I can do – the escape velocity of Venus. So here goes…

What is the escape velocity from the Venus exosphere, which begins about 220 km above the surface?

mass = 4.867 x 10^24 kg

radius = 6.05 x 10^6 m

height = 2.2 x 10^5 m

Formula:

Screen Shot 2016-05-01 at 2.16.56 PM.png

= 2 x 6.67 x 10^11 x 4.867 x 10^24 / (6.05 x 10^6 + 2.2 x 10^5) = 1.03 x 10^8

v = sqrt (1.03 x 10^8) = 10148 m/s = 10.1 km/s ~ 10 km/s

Please check the math and let me know if I have made a mistake along the way.

Watch BBC The Sky at Night Venus documentary https://www.youtube.com/watch?v=82fS9C9koxU for more information.

Finally…

Huge thanks go to Dr Frank Timmes for being an outstanding teacher during this course, your videos and notes were amazing, thank you sooo much! You have inspired me to learn more about the universe. Big thanks also go to the rest of the team at Arizona State University for putting together an amazing course and for all their support. This has been the best course I have enrolled in on edX and I would highly recommend it to anyone interested in astronomy.

https://courses.edx.org/courses/course-v1:ASUx+AST111x+2161B/info

Thanks for reading, bye bye!

venus hipster.jpg

5 Earth facts to celebrate Earth Day 2016

5. Earth is a terrestrial planet meaning it has these characteristics compared with Jovian planets:

  • Smaller size and mass
  • Higher density of rock and metal
  • Solid surface
  • Closer to the Sun
  • Warmer surface
  • Few moons
  • No rings

pale blue dot

4. Earth’s continents used to be one giant super-continent called Pangaea that existed around 200-300 million years ago.

pangea

3. Earth’s atmosphere is mainly nitrogen, followed by oxygen. So we breathe the second most abundant gas in our atmosphere.

2. If the Earth didn’t spin we would have nasty 200mph winds that blow from the tropics to the poles and back again. Our rotation, and the Coriolis effect, causes 3 convection cells per hemisphere that diverts air flowing north-south to east-west. Air is transported from hotter regions to cooler regions.

coriolis

1. Earth’s atmosphere formed after the world was created. The 3 sources of our atmosphere are:

  • outgassing
  • evaporation
  • surface ejection

We got our deposits of gases and liquids during the era of heavy bombardment during which asteroids and comets brought gases to Earth in frozen form. These were then deposited into the body of the planet.

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Code.org visit to Ravo

On Wednesday 30 March Code.org software engineer Brendan Reville paid a visit to Ravo to talk with students about his life, career, Code.org and the Hour of Code. I met Brendan a few weeks earlier at the Future Schools Expo at the Australian Technology Park in Sydney and I was impressed with his talk and the fresh, positive message he made that day. I have been a fan of the Hour of Code and Code.org for a few years so he didn’t have to sell me at all as I was already using the great resources he was responsible for. I was very impressed when he told us he was the mastermind behind the Star Wars Hour of Code last year, one of my favourite coding tutorials. The Code.org tutorials are brilliant, clear instructions are provided, helpful videos explain important concepts, fun scenarios to learn and a whole heap of extra resources to help teachers deliver the content to their classes. The Star Wars Hour of Code introduction video below is a must-see!

At the conference Brendan also mentioned the full curriculums Code.org provide for free on their website. I had looked at these before and dipped in and out of them to use some coding resources and some of the great unplugged resources, but he inspired me to take the courses more seriously and I am now teaching course 2 to my year 3 classes. I love the mixture of unplugged activities and online activities to teach computational thinking, coding and other technology constructs. The first few lessons have gone really well and students have been thoroughly engaged in all the different types of activities.

Brendan’s talk at Ravo was fantastic. He has had an interesting life and career so far and he inspired the students to take software design and coding as a serious career path. He talked about his schooling and university days in Sydney and at Macquarie University and how he started making computer games and first steps in coding. As a big Xbox fan he wanted to work for Microsoft so he moved to the USA to land his dream job. He talked about the great projects he was involved with at Microsoft, including developing user interface’s and the Xbox Music Mixer, as seen below.

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Wanting a new challenge Brendan moved to Code.org to be involved with coding and education and helping to deliver the world’s largest educational event – the Hour of Code!

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Reflection on completing an hour of code.

Brendan also spoke about the wide variety of skills needed to be successful when working for a tech company. It isn’t just coding skills that get you noticed, it is also skills including teamwork, creativity, communication, designing and more. He described his experiences of working for tech companies vividly and the year 9 and 10 students in attendance were enthralled.

Brendan delivered a positive and inspiring message to our girls that they can succeed in the tech industry and land their dream job for a great start-up or tech giant. Through the Code.org resources young people are learning some great skills that will benefit them not just in their schooling but also in their future careers that are sure to be dominated by STEM.

Thank you Brendan and Code.org! (And thanks for the cool Code.org stickers :))

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Code.org also has lots of other great videos to learn about computer science and technology such as the internet and cybersecurity.

Robotics in the Classroom – MacICT Workshop

Today I attended the Robotics in the Classroom professional learning workshop at Macquarie ICT Innovations Centre. The course was presented by John Burfoot, an experienced teacher and robotics educator who has spoken and presented at numerous events in Australia and internationally. He began by talking about a recent conference he attended in San Diego, USA, the LEGO Education Elementary Conference. The purpose of this conference was to gather together people who use the LEGO toolset to teach STEM related subjects in the classroom, and try out new activities, share experiences, meet new people and learn about new LEGO developments.

Our first activity today was to build a robot, specifically a robot called Harvey Mark II. We were given the hardware components, including the sensors, wheels, cables and EV3 brick. We also received, to keep, a small bag of LEGO Mindstorm pieces to construct our robot with. It took me 20 minutes to build the robot, shown below, from the instructions provided.

Harvey Mark II

Harvey Mark II

This robot included the 2 main motors, the ultrasonic sensor and the light sensor. We then used the Mindstorm software to code the robot to move and draw a square shape on the floor. The challenging part of this activity is the turn the robot needs to do. It takes a few guesses to make the robot turn the 90 degrees necessary, and when achieved the first turn is perfect, but the next 3 turns needed to complete the square are not 90 degrees, due to some oversteer the robot produces. Other people experienced the same problem, and part of the fun of robotics is collaborative problem solving, working things out with others, trial and error to see what works and what doesn’t in the quest for the perfect algorithm to produce the perfect output.

The next challenge was called ‘Bug in a Box’ and we needed to alter the build of the robot so it looked like a bug. I added some antennae to mine using a few extra pieces of LEGO. On the floor of the room we were in there were floor tiles, and some of them were red, some were beige. Some of the red tiles had masking tape around them, and the challenge we faced was to keep the robot moving inside the red tile only for 1 minute. This challenge meant we had to use the colour sensor to sense the colour of the floor, if the sensor read the red tile it kept moving in a straight line, however, if it sensed the colour of the masking tape around the outside of the red tile then the robot was programmed to turn around back to the red tile and keep moving straight. This challenge was not too difficult, and again people worked collaboratively to fix any problems that arose. People in attendance had mixed experience with LEGO products and robotics, but everyone was fully engaged throughout the day.

We then altered our program to include the ultrasonic sensor, and if the robot was close to an obstacle in the box it would also change direction. For this we used the loop and switch blocks to make the algorithm more complex and efficient. We could use logic like if the robot is less than 10cm from an obstacle then turn around and go back. We also got to program sound effects and images on the screen of the robot to improve the output when these events happened.

We filmed our robots for this challenge and were encouraged to join an Edmodo group to share our videos with the others in the group, which was a nice touch. The Edmodo group included lots of resources from the day as well as plenty of others, very useful indeed.

Some of the resources I learnt about today are:

This was a great workshop and the presenter was excellent. We got to build a robot, program it to move, turn, use the ultrasonic sensor, colour sensor, use loops, switches and more. It was a packed day and the time went really quickly. The course was very well catered and other participants were like minded and enthusiastic to learn new things. After this course I can’t wait to get back to school and use the EV3 with the kids!