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.


Image courtesy of

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.


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’.


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. (

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.


Image courtesy

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!


Image courtesy

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.

Screen Shot 2016-05-01 at 12.07.30 PM.png

Image courtesy

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.


Image courtesy

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


Double volcano on Venus. Image courtesy

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

venus pancake domes.gif

Pancake domes on Venus. Image courtesy

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.


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. (

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? (

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


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 for more information.


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.

Thanks for reading, bye bye!

venus hipster.jpg

Year 5, MARS & STEM in Term 1

What an awesome term of STEM we had in year 5! The main objectives were to learn about the planet Mars, space missions to Mars, the role of NASA and the Jet Propulsion Laboratory and the people that work there, discover if humans could live on Mars and what life would be like there.

So, lots of talk about lots of my favourite things: space, Mars, NASA/JPL, Adam Steltzner, The Martian, amazing technology, science and engineering, really inspiring stuff.


As well as the main learning objectives I had planned at the start of the course, some extra opportunities arose to fit into the busy schedule to enhance the course further. March 14 was Pi Day and I planned a special lesson with help from a great resource I found from the NASA website called Planet Pi. I adapted the lesson slightly for year 5 and they coped with some new and tough maths admirably. This lesson highlighted how NASA scientists use Maths in their jobs to learn about planets and other celestial bodies. I explained the maths and formulae clearly and used some great visuals to help the girls understand the maths and why it was needed. I loved the example of using Pi to explore a planet, this was such a great lesson!


Another great lesson we had this term, and which was a complete and unexpected surprise was the Skype with Andrea Boyd, an engineer with the European Space Agency. Andrea lives in Germany and was good enough to stay up late at night to speak to all of year 5 at 9am Sydney time. Andrea spoke about her education and career in the space industry, which was very interesting and inspiring for our young girls. Our students prepared some great questions to ask Andrea about space, the International Space Station, astronauts and more. Our girls did a great job, were beautifully behaved, very polite and engaged with this brilliant, young, Australian woman. We learnt so much about space and how astronauts live and work on the ISS. This was a really exciting lesson which everyone enjoyed! Big thanks go to Jackie Slaviero, founder of One Giant Leap Australia, for putting me in contact with Andrea and then for sending me an amazing pack of goodies from NASA.


The students seemed to love our STEM lessons this term. Space is such an interesting, exciting and inspiring topic for young and old, and I was so pleased with how they engaged. I love the questions they ask, they are so curious and what to learn everything. As well as learning about Mars we learnt about black holes, the Earth and Moon, the ISS, the speed of light, galaxies and more. We could quite easily study space for the whole year, and I gladly would.

Next term… students continue their STEM journey to Mars when they work in engineering groups to design and build their own Mars rover, based on the Mars Science Laboratory (MSL), aka Curiosity. Curiosity has been a common theme throughout the term and I talked a lot about it when I talked about JPL engineer and EDL team leader for Curiosity, Adam Steltzner, a really inspiring speaker.


His TED talk ‘How Curiosity changed my life, and I changed Hers’ is one of my favourites.

We also looked at rover facts and a great video called ‘7 minutes of terror’ which details how the rover made it from the top of the Mars atmosphere travelling at 30,000 mph to the surface travelling at a few mph in just 7 minutes. Another must-see video!

Like I said, I could teach this topic all year and not get bored! I used this video for an which included some questions about the EDL of Curiosity. A great resource for incorporating video into classes.

Students produced some wonderful work including ‘Selling Mars: selling land on Mars’ advertisements and a ‘NASA profile’ of an inspiring NASA scientist they found from the website We Are The Martians.

So next term… engineering groups, specific roles for each girl in the group, designing and making a Mars rover, making wheels and incorporating LittleBits electronics to make the rover move, engineering guide with project milestones, evaluations, presentations, creativity, teamwork and fun!

Let’s hope ours will look better than this one!


Amazing Skype lesson with Andrea Boyd – ESA

On Wednesday 16 March I arranged for the whole of year 5 to Skype with European Space Agency engineer Andrea Boyd. The Skype meeting was to compliment the unit I was leading about space, Mars and the Curiosity rover. Thanks to Jackie Slaviero I made contact with Andrea and we arranged the chat in just a couple of days.

The girls were prepped pretty much the day before the chat and I led a lesson about Andrea, ESA, ISS and engineering. The girls were then asked to write down their questions for Andrea. I read all of the questions and highlighted the best ones, 5 from each class. These girls were then chosen to ask their question to Andrea during the chat. The stage was set.

The Skype did not go 100% smoothly. The morning of the Skype was wet, very wet, so classes got a bit wet walking from junior school to the middle school learning studio. A small inconvenience but not ideal.

ICT came to help set up the Skype and everything seemed to be working well. We had video and audio and the test call connected no problem.

The girls arrived and were seated, I milled around nervously waiting to get started. At 9am I made the call to Andrea and the call did not connect, it didn’t event ring. I tried again, still not luck. I had no idea why. Andrea had messaged us on Skype to say that she was ready, she was online, we were online, yet no connection, what was happening? I called ICT and left a message for help. In the meantime I chatted to the girls and we asked a couple of space questions to spark some debate. Then ICT showed up, fixed the problem and we were away, at last!

The call was amazing! Andrea was lovely and really engaged the girls from the first moments. She spoke about herself and what she does at ESA and EAC in Germany. The girls behaved perfectly and asked their questions with poise and confidence. There manners were excellent and and they thanked Andrea for her time with great enthusiasm.

Andrea answered all of the questions and we learnt so much. Some of the things I learnt:

  • Spacewalks are very dangerous
  • Space suits can fill with water due to a leak inside
  • Astronauts’ faces get squashed in space due to the pressure
  • Eyes also get squashed
  • The ISS doesn’t need fuel when it is in Earth’s orbit
  • The gravity of Earth is enough to keep the ISS moving at 27,000 km/hr
  • The ISS is constantly falling towards Earth, every so often small bursts are made to push the ISS back up to around 400 km above Earth’s surface
  • Astronauts sleep floating around in the ISS
  • Astronauts either spit out their toothpaste and saliva into a towel or tissue after brushing their teeth or they swallow it
  • Astronaut training involves lots of swimming
  • Learning Russian and Chinese will help you be selected to become an astronaut
  • Teamwork and communication skills are also very important for future astronauts
  • Andrea would like to go to space for a weekend and then come home

We all learnt so much!

I loved this Skype lesson and will definitely be looking to do one again soon.