Operation Sea Urchin Fun

Just a short blog entry about some fieldwork I did today in Port Phillip Bay.

I work on these funky little animals called sea urchins and they look a bit funny and don’t move a lot but they’re a pretty cool species to study. The particular species I work on can cause problems when their population becomes too large. Like me, they eat a little too much and this hunger drives them to devour a lot of vegetation. This ruins a lot of habitat for lots of other marine animals that depend on algae and seaweed for shelter and food.

So, I am studying sea urchin larval behaviour and determining how this affects the little critters in moving from one site to another. This is why I went to go find some sea urchins with my supervisor, my lab mate and a very helpful phD student. We went looking for sea urchins in Beaumaris, a suburb quite conveniently located to the University of Melbourne. We found lots of urchins and everything went well. It was a lovely day to go out even though the weather looked a bit dangerous in the morning. Always fun to go out into the water and remember how fun fieldwork can be ❤️

Why Do I Like the Sea?

cerulean-sea-justin-jovellanos

Image Credit: Justin Jovellanos via Flickr

Last Friday, I attempted to find some sea urchins for my research project. My venture wasn’t particularly successful – all I found were a couple of dead urchins and realised that not taking a wetsuit was a stupid idea. But despite my failure, I could have stayed at the beach forever. I had re-discovered my love of the sea. Probably strange for a budding marine biologist to say but I have been cooped up at my desk for a LONG time. Friday was my first trip out to a body of water larger than my bathtub.

Now obviously not everyone is in love with the water like I am and there are plenty of people who are terrified of it. This fear makes a lot of sense. Our bodies are not adapted to the sea and if we were stuck in the sea with no aid we would die (except for these amazing people). Not only are we just unable to breathe underwater, but sea creatures can be frightening. Letting our imaginations run amok, humans have come up with all sorts of terrifying tales (like the Kraken, the Leviathan and Cthulu) that make the oceans and seas terrible places.

But really people love the seas and oceans. Aside from tangible benefits like resources and transportation, the coast brings to us better well-being. A study showed that people living closer to the seaside had better health than those that didn’t. In a survey, people who visited the seaside had more stress-reducing, positive emotions than those who visited urban parks or countryside. Why do we love the sea so much? Here are a couple of the many proposed theories.

Sea food eat food diet

Humans have a much larger brain size than our chimpanzee cousins and according to neuroscientist, Michael Crawford, our increase in brain size coincides with settlement in coastal regions. The sea change gave us a new diet filled with shellfish and fish, which contain omega-3.  Supposedly, this allowed our brains to grow larger and we are hot-wired to prefer coastal living because of the diet associated with it.

Omega-3 has been shown to be good for our bodies and coastal living is indeed attractive. But there is controversy surrounding the the idea of fishy diets equating to larger brains as well as larger brains meaning higher levels of intelligence. Accounting for body size, dolphins have a similar brain weight to us and are pretty smart, but on the other hand sharks have much smaller brains and they might not be as dumb as previously thought. Both have very fishy diets!

Naturally, I like nature

One could argue that liking the sea is just part of a greater attraction to natural landscapes and the biophilia hypothesis claims that this attraction has a genetic basis. This innate attraction is a result of our close relationship to nature during our evolutionary history. Despite our modern lives, where greenspaces can be rare, we still have this yearning to connect with nature.

Some evidence of this innate attraction includes certain phobias of harmful animals like spiders and snakes or philias of flowers which signal the oncoming fruit of a plant.

Nature = Good

There is a definite lack of consensus on why we like the sea and other natural landscapes. But there is overwhelming evidence on the positive health effects of visiting the seaside or hiking in the bush. So feel free to use this as an excuse to go the beach and not do any work next weekend!

Out of this World – Finding Exoplanets

I discuss this topic on a radio program called Einstein A Go-Go. If you prefer an audio format of this article, please see the bottom of this post 🙂

2m1207b_-_first_image_of_an_exoplanet

First direct image of an exoplanet (lower left red spot) orbiting its star (centre blue spot). Credit: European Southern Observatory via their website

Movies have long explored the ideas of discovering exotic new landscapes that we could colonise and the potential to find extra-terrestrial lifeforms. Whenever we find a new planet, these reveries have the potential to become real and people understandably get very excited.

Recently, a new planet named Proxima B has been discovered. Proxima B is an exoplanet, a planet located outside our solar system. It’s orbiting the closest star to our Sun (only a stone’s throw at 40 trillion kilometres away) but that’s not the interesting thing about Proxima B. Astronomers have deemed Proxima B as suitable for life.

How do we know a planet is “suitable” for life?

To be deemed suitable, a planet has to meet a huge range of criteria (arguably more extensive than that of the US presidency candidates). To be habitable, or at least our idea of habitable, a planet needs to have a few characteristics that Earth has.

One important characteristic is the ability to support liquid water. A planet that is located too close to its star may be too hot and all potential water on the surface would be vaporised. On the other hand, a planet located too far away from its star may be too cold and all the water is only present as ice. There’s a range of distances where the conditions are just right, called the Goldilocks Zone. Planets within the Goldilocks zone are not uncommon and planets with the potential for liquid water aren’t as rare as originally thought.

There are many other characteristics such as the planet needing to be rocky and having both the right atmosphere and the essential chemicals. But even if we know what criteria makes a planet, there’s still the question of finding an actual planet.

The search for exoplanets

It’s actually very difficult trying to look for exoplanets. Planets are obviously large but the universe in which they are located is vast. Looking for an exoplanet is like looking for a needle in a barn full of haystacks. Sometimes, we can look and find an exoplanet by looking through a telescope but this is very rare and only possible for planets that both very large and very hot. So to find exoplanets, astronomers use other more indirect methods. Here are two techniques that have discovered the majority of our known exoplanets.

Radial velocity method

When a star is orbited by planets, it doesn’t remain stationary but actually “wobbles” due to the gravitational force exerted by those planets. We can detect this wobbling by looking at the type of light emitted by the star. When a star moves towards an observer, the light emitted shifts to blue and when it moves away, the light shifts to red. This is called the Doppler effect and it also explains why an ambulance siren is high-pitched as the ambulance approaches you, but as it moves away it becomes low pitched.

The radial velocity method has found most of our exoplanets but has some disadvantages. Firstly, it can only detect stars with orbiting exoplanets if the orbit plane is within a certain range of angles. Secondly, radial velocity cannot accurately determine the mass of a planet, something that needs to be known to determine suitability for life.

Transit photometry

This method relies on not detecting the type of light emitted by a star but the amount it emits. When a planet moves in between a star and an observer, the amount of light emitted drops a little bit. When the planet moves away, the light emitted is at full strength again. Transit photometry relies on detecting this dimming and brightening to determine if a star has orbiting planets. This is what the Kepler Spacecraft uses to find exoplanets and it’s detecting them at a higher rate than the radial velocity method.

Kepler does occasionally get it wrong though. So when Kepler detects a potential star, another method such as radial velocity is used for confirmation. Also, transit photometry is completely reliant on catching the alignment of a star, its orbiting planet and the observer at the exact right time and this event is rare.

I spy with my little telescope…

But when the star, exoplanet and Kepler align and a ground-based telescope confirms the existence of the exoplanet, we have our candidate exoplanet. Hubble Space Telescope is then used to determine the characteristics of that candidate exoplanet and if it meets the criteria, that’s when we get exciting news of exoplanets like Proxima B.

Further Readings:

NASA on detection methods: https://exoplanets.nasa.gov/interactable/11/

Another great website on detection methods: http://www.planetary.org/explore/space-topics/exoplanets/how-to-search-for-exoplanets.html

This was originally published on another blog, but this is my own work.

Audio version:

Click this following link: http://www.rrr.org.au/program/einstein-a-go-go?an_page=2016-09-25

Exoplanets is on at 34.30 but I strongly encourage you to listen to all the other interesting topics!

If you have any spare time, our radio group would appreciate if you could fill out a feedback survey on: https://docs.google.com/forms/d/e/1FAIpQLSfkTnkRjjvyYLlvHzpb1aixYZvCUp38qzO9EhZ6TpODnBrCdQ/viewform

Thank you 🙂

Ice Ice Baby Volcano

photojournal-nasa-ahuna-monsAhuna Mons on the surface of Ceres. Credit: NASA

I’m terrified of volcanoes. They possess such almighty power and are completely capable of devastating human lives and their livelihood. With fiery spurts of lava, they wreck destruction on anything in its path. A few frightening examples include Mount Vesuvius’s destruction of Pompeii, Mount St Helens’ 1980 eruption and Mount Merapi’s constant eruptions in Indonesia.

Yes, they are awe-inspiring and some people like to get close and personal with them but I chose to live an existence of being located very far away from them. Isn’t Australia wonderful with its dormant and extinct volcanoes? A good volcano is a non-active one I say.

But really, not all volcanoes spurt out molten rock or have done so in the past. Some volcanoes could actually be ice volcanoes, otherwise known as cryovolcanoes. Instead of erupting with lava, cryovolcanoes eject cryomagma, a cool cocktail of water and gases.

Cool, so where are these ice volcanoes?

Cryovolcanoes don’t occur on Earth, but in outer space which makes sight-seeing a little difficult even if you’re an astronaut (I’ve handed in my resume and I expect to see a reply soon, NASA).

Astronomers theorise that cryovolcanoes could be found on cold celestial objects like Pluto and the moons orbiting Jupiter and Saturn. Of course, another requirement for cyrovolcanoes is the presence of water on that celestial body but this is proving less and less rare in space.

The latest discovery on a dwarf planet called Ceres has provided cold hard evidence for cryovolcanoes. Dawn, a space probe, has been tasked with monitoring Ceres and in 2015, the spacecraft discovered a bright shining mountain on the surface of the planet. In a recent paper published in Science, this mountain, Ahuna Mons, has now been proposed as a cryovolcano.

How do they work?

Cryovolcanoes work much in the same way our regular Earth volcanoes do where geothermal energy warms up magma. For cyrovolcanoes, tidal energy provides the heat that warms cryomagma and causes it to turn into a vapour that moves up the mountain. When cryomagma is expelled on the surface, it condenses into ice.

Ceres is an interesting case though. Ceres is located far enough away from giant celestial bodies that it experiences negligible tidal energy. So where does it get the energy to heat up cryomagma? Turns out that Ceres could still have some internal heat left over from its formation and this fuels the cryovolcanoes. Additionally, Ahuna Mons is a baby in geological time scales and the ice that we see surrounding it could have only lasted only about century. This all hints to Ceres being still geologically active.

Volcanism and the formation of planets

The scientific objective of the Dawn spacecraft is to curate geological information to help answer one of the universes’ big questions – how did our Solar System and its planets form?

Volcanic activity is important in shaping the surface of our planets. On rocky celestial bodies like Mercury, volcanic activity could help us understand how these planets came to be. Now with the help of Dawn, the evidence for volcanic activity is mounting for ice bodies too.

Ahuna Mons is one chill volcano I wouldn’t mind checking out. Hey NASA, I’m still waiting on that invitation.

If you liked reading about ice volcanoes, here are some additional links:

Ice volcano on Pluto: http://www.nasa.gov/feature/possible-ice-volcano-on-pluto-has-the-wright-stuff

Ceres and Ice Volcanoes: http://www.seeker.com/ceres-mystery-bright-dots-may-have-volcanic-origin-1769548974.html

Science magazine’s coverage: http://www.sciencemag.org/news/2016/09/ice-volcano-spotted-ceres-asteroid-belt-s-dwarf-planet

Author’s own work. This post was originally published on http://blogs.unimelb.edu.au/sciencecommunication/2016/09/18/ice-ice-baby-volcano/

Introduction to trishfishkoh

Hello! So this is my first post on a blogging website since my angsty teenage years on Tumblr. Please forgive me if my silly side comes out and I have too many puns.

My name is Trish and I’m a Master of Science student at the University of Melbourne. I am currently researching sea urchin baby movement (yes they have babies and they move!). I like the sea and marine biology but this won’t be the primary focus of my blog. Instead, I hope to entertain folks with some (hopefully) interesting titbits from all fields of science.

I plan to post every fortnight but let’s see how that goes first before I go and make any promises!

Happy reading!