Assig3sci102

Assessment item 3Demonstration of

Scientific KnowledgeLuke Burgess-sci102

Student Number: 11539636

Due Date:06/06/2014

Astronomy: Life

on other planets

For decades, scientists have been determined to discover whether there are other forms of life within our solar system through use of telescopes, satellites and probes being sent to voyage into the darkest parts of space. The various technologies used in the 21st century have led to astounding discoveries within our solar system and beyond, which leads to endless possibilities.

Within recent years, there has been several discoveries of ‘exoplanets’- which have been located outside our solar system, which display particular characteristics of being able to sustain life for even microbial organic life forms. But before their discovery, some planets within out solar system were considered to have held life during one point in their existence

The Planet Mars:

Mars is recognised as the fourth planet from the Sun, being identified to astronomers by its bright rust colour due to the minerals located within the loose and dust covering the surface being rich in iron-based minerals.

The geology of the planet Mars shows a cold thin atmosphere made up of approximately 95% Carbon Dioxide, while the rest of the atmosphere is comprised of nitrogen (2.7%) and argon (1.3%).

In comparison with Earth, Mars shares similar orbital characteristics due to the axis of the planet tilting much like Earth, leading to certain amounts of sunlight reaching certain parts of the planet during its year, giving the planet seasons.

However, due to the planet’s elliptical orbit, it experiences harsher seasons when particular hemispheres are facing the Sun, including short, hot summers and short, cold winters.

Martian Meteorites: Host

for life?In 1984, the meteorite ALH84001 was discovered in Antarctica by a team of meteor researchers from the ANSMET project, who believed this fragment of meteorite came from the planet Mars. From analysing this sample amongst the other 10 rocks from Mars found, researchers have concluded that they discovered organic carbon compounds that originated on Mars without involvement of life.

Furthermore, researchers were then led to believe that this meteorite could contain fossils from Mars. The claim was strongly disapproved, leading to the suggestion that this piece of meteorite dislodged from Mars over 16 million years ago falling to Earth around 13,000 years ago.({Greicius, 2012 #35})

Possibility of life on

Mars?

After years of scientific research, as far it has been determined, the surface of Mars is inhospitable to forms of life as we currently know. Due to the atmosphere being made up of mostly carbon dioxide, while the rest of the atmosphere compromises of argon and nitrogen, which is similar to Earth’s atmosphere.

The overall problem that the planet Mars holds is that due to the atmosphere itself, the planet wouldn’t be able to sustain it for too long due to its small size according to scientists.

Active missions

to Mars:In order to discover more about our neighbouring planet Mars, NASA has voyaged into space with probes such as the Curiosity rover, launched in 2011, taking over the responsibilities of its predecessors, the Spirit and Opportunity rovers. It successfully landed in 2012, relaying information back towards Earth ever since. In 2014, NASA plans to send the MAVEN orbiter to address key questions about Mars’ climate, understanding the nature of the planet itself.

The ISRO has also launched it’s own interplanetary spacecraft back in 2013, being a technology presentation, carrying 15 kilograms of scientific instruments that will help analyse the planet, also relaying its results back to Earth.

Jupiter’s and

Saturn’s Moons:

Europa and Titan

Besides Mars, the planet Jupiter and Saturn and its moons Europa and Titan have been suggested to once have held life due to their composition. The moon Europa is Jupiter’s sixth- closest moon, having its surface covered in ice, while also having a icy crust being severely fractured, indicated by its curved, linear bands from images on its surface. Europa’s density allows scientists to conclude that it has a layer of ice water, while liquid water could exist due to possibility of internal tidal heating from its gravitational relationship with the planet and its other moons.

Jupiter’s largest moon Titan has also been suggested to have held life due to its ammonia/methane chemistry within the atmosphere; a essential component in the synthesis of ‘amino acids’, leading to the possibility that primitive forms of life may exist on this moon, however it’s unlikely due to the temperature being extremely cold.

Can Saturn’s Moon

Enceladus support

life?

Scientists have discovered that underneath the icy surface of Saturn’s moon Enceladus, there is a watery ocean that could potentially harbour life. This discovery was made possible by NASA’s Nassini Spacecraft, which had been monitoring gravitational anomalies over the course of 10 years.

The moon keeps the water from freezing by warming tidal forces, that is generated by the gravity of the giant gas planets. This suggests that small microbial organic life forms may be able to survive on the surface of the moon Enceladus. From the research, it’s conclusive that a large body of water is causing the anomaly when scientists realised something denser than ice was giving the readings.

The discovery of

exoplanets:

Within recent years, there has been a major breakthrough in the discovery of planets that exist outside our solar system, being defined as ‘exoplanets’. In addition, some exoplanets have been recognised to be similar sizes to Earth, and some even being super-sized in comparison to our own planet.

To discover more exoplanets within our universe, scientists have developed a space telescope which has a specific role in locating ‘exoplanets’, gathering critical information on the characteristics of the planet/s itself. It’s called the Kepler Space Telescope.

The Kepler Space Telescope:

In 2009, NASA launched the Kepler Space Telescope into space to locate and record information on exoplanets that were located outside the solar system, the Milky Way.

The main focus of the Kepler Space Telescope is to also discover Earth sized planets within our solar system as well as outside the solar system and determine how many planets are located amongst the billions of stars within the universe.

Kepler-186 and the Solar System:

In the above diagram, this model of the Kepler-186 system shows a five planet system which is measured to be 500 light years away from Earth, in a constellation called Cygnus.

From the diagram, it shows that these planets orbit a ‘M dwarf’- a star that is recognised as being half the size and mass of our Sun.

The Exoplanet

Kepler 186-f:

As of April 2014, the Kepler Space Telescope made a major discovery; it found an Earth sized exoplanet orbiting a star within the ‘habitable zone’- meaning that it’s the perfect distance away from its star that it might have the capabilities of pooling water on its surface.

The planet Kepler 186-f is part of the Kepler-186 system, which is a five planet system, however the other planets within this system are be closer to the star than what Kepler 186-f is, not allowing life to be sustained due to them being too close to their orbiting star.

The Exoplanet

Kepler 10-c:

Astronomers have now discovered a new rocky planet, being identified as a ‘Mega Earth’, due to it being 17 times the mass of Earth. It is suggested that Kepler 10-c formed 11 billion years ago, being created less than 3 billion years after the universe began.

The Kepler Space Telescope has also analysed that this ‘Mega Earth is 560 light years away from Earth, orbiting its star very close, suggesting that life can’t exist on this planet, while the gravity is about twice of what Earth’s gravity is.

Is there life on

other planets?From the conclusive research into life on other planets, including exoplanets as well as planets within our solar system, the search for life continues due to the evidence that suggests life exists outside our own planet being somewhat inconclusive. However, from analysing certain planets’ moons such as Saturn, including Europa and Enceladus, they have provided results about how there is the possibility of life to be sustained outside Earth due to the discovery of water on these orbiting moons, which allows scientists to continue having hope in discovering some form of life out in space.