Space Movies – Fact or Fiction?

Posted on March 14, 2015 by bryancm1

Our in class discussion about some space movies had me venturing down a rabbit hole about Hollywood’s misconceptions about space. The most entertaining aspect for me is how movies portray character deaths in space. Movies always find creative and dramatic ways for their characters to die in space – none of which are accurate. In the original version of Total Recall, Arnold’s character’s lies screaming and his head nearly explodes when exposed to the atmosphere of Mars. The space horror film Event Horizon has one of its characters ejected from an air lock, after which he immediately began bleeding profusely through his skin and from his mouth and eyes.

But rather than expose you to some gruesome space deaths, I’d recommend checking out the below video. It’s a list of inaccuracies for the movie Gravity and the inaccuracies about space are explained by astrophysicist Neil deGrasse Tyson. Some of these inaccuracies you may already know – some you may be learning for the first time!

Source: Youtube


Posted in Space Travel | Tagged , , , , | Comments Off on Space Movies – Fact or Fiction?

Dark matter

Posted on March 14, 2015 by newbeelity

Dark matter is a hypothetical matter that neither emits nor absorbs light or any other electromagnetic radiations so that it cannot be seen with any telescopes nowadays. However, dark matter accounts for most of the matter in the universe, and it should be responsible for many phenomena occurring in the universe.

According to the standard model of cosmology, the total mass-energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Dark matter constitutes 84.5% of the total matter in the universe.

Evidence of the existence of dark matter:

Galaxy rotation curves

Stars that are rotating around the center of the galaxy are at increasing or the same speed at great distances from the center of the galaxy. The galaxy rotation problem is the discrepancy between observed galaxy rotation curves and the theoretical prediction. This discrepancy can be explained by postulating a large amount of dark matter that permeates the galaxy and extends into the galaxy’s halo.

M33_rotation_curve_HI

Gravitational lensing

From their gravitational lensing effects on background objects, usually more distant galaxies, the mass of galaxy clusters can be estimated. By measuring the distortion geometry, the mass of the cluster causing the phenomena can be obtained that clusters contain much more matter than the visible galaxies and gas.

Cosmic microwave background

Angular fluctuations in the cosmic microwave background (CMB) spectrum provide evidence for dark matter. Ordinary (baryonic) matter interacts strongly with radiation, but, by definition, dark matter does not. Both affect the oscillations by their gravity, so the two forms of matter will have different effects. The typical angular scales of the oscillations in the CMB, measured as the power spectrum of the CMB anisotropies, thus reveal the different effects of baryonic matter and dark matter.


Posted in Class | Tagged , , , | Comments Off on Dark matter

The Aurora Phenomenom

Posted on March 14, 2015 by bryancm1

Auroras are caused when particles from the sun become trapped in a planet’s magnetosphere. These particles gain energy and travel down the magnetic field and collide with atmospheric atoms and molecules. This collision is what produces the light that we see in an aurora.

We have all probably seen pictures of auroras on Earth. Do auroras occur on other planets? If a planet has the two requirements for an aurora – a magnetosphere and an atmosphere – then we should be able to observe occurrences of auroras as well.

Mercury – Has a magnetosphere but no atmosphere

Venus – Has an atmosphere but no magnetosphere

Mars – Has an atmosphere but no magnetosphere

Jupiter – Has an atmosphere and a magnetosphere

Saturn – Has an atmosphere and a magnetosphere

Uranus – Has an atmosphere and a magnetosphere

Neptune – Has an atmosphere and a magnetosphere

Jupiter, Saturn, Uranus, and Neptune all meet the criteria for auroras. We’ve also observed auroras on all four of these planets. Unfortunately, Neptune’s rings sweep away most of the trapped particles so its auroras are extremely faint. The other three planets’ auroras make for some awesome photos, though!

Jupiter’s aurora, viewed in ultraviolet light

Jupiter's Aurora

Source: ESA

Saturn’s aurora, viewed in ultraviolet light

saturn-aurora-100804-02

Source: Space.com

Uranus’s aurora

uranus-auroras-2011

Source: National Geographic


Posted in Light | Tagged , , , , | Comments Off on The Aurora Phenomenom

Climate Change

Posted on March 14, 2015 by newbeelity

Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). (Definition from Wikipedia)

Climate change is caused by biotic processes, variations in solar radiation, plate tectonics and volcanic eruptions. Human activities have also been regarded as a cause of recent climate change, known as “global warming”.

Causes:

Ocean variability

The ocean plays a significant role in the climate system. Even a tiny change by a slow and extremely deep movement of water in ocean processes such as thermohaline circulation will cause a great variation in redistribution of heat.

Orbital variations

Slight variations in Earth’s orbit cause changes in the seasonal distribution of sunlight and geographical distribution across the globe. There is very little change to the area-averaged annually averaged sunshine; but there can be strong changes in the geographical and seasonal distribution.

The three types of orbital variations are variations in Earth’s eccentricity, changes in the tilt angle of Earth’s axis of rotation, and precession of Earth’s axis.

Solar output

The Sun is the source of energy received by Earth. Variations in solar luminosity will affect the climate on Earth,

The Sun is emitting more power as it shines over time, causing the increase of global temperature and the change in atmospheric composition of Earth.

In addition, the 11-year solar cycle and the long-term modulations will cause climate change as well.

Volcanism

If over 0.1 Mt of SO2 is injected by volcanic eruptions to the stratosphere, the eruptions are large enough to affect the climate more than 1 year, for SO2 is a greenhouse gas.

Plate tectonics

The motion of tectonic plates reconfigures continents and oceans over millions of years. This reconfiguration can affect global patterns of climate and atmosphere-ocean circulation.

The position of the continents determines the geometry of the oceans and therefore influences patterns of ocean circulation. The locations of the seas are important in controlling the transfer of heat and moisture across the globe, and therefore, in determining global climate.

Human influences

A large part of recent changes in patterns of global climate can be attributed to human activities. Moreover, those change, such as the increase in CO2 levels, land use, ozone depletion, animal agriculture and deforestation, are irreversible or need a long time to recover.


Posted in Class | Tagged , , , | Comments Off on Climate Change

The Biggest Volcano in the Solar System

Posted on March 14, 2015 by emilyksharp

The biggest volcano in the solar system was discovered in 1971 by the space probe Mariner 9, though it is actually visible from most backyard telescopes. This volcano is called Olympus Mons and it is located on Mars. Its peak lies 14 miles above its base, making it more than four times taller than Mt. Everest. Its slope is very gradual, but the entire volcano is about the size of Arizona.

olympusmons

A digital reconstruction of Olympus Mons, The Museum of Unnatural Mystery

Olympus Mons is one of the key indicators for scientists on Earth that there is tectonic activity on Mars. It is unlikely that Olympus Mons is or was ever a stratovolcano (think tall, cone-shaped, and very explosive, such as Mt. Vesuvius or Mt. St. Helens) since it is very large and seems to have gradual lava flows down its sides that have built up the base, rather than intermittent explosive eruptions. Volcanoes like this on Earth, called shield volcanoes, often form above hotspots, hotter locations in the Earth’s mantle where magma rises to the surface and is ejected to the crust in slow, steady eruption of basaltic lava. The chain of Hawaiian islands are an example of this: as the Pacific plate moves northwest, volcanoes form above the hotspot but then move with the plate, only building up until that location on the plate is no longer above the hotspot (Space.com).

Astronomers have yet to find evidence of multiple tectonic plates on Mars, indicating that there is no plate movement or that the surface of the crust is just one big plate that may move with turbulence in the mantle. Thus, Olympus Mons has been sitting above the same hotspot since it first started to form (likely, since the hotspot first formed beneath the surface). The volcano thus had the opportunity to continue to grow and grow, layers of lava building up on top of each other with successive eruptions and creating the biggest volcano in the world. Evidence of these eruptions is visible in the multiple calderas seen on top of the volcano. Want to know more about Olympus Mons? Check out this informational page.

Curious about the biggest volcano on Earth? Read more here.


Posted in Terrestrials | Tagged , , , , , , , | Comments Off on The Biggest Volcano in the Solar System

Debating about the Dwarf Planets

Posted on March 14, 2015 by oliviasn

When I received an e-mail from my astronomy professor from last semester, David Weintraub, about an article that he had recently written for The Conversation, I was quite excited to read it. Professor Weintraub is very passionate about Pluto and quite vocal about his disapproval of its demoted status. This article, entitled “NASA missions may re-elevate Pluto and Ceres from dwarf planets to full-on planet status,” focuses on some possible implications that the current NASA missions may have on the status of these dwarf planets.

Personally, I am very conflicted as to whether or not Pluto and Ceres should be designated as planets. I grew up thinking of Pluto as a planet (and always as one of my favorite planets for some reason), so I was quite angry when it was demoted to a dwarf planet in 2006. On the other hand, I see why people do not believe that Pluto and other dwarf planets should not be considered planets, especially considering their sizes.

However, while reading the article, I found myself siding with Dr. Weintraub and concluding that Pluto and Ceres should officially be planets. I especially think that Dr. Weintraub’s point about location holds a lot of merit. Both Pluto and Ceres fit the aspects of the widely accepted definition of a planet in that they are spheroidal objects and that they both orbit a star. However, with the asteroid belt composing Ceres’ neighborhood and the Kuiper Belt composing Pluto’s neighborhood, neither has cleared the neighborhood around its orbit. This has served as one of the main argument for the demotion of Pluto. The controversy here becomes that there is no agreement currently as to either the definition of a planet’s neighborhood or what “clearing the neighborhood” precisely means. Moreover, it is not entirely agreed upon that this requirement is necessary for an object to be defined as a planet. This lays the basis for one of Weintraub’s strongest arguments: location should not be a factor in this argument and only an object’s intrinsic properties should factor into its status of a planet.

With this article in mind, I am currently leaning toward the position that argues for the promotion of Pluto and other dwarf planets to full planet status. However, especially with Dawn spacecraft and New Horizons spacecraft and all of the information that we may gain from these missions, I am open to other ideas and may be persuaded._42086172_solar_system_planets4_416-1

A view of the Solar System with Pluto and Ceres as dwarf Planets (Source: BBC)


Posted in Dwarf Planets | Tagged , , , , | Comments Off on Debating about the Dwarf Planets

A Moment of Appreciation for the Sun

Posted on March 14, 2015 by oliviasn

One object in the Solar System that I tend to take for granted proves to be the Sun. Because it is a constant in my life and I always know that I can depend on it rising and setting everyday, I often overlook how powerful it is. The Sun has been shining for 4.6 billion years and will continue to shine for about 5 billion more. Today, we learn so much from the Sun and the effects that it has on the entire Solar System. For many years, however, the Sun represented a great mystery for scientists.

Although the idea may seem a bit ridiculous to us today, it is easy to understand why many ancient thinkers thought that the Sun had to be some type of fire, such as burning coal or wood. When it became obvious that burning could never sustain the Sun’s high energy output, astronomers proposed the idea of gravitational contraction, or that the Sun slowly contracts in size to generate energy. Once again, this idea could not sustain the Sun’s energy output for as long as the Sun had existed, as gravitational contraction could only keep the Sun shining for about 25 million years. Fortunately, Einstein came to the rescue in 1905 with his famous theory of relativity and the equation E=mc^2. This equation demonstrated that the Sun could power itself for billions of years by converting its mass into thermal energy. Within a few decades, scientists ironed out the idea that the Sun uses nuclear fusion to convert mass to energy.

With the great mystery of how the Sun continues to shine after billions of years solved, scientists can observe multiple balances within the Sun. The Sun has gravitational equilibrium, or the balance between internal gas pressure pushing outward and gravity pulling inward. Moreover, the Sun also maintains an energy balance between the rate at which energy is released through fusion in the Sun’s core and the rate at which energy is radiated into space from the Sun’s surface.

sun-2

The Sun, as compared with other planets (Source: Nine Planets)

The Sun is incredible not only because it powers itself through fusion, but also because it maintains balance and stability. We depend so much on the Sun, and it is easy to see why such an important object has served as the inspiration for countless scientists and artists, from Einstein to the Beatles.


Posted in Historical, Sun | Tagged , , , , , | Comments Off on A Moment of Appreciation for the Sun

Surface of Venus Revealed from Earth Telescope

Posted on March 13, 2015 by jclyncmp

As many of us know, Venus is covered in a thick atmosphere of carbon dioxide that makes it very difficult for scientist to view the surface of Venus. In the past, NASA’s Magellan spacecraft has used radar to penetrate the atmosphere to gather date on the surface. However recently, astronomers were able to take pictures of Venus’ surface with a telescope on Earth. The telescope is a powerful radar transmitter at the NSF’s (National Science Foundation) Arecibo Observatory, located in Puerto Rico. The Arecibo Radio telescope is the largest dish antenna in the world, measuring in at 1,000 feet across. Check out an ariel view of the telescope below:

Arecibo Radio Telescope Ariel View Photo Credit: naic.edu

The ability to use this telescope to study the surface of Venus will allow astronomers to continually monitor the surface of Venus to study for geological activity that might reveal clues about the planet’s formation. Check out the stunning images from the telescope on Venus’ surface.

The Surface of Venus from the Arecibo Radio Telescope Photo Credit: astronomynow.com

Posted in Terrestrials | Tagged , , , , | Comments Off on Surface of Venus Revealed from Earth Telescope

Sun Triggers Radio Blackout with First X-Class Flare

Posted on March 12, 2015 by jclyncmp

The Sun triggered a radio blackout with the first X-class solar flare of 2015 on Wednesday, March 11th at 12:22pm ET. A solar flare is a sudden flash of brightness on the Sun’s surface. Solar flares are classified as A, B, C, M, or X, with X-class being the most intense of the flares. The solar flare sent a blast of energy (mostly X-rays and UV radiation) towards Earth that caused a radio blackout over large areas of the globe, including most of the Americas. The solar flare also created a coronal mass ejection (CME), which is a massive burst of gas and magnetic field. The CME might be headed towards Earth, so astronomers will be keeping a close look at it! Below is a picture of the Sun right after the solar flare occurred on Wednesday. You can see where the flare took place, it is the bright white spot on the surface.

An observation of the sun -- at a wavelength of 304A -- made by NASA's Solar Dynamics Observatory shortly after Wednesday's X-class flare.
The Sun after Wednesday’s X-class flare

Posted in Sun | Tagged , , , | Comments Off on Sun Triggers Radio Blackout with First X-Class Flare

Sun Triggers Radio Blackout with First X-Class Flare

Posted on March 12, 2015 by jclyncmp

The Sun triggered a radio blackout with the first X-class solar flare of 2015 on Wednesday, March 11th at 12:22pm ET. A solar flare is a sudden flash of brightness on the Sun’s surface. Solar flares are classified as A, B, C, M, or X, with X-class being the most intense of the flares. The solar flare sent a blast of energy (mostly X-rays and UV radiation) towards Earth that caused a radio blackout over large areas of the globe, including most of the Americas. The solar flare also created a coronal mass ejection (CME), which is a massive burst of gas and magnetic field. The CME might be headed towards Earth, so astronomers will be keeping a close look at it! Below is a picture of the Sun right after the solar flare occurred on Wednesday. You can see where the flare took place, it is the bright white spot on the surface.

An observation of the sun -- at a wavelength of 304A -- made by NASA's Solar Dynamics Observatory shortly after Wednesday's X-class flare.
The Sun after Wednesday’s X-class flare

Posted in Sun | Tagged , , , | Comments Off on Sun Triggers Radio Blackout with First X-Class Flare