Tag Archives: stars

New Plasma-Fueled Rocket is 165 Times Faster than Speed of Sound!

Most of us only learned about three states of matter while in school: solids, liquids and gases. But there is a fourth state as well- it’s called plasma.

You’ve probably seen a plasma globe before, but lightning, our Sun and all stars, and even the gas you see in a neon sign are all every-day examples of plasma as well.

This slideshow requires JavaScript.

Plasma is basically a gas with such high energy that the molecules begin to ionize- that is the positively and negatively charged components of the gas molecules break away from one another.

Because of this ionization, an electromagnetic field can be used to focus the plasma in a specific direction.

Although using plasma for propulsion was first proposed in 1977, it is just now becoming a reality with the advent of new technologies.

Artist-rendering of the VASIMR Rocket (click to enlarge)

The VASIMR (Variable Specific Impulse Magnetoplasma Rocket) Plasma Rocket, which is now being tested out by NASA, uses a renewable energy source (radio waves in the form of light which are plentiful in space) to heat Argon gas until it reaches its plasma state.

The rocket then uses an electromagnetic field to focus the plasma, creating a propulsion system.

VASIMR Propulsion System (click to enlarge)

Developers estimate that the VASIMR Rocket will be able to travel at speed up to 126,000 mph (that’s 35 miles every second). The speed of sound is a sluggish 761 mph.

Because of its speed and use of renewable energy sources, the VASIMR greatly increases the limitations of our exploration, allowing us to explore parts of space that we never could before.

But what has NASA scientists most excited is the VASIMR’s application for Mars missions. Currently, the journey to Mars requires too much fuel to make a return trip feasible.

However, since the VASIMR can make this trip in just 39 days (almost 6 times faster than current methods) and employs renewable energy, it makes round-trip missions to Mars a reality.

Read the full story here.

VASIMR7
The surface of Mars

 

Advertisements

Most Breathtaking Space Photos and Time-Lapse Videos of 2013

With only a week left in 2013, it’s a good time to review some of the most amazing images taken from space this year.

Click an image to enlarge and read brief descriptions about each photo.

These two awesome time-lapse videos will make you feel like you’re flying through space. David Peterson, a film student and programmer, put them together using imagery captured by astronauts aboard the International Space Station.

Mind-Blowing Video: What Don’t You See When You Look at the Sun?

The Sun is composed of a number of different compounds and elements which exist at different temperatures and therefore emit radiation with different wavelengths (this is explained in more depth below the video).

All of the light we see with our eyes is electromagnetic radiation that falls within the “visible spectrum”, meaning that the photons, or light particles, have a wavelength between 400 and 700 nanometers (a nanometer is 1 billionth of a meter).

The range of wavelengths within the sun in 250-2500 nanometers. This video shows you all of the the other forms of radiation that our eyes can’t see.

Since all photons travel at the speed of light (roughly 30million m/s or 670,616,629mph), a photon with a longer wavelength must have a shorter frequency (how many waves pass a point in a given time).

For example, imagine you have two waves traveling past a line you have drawn: one wave that has a wavelength of one meter and another that has a wavelength of two meters. If they travel at the same speed, two of the one-meter waves will pass your line in the time it takes one full two-meter wave to pass it, so we say the shorter one has twice the frequency. In fact, multiplying the wavelength and frequency of any photon will give you the speed of light.

Frequency and temperature are directly proportional so different materials release photons with different frequencies, depending on how hot the material is. Here’s a great chart that shows the relationships between wavelength, frequency and temperature. Click to see full size.

For more information, visit the project’s page on NASA’s website by clicking the image below.

Chair of the Astronomy Department at Harvard Says Other Complex Life in Universe Very Possible

Abraham (Avi) Loeb an American/Israeli theoretical physicist who works on astrophysics and cosmology and is Chair of the Astronomy Department at Harvard says that “it’s quite possible that life is everywhere and we are the late-comers”. Today Forbes released an article that summarizes a paper submitted by Avi Loeb to the journal of Astrobiology. The entire article can be viewed below.

The following passage comes directly from Forbes (Note I have bolded certain key points)

   The evolution of complex life in the universe has, heretofore, thought to have been quite a long slog.

But in a paper submitted to the journal Astrobiology, theoretical cosmologist Avi Loeb argues that some form of complex life may have arisen within the first billion years of our universe’s existence.

Loeb, Chair of the Astronomy Department at Harvard, says that some fraction of the cosmos’ first so-called Population III stars may have produced supernovae that seeded the early cosmos with large amounts of metals, like iron. Such heavy elements, Loeb notes, are crucial when forming terrestrial planets like our own.

These first stars — thought to on average have been some 100 times more massive than our sun — likely had hydrogen-burning lifetimes of only 3 million years. Yet Loeb says a follow-on population of Population II stars that formed within these very first stars’ metal-rich vicinity, could have spawned earthlike planets, some fraction of which may have harbored complex life.

“These were stellar “islands” enriched by heavy elements where you could make planets,” said Loeb. “But most of the early universe either had pristine [hydrogen] gas or low metallicity gas.”

The Cosmic Microwave Background (CMB), relic radiation leftover from the Big Bang, was roughly room temperature when the universe was only 15 million years old.

A rocky planet at such early times, wouldn’t have needed the warmth of its parent star, but Loeb says could simply have bathed in the CMB’s radiation, which for some 3 million years at least could have allowed for planetary liquid water and, in principle, the chemistry of life.

And if that prospect isn’t tantalizing enough, Loeb says conceivably tens of millions of years after the Big Bang, Population II stars could have also had metal-rich proto-planetary disks capable of forming earth-like planets.

These longer-lived Population II stars would have provided stable long-term conditions for these young earths and may have led to life as we know it literally near the dawn of time.

Theoretical Cosmologist Avi Loeb.  Credit:  CfA Public Affairs

Cosmologist Avi Loeb

In his paper Loeb also says that even in a cosmos that had an initial high value cosmological constant, or energy density of the spacetime vacuum, complex life would have still had time to evolve within the first one billion or so years of the universe’s ex

istence. That is, before this accelerating vacuum energy caused space to expand so rapidly that gravity could not have done its work and galaxies like our Milky Way — rife with stars and planets like our own — could not have formed.

To date, however, the standard paradigm for the evolution of intelligent life in the universe is that if it’s out there, it’s probably only been around for the last 6 billion years, or about a billion years after the peak of cosmic carbon production.

But what if life did evolve on an earth-like planet circling an early Population II star?
One born only 50 million years after the Big Bang?

If it vectored into intelligence that somehow persisted over much of the universe’s 13.8 billion-year history, by now such an ancient civilization’s technology would arguably be nothing short of “godlike.”

firststars

Simulated Image of the Universe’s first Stars

“The picture that we have of the [early] universe is that the cosmos is sort of dead,” said Loeb. “But it’s quite possible that life is everywhere and we are the late-comers.”

 

Pulverized Asteroid around Distant Star Was Full of Water

Pulverized Asteroid around Distant Star Was Full of Water

(click the link above to read the full story)

Using spectroscopy (a process where researchers can determine the contents of a substance by seeing the way it refracts light), scientists found a number of heavy elements, including iron, magnesium and silicon inside the asteroid. Even more interestingly, the researchers also found, “…a huge excess of oxygen—an amount, they say, that indicates the asteroid…was originally composed of 26 percent water. That’s pretty wet—Earth, by contrast, is only 0.02 percent water.”

*NOTE: 70% of Earth’s surface is covered in water. However, only 0.02% of Earth’s mass is water.