THE SUN, A DAYTIME STAR

Hello again dear readers, I’m glad to continue posting in this sidereal blog (if it could be called that way). This time I would like to talk about the main celestial body of our Solar System: 
The Sun.

This huge friend comprises 99.8 percent of the entire mass of the Solar System: the other 0.2 percent is everything else: planets, moons, asteroids, dust, etc. (Burnham 126) So we are just like a very little piece of rock together with Mars, Venus and Mercury when compared with the sun and the exterior planets 

Today, scientists recognize the sun as a medium-sized star of fascinating complexity, composed largely of hydrogen and helium, and powered by a thermonuclear furnace. (Frazier 59)


So now imagine the big-sized stars that are thousands of times the size of the sun. But, despite of its size, our sun is a very stable a powerful star. 

Its source of energy is a nonstop succession of nuclear reactions in its core, where hydrogen atoms fuse to form helium. (Burnham 126)
This can be possible because the massive outer layers of the sun press inward in the core with more than 200 billion times the atmospheric pressure on Earth, squeezing its hydrogen to a density more than 160 times greater than water, generating temperatures of 27 million degrees Fahrenheit; high enough to ignite and sustain the fusion of hydrogen into helium. (Frazier 78)


Just imagine such power that literary transform an element to another!


With the rapid advance of scientific knowledge, the sun becomes an ever more fascinating star… The ancients had good reason to worship the sun. Under its wondrous light, human beings bask in warmth and pale to insignificance. The planets, asteroids and comets dance in stately orbit, locked in the sun’s gravitational embrace. (Frazier 79).

The Mysterious Brother: Uranus

Hi everybody, sorry for forgetting posting last week. But I would like to retake the theme that I wanted to talk about.

I don’t know why but I feel chills when I think about the planet Uranus. This enigmatic blue-green world:

• Is about four times the size of Earth and is 2.9 billion kilometers (1.8 billion miles) from the Sun. (Burnham 160).

• His name comes from the ancient Greek deity of the Heavens, the earliest supreme god.
• It is the only giant planet whose equator is nearly at right angles to its orbit.
• It takes 84 terrestrial years to complete his orbit around the Sun.
• Is thought to have a small rocky core enveloped in a thick layer of liquid ice and rock, but unlike Jupiter and Saturn it lacks a layer of metallic hydrogen. (Burnham 160).

 The opaque atmosphere seems to hide some kind of exciting millenary secrets. But you wouldn’t like to visit this planet if you’d know that Uranus is plenty of methane and ammonia, both substances are highly poisonous for any kind of living thing.

The methane is largely responsible for the planet’s blue-green color, so we could say that it is a very poisonous world. Actually, Most of our knowledge of the planet came from a single spacecraft, Voyager 2, which sped by Uranus at close range in 1986. (Burnham 160)

Up until Voyager’s visit to Uranus; we knew of just 5 moons; Voyager spied 10 more and subsequent discoveries added 6, giving a total of 21.

Special Fact: Almost all Uranus moons are named after characters from Shakespeare’s plays. (Burnham 161).

Sources:

Burnham, Robert. Astronomy: The Definitive Guide. Singapore: Barnes & Noble, Inc., 2003.

The little daugher of Earth: the Moon

Hi over there, so I´m back again to give you another interesting fact about our cosmic neighborhood (our Solar System). But now, I’d like to focus on our closest cosmic neighbor: our dear Moon. Did you know how it was formed?

When I was a little kid I heard several stories about the Moon, for example that when an angel was playing around somewhere in the Universe his white pearl necklace broke and the pearls spread over the cosmos and one of those was captured by Earth, so that white pearl became what we know now as the Moon. And there is also another story that is actually a Mayan legend that goes more less like this:

“Once upon a time Quetzalcoatl (the main Mayan god) decided to take a human form and walk all day long on Earth. When it went dark, he decided to take a break but then a little rabbit got close to him and when he told the rabbit he was hungry the rabbit offered itself as a meal for the man. Quetzalcoatl was so impressed of the attitude of the rabbit that he stamped the image of the rabbit in the Moon so the rabbit could be always remembered for its gentle hood.” (Nayita 2007)

Ok, now I’ll focus on the real story of the creation of the Moon. Nevertheless, there are actually four dominant theories about the formation of the Moon.

1. The capture theory: the Moon formed in some other part of the Solar System and was gravitationally snared by Earth. (Burnham 138)

2. The fission theory: the Moon was once part of Earth but calved from it early in their story. (Burnham 138)

3. The sister theory: Earth and Moon formed together but independently, as many of the moons in the outer Solar System formed. (Burnham 138)

4. The giant impact theory: a glancing, high-speed collision between the primitive Earth and a Mars-size body smashed Earth’s crust and melted rock deep within its mantle. Melting rock from both Earth and the impacting body was jettisoned into space, condensing into a ring orbiting debris (so Earth actually had a ring!, well, it’s supposed to, but it’s just a theory). This material coalesced, cooled, and solidified into the Moon. (Burnham 139)

Bibliography:

Burnham, Robert. Astronomy: The Definitive Guide. Singapore: Barnes & Noble, Inc., 2003.

NAYITA. NAYITA'S BLOG. 3 august 2007. 13 september 2011 <http://nayita.wordpress.com/2007/08/03/un-conejo-en-la-luna-leyenda-maya/>.

Is that a planet or a sleepy star? It's a Star Planet!

I have been thinking about when did my interest in astronomy was born. I remember that when I was in elementary school, like in 4th grade, I took a curious book that had as title something like “Our Universe”. Since the moment I opened it I couldn’t take my eyes out of those colorful pages, in fact, I asked my teacher if I could keep it for some days. I couldn’t even stop reading it at home: if fell in love with the immensity of the Universe that I was watching through the fabulous pictures. But something called my attention: when I began the chapter about Jupiter I couldn’t believe what it said: “Jupiter could have become a star”.

Wooow! I said… but then I discovered that it wasn’t as illogical as I first though because Jupiter is TWO TIMES more massive than all other planets of the Solar System together (and 317 as massive as Earth, what a small world!, don’t you think?). That’s why this HUGE NEIGHBOR was called after the chief god in Roman mythology: JUPITER. It is the undisputed senior member of the Solar System. (Burnham, 152)

Had Jupiter been 80 times more massive, pressure from its outer layers could have raised interior temperatures enough to trigger nuclear reactions, thereby making it a low-mass star. (Burnham, 152) And how much would it need to become a high-mass star?

Ok, now let’s talk about some basic facts about this big friend:

 

Diameter	88, 730 miles (142, 796 km)
Mass	317.8 Earth masses
Rotation period	0.41 Earth days
Inclination of equator to orbit	3.1 degrees
Mean orbital speed	8 miles/second (13km/s)
Mean distance from the Sun	485 million miles (778 million km)

(Burnham, 153)

If we could travel as fast as light we could reach Jupiter in about 43 minutes, knowing that Jupiter is about 780 million km. from us and the velocity of light is about 300,000 km/s (can you imagine that?) But I’m so sorry to inform you that it’ll be pretty difficult. Nevertheless, we don’t know how far could we get with the contant advance of technology.

Even though, the entusiam of scientist never gave up so they began to sent spacecrafts such as Pioneer 1(1972), then Voyager 1 and 2 (both in 1977) and the most recent: the Galileo spacecraft, which arrived to Jupiter in 1995. (Burnham, 153)
All these brave explorer robots allowed humanity to contemplate the Big Brother of the Solar System planets.

Bibliography:

Robert Burnham, Alan Dyer, Jeff Kanipe. Astronomy: The Definitive Guide. Singapore: Barnes & Noble, Inc., 2003.

The adopted sons of the Sun: The Dwarf Planets

Unlike planets, dwarf planets lack the gravitational muscle to sweep up or scatter objects near their orbits. They end up orbiting the sun in zones of similar objects such as the asteroid and Kuiper belts. Pluto, Eris and the asteroid Ceres became the first dwarf planets in our solar system, recognized in world-wide astronomy.

On August 24, 2006, the International Astronomical Union voted at the end of its 26th General Assembly to establish definitions for three classes of substellar objects in the Solar System:

Planet - This is a celestial body that: (a) is in orbit around the Sun; (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape (due to a hydrostatic equilibrium); and (c) has cleared the neighborhood around its orbit. As now defined, the Solar System has eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Dwarf Planet - This is a celestial body that: (a) is in orbit around the Sun; and (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape (due to a hydrostatic equilibrium); but (c) has not cleared the neighborhood around its orbit; and (d) is not a satellite of another planet. As defined, the Solar System has probably has at least one dwarf planet in the Main Asteroid Belt (Ceres), Edgeworth-Kuiper Belt (Pluto and Eris); and Oort Cloud (possibly Sedna). In addition, the "dwarf planet" Pluto is recognized as a prototype of a new class of trans-Neptunian objects.

Earth in comparison with Dwarf Planets

Smaller Solar System Bodies - This category collectively refers to all other celestial bodies orbiting our Sun, Sol (including asteroids, comets, and satellites).

Bibliography:

Sol Company. SolStation.com. 2008. 25 august 2011 <http://www.solstation.com/stars/dwarfpla.htm>.

The Mysteries of Quasars

Ok, first I'm going to introduce myself.

I'm a high school student named Rafael Guevara (Id. number: A01280452), but people call me Rafa or Alex, both are fine to me, but I like more the first way. Well, now I would like to talk a little bit about what my pseudonym, Quasar Man, actually means.



First of all, a quasar:

1) Is a compact region in the center of a massive galaxy.

2) It has an incredible quantity of energy that produce a lot light, that’s why quasars seem to be stars, in fact, the name “quasar” (quasi-star = star-like) comes from this similarity.

3) Quasars are relatedly a recent discovery in astronomy. It was in 1963 when Thomas Matthews and Allan Sandage, both scientists from the Californian observatory Monte Palomar, discovered a very curious object in space: it was too small for the quantity of light it produced. They called it quasar (star-like), although it was much more powerful than any star.

4) They are extremely far away. One of the shiniest quasars is about 2 billion light-years away, but they shine much more than one of the greatest galaxies.

5) Quasars allow astronomers to know how the Universe was in its early years because light takes a lot of time to travel such distances, so we are actually looking the quasars as when they were very youth, since the beginning of the Universe itself.

<------------------------------------------------------ O -------------------------------------------------------------->

I don’t know what do think, but I really love all this stuff about Outer Space, I don’t think we are alone in Universe, it’s not logical to think that way, I mean, there are billions of galaxies, and each galaxy has billions of stars, and, I don’t know, at least millions of those stars must have several planets around them. Just imagine the huge possibility for life to develop somewhere in those innumerable planets.

Hope you enjoy this humble web blog, you can comment freely, seriously, all humans (and any intelligent life-form) are welcome ;)

Bibliography:

Mienciclo Universal. 2010. 22th august 2011 <http://0-www.mienciclo.es.millenium.itesm.mx/enciclo/index.php/Qu%C3%A1sar>.