The Comet in Queenstown by Trey Ratcliff
Milky Way
This name derives from its appearance as a dim “milky” glowing band arching across the night sky, in which the naked eye cannot distinguish individual stars.
(Source: flickr.com)
20 Things You Didn’t Know About Eclipses
1 The longest total solar eclipse of the century occurred on July 22 over India, Nepal, Bhutan, and China. It peaked over the Pacific Ocean, but even there the darkness lasted a mere 6 minutes and 29 seconds.
2 Fast and furious: The moon’s shadow zooms across Earth’s surface at up to 5,000 miles per hour.
3 Canadian astronomer and renowned eclipse chaser J. W. Campbell traveled the world for 50 years trying to see 12 different eclipses. He ran into overcast skies every time.
4 Don’t repeat J. W.’s mistakes: Monsoon season throughout south Asia means that there is a good chance the eclipse this July will be clouded out too.
5 Just before full eclipse, dazzling “Baily’s beads” appear where sunlight shines through valleys on the moon. The last bead creates the impression of a diamond ring in the sky.
6 On eclipse-viewing expeditions, this phenomenon is frequently accompanied by a marriage proposal.
7 The beautiful symmetry of a total solar eclipse happens because—by pure chance—the sun is 400 times larger than the moon but is also 400 times farther from Earth, making the two bodies appear the exact same size in the sky.
8 In case you were thinking about relocating: Earth is the only place in the solar system where that happens.
9 Other planets get other kinds of fun, though. Jupiter can have a triple eclipse, in which three moons cast shadows on the planet simultaneously. The event is easily visible through a backyard telescope.
10 The Chinese word for solar eclipse is shih, meaning “to eat.” In ancient China people traditionally beat drums and banged on pots to scare off the “heavenly dog” believed to be devouring the sun.
11 Then again, China also produced the first known astronomical recordings of solar eclipses, inscribed in pieces of bone and shell called “oracle bones,” from around 1050 B.C. or earlier.
12 By comparing those ancient records with modern calculations of eclipse patterns, scientists have determined that the day is 0.047 second longer today than it was back then.
13 Tidal friction, which causes that lengthening of the day, is also making the moon drift away. In about 600 million years it will appear too small to cover the sun, and there will be no more total solar eclipses.
14 In any given location, a total solar eclipse happens just once every 360 years on average.
15 Luckiest place on Earth Carbondale, Illinois, will beat the odds: Folks there will see an eclipse on August 21, 2017, and again on April 8, 2024.
16 In contrast, everyone on the night side of the world can see a lunar eclipse, where the moon slips into Earth’s shadow.
17 During a total lunar eclipse, the moon takes on a deep reddish hue due to the sunlight filtering through our atmosphere—the cumulative glow of all the world’s sunsets.
18 While stranded in Jamaica, Christopher Columbus was famously saved by the lunar eclipse of February 29, 1504, which he had read about in his almanac. After a fracas with the locals, Columbus warned that the moon would disappear if they did not start supplying his men with food.
19 When the moon vanished, the locals promptly complied, and Columbus breathed a huge sigh of relief: His almanac was calibrated for Germany, and he was not sure that he had adjusted correctly for local time.
20 Who knows—it might be useful to you, too. The next lunar eclipse visible from the United States will take place on December 21, 2010.
What if we had a planet instead of a Moon?
Our moon is a pretty big object. It’s big enough to be a respectable planet in its own right, if it were orbiting the sun instead of the Earth. (Actually, it is orbiting the sun in a nearly perfectly circular orbit, that the Earth only slightly perturbs… but that’s a topic for another day.) The Moon is a quarter the diameter of the Earth. Only Pluto has a satellite that is larger, in proportion to the size of the planet it orbits.
But what if the Moon were size of Mars, instead? It would like the picture above. Check out how some of the other planets of the Solar System would look in our sky, if they took the Moon’s place.
At a distance of about 240,000 miles, the Moon occupies a space in the night sky about half a degree wide. By sheer coincidence, this is almost exactly the same size the sun appears, which is why we occasionally get total solar eclipses. (We don’t get a total eclipse every time the Moon passes in front of the sun because the Moon is sometimes a little closer to the Earth and sometimes a little further away, so it will cover more or less of the sun during any eclipse.)
But it’s interesting to imagine what the night sky might look like if one of the Solar System’s planets were to replace our moon. (We’d have to ignore things like tides and gravitation, but that’s the advantage of doing things in the mind’s eye.) So what would we see if we were to replace the moon with Mars? The red planet is almost exactly twice the size of the Moon, so it would appear twice as big in the Earth’s sky. It would be easy to see with the naked eye details on the surface of the planet that were previously visible only through telescopes. You could watch the ice caps grow and shrink during the changing seasons, see dust storms form and move across the planet and make out features like Vallis Marineris and Olympus Mons.
10 Things You Didn’t Know About Black Holes
Stars whose size is 10 or 15 times as massive as the Sun, generally have a fate of becoming black holes. Small stars, however, die as white dwarfs or neutron stars. So how do large stars become black holes? As stars begin to grow old, they gradually expand and they slowly run out of their supply of hydrogen and then helium. This causes contraction of their cores and expansion of the outer layers. The stars start becoming cooler and less bright and they come to a stage which is known as the red giant phase. Now, for a star which is even 3 times or more the mass of the Sun, undergoes detonation (a violent release of energy caused by a chemical or nuclear reaction) in cataclysms known as supernovae. Such kind of explosion results in scattering of most of a star into the space. However, it also leaves behind a cold remnant of the star, which is no longer able to execute any nuclear fusion reaction.
As there is no fusion in the dead remnants of a massive supernova star, there is no creation of any energy which can oppose the inward pull of gravity caused by the star’s own mass. Thus, the star enters a phase where it begins to collapse in upon itself. This is the formation of the black hole, wherein, it starts shrinking to zero volume. So, with volume being zero, density becomes infinite, so much that even light becomes unable to escape its massively strong gravitational pull. As a result of this, even the light of the dead remnants of the star gets trapped in its orbit and this dark star evolves to become what is known as a black hole.
- It has been estimated that there might be black holes of enormous size, which may be existing at the center of our galaxy, ‘The Milky Way’. These holes are assumed to be having the mass of 10 - 100 billion suns. Now, that is something which is ‘HUGE’, in block letters!
- Cygnus X-1 is the black hole that is located about 8000 light years away from our planet Earth. This is the closest black hole to Earth, known to man.
- Although, black holes are associated with the reputation of having the strongest suction force, they do not bear the capability to absorb the whole universe. Anything such as planets, light and other matter, can be pulled into the grasp of black holes, only if they happen to cross what is known as the event horizon. The radius of this event horizon is known as the Schwarzschild radius and at this radius, the escape velocity equals the speed of the light. So, once an object has passed through it, it must travel faster than light in order to escape it. That is the reason why, even light cannot escape the event horizon of a black hole.
- As mentioned earlier, in this part of black holes in space, only the largest of stars are capable to end up as black holes. Only these stars are massive enough to get compressed to the Schwarzschild radius. While, smaller stars end up as white dwarfs or neutron stars.
- There are several black holes which exist in binary star systems. Stars which are neighboring such holes, will keep on shrinking as their mass will continually be pulled by these holes. Gradually, the black holes will go on increasing, until the other stars have vanished.
- As light cannot escape from a black hole, it cannot be directly observed. However, scientists use the presence of matters which swirl around the hole. Such matters are usually gas and dust and they heat up and emit radiation which can be detected.
- Talking about our Sun becoming a black hole, the phenomenon won’t occur. This is because the sun is not massive enough to shrink into a black hole. However, it will end up to become a white dwarf, after several billion years.
- The center of a black hole is void of time and space.
- A giant elliptical galaxy in the constellation Virgo, is assumed to home the largest known black hole. This hole is about 3 billion times the mass of the Sun.
- Larger black holes are known to suck up other smaller ones which are close to their vicinity.
No matter, how many facts people come up with, black holes represent an endless journey in the vast darkness of the space. The concept which lay hidden in the lap of black holes, perhaps, is the most appropriate analogy to the saying ‘sky is the limit!’
In the image: Simulation of gas cloud approaching the black hole at the center of the Milky Way
10 Things You Didn’t Know About Space
There is still so little known about outer space by modern science, but of that little we do know, there are some extraordinarily amazing things. This is a list of the top 10 cool facts about Space.
10. Lightweight
Fact: If you put Saturn in water it would float
The density of Saturn is so low that if you were to put it in a giant glass of water it would float. The actual density of Saturn is 0.687 g/cm3 while the density of water is 0.998 g/cm3. At the equator Saturn has a radius of 60,268 ± 4 km – which means you would need an extremely large glass of water to test this out.
9. Constantly Moving
Fact: We are moving through space at the rate of 530km a second
Our Galaxy – the Milky Way is spinning at a rate of 225 kilometers per second. In addition, the galaxy is travelling through space at the rate of 305 kilometers per second. This means that we are traveling at a total speed of 530 kilometers (330 miles) per second. That means that in one minute you are about 19 thousand kilometers away from where you were. Scientists do not all agree on the speed with which the Milky Way is travelling – estimates range from 130 – 1,000 km/s. It should be said that Einstein’s theory of relativity, the velocity of any object through space is not meaningful.
8. Farewell old friend!
Fact: The moon is drifting away from Earth
Every year the moon moves about 3.8cm further away from the Earth. This is caused by tidal effects. Consequently, the earth is slowing in rotation by about 0.002 seconds per day per century. Scientists do not know how the moon was created, but the generally accepted theory suggests that a large Mars sized object hit the earth causing the Moon to splinter off.
7. Ancient Light
Fact: The light hitting the earth right now is 30 thousand years old
The energy in the sunlight we see today started out in the core of the Sun 30,000 years ago – it spent most of this time passing through the dense atoms that make the sun and just 8 minutes to reach us once it had left the Sun! The temperature at the core of the sun is 13,600,000 kelvins. All of the energy produced by fusion in the core must travel through many successive layers to the solar photosphere before it escapes into space as sunlight or kinetic energy of particles.
6. Solar Diet
Fact: The Sun loses up to a billion kilograms a second due to solar winds
Solar winds are charged particles that are ejected from the upper surface of the sun due to the high temperature of the corona and the high kinetic energy particles gain through a process that is not well understood at this time. Also, did you know that 1 pinhead of the sun’s energy is enough to kill a person at a distance of 160 kilometers? [Sourced from Planet Science]
5. The Big Dipper is not a constellation
Fact: The Big Dipper is not a constellation, it is an asterism
Many people consider the big dipper to be a constellation but, in fact, it is an asterism. An asterism is a pattern of stars in the sky which is not one of the official 88 constellations; they are also composed of stars which are not physically related to each other and can be vast distances apart. An asterism can be composed of stars from one or more constellations – in the case of the Big Dipper, it is composed entirely of the seven brightest stars in the Ursa Major (Great Bear) constellation.
4. George’s Star
Fact: Uranus was originally called George’s Star
When Sir William Herschel discovered Uranus in 1781, he was given the honor of naming it. He chose to name it Georgium Sidus (George’s Star) after his new patron, King George III (Mad King George). This is what he said:
In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third.’
Uranus was also the first planet to be discovered with the use of a telescope.
3. Extra Moons
Fact: Earth has at least 4 moons
Okay – that is not actually true – but it is very close. In 1986, Duncan Waldron discovered a asteroid (5km across) that is in an elliptic orbit around the sun with a period of revolution virtually identical to that of Earth. For this reason the planetoid and earth appear to be following each other. The periodic planetoid is named Cruithne (pronounced krin-yə) after an ancient group of Scottish people (also known as the Picts). Because of its unusual relationship with Earth, it is sometimes referred to as Earth’s second moon. Cruithne, is fainter than Pluto and would require at least a 12.5 inch reflecting telescope to attempt to be seen. Since its discovery, at least three other similar asteroids have been discovered. These types of objects are also found in similar relationships to other planets in our Solar System. In the image above (courtesy of Paul Wiegert), the earth is the blue circle with a cross in it, and Cruithne’s orbit is shown in yellow.
2. Sunspot Music
Fact: Sunspot activity may be the primary reason for the beautiful sound of Stradivarius violins
Antonio Stradivari is considered to be the greatest violin maker ever. He lived in Italy in the 17th and 18th centuries. Scientists have been unable to work out what it is about his violins that makes them so incredible, but they do know that the timber used to make them is a very important contributing factor. From the 1500s to 1800s, the earth underwent a little ice age mostly due to increased volcanic activity and decreased solar activity (this is called the Maunder Minimum). As a result of this cooling, the types of trees that Stradivari used for his violins were particularly hard (due to slow growth). Hard timber is especially good when making violins. It is very probable that had Stradivari lived in a different age, his violins would not be prized as they are today. This picture above is made of three overlapping photos. It shows the rings in the spruce tree used to make the most famous Stradivarius violin, the “Messiah.” The first row of numbers gives the width of each ring in millimeters (one mm is about the thickness of a fingernail). The bottom row gives the years in which each ring grew.
1. Cold Welding
Fact: If two pieces of metal touch in space, they become permanently stuck together
This may sound unbelievable, but it is true. Two pieces of metal without any coating on them will form in to one piece in the vacuum of space. This doesn’t happen on earth because the atmosphere puts a layer of oxidized material between the surfaces. This might seem like it would be a big problem on the space station but as most tools used there have come from earth, they are already coated with material. In fact, the only evidence of this seen so far has been in experiments designed to provoke the reaction. This process is called cold welding. For those who still don’t believe it, here is the Wikipedia article on Cold Welding.
(Source: expose-the-light)
Beautiful Ocean Waves from Incredible Perspectives by CJ Kale and Nick Selway
7 Things You Didn’t Know About Lightning
1. Lightning can form without rain storms.
Yes, it’s true. Lightning can also occur during volcanic eruptions or dust storms, and doesn’t really require massive cloud formations. Lightning has been observed striking the Apollo 12 soon after takeoff, and was even recorded striking soon after thermonuclear explosions. Some of the largest volcanic eruptions can trigger lightning, due to the gases and solid material they eject high into the atmosphere.
2. Lightning can form on other planets
While it’s true that it cannot form in the vacuum of space, requiring the electrical breakdown of gas, lightning has been spotted in the atmospheres of planets like Venus and Jupiter. On the gas giant, it can be 100 times more powerful, though 15 times less frequent, than on Earth.
3.Lightning can and does strike the same place twice
In fact, lightning favors certain spots, particularly high locations, like trees and buildings. The Empire State Building is struck by lightning on average 23 times each year, and was once struck 8 times in 24 minutes. Actually, most lightning strikes are made up of multiple individual strokes, meaning that what we see as a pulsating lightning actually consists of three or four different strokes following the same pathway.
4. Lightning can strike from ground to the clouds
Also true. Called positive lightning, this type makes up less than 5% of all lightning. It forms when cloud tops become positively charged and the ground is negatively charged. When the tension is high enough, electrons from the ground will “climb” to the top of the cloud, forming an inverted lightning. They usually carry about ten times as much current as a bolt of negative lightning, the “normal” one.
5. Lightning can appear as a sphere
There are many historical accounts of spherical lightnings, or “ball lightnings”. A ball lightning has the strange tendency to float (or hover) in the air and take on a ball-like appearance. Many witnesses reported them as being red to yellow in color, sometimes transparent, and some containing radial filaments or sparks. Other colors, such as blue or white occur as well. Recent laboratory experiments are just beginning to shed light on the nature of ball lightning, a phenomenon that has baffled scientists for centuries.
6. What is the thunder?
The thunder is the noise heard after the lightning occurred. It’s actually an explosion of the air molecules in the discharge channel, a rapid expansion caused by the electrical discharge. The rolling and gradually dissipating rumble of thunder is caused by the time delay of sound coming from different portions of a long stroke.
7. Can a lightning strike out of the blue?
Yes, a lightning can really strike without a thunderstorm being present in the area. This is not the type of lightning previously mentioned, it’s actually a weather phenomenon that scientists dubbed as ”bolt from the blue” or ”dry lightning” because it falls from clear, blue skies.
David Canales, 41, of West Miami-Dade, US, was killed last week after a lightning came apparently out of nowhere, struck a tree nearby and then the unfortunate man. This unusual lightning packs a bigger, deadlier punch and forms differently, being able to carry as much as 10 times the current, is hotter and lasts longer.
So, with lightning striking the Earth around 100 times every second, on average, this is one of nature’s deadliest forces, that may unintentionally affect our life in dramatic ways, and can even bring it to an abrupt end.
Ten things you may not know about the solar system
10 ) The hottest planet isn’t closest to the sun
Many people know that Mercury is the closest planet to the sun, well less than half of the Earth’s distance. It is no mystery, therefore, why people would assume that Mercury is the hottest planet. We know that Venus, the second planet away from the sun, is on the average 30 million miles farther from the sun than Mercury. The natural assumption is that being farther away, it must be cooler. But assumptions can be dangerous. For practical consideration, Mercury has no atmosphere, no warming blanket to help it maintain the sun’s heat. Venus, on the other hand, is shrouded by an unexpectedly thick atmosphere, about 100 times thicker than our own on Earth. This in itself would normally serve to prevent some of the sun’s energy from escaping back into space and thus raise the overall temperature of the planet. But in addition to the atmosphere’s thickness, it is composed almost entirely of carbon dioxide, a potent greenhouse gas. The carbon dioxide freely lets solar energy in, but is far less transparent to the longer wavelength radiation emitted by the heated surface. Thus the temperature rises to a level far above what would be expected, making it the hottest planet. In fact the average temperature on Venus is about 875 degrees F, hot enough to melt tin and lead. The maximum temperature on Mercury, the planet closer to the sun, is about 800 degrees F. In addition, the lack of atmosphere causes Mercury’s surface temperature to vary by hundreds of degrees, whereas the thick mantle of carbon dioxide keeps the surface temperature of Venus steady, hardly varying at all, anywhere on the planet or any time of day or night!
9 ) Pluto is smaller than the USA
The greatest distance across the contiguous United States is nearly 2,900 miles (from Northern California to Maine). By the best current estimates, Pluto is just over 1400 miles across, less than half the width of the U.S. Certainly in size it is much smaller than any major planet, perhaps making it a bit easier to understand why a few years ago it was “demoted” from full planet status. It is now known as a “dwarf planet.”
8 ) George Lucas doesn’t know much about “Asteroid Fields”
In many science fiction movies, spacecraft are often endangered by pesky asteroid fields. In actuality, the only asteroid belt we are aware of exists between Mars and Jupiter, and although there are tens of thousands of asteroids in it (perhaps more), they are quite widely spaced and the likelihood of colliding with one is small. In fact, spacecraft must be deliberately and carefully guided to asteroids to have a chance of even photographing one. Given the presumed manner of creation, it is highly unlikely that spacefarers will ever encounter asteroid swarms or fields in deep space.
7 ) You can make volcanoes using water as magma
Mention volcanoes and everyone immediately thinks of Mount St. Helens, Mount Vesuvius, or maybe the lava caldera of Mauna Loa in Hawaii. Volcanoes require molten rock called lava (or “magma” when still underground), right? Not really. A volcano forms when an underground reservoir of a hot, fluid mineral or gas erupts onto the surface of a planet or other non-stellar astronomical body. The exact composition of the mineral can vary greatly. On Earth, most volcanoes sport lava (or magma) that has silicon, iron, magnesium, sodium, and a host of complicated minerals. The volcanoes of Jupiter’s moon Io appear to be composed mostly of sulfur and sulfur dioxide. But it can be simpler than that. On Saturn’s moon Enceladus, Neptune’s moon Triton, and others, the driving force is ice, good old frozen H20! Water expands when it freezes and enormous pressures can build up, just as in a “normal” volcano on Earth. When the ice erupts, a “cryovolcano” is formed. So volcanoes can operate on water as well as molten rock. By the way, we have relatively small scale eruptions of water on Earth called geysers. They are associated with superheated water that has come into contact with a hot reservoir of magma.
6 ) The “edge” of the Solar System is 1,000 times farther away than Pluto
Most people have been taught that the solar system just goes out to the orbit of Pluto. Today we don’t even consider Pluto a full-fledged planet, but the impression remains. Still, we have discovered numerous objects orbiting the sun that are considerably farther than Pluto. These are “Trans-Neptunian Objects” (TNOs), or “Kuiper Belt Objects” (KBOs). The Kuiper Belt, the first of the sun’s two reservoirs of cometary material, is thought to extend to 50 or 60 astronomical units (AU, or the average distance of the Earth from the sun). An even farther part of the solar system, the huge but tenuous Oort comet cloud, may extend to 50,000 AU from the sun, or about half a light year – more than a thousand times farther than Pluto.
5 ) Almost everything on Earth is a rare element
The elemental composition of planet Earth is mostly iron, oxygen, silicon, magnesium, sulfur, nickel, calcium, sodium, and aluminum. While such elements have been detected in locations throughout the universe, they are merely trace elements, vastly overshadowed by the much greater abundances of hydrogen and helium. Thus Earth, for the most part, is composed of rare elements. This does not signify any special place for Earth, however. The cloud from which the Earth formed had a much higher abundance of hydrogen and helium, but being light gases, they were driven away into space by the sun’s heat as the Earth formed.
4 ) There are Mars rocks on Earth (and we didn’t bring here)
Chemical analysis of meteorites found in Antarctica, the Sahara Desert, and elsewhere have been shown by various means to have originated on Mars. For example, some contain pockets of gas that is chemically identical to the martian atmosphere. These meteorites may have been blasted away from Mars due to a larger meteoroid or asteroid impact on Mars, or by a huge volcanic eruption, and later collided with Earth.
3 ) Jupiter has the biggest ocean of any planet
Orbiting in cold space five times farther from the sun than Earth, Jupiter retained much higher levels of hydrogen and helium when it formed than did our planet. In fact, Jupiter is mostly hydrogen and helium. Given the planet’s mass and chemical composition, physics demands that way down under the cold cloud tops, pressures rise to the point that the hydrogen must turn to liquid. In fact there should be a deep planetary ocean of liquid hydrogen. Computer models show that not only is this the largest ocean known in the solar system, but that it is about 40,000 km deep – roughly as deep as the Earth is around!
2 ) Even really small bodies can have moons
It was once thought that only objects as large as planets could have natural satellites or moons. In fact the existence of moons, or the capability of a planet to gravitationally control a moon in orbit, was sometimes used as part of the definition of what a planet truly is. It just didn’t seem reasonable that smaller celestial bodies had enough gravity to hold a moon. After all, Mercury and Venus have none at all, and Mars has only tiny moons. But in 1993, the Galileo probe passed the 20-mile wide asteroid Ida and discovered its one-mile wide moon, Dactyl. Since then moons have been discovered orbiting nearly 200 other minor planets, further complicating the definition of a “true” planet.
1 ) We live inside the sun
Normally we think of the sun as being that big, hot ball of light 93 million miles away. But actually, the sun’s outer atmosphere extends far beyond its visible surface. Our planet orbits within this tenuous atmosphere, and we see evidence of this when gusts of the solar wind generate the Northern and Southern Lights. In that sense, we definitely live “inside” the sun. But the solar atmosphere doesn’t end at Earth. Auroras have been observed on Jupiter, Saturn, Uranus, and even distant Neptune. In fact, the outer solar atmosphere, called the “heliosphere,” is thought to extend at least 100 A.U. That’s nearly 10 billion miles. In fact the atmosphere is likely teardrop shaped due to the sun’s motion in space, with the “tail” extending tens to hundreds of billions of miles downwind.
