Quasar

one of a number of star-like heavenly bodies which are very distant from Earth and which give out light. They are extremely compact and give out light even though they are vast distances away, up to 10¹⁰ light years.

Taken from Dictionary of Science

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A quasi-stellar radio source (quasar) is a very energetic and distant galaxy with an active galactic nucleus. Quasars were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than extended sources similar to galaxies.

While there was initially some controversy over the nature of these objects—as recently as the early 1980s, there was no clear consensus as to their nature—there is now a scientific consensus that a quasar is a compact region in the centre of a massive galaxy surrounding the central supermassive black hole. Its size is 10-10,000 times the Schwarzschild radius of the black hole. The quasar is powered by an accretion disc around the black hole.

Taken from Wikipedia

Magma

the fluid rock beneath the Earth's surface, which solidifies to form IGNEOUS ROCKS. During volcanic eruptions, the LAVA extruded at the Earth's surface is not necessarily the same in composition as the magma that arises to form lava, since the magma may have lost some of its gaseous elements and some solids of the magma may have crystallized.

Taken from Dictionary of Science

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Magma [from Greek μάγμα, paste] is molten rock that is found beneath the surface of the Earth, and may also exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma often collects in a magma chamber inside a volcano. Magma is capable of intrusion into adjacent rocks, extrusion onto the surface as lava, and explosive ejection as tephra to form pyroclastic rock.

Magma is a complex high-temperature fluid substance. Temperatures of most magmas are in the range 700°C to 1300°C (or 1300°F to 2400°F), but very rare carbonatite melts may be as cool as 600°C, and komatiite melts may have been as hot as 1600°C. Most are silicate solutions.

Environments of magma formation and compositions are commonly correlated. Environments include subduction zones, continental rift zones, mid-oceanic ridges, and hotspots, some of which are interpreted as mantle plumes. Despite being found in such widespread locales, the bulk of the Earth's crust and mantle is not molten. Rather, most of the Earth takes the form of a rheid, a form of solid that can move or deform under pressure. Magma, as liquid, preferentially forms in high temperature, low pressure environments within several kilometers of the Earth's surface.

Magma compositions may evolve after formation by fractional crystallization, contamination, and magma mixing. By definition, all igneous rock is formed from magma.

While the study of magma has historically relied on observing magma in the form of lava outflows, magma has been encountered in situ three times during drilling projects—twice in Iceland, and once in Hawaii.

Taken from Wikipedia

X-ray Astronomy

stars emit a variety of electromagnetic radiation including X-rays, but this is unable to penetrate the Earth's atmosphere to be detected. Very hot stars send out large amounts of X-rays which can be detected by equipment contained on space satellites. The satellite ROSAT launched in 1990 has equipment to undertake X-ray astronomy and obtain information about distant bodies in space (e.g. WHITE DWARFS and SUPERNOVAE) that are emitting X-rays.

Taken from Dictionary of Science

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X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray emission from celestial objects. X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites. X-ray astronomy is part of space science.

X-ray emission is expected in sources which contain an extremely hot gas at temperatures from a million to hundred million degrees kelvin. In general, this occurs in objects where the atoms and/or electrons have a very high energy. The discovery of the first cosmic X-ray source in 1962 came as a surprise. This source is called Scorpius X-1, the first X-ray source found in the constellation Scorpius. Based on discoveries in this new field, Riccardo Giacconi received the Nobel Prize in Physics in 2002. It was found that the X-ray emission of Sco X-1 was 10,000 times greater than its optical emission, based on a precise location obtained with a modulation collimator - a specific type of coded aperture imager. In addition, the energy output in X-rays is 100,000 times greater than the total emission of the Sun in all wavelengths. It is now known that such X-ray sources are compact stars, such as neutron stars and black holes. The energy source is gravity. Gas is heated by the fall in the strong gravitational field of celestial objects.

Many thousands of X-ray sources are known. In addition, it appears that the space between galaxies in a cluster of galaxies is filled with a very hot, but very dilute gas at a temperature between 10 and 100 megakelvin (MK). The total amount of hot gas is five to ten times the total mass in the visible galaxies.

Taken from Wikipedia

Lagrangian Points

in particular, with respect to the Earth and Moon, the locations where the gravitational forces are equal and so objects positioned at such points remain fixed. There are five such points between the Earth and Moon.

Taken from Dictionary of Science

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The Lagrangian points (pronounced /ləˈgrandʒiən/; also Lagrange points, L-points, or libration points), are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be stationary relative to two larger objects (such as a satellite with respect to the Earth and Moon). The Lagrange points mark positions where the combined gravitational pull of the two large masses provides precisely the centripetal force required to rotate with them. They are analogous to geostationary orbits in that they allow an object to be in a "fixed" position in space rather than an orbit in which its relative position changes continuously.

More technically and precisely, Lagrangian points are the stationary solutions of the circular restricted three-body problem. For example, given two massive bodies in circular orbits around their common center of mass, there are five positions in space where a third body, of comparatively negligible mass, could be placed which would then maintain its position relative to the two massive bodies. As seen in a rotating reference frame with the same period as the two co-orbiting bodies, the gravitational fields of two massive bodies combined with the centrifugal force are in balance at the Lagrangian points, allowing the third body to be stationary with respect to the first two bodies.

Taken from Wikipedia

Eclipse

the total or partial disappearance of one astronomical body by passing into the shadow of another. A solar eclipse occurs when the new moon passes between the earth and the sun. A lunar eclipse occurs when the moon moves into the shadow of the earth, i.e., the earth is situated between the sun and the moon.

Taken from Dictionary of Science

Bacteriophage or Phage

a virus that attacks and infects a BACTERIUM.

Taken from Dictionary of Science

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A bacteriophage (from 'bacteria' and Greek φᾰγεῖν phagein "to eat") is any one of a number of viruses that infect bacteria. Bacteriophages are among the most common organisms on Earth. The term is commonly used in its shortened form, phage.

Typically, bacteriophages consist of an outer protein capsid enclosing genetic material. The genetic material can be ssRNA, dsRNA, ssDNA, or dsDNA ('ss-' or 'ds-' prefix denotes single-strand or double-strand) long with either circular or linear arrangement. Bacteriophages are much smaller than the bacteria they destroy.

Phages are estimated to be the most widely distributed and diverse entities in the biosphere. Phages are ubiquitous and can be found in all reservoirs populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×10⁸ virions per milliliter have been found in microbial mats at the surface, and up to 70% of marine bacteria may be infected by phages. They have been used for over 60 years as an alternative to antibiotics in the former Soviet Union and Eastern Europe. They are seen as a possible therapy against multi drug resistant strains of many bacteria.

Taken from Wikipedia

Earth

the Earth is one of a group of nine planets which orbit a star that we call the sun. It occurs in one small part of the galaxy (also called the milky way) which is referred to as the solar system. The Earth is the fifth largest of the planets and the third nearest to the Sun. Most of the Earth's surface is covered by the oceans -- about two-thirds compared to one third which is land. A layer of air, the atmosphere, surrounds the Earth which is sub-divided into a number of different regions according to height above the surface. The Earth, as viewed from space, is like a blue ball or sphere which is flattened at both the poles. At the equator, the radius of the Earth is 6378 km or 3963 miles.

The Earth itself is composed of four main layers; an outer crust overlying a mantle, followed by an outer core and inner core. The rocky crust varies in thickness, being about 40 km thick under the continents and 8 km under the oceans. It 'floats' on the mantle which is made up of extremely hot rock and is about 2900 km thick. The core is so hot that it is part liquid, with a temperature in the region of 6500 km. The outer core is believed to be about 2250 km thick and is thought to be more liquid than the inner core which is solid and composed mainly of iron and nickel.

Taken from Dictionary of Science

PLANET EARTH NEEDS YOU!

If you’re concerned about our planet, but not sure what to do, here are nine ways you can help save the environment.

By Rick L. Shallenberger

“The earth is slowly dying, and the inconceivable—the end of life itself—is actually becoming conceivable.”

These words, spoken by Queen Beatrix of the Netherlands, reflect the thinking of people worldwide.

Surveys among young people in the United States and Europe reveal that you are concerned about the environment and for good cause.

Look around you. Chances are you are surrounded by air pollution. You may have to drink filtered or bottled water because the water in your area is polluted.

Landfills around the world are filling up and we are running out of places to put our garbage. It is a serious concern for many nations, especially the United States.

Many lakes and streams are no longer fit for swimming or fishing. Much of the pollution is caused by waste being dumped into the streams and a general lack of care.

You’ve probably heard of the forests being cut down in South America and Alaska. This leads to the extinction of animals and insects that may not have even been discovered yet.

What can you do?

While you can't solve all the world's pollution problems, you can make a difference in helping to save the environment. Too many people think they can't change anything, but that's just not true.

No matter where you are, you do make a difference. The average person in the United States, Canada and Britain discards three to four pounds (up to 1.8 kilograms) of refuse-- daily. The West Germans discard about 2 pounds (.9 kilograms) and the Italians 1.5 pounds (.7 kilograms). Most of that ends up in landfills.

Here is a list of nine things you can do to lessen your personal impact on our endangered ecosystem.

1. Cut down on your trash. Trash can often be reused, repaired or made available to others. Your trash can be another's treasure.

Before you throw something away, whether old clothes, shoes, albums or toys, offer it to someone else.

There are organizations that make used clothing available to the needy. These include charities such as Goodwill Industries and the Salvation Army.

One organization in the United States is looking for old tennis shoes. They clean and relace them and make them available to the homeless. (Those in the United States can send them to World Shoe Relief, P.O. Box 423, Trabuco Canyon, CA 92678.)

2. Up to 18 percent of trash is yard waste. Grass clippings, leaves and vegetable waste can be put into a compost heap. This can be used as mulch and fertilizer for plants and gardens. Talk to your parents about composting your yard waste.

3. Recycle all you can. Check around for places to recycle glass, cans, plastic, newspapers and other paper products such as magazines, junk mail and cardboard.

One archaeologist from the University of Arizona was digging through an old landfill and found a newspaper from 1951. It was still readable after being buried 37 years.

Things generally do not decompose in landfills. We need to recycle all we can.

4. Don't litter. Litter really damages the environment. Plastic is especially harmful because it doesn't decompose for years, if at all. Many animals choke and suffocate on it.

5. Make a habit of cleaning up messes with rags rather than paper towels. Rags can be washed and reused. On the other hand, most paper towels end up in landfills.

6. Car pool, walk, ride your bike or use public transportation to and from school or work. Walking and riding a bike are good exercise and don't pollute the air.

Driving is something we all look forward to, but every car on the road adds to air pollution. Save driving for special or must drive occasions.

7. Plant a tree. (Check with your parents first.) Trees absorb carbon dioxide and every one planted helps cut down on air pollution.

Trees can also save your family in heating and cooling costs. They also help prevent soil erosion and add beauty.

8. Avoid purchasing endangered plants or animals or products made from these species. The extinction of any species can have a serious effect on the ecology. Even things as small as earrings or rings can have products made from endangered species.

The world's lust for ivory has all but wiped out the elephant populations in Africa.

9. Organize a cleanup party. Get a group of friends or your church group to clean up a park or an empty lot in your town. (Check with the owner first.) Recycle what you can and dispose of the trash.

While you can't solve all the world's pollution problems, you can make a difference...

These are just a few things you can do to help the earth. You can make a difference.

Taken from Youth 90 magazine