World’s Largest Flooded Cave Discovered in Mexico

In one of the world’s biggest underwater discoveries, Mexican divers have found a flooded cave near Tulum, a beach resort on the Yucatan peninsula. The cave is part of the Sac Actun cave system, which now measures a total length of 347 km.

The discovery was made by members of Gran Acuifero Mayaa, a  project dedicated to the study and preservation of underground water systems in Yucatan. After a few months of exploring divers found an underwater link between two existing caves. After examining the flooded area divers found rocks and stones with ancient markings, grave sites and remains of human bones.

The flooded cave may be connected with the ancient Maya civilisation and could help us understand the Mayan culture. The Yucatan peninsula is full of monuments and ancient Mayan sites.

Mayan cities and temples were built over sinkholes, so-called cenotes. They were natural pits that were formed by the collapse of limestone, revealing subterranean rivers.

 

Flooded cave
Flooded cave – Image: Blueway

Words

  • ancient = very old
  • collapse = when something suddenly falls down or apart
  • connect = to join together
  • dedicated = to work on something very hard
  • discovery = to find something new for the first time
  • diver = person who swims or works under water  using special equipment that helps them breathe
  • examine = to look at something very closely
  • flooded cave = natural hole in the earth that is full of water
  • grave site = place where people are buried
  • length = how long something is
  • limestone = type of rock that lets water through and has calcium in it
  • link = connection
  • measure = how large something is
  • peninsula = piece of land that is surrounded by water on three sides
  • pit = hole in the ground
  • preservation = to try to keep something in its original state
  • remains = what is left over from a human body
  • resort = town where people spend their holidays
  • reveal = to show something that you didn’t see before
  • sinkhole = a hole in the ground caused when the surface collapses

 

Ozone Layer Over Antarctica Is Slowly Recovering

According to the American space agency  NASA, the world’s ozone layer is slowly recovering. A report states that, for the first time,  scientists have observed a decrease in the amount of chlorine in the ozone layer over Antarctica.

Ozone in the atmosphere is essential because it protects life on our planet by absorbing dangerous ultraviolet radiation, which causes skin cancer and damages plant life. Is the 1980s, scientists discovered a hole in the ozone layer, which has become larger ever since.  It is especially large over the Antarctic continent and Australia.

Shortly after the discovery, an international agreement, the Montreal Protocol, was signed, banning the use of substances that are responsible for the destruction of the ozone layer. It limits the use of CFCs, chemical compounds that rise into the upper layers of the atmosphere where they are broken down by the sun’s ultraviolet light. In the process, chlorine is released which destroys the ozone molecules.

Since the ban has taken effect major companies have started looking for alternatives to CFCs.

Changes in the ozone level are usually measured during the Antarctic winter, between July and September, when temperatures are lower and results are more accurate. Since 2005, there has been a 20% rise in the amount of ozone. Even though it is the first time that the hole in the ozone layer has become smaller it will take decades to recover completely.

Environmentalists around the world have welcomed the announcement, stating that we can actually save the environment by acting decisively.

 

Largest ozone hole ever recorded over the Antarctic in 2006
Largest ozone hole ever recorded over the Antarctic in 2006

Words

  • absorb = take something in
  • according to = as reported by …
  • accurate = exact
  • act decisively = to do something about a problem
  • agreement = promise by two or more countries to take action
  • announcement = official statement
  • atmosphere = mixture of gases that surrounds a planet
  • ban = forbid
  • break down = chemical change
  • cancer = serious disease in which cells in your body grow in an uncontrolled way
  • CFCs = chlorofluorocarbons = a gas used in refrigerators and spray cans; they are responsible for the destruction of the ozone layer
  • chlorine = greenish-yellow gas with a strong smell, that is also used to keep swimming pools clean; it is one of the gases that are responsible for the destruction of the ozone layer
  • completely = fully
  • compound = substance containing two or more atoms
  • decade = ten years
  • decrease = when something goes down
  • destruction = when something is damaged completely
  • discover = find for the first time
  • environmentalist = person who cares about nature and the world we live in
  • especially = above all
  • essential = very important and necessary
  • even though = true, but other things are true too
  • limit = control, check
  • measure = to find out how big something is
  • molecule = smallest unit made up of two or more atoms
  • observe = watch closely
  • protect = to keep something safe
  • recover = to return to a normal condition
  • release = set free
  • responsible = the reason for
  • scientist= person who is trained in science and works in a lab
  • sign = put your name on a document
  • state = say in public
  • substances = elements; material
  • take effect = start
  • ultraviolet radiation= light that comes from the sun but cannot be seen; it makes your skin darker
  • welcome = to be glad that something has happened

Bleaching Endangers World’s Coral Reefs

A recent study shows that the world’s coral reefs have been showing signs of strong bleaching due to global warmingIn the 1980s bleaching was rare, occurring about once every 25 years. Now the rate has risen to about once every five years. Environmentalists predict that by 2050 bleaching will happen every year or two.

Bleaching is caused when warm water breaks down the algae inside the reefs. They provide food for the corals and keep them healthy. When algae fall off, corals lose their colour and can die within a short period of time. Even if the water surrounding the reefs gets colder again it may take years for the damaged reefs to recover completely.

While bleaching is especially a problem in the waters of the Carribean Sea and Western Atlantic, reefs around Australia and South Africa have hardly been hit. In addition to the warming temperatures of the oceans, coral reefs are also endangered by pollution and overfishing.

Coral reefs are an important ecosystem. They are home to 25% of all marine species and provide a  habitat for countless types of fish. Reefs protect coastal regions from flooding and tidal waves. In addition, coral reefs are tourist attractions that lure millions of people every year.  The tourist industry around the Great Barrier Reef in Australia, for example, is worth about 5 billion dollars a year.

 

Healthy coral on the left and bleached coral on the right
Healthy coral on the left and bleached coral on the right

Words

  • billion = a thousand million
  • bleaching = to make something pale or white; when an object loses its colour
  • break down = to change its structure
  • Carribean Sea = sea between North and South America
  • cause = the reason for something; why something happens
  • countless = too many to be counted
  • due to = because of
  • ecosystem = all the animals and plants in a certain area and the way they live together
  • endangered = to be in danger
  • environmentalist = a person who cares about the world around us
  • especially = above all
  • global warming = when the temperatures in the atmosphere get higher because of increased amounts of carbon dioxide
  • habitat = place to live
  • in addition = also
  • lure = attract; here: bring people to the area
  • marine species = animals and plants that live in the oceans
  • occur = happen
  • overfishing = when you take too many fish from the sea so that the overall number of fish becomes too low
  • pollution = when water becomes dirty so that it cannot be used anymore
  • predict = to say that something will happen in the future
  • protect = keep safe
  • provide = give
  • rare = not very often
  • recent = a short time ago
  • recover = to become as healthy as they were before
  • sign = to show that something is happening
  • study = a piece of work that is done to find out more about a certain topic
  • surrounding = around
  • tidal wave = very large ocean wave that flows over land and destroys things

 

 

 

Chocolate in Danger of Becoming Extinct

Chocolate may be in danger of becoming extinct by the middle of this centuryPests and fungal diseases have been found in cacao trees that may endanger the crop’s survival.

In addition, cacao is also under attack by global warming. Trees grow in a very small area about 20° north and south of the equator, where humidity and temperatures are the same all year round. By 2050 rising temperatures and drier weather will push cacao production up into mountainous areas, many of which are home to wild animals.

Scientists from the University of California are trying to save the plant. Together with researchers from the American food company Mars, they are trying to grow cacao seeds that are more resistant and can grow at higher altitudes.

Most of the world’s cacao production comes from two countries in western Africa, Cote d’Ivoire and Ghana. These areas may not be suitable for cacao production in the decades to come. Millions of farmers depend on cacao for a living.

 

Cacao tree
Cacao tree – Image: Luis Ovalles

Words

  • altitude = how high up something is
  • cacao = seeds from which chocolate is made
  • decade = ten years
  • endanger = to be a threat to something
  • equator = line around the middle of the earth
  • extinct = die out; not exist anymore
  • century = a hundred years
  • depend on = need
  • fungal disease= disease caused by  a simple plant that has no leaves  and grows in the ground or on other plants; mushrooms are a type of fungus
  • global warming = an increase in the world’s temperatures caused by growing carbon dioxide levels in the atmosphere
  • humidity = the amount of water that is in the air
  • in addition = also
  • mountainous = in the mountains
  • pest = a small animal or insect that can destroy crops and plants
  • researcher = person who studies a topic in order to find out more about it
  • resistant = here: it cannot be destroyed or damaged
  • rise = to go up
  • scientist = person who is trained in science and works in a lab
  • seed = small hard object from produced by plants, from which a new plant can grow
  • suitable = here: to be the ideal place to grow something
  • survival = existence ; staying alive
  • under attack = to be attacked by something

NASA Plans Mission to Alpha Centauri

NASA has announced that it plans to send a spacecraft to the nearest star outside the solar system, Alpha Centauri,  in 2069. The bold mission is scheduled to coincide with the 100th anniversary of the first manned lunar landing in 1969.

The announcement comes from the Jet Propulsion Laboratory, which is responsible for planning new missions within the solar system and beyond.

Alpha Centauri is a system of three stars,  just four light years away.  Even at a tenth of the speed of light, which NASA experts say may be possible,  it would take a spacecraft 44 years to reach the constellation.

The technology for such a mission, however, does not even exist yet. Some form of laser-powered sails or a nuclear propulsion system would have to be created to reach such a speed.

 

NASA’s  first interstellar mission would concentrate on exploring one of the system’s exoplanets, Proxima Centauri b, which may be habitable.

Experts say that it would take half a century before such a mission could even be launched. As a result,  the spacecraft would probably not reach its destination before the beginning of the next century. In addition, considering cuts to NASA’s budget, the agency does not nearly have enough money to develop a spacecraft that could actually make the mission.

Currently, Voyager 1, launched in 1977,  is the farthest spacecraft and man-made object from earth.

 

The Alpha Centauri star system
The Alpha Centauri star system – Image: David Benbennick

Words

  • agency = organisation
  • anniversary = date on which something important happened in the past
  • announce = to say officially, in public
  • beyond =  here: outside the solar system
  • bold = exciting; not afraid of being difficult to do
  • century = a hundred years
  • coincide = be at the same time as
  • considering = if you look at or think about something
  • constellation =gourp of stars
  • currently = at the moment; now
  • destination  = place where you want to go
  • develop = plan, design and make
  • exoplanet =planet that is not in the solar system
  • explore = to travel to a place to find out more about it
  • habitable = a place with water and air, that allows you to live there
  • in addition = also
  • interstellar = between stars
  • laser = a narrow beam of light
  • light year = the distance light travels in one year = 9 500 000 000 000 kilometres
  • lunar = moon
  • mission = here: a trip to a faraway destination
  • nuclear propulsion system  = a system that uses nuclear energy to make a spacecraft  move forward
  • reach = get to
  • responsible = in charge of
  • scheduled = planned
  • solar system = our sun and the planets that go around it
  • spacecraft = object that can reach space and travel to the sun and other planets
  • technology = objects and machines to make something work

NASA Discovers Star System With 8 Planets

NASA has discovered the eighth planet of a star system, similar to our solar system. The star, Kepler-90  is over 2,500 light years away and larger and hotter than our sun. It is the first star known to have as many planets as our solar system.

The Kepler-90 star system is much more compact than our solar system. The outermost planet orbits the star at about the same distance as the earth orbits the sun.  its inner planets are small and rocky while the outer ones are larger and made up of gas

The newly discovered planet, Kepler -90i, is the third celestial object in the star system. It is probably rocky and similar to our earth, but because of its closeness to its home star has an average surface temperature of about 400° C. It moves around the star once every 14.4 days.

The discovery was made based on data provided by the Kepler space telescope. Launched in March 2009, the telescope has constantly been scanning certain sections of the universe in search of new stars and planetary systems. Up to now, over 2,000 new worlds have been discovered.

To help analyse the data NASA has been relying on artificial intelligence software supplied by Google.  This software examines weak signals of light when objects pass in front of a star.  The new way of examining data is expected to reveal even more new planets in the future.

 

Kepler 90 star system compared to our solar system
Kepler 90 star system compared to our solar system

Words

  • artificial intelligence = when computers do intelligent things  that only people can do, such as think and make their own decisions
  • average = normal, usual
  • based on = use
  • celestial = about the sky
  • closeness = being close to something
  • compact = here: the planets are closer together and near to the star
  • constantly = always
  • data = information
  • discover = to find something for the first time
  • distance = the amount of space between two objects
  • examine = look at something closely
  • launch = to send  an object into space
  • light year = the distance light travels in one year = 9,460,000,000,000 km
  • orbit = to go around
  • outermost = the farthest away from something
  • planetary system = star with planets moving around it
  • provide = give
  • rely = depend on; need
  • reveal = to show something that was not known before
  • rocky = covered with or made of rocks; here: a hard surface
  • scan = when a machine looks at things carefully but quickly
  • similar = like
  • solar system = our sun and the eight planets that move around it
  • surface temperature = temperature you get when you stand on the planet
  • weak = not strong

 

 

The Earth’s Hum – A Mysterious Noise

For the first time, scientists have recorded a humming sound that the earth has probably been producing for a long time. Scientists have been aware of the hum for decades, but for the first time, a team of experts have actually been able to record it

57 seismometers were placed over millions of square kilometres of the Indian Ocean.  Ultralow radio frequencies were recorded on the ocean’s floor

For some time, geologists have pointed out that the earth is not silent but vibrates almost everywhere. However, it is a sound with a frequency thousands of times lower than what the human ear can hear.

Scientists don’t know what causes the earth’s hum but could learn more by getting a clearer audio signal. There are a few theories about where the sound may come from. Some say that it’s the echo of waves crashing onto the coast, while others think that it may be the atmosphere in motion. Geologists, however, agree that the sound does not come from earthquakes because it is continuous.

In 1998 Japanese scientists proved that the earth’s hum was real, but nobody has been able to record it until now. Geologists hope that by analysing the recording they can get more information on the interior structure of the earth.

 

Seismometers record all kinds of noises and disturbances on the surface of the earth
Seismometers record all kinds of noises and disturbances on the surface of the earth

Words

  • agree = to have the same opinion
  • analyse = look at very closely in order to get more facts
  • atmosphere = the mixture of gases that surrounds a planet
  • audio signal = sound
  • aware = to know that something exists
  • cause = the reason for something
  • continuous = when something goes on all the time
  • crash = to hit something very hard
  • decade = ten years
  • earthquake = a sudden shaking of the earth’s surface that causes a lot of damage
  • geologist = person who studies rocks and how they make up the surface of the earth
  • humming = a steady low sound
  • in motion = moving
  • interior structure = what something consists of, or what it is made up of inside
  • place =  put, install
  • point out = to say how important something is
  • radio frequency = waves that are produced when you send out a radio signal
  • record = information about something that is written down or stored on a computer
  • seismometer = machine that measures how the ground moves
  • vibrate = to shake quickly and steadily in very small movements

 

NASA Fires Voyager 1 Thrusters After 37 Years

Voyager 1 is the first man-made object to leave the solar system. 37 years after it was launched, NASA’s engineers fired the spacecraft’s backup thrusters. The primary thrusters have been getting weaker over the last few years. 

Voyager’s thrusters were fired for a few milliseconds from a distance of 13 billion miles in order to reposition the spacecraft so that the antennae would point towards earth.

Nobody at NASA knew if firing the thrusters would work after decades of inactivity. After 19 hours, the time which it took for the signal to get back to earth, it was confirmed that the thrusters had actually been fired. Voyager 1 will now be able to operate and send data back to earth for another 2 to 3 years.

As Voyager 1 software dates back to the 1970s,  scientists had to examine the software code to make sure the engines worked correctly.

Voyager 1 and its twin Voyager 2 were launched in 1977  to carry out a grand tour of the solar system. They passed Jupiter, Saturn, Uranus and Neptune. After that, the spacecraft kept on flying and passed the boundaries of the solar system. In the past decades, the two spacecraft made great discoveries, including active volcanoes on Jupiter’s moon Io and a methane atmosphere on Saturn’s moon Titan.

Although Voyager 2’s thrusters are in a better condition than it’s sister craft NASA also plans to fire them in the near future.

 

Voyager 1
Voyager 1

Words

  • although = while
  • backup = something that you use to replace something that doesn’t work
  • billion = a thousand million
  • boundary = where something ends
  • condition = shape
  • confirm = know for sure that something has worked
  • correctly = in the right way
  • data = information
  • dates back = here: is from a certain time in the past
  • decade = ten years
  • discovery = to find something for the first time
  • distance = the amount of space between two objects
  • engine = machine that makes something travel
  • engineer = someone whose job it is to design and build machines, rockets, bridges etc..
  • examine = look at something very closely
  • fire = here: to make something work
  • grand tour = here: a journey that takes you far away to all the planets of our solar system
  • inactivity = here : not in operation
  • launch = start into space
  • man-made = made by a person, not nature
  • methane = gas that you can not see or smell, but which is burned to give heat
  • near future = sometime soon
  • operate = work the way it should
  • primary = most important, main
  • reposition = here: to move it into a new position
  • scientist = person who is trained in science and works in a lab
  • solar system = our sun and the planets that go around it
  • spacecraft = object that can travel in space
  • thruster = small engine in a spacecraft that controls how it flies by  pushing out small amounts of gas
  • twin = here: built in the same way

Did the Indus Valley Civilisation Grow Without a River?

Many great civilisations in history developed along rivers.  Up to now, historians have assumed that one of the oldest civilisations grew on the banks of the Indus River and its tributaries. Now, scientists may have found proof that people settled in the region after the Indus River had changed its course.

Archaeologists and scientists who have been working the region took probes from dried up river beds.  They found out that water hadn’t run through the Indus Valley for over 8,000 years. That means that when people started settling in the area about 5,000 years ago there was no river.   In addition, some ancient sites were found in the old river bed, which would not have been the case if a river had been flowing through it.

According to experts, the people who lived during that time may have got their water from yearly monsoon rains. There may have also been underground water supplies that they accessed.

Other great cultures used the advantages of a river to bring water to their fields and as a means of transporting goods throughout the region. That happened in Ancient Egypt and Mesopotamia.

Historians point out that civilisations do not necessarily need to be near a river in order to grow. In fact, not having a river nearby may have advantages as well because people would not have to deal with regular floods.

 

Archaeological ruins along the Indus River in Pakistan
Archaeological ruins along the Indus River in Pakistan – Image : Junhi Han

Words

  • access = use
  • according to = as said by …
  • advantage = good side of something
  • Ancient Egypt = old civilisation that grew along the Nile River thousands of years ago
  • ancient site = a place where something was built a long time ago
  • archaeologist = person who studies old societies by looking at what is left of buildings or the objects that people made at that time
  • assume = think that something is true although you can not prove it
  • bank  = land along the side of a river
  • course = path
  • deal with = handle a problem
  • develop = grow
  • flood = when an area of land becomes covered with water
  • goods = products
  • historian = someone who studies history
  • in addition = also
  • means of transporting = what you use to bring things from one place to another
  • Mesopotamia = area in western Asia along the River Tigris and Euphrates; in ancient times the world’s first cities were built andan advanced  civilisation developed there
  • monsoon = rainy season in India and southeast Asia; it lasts between April and October
  • not necessarily = when you don’t really need something in order for  something else to work
  • probe = rocks from an area
  • proof = facts, information or documents  that show that something is true or has happened
  • river bed = the ground at the bottom of a river
  • scientist = person who is trained in science and works in a lab
  • settle = to start living in a place for the first time
  • supply = something that you need and use every day
  • tributary = a small river that flows into a larger one

 

Plague May Have Entered Europe in Prehistoric Times

According to recent scientific research conducted by Germany’s Max Planck  Institute, the plague was in Europe as far back as the Stone Age. When scanning the remains of 500 prehistoric skeletons, scientists found plague bacteria in six individuals. The samples come from Russia, Germany and the Baltic countries.

The deadly bacterium came to Europe during the mass migration of people who moved from Central Asia eastwards about 5,000 years ago. The findings suggest that the disease came to Europe in waves during the Neolithic and Bronze Ages. Some experts think that people may have been moving eastwards to escape the bacterium.

Most of the people at that time were nomadic farmers who travelled with their livestock. Animals may have harboured the plague bacterium and helped spread it.

By analyzing the bacterium scientists hope to find out how it evolved and became more deadly over periods of time.

The plague was responsible for many mass killings in history.  The deadliest was the Black Death which occurred in Europe during the 14th century and killed about a third of the continent’s population.   It still causes deaths in certain areas of the world. Recent outbreaks in Madagascar have killed hundreds of people.

Stone Age people may have spread the plague from Central Asia to Europe - Image: Gugatc
Stone Age people may have spread the plague from Central Asia to Europe – Image: Gugatchitchinadze

Words

  • according to = as said by …
  • bacterium, bacteria  = some living things, some of which cause illnesses or diseases
  • Baltic countries = Estonia, Latvia and Lithuania
  • Bronze Age = time between  6,000 and 4,000 years ago when bronze was used for making tools
  • century = a hundred years
  • conduct = do, carry out
  • disease = illness
  • escape = get away from
  • evolve = grow; develop; change
  • harbour = here: to have something in them that is dangerous
  • livestock = animals such as cows, sheep, goats that are kept on a farm
  • mass migration = when many people leave their homes, often  in order to escape from a dangerous situation
  • Neolithic = the last period of the Stone Age, about 10,000 years ago, when people started to live in small groups
  • nomadic = people who travel from place to place  instead of living in one place all the time
  • outbreak = when something suddenly starts to happen
  • plague = deadly disease that produces high fever and swollen places in the body; it often leads to deaths of a large number of people
  • prehistoric = time in history before anything was written down
  • recent = a short time ago
  • remains = what is left of a body
  • research = to study a subject seriously so that you can find out more about it
  • responsible = the reason for something
  • scan = look at something carefully
  • scientist = a person who is trained in science and works in a lab
  • spread = take from place to place
  • suggest = imply; to say that something is probably true
  • Stone Age = early time in human history when stone was used for making tools