Category: Earth

New York City says goodbye to plastic drinking straws
New York City says goodbye to plastic drinking straws

During a conference in Manhattan, a member of the New York City Council, Rafael Espinal, announced a bill aimed at banning plastic drinking straws.
According to the National Park Service, more than 500 million straws per day are consumed in the United States! Many restaurants in New York have already joined the Give a sip campaign, promoted by the Wildlife Conservation Society, and are committed to using straws made of alternative materials to plastics, such as bamboo or paper.
New York, forse, metterà al bando le cannucce di plastica

According to the Guardian, the bill provides fines of 100 to 400 dollars for the premises surprised to distribute plastic straws, but will admit exceptions for disabled or sick people who, for drinking, need a straw.

Meteorological vs astronomical seasons
Meteorological vs astronomical seasons

In the field of meteorology the year is divided into 4 seasons following the climate: winter is made out from the coldest months of the year (Dicember, January and February); summer consists in the hottest months (June, July and August). The seasons in between these two are spring (March, April and May) and fall (September, October, November). These are the meteorological seasons.

So what’s the difference with the astronomical seasons?

Well, the year can also be divided following the movements of the Earth, the tilt of the Earth’s axis, and its position around the Sun. The Earth’s orbit is not a perfect circle, but seasons are not a consequence of how far or near the Earth is to the Sun. The distance has no effect on our weather or our seasons. So why do we have different seasons?
The solution lies behind the Earth’s axis. It’s is an imaginary pole going right through the center of Earth from “top” to “bottom.” Earth spins around this pole, making one complete turn each day. That is why we have day and night, and why every part of Earth’s surface gets some of each.
So, we have seasons on Earth because its axis doesn’t stand up straight.

Equinox and Solstice dipend on this: when the North Pole tilts toward the sun (around June) summer starts for the Northern Hemisphere; when the South Pole tilts toward the sun (around December) the winter starts for the Northern Hemisphere.

It is summer in June in the Northern Hemisphere because the sun’s rays hit that part of Earth more directly than at any other time of the year. It is winter in December in the Northern Hemisphere, because that is when it is the South Pole’s turn to be tilted toward the sun. Since this movement is not stable, the moment of Equinoxes and Solstices vary each year.
From the winter solstice the winter begins, spring starts from the spring equinox, summer starts from the summer solstice, autumn starts from the fall equinox.

In April the Arctic sea ice nearly set a new record
In April the Arctic sea ice nearly set a new record

Bad news form the North Pole. The Arctic sea ice extent was 980,000 square kilometers (378,400 square miles) below the average and only 20,000 square kilometers (7,700 square miles) above the record low April extent set in 2016. Sea ice in the Arctic expands and shrinks following the seasons: in summer the ice extent reaches its minimum, in winter its maximum size. During the month of April the ice starts to melt but usually not this much. Arctic sea ice extent for April 2018 averaged 13.71 million square kilometers (5.29 million square miles). Just to give an idea, the ice surface missing is 3 times the size of Italy! Only in April 2016 the situation was worse that today with 20.000 square kilometers more missing.

Greenland shark: the longest-lived vertebrate known
Greenland shark: the longest-lived vertebrate known

Greenland shark – known in science with the name of somniosus microcephalus – lives in the cold and deep waters of the Arctic Seas and, according to a recent study can live up to 500 years old! They studied 28 female Greenland sharks and they discovered that the bigger shark they examined had more that 400 years old. Impressive, isn’t it?! This shark was alive during the Renaissance! Incredible!

The Greenland shark is one of the biggest shark of the world: he’s as big as the most known white shark. He likes fishes but he can even bite some marine mammals too.

Julius Nielsen, author of the study and biologist at the University of Copenhagen, explained that this finding was a big surprise even for him! The experts knew that this shark was one of the most long-living sharks, but no one could ever imagine that much!

What are Polar Lights?
What are Polar Lights?

Polar Lights are one of the most spectacular shows mother nature can offer us. Polar lights can appear in the sky near the North and South Poles. Polar lights are also known as aurora that can be boralis (north pole) and australis (south pole). An aurora is a natural light display in the sky, particularly in the arctic and antarctic regions, caused by the collision of energetic charged particles with atoms in the high-altitude atmosphere.

Earth is constantly “bombed” by high-energy electrons and protons that originate at the sun, what is known as solar winds, and collide with the Earth’s atmosphere. The Earth’s magnetic field directs the charged particles to the Earth’s magnetic poles. This is why near the poles is way easiest to see the auroras. The movement of these charged particles also causes electricity, which serves to further excite the molecules in the Earth’s atmosphere.


The pink lake
The pink lake

Sometimes during the year Lake Urmia waters turn pink. This curious phenomenon is visible also from space: blue water turn to a pink-red bright colour. This happens during the warmest months of the year and it’s caused by the fact that this Lake is drying up. Urmia lake is infact disappearing, just like the Aral Lake. Lake Urmia, in north-western Iran, was the largest salt-water lake in the Middle East in the ’90s, but in 2008 it shrunk to half the size.

Less water means that the water left is saltier. Beacuse of the water conditions many migratory birds including flamingos, pelicans, ducks and egrets don’t stop here anymore. The desiccation of Lake Urmia is also destroying one of the world’s largest natural habitats of the brine shrimp Artemia, a hardy species that can tolerate water that are eight times more saltier than ocean water. In this Lake, from april to june, the water color changes and turns blood-red because of algae and bacteria that flourish here. The coastline of the Lake, as we can see from space,  is whitish beacuse of the salt that sets down where water completely evaporates.



Let’s talk about hail
Let’s talk about hail

Simone Abelli, meteorologist at Centro Epson Meteo, answered MeteoHeroes’s  questions about hail.

How and when does hail form?

Hail forms during thunderstorms, in cumulonimbus clouds which are very high clouds due to the energy involved. Hail forms in the part of the cloud where temperature are below zero.

How big can a hailstone get?

Hailstone dimension can vary and it dipends on the energy triggered by the thunderstorm: if there’s a lot of energy, the vertical draft (a small‐scale current of rising air within a cloud)  is more intense and it keeps the hailstones up in the air. This way hailstone have the time to grow in size, moving up and down in the cloud.
Only when hailstones are too heavy for the vertical draft, they fall down on Earth.

When, during the year, is more common to see hailsones?

Without a doubt hail is more common during the summertime, a little less common during autumn or spring. During the cold season thunderstorms can still form, but mainly by the sea: this happens when colder air moves in higher layers of the atmosphere above the warmer sea. This triggers the energy needed for thunderstorms to form.


Mapping Air Pollution
Mapping Air Pollution

The European Space Agency, aka ESA, launched the Sentinel-5P satellite that is mapping air pollution like never before. The first image was taken november 22nd 2017 and it showed nitrogen dioxide over Europe. Caused largely by traffic and the combustion of fossil fuel in industrial processes, the high concentrations of this air pollutant can be seen over parts of the Netherlands, the Ruhr area in western Germany, the Po Valley in Italy and over parts of Spain. This new mission promises to image air pollutants in more detail than ever before. And, while these first results demonstrate the sophistication of the satellite’s instrument, they certainly bring the issue of air pollution sharply into focus.

Concentrazioni di diossido di azoto in Europa

 Josef Aschbacher, ESA’s Director of Earth Observation Programmes, said, “Sentinel-5P is the sixth satellite for the EC Copernicus environmental monitoring programme but the first dedicated to monitoring our atmosphere. These first images offer a tantalising glimpse of what’s in store and are not only an important milestone for the Sentinel-5P mission, but also an important milestone for Europe. Data such as we see here will soon underpin the Copernicus Atmosphere Monitoring Service, and will be used to issue forecasts, and will ultimately be valuable for helping to put appropriate mitigation policies in place.”

Sentinel-5P carries the most advanced sensor of its type to date: Tropomi. This state-of-the-art instrument can map pollutants such as nitrogen dioxide, methane, carbon monoxide and aerosols, all of which affect the air we breathe and our climate.

This, for example is the map of carbon monoxide

What is a Tornado?
What is a Tornado?

Have you ever heard of tornadoes? A tornado is one of the most impressive and dangerous weather events, it’s the most powerful thing that can occur during a thunderstorm.

What’s a tornado?

A tornado is a a violently rotating column of air, pendant from a cumulonimbus cloud, the typical cloud of thunderstorms. Tornadoes are often visible as a funnel cloud, but not always. The column of air is rotating counterclockwise in the northern hemisphere and clockwise south of the equator.

During thunderstorms the clouds can grow upwards, higher and higher, into the atmosphere until they reach the tropopause at 18,000 metres (59,000 ft). During this events gusts, heavy rain, lightnings and tornadoes can occur. In the center of the tornado the air pressure is very different from the air pressure outside the tornado: this is why strong winds go from the ouside-in the tornado at high speed. Winds can blow over 65 mph up to 200 mph!

Diagram of a thunderstorm with a tornado – Credits: NOAA


How can we measure the intensity of tornadoes?

Measuring the wind’s speed is very difficult and extremely dangerous. This is why Professor Fujita came up, in 1971, with the Fujita Scale, a particular scale that goes from F0 to F5 that estimate the wind strenght based on the damage made by a tornado. In 2007 this scale was perfected and now it’s called the Enhanced Fujita Scale. Its uses three-second gusts estimated at the point of damage. A tornado EF0 has gusts that blow up to 65-85 mph; an EF1 up to 110 mph; EF2 up to 135 mph; EF3 up to 165 mph; EF4 up to 200 mph; EF5 over 200 mph.

What if we could build our roads with recycled plastic?
What if we could build our roads with recycled plastic?

Billions of litres of oil make up the world’s roads and there are currentrly trillions of pieces of plastic in the ocean. Today, we can build our roads with recycled plastic!

We can do it thanks to a Scottish engineer, Toby McCartney: he founded MacRebur, a company that uses waste materials to replace part of bitumen in any asphalt mix.

Toby McCartney found a revolutionary invention with which MacRebur intends to solve 3 world challenges:

– Use up millions of tons of waste plastic that sit in our landfill sites
– Reduce the millions spent on new roads, maintenance, and pothole repair
– Make roads stronger and longer lasting

By paving roads with recycled plastic it’s possible to help solve our plastic waste epidemic, reduce global carbon emissions and make our roads more lasting: the road is 60% stronger than a regular asphalt road and can last 10 times longer.
Many countries are paving the way forward with “plastic roads”: the Netherlands plans to pave roads entirely from recycled ocean waste and India is already fixing potholes with plastic waste!

The Sahara Desert got bigger
The Sahara Desert got bigger

Climate changes in the last century caused the expansion of the world’s biggest desert, the Sahara. According to a study published on the Journal of Climate the Sahara Desert has grown by 10 percent over the last century due to a combination of natural climate variations and global warming.

The growth of the Sahara has been influenced by the Atlantic Multidecadal Oscillation, a natural climate cycle that changes the Atlantic Ocean from warm to cold phases every 60 to 80 years and can impact rainfall patterns across much of Africa. Also global warming may also be altering atmospheric circulation patterns, such as the Hadley cell, which moves air from the Equator to the subtropics, drying it out as it goes and creating many subtropical deserts, including the Sahara.

Researchers estimate that around one third of the Sahara’s expansion is down to climate change caused by human activity. That has implications for those who live in the Sahara as well as the wider world.

Turtle with green mohawk faces extinction
Turtle with green mohawk faces extinction

The “punk” turtle living in the Mary River in Australia, only a few years after being discovered is already on the road to extinction. The Mary river turtle, the one with the green “mohawk” hair formed by algae, has special organs in its cloaca that allow it to draw oxygen from the water. It can stay underwater for up to three days!

But this particular turtle is thirtieth on a new list of reptiles in trouble put out by the Zoological Society of London. The Edge of Existence program at the society looks at the evolutionary trees of animals that are endangered to determine which are most evolutionary distinctive.

Rikki Gumbs, a reptile biologist at Zoological Society London (ZSL), told CNN that because of the exotic pet trade in the 1960s and ’70s, the turtles were often kept as pets and were already at risk of being endangered when they were first recognized as a species in the 1990s.

“The turtle takes a long time to reach sexual maturity, taking up to 25 to 30 years,” he said. “As their vulnerability was discovered late, we lost a whole generation due to the pet trade and now their population has become very small.”

Ten interesting facts about Earth
Ten interesting facts about Earth

Earth is not a perfect sphere.

Earth is wider around the equator, the imaginary line around the middle. How much wider? Well, only 0.3%. Although Earth appears round in photos, it is just barely not.

Days are getting longer.

4.6 billion years ago when planet Earth was formed, days were much shorter, only about six hours long because it was spinning fast. Since then days have become longer and longer, about 0.0017 seconds longer every one hundred years. Why has Earth has slowed down? It’s all because of the Moon. The tides it creates all around the world slow down Earth’s rotation.

Continents don’t stay in one place.

Pangaea is the name of a supercontinent that grouped all the continents we see today about 250 million years ago. Since then they have spread apart to form the world as we see it today. North America, South America, Africa, Europe, Asia, Australia, and Antarctica are all separate entities now. But even before that time, over 800 million years ago there was another supercontinent called Rodinia.

One Ice Age? No, several.

Ice covered the Earth and woolly mammoths roamed during a recent Ice Age 300,000 years ago. But this wasn’t the only time ice completely covered the Earth. Scientists have discovered at least four other separate Ice Ages in the past .

How can the most arid desert be near the ocean?

The driest place on Earth, where there is a town people say that hasn’t seen a drop of rain for 400 years, is the Atacama Desert in northern Chile. It is funny that this desert is right next to the world’s largest body of water, the Pacific Ocean!

Gravity isn’t the same all over the Earth.

Earth has high mountains, deep valleys and other different features. If it were as smooth as a pool ball, gravity on Earth would be the same everywhere. GRACE is a special mission involving a satellite that maps out the gravity across the Earth’s surface showing  the differences in gravity.

Sea levels were higher (and lower) in the past.

Imagine if the seas were 390 feet lower than today, there would be lots more land and some islands would be attached to the mainland. This was the situation during the last Ice Age when so much water was trapped in icy glaciers. But long before that, the sea level was actually about 230 feet higher than it is now. There are parts of land today that used to be far beneath the ocean waters.

The sun has its own lifespan.

Like all stars, the sun goes through different phases, before it uses up all its energy. We don’t need to worry though, the sun won’t run out of energy for a long time, at least  five billion years! If people are still living on Earth they would have to leave and move to another planet, but there’s plenty of time to find one!

Earth has more than one “moon”.

The satellite that we call moon is not the only object orbiting near Earth. Two other asteroids that we cannot define strictly as moons are present near Earth. Cruithne  is an asteroid that follows the Earth around the Sun. The other, called Asteroid 2002 AA29 , has a horseshoe shaped orbit and passes near Earth every 95 years.

The calm before a storm.

When there is about to be a big storm  sometimes we sense a strange moment of absolute calm. The explanation is this. As a storm is building up the warm humid air around it is pulled inside, goes into the cloud  and comes out over the top. This air then comes back down on the outside of the cloud getting warmer and drier as it moves.  This makes the weather  calm and stable, which is the calm before the storm.

10 different ecosystems on Earth
10 different ecosystems on Earth

The incredible and fragile Coral reefs.

Also called the “rainforests of the sea”, Coral reefs are complex ecosystems under the sea. Corals are hard calcium carbonate structures built by small polyps, lots of people mistake them for rocks but they are alive!  Corals form a base for many other ocean creatures like worms, sponges, jellyfish, sea turtles and lots of fish. Coral reefs are very fragile and complex systems and easily damaged by pollution and global warming.

Tropical rainforests host half of the animal and plant species in the world.

Near the equator where the weather is usually hot and humid, Tropical rainforests prosper. Heat and lots of rain are what make plants and trees grow lushly. Half of all types of living things live in tropical rainforests. This ecosystem is home to many species of plants, animals, fungi and microscopic organisms that find their ideal habitat here and nowhere else on the planet. Remember also that tropical rainforests provide the Earth with 40% of all the world’s oxygen.

Learning to save water is essential to live in the desert.

It doesn’t rain much in the world’s deserts. Here the land is really dry. Animals and plants that live in deserts have creative ways of not wasting any water. Cactuses store water in their trunks and have no leaves, only thorns. They can live for months without any rainfall. One animal that never drinks water is the kangaroo mouse that lives in the Nevada desert. It gets all the water it needs from the seeds it eats.

Grasslands are found all over.

The only continent without grasslands is Antarctica. Grasslands are plains with an average rainfall, where all types of grasses, herbs and flowers grow together. Grasslands can be found in America where they are called prairies and in Africa too. Here they are called savannahs, or in Asia where they are called steppes. Grasslands are home to many different species that live on and under the soil, eat the grass or who prey on the grass-eaters. In the United States these animals are buffalos and wolves, in Africa gazelles and lions.

Freshwater ecosystems have rare species.

There are many species that do not live in salt water. Freshwater ecosystems are wherever there is fresh water. Frogs, fish, crayfish, bivalves, insects and microscopic organisms like amoebas populate ponds, lakes, streams, and rivers. Bigger animals also live in or near fresh water. Some of these are otters and  beavers in Europe and America, crocodiles and hippos in Africa, platypuses in Australia and rare river dolphins in Asia and South America.

Life is harsh in the Tundra.

The weather in the tundra is wintery all year round, windy and cold. You can find tundra near the north and south poles of the Earth. They are called Arctic and Antarctic tundra.  There is also tundra near the top of the world’s tallest mountains. Life is difficult here, the vegetation is resistant to the cold, there are shrubs, mosses and lichens. Reindeer and rabbits eat these and are prey to foxes, wild lynx and polar bears. The Antarctic tundra is a resting place for seals and penguins.

There are ecosystems at the bottom of the ocean.

The bottom of the ocean receives no light from the sun so how can plants and animals live? It’s so cold and dark! In certain areas at the bottom of oceans there are Hydrothermal Vents. These are small underwater volcanoes that emit very hot water along with gases like methane and chemicals like ammonia. Some animals like clams and shrimp live near these vents. A weird worm also lives here, it’s called giant tube worm and it’s six feet long! It has special bacteria inside that transform the methane and ammonia from the vents into food.

Wetlands are fish nurseries.

Wetlands are found near bodies of fresh and/or salt water. Here we can see bogs, swamps and marshes. They can also be found at a river’s estuary or delta. These are areas where salt or fresh water dominate or even a mixture of the two. Lots of aquatic plants and animals live here. Alligators, crocodiles , frogs and many fish lay their eggs here because it is a safe place to hatch and grow. Insects also like the humidity and mosquitos and dragonflies thrive.

Many trees are found in Boreal forests.

Between the Arctic and the subtropics is a temperate region. Here the climate is neither too hot or too cold and the year is divided into seasons. A large part of North America, Europe, and Asia is in a temperate region. There are lots of big forests of pine, spruce and larch trees. These have  needles and most are green all year round. Brown bears, wolves, deer, porcupines and eagles live in these great forests.

There are ecosystems even in big cities.

Since an ecosystem by definition is everything that lives in a particular environment we can say that big cities around the world are peculiar ecosystems. People share their living space with many animals, birds and insects. Raccoons, coyotes, foxes, skunks, boar, mice, rats and deer are only a few. To allow these animals a safe way into and out of cities there are special bridges called wildlife crossings where animals can cross over busy roads in safety from traffic.