IELTS শব্দভাণ্ডার ফ্ল্যাশকার্ড

Astronomers are scientists who study astronomy. An astronaut is a person who is trained for traveling in a spacecraft. Don’t mistake astronomers for astronauts.

Astronomers are scientists who study astronomy. An astronaut is a person who is trained for traveling in a spacecraft. Don’t mistake astronomers for astronauts.

Astronomical is the adjective. It means relating to astronomy. For example:

• astronomical research, astronomical observations, astronomical knowledge, astronomical phenomena

Let’s look at an example paragraph

• Radio astronomy has led to substantial increases in astronomical knowledge, particularly with the discovery of several classes of new objects such as radio galaxies. This is because radio astronomy allows us to see things that are not detectable in optical astronomy.
• It seems likely that a number of astronomical phenomena, such as the formation of planetary nebula, are caused by the interaction of two stars orbiting each other.
• It was the first known astronomical observations made by Galileo. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe.

We also often use “astronomical” to describe an amount like the cost of something is large. For example:

• Houses in the village are selling for astronomical prices.
• The cost is astronomical.

We also often use “astronomical” to describe an amount like the cost of something is large. For example:

• Houses in the village are selling for astronomical prices.
• The cost is astronomical.

The adverb “astronomically” also has the same usage. For example:

• He was astronomically wealthy.
• House prices had risen astronomically.
• The bill was astronomically high

Definition: The branch of science which deals with celestial objects, space, and the physical universe as a whole.

Example senences:

• He made a number of contributions to mathematics, physics and astronomy.
• In present-day southern Mexico, Guatemala, northern Belize and western Honduras. Building on the inherited inventions and ideas of earlier civilizations such as the Olmec, the Maya developed astronomy, calendrical systems and hieroglyphic writing. The Maya were noted as well for elaborate and highly decorated ceremonial architecture, including temple-pyramids, palaces and observatories, all built without metal tools.
• Radio astronomy has led to substantial increases in astronomical knowledge, particularly with the discovery of several classes of new objects such as radio galaxies. This is because radio astronomy allows us to see things that are not detectable in optical astronomy.

An aurora, sometimes referred to as polar lights, northern lights or southern lights, is a natural light display in the Earth's sky, predominantly seen in the high latitude regions.

It took astronomers a century after the discovery of the first celestial spiral to prove that the Milky Way itself looks like a giant spiral.

The Hubble Space Telescope, which in 2015 completes 25 years in orbit, has gathered dramatic new views of two well-known celestial objects.

Comets, celestial bodies of dust, ice and complex molecules, are remnants of the birth of our 4.6 billion-year-old solar system.

Both the asteroid and the comet are large, irregularly shaped objects in space that orbits our Sun. However, while comets are mostly made of ice, asteroids are made up of rock or even metal. 

Definition: A group of stars forming a recognizable pattern that is traditionally named after its apparent form or identified with a mythological figure. Modern astronomers divide the sky into eighty-eight constellations with defined boundaries.

Example sentences:

• Maria and her father lay out under the stars, naming the constellations.

Definition: The action of forming or process of being formed:
 

The formation of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a planetary disk out of which the planets, moons, asteroids, and other small Solar System.

The formation of glacier is an accumulation of snow that lasts for more than a year. As more and more snow piles up, the ice at the bottom becomes compressed. Living organisms have an important function in the formation of soil. The numerous animals and plants that live in the soil use minerals found there, and in turn create organic matter that aids in the translocation (movement) and aeration of the soil, and helps protect the soil from erosion.

Tectonic plates have also collided with one another, at what are called convergent boundaries. The edge of one plate slides beneath the other, pushing it up, resulting in the formation of mountains.

A galaxy is a group of many stars. Our sun is a star. The galaxy that we live in is known as milky way. It contains 300 billion stars.

Definition: related to gravitation

Example senences:

• In walking, kinetic energy is converted to gravitational potential energy and back again, as in a pendulum

New observations confirm that interstellar dust can come from explosions known as supernovae.

A solar eclipse can only happen during a phase of the lunar cycle where the Moon lies between the Earth and the sun. If everything lines up just right, the sun is fully or partially covered by the Moon.

Definition: The region surrounding the earth or another astronomical body in which its magnetic field is the predominant effective magnetic field

Example sentences:

• Observations from Earth showed that Jupiter has a massive magnetosphere and that the planet emits radiation at radio wavelengths.

When a meteoroid enters the atmosphere, friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate that energy, thus forming a fireball, also known as a meteor or shooting/falling star.

Most meteoroids that enter the Earth's atmosphere vaporize completely and never reach the planet's surface. If any part of a meteoroid survives the fall through the atmosphere and lands on Earth, it is called a meteorite.

A meteoroid is a small piece of debris from an asteroid or comet orbiting the Sun.

Radio telescopes can detect invisible gas, and can reveal areas of space that may be obscured with cosmic dust.

If something such as a satellite orbits a planet, moon, or sun, it goes around it in a continuous, curving path.

These phrases "go around, revolve around, be in orbit around" have the same meaning of  “orbit”.

Look at this sentence:

• Planets go around the sun.

We can paraphrase it to

• Planets orbit the sun.
• Planets revolve around the sun.
• Planets are in orbit around the sun.

"Orbital" describes things relating to the orbit of an object in space. 

Example sentences:

• The newly discovered world followed an orbital path unlike that of any other planet.
• The orbital period of the moon is 27 days.
• Earth's orbital speed averages about 30 km/s.

A planet is an object that revolves around the star. Our earth is a planet. In our solar system, there are 8 planets:

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

The adjective of the word “planet” is “planetary”. “Planetary” describes anything related to the planet. For example:

• A Planetary system
• Planetary scientists

An example sentence would be :

• Within our own galaxy, there are probably tens of thousands of planetary systems.

A planet is an object that revolves around the star. Our earth is a planet. In our solar system, there are 8 planets:

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

The adjective of the word “planet” is “planetary”. “Planetary” describes anything related to the planet. For example:

• A Planetary system
• Planetary scientists

An example sentence would be :

• Within our own galaxy, there are probably tens of thousands of planetary systems.

Definition: An ionized gas consisting of positive ions and free electrons in proportions resulting in more or less no overall electric charge, typically at low pressures

Example sentences:

• This expansion of the atmosphere significantly increases the number of microscopic collisions between the satellite and the gases and plasma of the upper atmosphere.
• The photons can break apart, or ionize, molecules and atoms of the atmosphere into protons and electrons, producing plasma.

Presence is the state of being somewhere. Here are example sentences:

• The test results showed the presence of bacteria in the water. (This means the results showed that there were bacteria in the water)
• No one was aware of the stranger's presence.
• His very presence on the basketball court intimidated opponents.

The phrase "in someone's presence" or "in the presence of someone" means when someone is present. Here are example sentences:

• Please don't smoke in my presence. = Please don't smoke when I am here.
• She asked them not to talk about the accident in her presence.
• I am usually shy in the presence of strangers.

Let’s take a look at the phrase "make your presence felt/heard/known". The phrase means to make people aware of you by gaining power or influence over them. Example sentences:

• Women are making their presence felt in the industry.
• The Internet service is making its presence known by doing a lot of advertising.

Definition: The emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization

Example senences:

• We now know that invisible forces do control some things: gravity, radiation, electricity. Because it uses sound waves instead of radiation, ultrasound is safer than X-rays

A supernova is a stellar explosion of a massive star.

New observations confirm that interstellar dust can come from explosions known as supernovae.

Definition: Not having or needing a crew or staff:

Example senences:

• Baxter's book was fiction, but we're seeing the same trade-off now in NASA's decision to cancel further unmanned missions and bring down the Hubble space telescope in order to spend more money on manned spaceflight development.