What is Gravitational Lensing and its Cosmological Applications

Einstein Ring due to gravitational lensing
Ring shaped image due to gravitational lensing. Source: NASA

The size of the observable universe is unimaginably large. The galaxies are separated from each other by such a large distance that even light takes millions and billions of year to travel from one galaxy to other. The galaxies present at these distant positions appear as point size and their brightness is so dim that they are invisible to naked eyes. We need various astronomical instruments to observe these distant galaxies. Continue reading “What is Gravitational Lensing and its Cosmological Applications”

Celestial Sphere – The Equatorial Coordinate System

Earth within Celestial Sphere
The Earth within Celestial Sphere. Source: Wikipedia

The Equatorial Coordinate System is used to locate the position of star on Celestial Sphere. The Equatorial Coordinate System is similar to the coordinates of longitude and latitude that we use to locate the position of any place on the surface of Earth. Let us first learn how to locate an observer on the surface of Earth.

We know that Earth moves from West to East along an axis which Continue reading “Celestial Sphere – The Equatorial Coordinate System”

Comet Lovejoy: First Naked Eye Comet of the Year 2015

Comet Lovejoy
Comet Lovejoy is the first naked eye comet
of the year 2015. Image credit: NASA/MSFC/MEO/Aaron Kingery

Comets are one of the most fascinating objects in the universe. The view of the bright comet with long tail is one of the rare events which do not happen frequently. It is very rare when you get the chance of watching the comet with naked eye. This New Year has given us a gift in the form of comet which can be seen with naked eye in the first few weeks of January. This comet is known as Comet Lovejoy or more formally C/2014 Q2. This is one of the Continue reading “Comet Lovejoy: First Naked Eye Comet of the Year 2015”

What are Comets?

Comet Neat
Icy Comet Neat. Credit: National Science Foundation

Comets are the most wonderful and dreadful members of the solar system. In the ancient times Comets were considered as warning of God and cause of death of monarch, disasters, plague and famine etc. Comet frightened the people for many centuries but actually Comets are very harmless and powerless. Continue reading “What are Comets?”

What will happen during Collision of Milky Way with Andromeda Galaxy?

Andromeda Galaxy
Andromeda Galaxy is 50% bigger than our Milky Way. (Credit: NASA)

You must have heard about the collision of an asteroid with the planet and aware of the destruction that can be caused by such an event. But there is one bigger cosmic event that is the collision of our Milky Way Galaxy with the Andromeda Galaxy. These two galaxies will merge to form a new galaxy in future. This was the common process of formation of new galaxies after the big bang. Continue reading “What will happen during Collision of Milky Way with Andromeda Galaxy?”

Amazing Outer Planets with no Surface

Surface of The Planet Jupiter
The planet Jupiter does not have well-defined
surface boundary

Earth is a beautiful planet which has beautiful mountains, valley, rivers, lands, lakes, and plants etc. All these things are present on the surface of Earth. Just imagine the Earth without any surface; you can’t imagine life on Earth if the surface is not present. Continue reading “Amazing Outer Planets with no Surface”

The Great Red Spot Puzzling Astronomers for more than 400 Years

The great red spot of Jupiter
The Great Red Spot of Jupiter captured by Voyager 1 in 1979.
(Credit: NASA )

The Great Red Spot (GRS) is an anticyclonic atmospheric storm which is present in the southern hemisphere of Jupiter. Since it is anticyclonic, it is a high-pressure storm opposite to the cyclones present on Earth. It is also called the eye of. The GRS is a very old storm and first observed and described by Giovanni Cassini in 1665. It is believed that it had just formed at that time. Continue reading “The Great Red Spot Puzzling Astronomers for more than 400 Years”

How do astronomers measure the speed of the Galaxy?

The Andromeda Galaxy
The Andromeda Galaxy is moving towards us with relative speed 225 Km/s (Credit: NASA/JPL-Caltech)

The galaxies are present at such a large distance from the Earth that the motion of galaxies cannot be observed through a telescope. No observable change in the position will be detected even if we observe any galaxy throughout life. Then, you must be wondering how the speed of the galaxy is measured by astronomers? Continue reading “How do astronomers measure the speed of the Galaxy?”

How do Venus and Mercury act as Morning and Evening star?

Most of the people whenever to look towards night sky; they try to find out the brightest star in the sky. If you also had tried the same then you must have observed that the brightest star in the sky can be viewed only during evening or morning. Continue reading “How do Venus and Mercury act as Morning and Evening star?”

Difference between Astronomy and Astrophysics

Astronomy is a study of Celestial bodies outside the atmosphere of Earth in deep space, it basically deals with the motion, position, composition, and size of the celestial bodies. Examples of such heavenly bodies are Moon, Sun, Planets, Dwarf planets, Comets, Stars, Meteors, and Galaxies etc. Continue reading “Difference between Astronomy and Astrophysics”