Category: Astronomy

How disorderly is the universe? Entropy – disorder – increases with time, according to the second law of thermodynamics. When it maxes out, the temperature will be the same everywhere across the universe. This will happen when stars and galactic cores stop producing energy and are so far apart that

In 1997, a host of ground-based and space telescopes confirmed that gamma-ray bursts – fleeting blasts of high energy radiation – are nature’s biggest explosions. The Italian-Dutch satellite BeppoSAX pin-pointed the February 28 burst, and Earth-based optical instruments were then able to spot its faint host galaxy several billion light-years

The Cosmic Web Starting in the 1980s, astronomers came to realize that the contents of the universe are not spread smoothly throughout space. Clusters of galaxies bunch together along filaments separated by huge voids where few galaxies exist. The overall structure, dubbed the ‘cosmic web,’ likely arose in the early

With a recently acquired beginner telescope, the Lyra Constellation’s various stars came into full view with a clarity previously denied through a pair of binoculars. Lyra is a constellation in the northern hemisphere. It was introduced by the Greek astronomer Ptolemy in the 2nd century. The constellation is associated with

Dark Matter in the Universe In 1933, Swiss astronomer Fritz Zwicky discovered that the visible matter contained in the galaxies of the vast Coma cluster is barely 10% of the amount needed to keep the galaxies bound together. This is the first indication that the universe has vast quantities of

Measurement of Stars’ Luminosities In the 1910s, Danish astronomer Ejnar Hertzsprung and American Henry Norris Russell independently plotted the luminosities or intrinsic brightnesses of stars against their temperatures or colours. They found that most stars lie along a narrow strip that runs from hot and luminous to cool and dim

Inflation in the Universe The Universe has been expanding since the Big Bang, but there may have been a time called the inflationary era, when the Universe grew10⁷⁸ times its size in 10³⁶ seconds. If the inflationary epoch happened, it would make the current Universe much bigger than it would

Telescopes can see galaxies whose light has been travelling almost 13.8 billion years and thus look as they did just after the Big Bang. Because the Universe is expanding at an accelerated rate, those galaxies are now some 46 billion light-years away. The observable Universe thus has a diameter of

Cygnus, the Swan, is a beautiful, easily recognized constellation in the form of a giant cross; it is sometimes called the Northern Cross. Deneb, its brightest star is a brilliant white star of magnitude 1.3 (18th of the 20 brightest stars) marks the bottom of the cross (from my view).

The visible universe—including Earth, the sun, other stars, and galaxies—is made of protons, neutrons, and electrons bundled together into atoms. Perhaps one of the most surprising discoveries of the 20th century was that this ordinary, or baryonic, matter makes up only 4.9% of the mass of the universe (heavy elements

Our Milky Way Galaxy is a spiral galaxy that is about 100,000 light-years in diameter containing 200–400 billion stars. Our own Sun is just one of those stars. The Solar System is located within the disk, around two thirds of the way out from the Galactic Center, on the inner

A telescope, a pair of binoculars, or the human eye collects light that was either emitted from an object in space (such as a star, a galaxy, or the Sun) or reflected off of the surface of an object (such as the Moon or planets within our own Solar System).

Collision with the Andromeda Galaxy NASA’s Hubble Space Telescope Shows that the Milky Way Galaxy (where our planetary system is located) is destined for a head-on collision with the Andromeda Galaxy. But nothing to worry about as it’s not going to take place in any of our lifetimes. Watch NASA’s