Astronomy had fascinated mankind since the beginning of time — from the days when an eclipse was feared until today when we can see billions of light-years from Earth.
Curious about astronomy? Here are some interesting things about it.
1. Astronomy is Like Looking Back in Time
Astronomy is like looking back in time, seeing past events. When you look at the night sky, the light you see from those stars took 20, 30, and hundreds of years to reach your eyes.
In astronomy, distances are given in light-years. A light-year is the amount of time it takes light to travel in one year. One light-year is 5.88 trillion miles (9.5 trillion kilometers.)
At a distance of 2.5 million light-years, the Andromeda Galaxy is the furthest object you can see with the naked eye. When you see it, you are looking back to something that occurred 2.5 million years ago.
2. The Brightest Star is Not the Closest Star
The brightest star in the sky is Sirius, officially called Alpha Canis Majoris. It is located in the Canis Major constellation. Sirius is the 7th closest star to the Earth and located 8.7 light-years away.
The reason closer stars are not brighter is because Sirius is a class A1V star. In comparison with our sun, Sirius is hotter, has twice the mass, and almost twice the diameter.
3. The Furthest Star
The furthest star discovered so far is MACS J1149+2223 Lensed Star 1, nicknamed Icarus. At nine billion light-years from Earth, Icarus is a blue super-giant star, which makes it larger, hotter, and possibly a thousand times brighter than our sun.
It is unlikely that Icarus is still there today since a blue giant star cannot survive for nine billion years. The star could have collapsed into a neutron star or black hole years ago.
4. The Guest Star
In 1504 A.D., Chinese astronomers wrote about a bright “guest” star appearing in the sky. This bright guest star was the light from an exploding star, a supernova, about 6,500 light-years from Earth. Today, this supernova can be recognized as the Crab Nebula. The supernova was so bright that for several weeks it was seen during the day.
5. The Odd Orbit of Uranus
Because it is tilted so far, it basically orbits the sun on its side. The unusual orbit is possibly due to a massive collision with another planet shortly after Uranus was formed. Due to its orbit, one season on Uranus lasts the equivalent of 20 years on Earth. Uranus is the only planet in our solar system that has this unusual tilt.
So far, astronomers have discovered 4,108 planets outside of our solar system, these are called exoplanets. It is estimated that there is approximately 1 planet for every star in our galaxy. This would mean there could be 100 thousand million exoplanets in the Milky Way.
7. The Planet of Burning Ice
Located 30 light-years from Earth, Gliese 436b is a fascinating planet. Gliese 436b revolves around its sun at a distance of only 2.5 million miles, compared to the Earth, which is 93 million miles from the sun.
The surface temperature is estimated at 822° F (439° C), yet the surface is covered in ice. Astronomers believe that a certain form of ice is kept solid by the immense gravitational forces in the planet’s core. This force increases in depth, preventing water from evaporating. Like carbon is made into diamonds under pressure, water on Gliese 436b is turned into burning ice.
8. The Orphan Planet
Most of the exoplanets that have been discovered are found orbiting a star. Astronomers recently found an orphaned planet that does not orbit a parent star. Discovered in 2012, CFBDSIR 2149-0403 is most likely a gas giant planet about 4 to 7 times more massive than Jupiter. Located 100 light-years from Earth, this orphaned planet is situated in AB Doradus moving group, a stream of young stars.
9. The Fastest Spinning Neutron
A neutron star is formed when a star explodes, leaving behind a dense spinning ball of neutrons, called pulsars. PSR J1748-2446ad rotates at an amazing 716 times per second (716 hertz). As they rotate, they emit radio waves. This pulsar breaks the previous speed record of 642 hertz.
10. Finding Vulcan
The Creator of Star Trek, Gene Rodenberry, proposed that the fictional Vulcan world would orbit the star, 40 Eridani A.
Located 16 light-years from Earth, planet HD 26965 has been found orbiting 40 Eridani A in the star’s optimal habitable zone. 40 Eridani A is slightly cooler and less massive than our sun, and an almost identical solar cycle.
Astronomy, The Final Frontier
Astronomy is filled with incredible discoveries. You can join this fascinating world by becoming an amateur astronomer and maybe making your own discoveries one day.