01 Jul A GUIDE TO OUTER SPACE SURVEILLANCE
A Guide to Outer Space Surveillance!
If you look into the sky at night while in the city, you will see fewer stars than you would if you looked into the night sky from out in the country. This is because of light pollution. The lights we use on Earth, such as streetlights and car headlights, help us see at night but too much light actually limits our ability to see up into space. Scientists are able to use telescopes to see the objects in space much closer than we can by just looking up. While space is still mysterious to even the smartest scientist, we have discovered a lot of information about the stars, planets, and other bodies that exist in outer space.
Types of Stars
Stars shine so brightly because they are on fire. You might be wondering how that can be possible. You have probably seen a campfire die out, so how can a star keep burning for so long? They use a process called nuclear fusion to turn hydrogen into helium over and over again. Just in our galaxy there are over 100 billion stars, one of which is the Sun. Like snowflakes, no two stars in the universe are the same, and hotter stars tend to burn brighter. One type of star is the Red Giant. These are usually stars that have run out of hydrogen to fuse. They get really, really big and can suck in planets and other space objects. White dwarfs are another type of star. They are incredibly heavy but only a little bigger than the Earth. They are usually stars that were Red ?Giants at an earlier time but cooled down. When a White Dwarf cools down, it becomes a Black Dwarf.
A little bit of information on star spectrums.
Learn what white dwarf stars look like and how they’re formed.
The Solar System
Our solar system only has one star: the Sun. But it supplies light and heat for lots and lots of other objects. Our solar system has eight planets. In order from the closest to the sun they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. There are also several dwarf planets, a belt of metal space rocks known as asteroids between Mars and Jupiter, and comets which are flying clouds of gas, dust and rock.
Learn about the different objects that can be found in our solar system.
The universe is made up of billions of galaxies, which are collections of dust, stars and gas. Galaxies range from 1,500 to 300,000 light years in size. Our solar system is part of the Milky Way Galaxy, which is about 100,000 light years across. There are three main types of galaxies. Spiral galaxies are those that have gas and dust arms spreading outward from its center in a spiral pattern. The Milky Way is a spiral galaxy. There are also elliptical galaxies that are more circular. They are the most common type of galaxy and they are made up mostly of stars. Finally, irregular galaxies do not have a defined shape and they are the most likely place where new stars will be formed.
A brief summary of what are inside galexies.
Our solar system is huge. It measures about two light years across. However, the Universe is many billions of light years across; hundreds, perhaps thousands of billions of light years in fact. When we look up at the night sky we can see light from stars that may have burned out millions of years ago. It’s just taking a long time for the light to get here. No one is sure how the Universe came to be, but there are many educated theories. One of the most popular is the Big Bang Theory. It suggests that all matter was once squished together in a tiny, dense space and then exploded with a big bang. Theories such as this are researched by astronomers, who are scientists that study space.
Check out awesome pictures of real space objects taken by the Hubble Telescope.
The Universe is made up of a lot of dark energy and dark matter. Learn more about them.
A black hole is perhaps the most powerful force in the universe. They are created when giant stars explode in a supernova. They are so powerful that they absorb light, so we can’t actually see them. The objects that surround them sometimes reflect light so it isn’t impossible to determine where one is. In 2011, people actually saw a star sucked into a black hole in the visible night sky. Scientists believe that the center of every galaxy is actually a supermassive black hole. An object needs to be quite close to a black hole to fall in, so the Earth is not at risk of falling into the hole at the center of the Milky Way.