Lots in space
What is in space besides planets, moons and stars?
EVEN though most of the universe is empty space, called a vacuum, it does not mean that space is completely void.
There are many beautiful, strange and mysterious objects out there.
‘Space’ begins about 100km above the Earth, where the shell of air around our planet disappears. At night space appears as a black blanket dotted with stars but there’s more to it than that.
In the tiny patch of deep-sky that we think of as the entire Universe observable to us, are hundreds of billions of galaxies of which about 8700 have been identified. Each one of those galaxies contains hundreds of billions of stars, just like our Milky Way.
Space encounters
With powerful telescopes and satellites and missions going into orbit around the Earth or other celestial objects, we have learnt a lot about what’s in space over the past five decades.
There’s the Milky Way and other galaxies, black holes, black matter, quasars, solar wind, isolated particles and hydrogen atoms, nebulae, bits of rubble called planetoids, asteroids, comets, meteors, electromagnetic radiation, solar flares, radio waves and interstellar dust.
In addition, there’s all the man-made objects we put into space – satellites, probes and space junk from spacecraft.
Orbiting objects
Above Earth there are many man
made objects large and small circling our planet in orbits that range from 240km to 36,200km away. The Soviets launched the first satellite, Sputnik 1, in 1957. Since then along with the International Space Station (ISS) and the Hubble Space Telescope, 2500 satellites have been sent aloft for many purposes including global positioning systems.
Life in space?
With all of the countless billions of stars, planets and moons in space, the question arises is there life beyond Earth in space? It is believed that under the right conditions, life can exist elsewhere in space but there is no evidence for this yet. Several missions are planned to search for evidence of life on Mars and on the moons of Jupiter and Saturn and to find Earth-like planets around other stars.