Fast Facts
- Approximate distance from the Earth to Sun = 93 million miles (149 million km)
- Distance from the centre of the Milky Way Galaxy = 30,000 light-years
- Main components = hydrogen and helium
- Period of rotation = 25.4 days
- Equatorial diameter = 1.4 million km or 865,000 miles
- Relative size to Earth = 109 times larger
- Core temperature = 27 million-degree Fahrenheit (15 million degrees Celsius)
- Expected life = 5 billion years +
Distinguishing features
About 99% of the solar system’s mass is housed within the Sun.
Visibility
DO NOT look directly at the Sun, with or without a telescope (unless you have the proper filters). Galileo went blind observing the Sun!
There are several safe ways you can observe the Sun and even sunspots. Projecting the image of the Sun by creating your own pinhole camera is the simplest and safest way. You can get a solar philtre if you have your own telescope. Also, solar telescopes are online, which you can use to observe the Sun through the internet.
Probing the facts
Ulysses launched 1990 and the Solar and Heliospheric Observatory (SOHO), launched 1995, are two very sophisticated solar probes that have returned data providing much of what we understand about the sun today. Ulysses’ mission was to study the sun’s activity at its north and south pole and in the space above and below the poles.
SOHO’s mission, in addition to studying the sun, was to collect information on the heliosphere – the vast region permeated by the solar wind that surrounds the sun and extends through the solar system.
