Brightness
Light is the main signal we receive from space. Almost everything we know about space has been found by measuring light.
One of the main ways to measure light is to look at the brightness. Measuring the brightness of something in space isn't as easy as you'd think though.
(1) Luminosity
This is a more physical measurement. It measures the energy output of the object. This is done by looking at how much light is given out by the object over time.
The units of luminosity are more standard, given in Watts - much like a light bulb! A typical LED light bulb in a house might be 20 Watts - the Sun is 20 million billion billion (2 x 1025) times brighter!
Johannes Kepler
Occupation
Astronomer, Mathematician, Scientist, Teacher
Year born
1571
Research Areas
Planetary motion, Optics, Geometry
- Early Life
Johannes was born in Weil der Stadt (now part of Germany). He had an interest in astronomy from a very young age. When he was 6, his mother took him up to a high place to see the Great Comet of 1577. When he was 9, he was called outdoors to see a lunar eclipse. His family were poor, but Johannes got a scholarship to study at the University of Tübingen.
Hypatia
Occupation
Astronomer, Mathematician, Philosopher
Year born
Sometime between 350 – 370 AD
Research interests
Geometry, Algebra
- Early Life
Hypatia was born to a Greek family in Alexandria, Egypt. Her father was a mathematician and educator. Very little is known about her mother.
- Career Highlights
Hypatia worked with her father to keep maths and astronomy knowledge up to date and safe during a period of religious conflict. At this time, property and buildings (including books and libraries) were at risk of damage or destruction.
Hunt the Asteroids
How do we find asteroids?
Distances in Space
Investigate the Size of a Galaxy
Have you ever wondered how big a galaxy is? They contain millions to billions of stars but what does that really mean for size?
Reading about sizes in a book is one thing, but what if you could make an observation of a galaxy and then measure its size?