Hubble Telescope not only sees the stars and galaxies but also shows us a path to measure an invisible element of cosmos called DARK MATTER. This can stop DARK ENERGY. Dark Matter is also known as cosmic glue is a positive force because it attracts other objects with its gravity. Dark Matter is responsible for producing galaxies in our universe. Gravity of atoms alone cannot produce these galaxies in finite amount of time. And we wouldn't be here today if there was no Dark Matter.
It is proven by observing images taken with Hubble Telescope that Dark Matter do exist. Sometimes it is seen that some other galaxies surround a galaxy. But actually they are not there. They are reflections of more distant galaxies coming from behind. This optical illusion is caused by Dark Matter which distorts the light. This phenomenon is called Gravitational Lensing.
The light from distant galaxies is bent by the curvature of space due to the stars and Dark Matter. The more Dark Matter there is the more bending occurs. By measuring the bending scientists can get an idea how much Dark Matter is around and whether it is enough to stop BIG RIP that may result in a BIG CHILL or BIG CRUNCH. Gravitational Lensing is a useful way to measure Dark Matter.