The Hubble Space Telescope is primarily designed to observe distant galaxies, stars, planets, and other celestial objects in the universe.

The Hubble Space Telescope was launched into orbit on April 24, 1990, aboard the Space Shuttle Discovery.

The Hubble Space Telescope orbits Earth at an altitude of approximately 550 kilometers (342 miles).

The Hubble Space Telescope is a reflecting telescope, meaning it uses mirrors to focus light and create images.

The primary mirror of the Hubble Space Telescope is made of gold-plated aluminum.

The primary mirror of the Hubble Space Telescope has a diameter of 2.4 meters (7.9 feet).

The Hubble Space Telescope's field of view is approximately 0.1 square degrees, which is equivalent to the size of a postage stamp held at arm's length.

The Hubble Space Telescope's angular resolution is approximately 0.01 arcseconds, which is equivalent to being able to distinguish between two objects separated by the width of a human hair from a distance of one kilometer.

The Hubble Space Telescope's sensitivity is approximately 10^-18 Jansky, which is equivalent to being able to detect the light from a single candle from a distance of one billion light-years.

The Hubble Space Telescope's wavelength range extends from ultraviolet to visible light, allowing it to observe objects that emit light in these wavelengths.

The Hubble Space Telescope was originally designed to have a lifetime of 15 years, but it has been extended to 25 years through servicing missions.

There have been five servicing missions conducted on the Hubble Space Telescope, the last one being in 2009.

The James Webb Space Telescope is the successor to the Hubble Space Telescope and is expected to launch in 2022.

The main scientific goal of the James Webb Space Telescope is to study the early universe, including the first stars and galaxies that formed.

Dark energy is a mysterious force that is causing the expansion of the universe to accelerate. Its nature and properties are still not fully understood.