How a single telescope can see billions of years into the past
The Hubble Space Telescope is more than a camera; it is a high-precision instrument capable of extraordinary feats. From orbiting Earth every 95 minutes to detecting light from 13.4 billion years ago, its technical specifications reveal a machine designed to push the very limits of human observation.
Operating in an orbit approximately 300 miles above Earth, Hubble travels at a staggering 17,000 miles per hour. This constant motion allows the observatory to capture data from the deep cosmos, including light from the galaxy GN-z11, which traveled 13.4 billion light-years to reach us. The telescope's precision is equally profound; its pointing accuracy of 0.007 arcseconds is equivalent to hitting a dime with a laser beam from over 200 miles away. This stability allows it to resolve infrared details so fine that it could theoretically distinguish a pair of fireflies in Tokyo from a vantage point in Washington, D.C.
The hardware itself is a marvel of engineering, weighing 27,000 pounds—roughly the weight of two elephants. Its primary mirror, 7.8 feet in diameter, collects 40,000 times more light than the human eye. To maintain its mission for over 30 years, Hubble was uniquely designed as the first space-based observatory intended for in-orbit servicing. This capability was realized through six Shuttle missions, involving 17 different spacewalkers who spent a total of 171 hours and 3 minutes performing repairs and upgrades.
The scale of Hubble's scientific output is immense. As of March 2024, the telescope has recorded over 1.7 million observations and contributed to 23,000 peer-reviewed science papers. These discoveries have been cited over 1.4 million times, driven by a global community of 29,000 astronomers. While it has only observed about 0.1% of the sky, the data archive spans 477 terabytes, documenting 108 million different astronomical objects and fundamentally altering our understanding of the universe's history.
Source: Hubble By The Numbers
