Aiming high: Hubble’s Legacy
As we continue to explore deeper into Space with plans of a Manned Mission to Mars well underway, its important to reflect on how this is now possible.
Part of the story lies with the Hubble Space Telescope which has helped us Map and understand our Universe since the early 90s…So as part of our journey to Mars, we pay homage to the Hubble Space Telescope which has helped make it possible courtesy of Astronomy.com
Since the invention of the Telescope in 1609, astronomers have been plagued by the unsteadiness of Earth’s atmosphere, which distorts starlight from cosmic objects. As early as 1923, rocketry pioneers conceptualized a telescope launched into space, thereby avoiding atmospheric turbulence, with its captured data sent via signals to the ground and assembled into information and pictures. In 1946, just as the Hale Telescope was nearing first light, Lyman Spitzer, an influential American astronomer, penned a paper in which he examined the advantages and challenges of a space-based telescope for the first time.
The exquisite stability and clarity of Hubble’s images combined with the ability to view the universe at wavelengths of light that are unavailable to observatories on Earth make Hubble by far the most powerful telescope available — even 25 years after its launch!
Hubble peers out into the universe from so-called low-Earth orbit, about 353 miles (569 kilometers) above the planet’s surface, flies along at 17,500 mph (28,000 km/h), and orbits Earth once every 97 minutes. It’s possible to periodically see the telescope in the night sky, if it passes over your location, as a bright “star” slowly moving across the sky like other satellites do.
Since 1994, Hubble has rewritten astronomy and astrophysics, making more key observations over the ensuing 20 years than the sum of all the telescopes that came before it.
Hubble’s amazing legacy
The depth of Hubble’s data, however, has touched or rewritten nearly every area of astrophysics. Ever since the discovery of the expanding universe in the 1920s, astronomers had struggled with the rate of expansion and what it means. The so-called Hubble constant, the universal rate of expansion, was much in doubt, with two factions arguing very different conclusions from the data. The Hubble constant is also inversely proportional to the age of the universe, another key holy grail of science. One of the primary goals of Hubble was to measure the Hubble constant accurately, using a variety of distance indicators, and by the turn of the 21st century, this helped define a relatively accurate Hubble constant of 72±8 and an age of the universe, which the more recent European Planck satellite has refined further to 13.8±0.04 billion years.
Hubble has also played a key role in exploring another mysterious aspect of the universe, dark matter. Astronomers also used Hubble to record a historic series of so-called deep fields to study distant galaxies and the star formation rate in the universe in unprecedented detail.
In addition, scientists using Hubble have shone light onto the earliest days of the cosmos in their quest to understand how the Big Bang transformed into the universe we now know. Soon after the Big Bang, the cosmos was an opaque sea of plasma, and only some 380,000 years later did it cool sufficiently to undergo a so-called phase transition — protons and electrons combined to form neutral hydrogen atoms. The universe suddenly became transparent, and the cosmic microwave background radiation, so famous for being discovered in 1964 and for proving the Big Bang theory, was born.
No area of astronomy has been hotter or more rapidly changing over the past few years than the discovery of exoplanets, planets orbiting stars other than the Sun. Hubble has played a key role here, too, enabling planetary scientists to study the atmospheres of exoplanets.
And these are but a few areas, important as they are, touched or redefined by the existence of the world’s greatest telescope. The effects, the influence of Hubble, are woven like a dominant thread throughout the last quarter-century of astrophysics, of cosmology, of planetary science. In 2011, NASA’s star instrument passed a milestone when the ten-thousandth scientific paper using its data was published. Each year, about 10 percent of the most cited papers published are based on Hubble data. Many thousands of images of all manner of astronomical objects have poured out of Hubble, redefining how the public sees the cosmos.
In an age when science funding and support are often lacking, when a public basks in the benefits of science and technology mostly without providing for their futures, Hubble is a standout. The Hubble Space Telescope, now 25 years into its spectacular run, stands triumphant as the instrument that explored and redefined the cosmos. This magnificent telescope has allowed, for a time, astronomers to take off on a new and unprecedented voyage to the stars.
You can view Documentaries on the Hubble Space Telescope on our YouTube Channel’s ‘Science & Universe’ Playlist.
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