Astronauts work on the Hubble Space Telescope during the servicing mission on May 14, 2009. This mission was expected to keep Hubble functioning until 2014.
On February 1, 2003, tragedy occurred when the space shuttle Columbia exploded after reentering Earth’s atmosphere. All seven astronauts on board were killed. As a result, NASA grounded its shuttle fleet. This meant the Hubble could not be serviced. It would be almost three years before NASA announced a new service mission for the Hubble telescope.
In all, three more servicing missions took place on the Hubble between 1999 and 2009. Service included replacing gyroscopes, adding new solar arrays, and computer updates. The 2009 mission also added two new instruments: the Wide Field Camera 3 and the Cosmic Origins Spectrograph. This last mission was expected to keep the Hubble functioning through at least 2014.1
The most recent improvements on the Hubble made it more powerful than ever. Research and discoveries related to the telescope’s observations continued at an incredible pace. Through August 2011, more than nine thousand papers based on Hubble data had been published.2 This is a greater output of work than any other modern scientific instrument has prompted.3
Astronauts work on the Hubble Space Telescope during the servicing mission on May 14, 2009. This mission was expected to keep Hubble functioning until 2014.
The Hubble helped solve many mysteries of the universe, as well as confirm other theories long held by scientists. For example, it was widely accepted that any large galaxy would have a black hole at its center. However, the centers of most galaxies are packed so tight with stars that we cannot see them clearly with an Earth telescope. But the Hubble can see and track these individual stars. The velocity of these stars makes it clear that a black hole is attracting them.4
One of the great mysteries that had puzzled scientists throughout the ages is this: How old is the universe? The answer to this question has been largely answered, thanks to both the Hubble telescope and the scientist for whom the telescope was named.
In 1929, Edwin Hubble came up with the formula for what we now call Hubble’s law. This law says (basically) that the velocity of objects moving in space and their distance from other objects is proportional. In theory, Hubble’s law should have allowed scientists to determine the age of the universe. But for many years, we lacked accurate data. Some scientists thought the universe was about 10 billion years old, while others contended that it was 20 billion years old.5 Thanks to the Hubble telescope, we finally have data accurate enough to tell the age of the universe. We can now say (with a margin for error of about 1 percent) that the universe was born 13.7 billion years ago.6
The magnificent images that Hubble captures and the unique data it provides have helped solve many mysteries of the universe. This image created from three separate photos taken by Hubble shows a column of molecular hydrogen gas and dust that is an incubator for new stars. The stars are embedded inside the finger-like bulges at the top of the column.
The Hubble has also helped us learn more about our own galaxy. It brought us our first clear images of Pluto and detected a thin atmosphere of oxygen around Europa, one of Jupiter’s moons. It also recorded a huge storm on the planet Saturn that was so big it was larger than our planet Earth! The Hubble even helped us to predict the weather on Mars when the NASA mission of Pathfinder was sent there in 1997.
It was also in July 1997 that the Hubble discovered a young galaxy 13 billion light-years away. The following month, the telescope recorded what may be the first image of a planet there. This would be the first planet discovered outside of our solar system.7
This photo shows the giant planet Jupiter with one of its moons, Ganymede (right). The Hubble Space Telescope has given scientists clear images and important data about planets in our galaxy.
The Hubble Space Telescope celebrated its twentieth birthday on April 22, 2010. To commemorate the occasion, NASA, the European Space Agency (ESA), and the Space Telescope Institute (STScI) released an image from the Carina Nebula.8 The following year, the telescope made its one millionth observation.9
It was also early in 2011 that it was reported the telescope had observed what is likely the farthest galaxy yet discovered. This tiny speck of light has been traveling to us for about 13.2 billion years—which means it began when the universe was less than a half-billion years old. This is about 4 percent of the universe’s current age.10
A view of Messier 81, a spiral galaxy similar to the Milky Way, from the Hubble Space Telescope. This is one of the brightest galaxies seen from Earth. Hubble has also allowed scientists to study galaxies far from our planet. In 2011, Hubble observed the farthest-known galaxy, a tiny speck of light that has been traveling toward Earth for 13.2 billion years.
“In essence, the most important aspect of this is, it provides us with some sense of how fast galaxies are building up,” said Dr. Rychard J. Bouwens of the University of California, Santa Cruz. “It provides a sort of measuring stick.”11
Based on this latest discovery, Bouwens and his team concluded that the birthrate of stars increased tenfold between the time of this galaxy and that of the next, earliest-known galaxy (about 150 million years later). This is faster than most astronomers had previously believed.12
The next and final mission for the Hubble will be to deorbit the telescope, as it will have reached the end of its service life. Its scientific successor, the James Webb Space Telescope (JWST), is currently due to be launched by 2018. The JWST is poised to take us even farther than the Hubble has. It has been specially designed to reach these deep galaxies that the Hubble can only offer the tiniest glimpse.
“We really are not probing faint enough with the current Hubble observations to see beyond the tip of the iceberg,” said Dr. Bouwens.13
It is amazing to consider that as much as we have learned from the Hubble and as far as it has taken science, there is still so much further to go. The wonders and mysteries of the universe seem truly endless.