Hubble Space Telescope

The Hubble Space Telescope (HST) has transformed our understanding of the universe since its launch on April 24, 1990. Celebrating over 35 years of operation, Hubble has provided breathtaking imagery and groundbreaking discoveries. From identifying distant galaxies to measuring the universe’s expansion, its contributions are monumental. NASA recently commemorated this journey with a collection of stunning images captured by Hubble.

Development and Launch

The concept of a space telescope was proposed by Lyman Spitzer in the 1940s. In 1969, NASA, backed by the US Congress, approved the project. The European Space Agency contributed 15% of the funding. The HST was constructed by a coalition of 20 companies and institutions. Originally slated for launch in 1986, it faced delays due to technical issues and the Challenger disaster. Ultimately, it launched in 1990.

Initial Challenges

Upon its launch, Hubble’s images were blurred due to a mis-shaped primary mirror. Engineers developed a corrective device called COSTAR to rectify this issue. Astronauts conducted a servicing mission in 1993 to install this device and replace the Wide-Field and Planetary Camera (WFPC) with WFPC 2.

Scientific Instruments

Hubble is equipped with various instruments. Its initial setup included the Wide-Field and Planetary Camera, Faint Object Camera, and two spectrographs. Over the years, these instruments have been upgraded to enhance Hubble’s observational capabilities. The Space Telescope Imaging Spectrograph replaced the older spectrographs in 1997.

Key Discoveries

Hubble has made numerous discoveries. It has observed over 52,000 stellar objects in 1.6 million observations. A very important achievement was estimating the universe’s age at approximately 13.8 billion years. This was accomplished through the study of Cepheid variable stars, which helped measure distances to other celestial bodies.

Mapping Dark Matter

Hubble has contributed to the creation of a 3D map of dark matter in the universe. This mapping has provided vital information about the structure and formation of galaxies. Additionally, Hubble has identified the relationship between gamma-ray bursts and star formation in galaxies.

Exploration of the Solar System

HST has played a vital role in solar system exploration. It discovered two moons of Pluto and observed seasonal changes on its surface. Hubble’s data has also been instrumental in estimating the mass of Eris, the heaviest known dwarf planet in the solar system.

Exoplanet Research

Hubble was the first to study the atmosphere of an exoplanet, HD 209458-b, also known as Osiris. This hot exoplanet, located 150 light years away, has a surface temperature of approximately 1,100°C. Hubble’s observations have expanded our knowledge of exoplanet atmospheres.

Legacy and Future

Initially expected to operate for 15 years, Hubble continues to thrive after 35 years. Its images and data have revealed new worlds and deepened our understanding of the cosmos. Hubble remains a mainstay of modern astronomy, inspiring future generations of scientists.

Questions for UPSC:

1. Critically analyse the impact of the Hubble Space Telescope on modern astronomy and its contributions to our understanding of the universe.
2. Explain the significance of the discovery of Cepheid variable stars in estimating the age of the universe. What methods were employed?
3. What are the implications of Hubble’s findings on dark matter for our understanding of galaxy formation? Discuss with examples.
4. Comment on the role of international collaboration in the development and success of the Hubble Space Telescope. How has this shaped future space missions?

Answer Hints:

1. Critically analyse the impact of the Hubble Space Telescope on modern astronomy and its contributions to our understanding of the universe.

1. Hubble has provided over 1.6 million observations, revealing over 52,000 stellar objects.
2. It has transformed our understanding of cosmic phenomena, including galaxy formation and expansion.
3. Hubble’s vivid imagery has inspired public interest and new generations of astronomers.
4. Its discoveries, including the age of the universe, have reshaped fundamental scientific theories.
5. The telescope has set a precedent for future space telescopes, influencing design and observational strategies.

2. Explain the significance of the discovery of Cepheid variable stars in estimating the age of the universe. What methods were employed?

1. Cepheid variable stars have a predictable luminosity based on their pulsation rates.
2. Hubble identified over 800 Cepheid stars in 24 galaxies to determine distances in the universe.
3. This data allowed astronomers to calculate the expansion rate of the universe, known as the Hubble Constant.
4. Using the expansion rate, scientists estimated the universe’s age at approximately 13.8 billion years.
5. The method established a reliable cosmic distance ladder, critical for measuring astronomical distances.

3. What are the implications of Hubble’s findings on dark matter for our understanding of galaxy formation? Discuss with examples.

1. Hubble contributed to creating a 3D map of dark matter, revealing its distribution in the universe.
2. Dark matter plays important role in galaxy formation, influencing the gravitational pull necessary for structure formation.
3. Hubble’s observations linked gamma-ray bursts to star formation in galaxies, indicating dark matter’s role in these processes.
4. Examples include the mapping of dark matter around galaxies like the Milky Way, providing vital information about their formation history.
5. About dark matter helps explain the dynamics of galaxies and their interactions in the universe.

4. Comment on the role of international collaboration in the development and success of the Hubble Space Telescope. How has this shaped future space missions?

1. The European Space Agency contributed 15% of Hubble’s funding, showcasing international investment.
2. Collaboration among 20 companies and institutions led to Hubble’s successful construction and launch.
3. This partnership set a model for future missions, emphasizing shared resources and expertise.
4. International collaboration on Hubble has encourageed a global scientific community in space exploration.
5. Future missions, like the James Webb Space Telescope, continue this trend of international cooperation in astronomy.