New Delhi, March 28: The Hubble Space Telescope is often referred to as a cosmic time machine. It captures light from distant celestial bodies, allowing us to journey back in time. The light takes time to reach Hubble, meaning the images we see today depict those objects as they were years or even billions of years ago.
Astrophysics can be likened to cosmic archaeology. Through light, we uncover the mysteries of celestial bodies’ lives and the evolution of the universe. Telescopes like Hubble help us understand our place in the cosmos and how it operates. Hubble does not merely take pictures; it transports us to the edges of time. Scientists utilize Hubble’s data to piece together the history of the universe and seek answers to unresolved questions.
The Hubble Space Telescope is more than just a telescope; it is an observatory, a satellite, and a scientific-cultural symbol. Orbiting at an altitude of approximately 550 kilometers above Earth, it completes a full orbit in about 95-96 minutes. Being above Earth’s hazy atmosphere allows Hubble to capture clear and stunning views of the universe.
The secret of its time journey lies in light. In astronomy, a ‘light-year’ is a unit of distance, representing how far light travels in one year. Light moves at nearly 300,000 kilometers per second, covering about 9.5 trillion kilometers in a single light-year. For instance, the Sun is about 150 million kilometers away from Earth, and its light takes approximately 8 minutes to reach us. Therefore, when we look at the Sun, we see it as it was 8 minutes ago. This distance is relatively small on a cosmic scale. The closest star after the Sun, Proxima Centauri, is about 4.2 light-years away.
Even in Hubble’s powerful view, Proxima Centauri appears as a tiny dot. This illustrates the vastness of the universe. When Hubble observes objects far beyond our solar system, the experience of time travel becomes even more thrilling. The galaxy GN-z11 is one of the most distant known galaxies, with its light taking 13.4 billion years to reach us. This means Hubble allows us to see that galaxy as it was just 400 million years after the Big Bang, when the universe was only 3 percent of its current age.
Similarly, the star named Earendel, observed by Hubble, is the most distant star known, with light that is 12.9 billion years old. When this light was emitted, the universe was merely 7 percent of its current age. These distant observations provide scientists with crucial insights into the early stages of the universe. Hubble offers us glimpses into the universe’s formative moments.
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