A Peek through the Night Sky

You look back in time as you gaze up at the night sky…….

For many years we have been fascinated by the heavenly bodies. Every generation has a pop culture reference inspired in one form or another by these celestial creations or originated from these bodies. Jane Taylor’s poem “Twinkle, Twinkle Little Star” from our school days has served to comfort our childhood minds, subconsciously turning our attention to the stars, and leaving our minds full of curiosities about the night sky.

As early as 1608, with the invention of the telescope by Dutch lensmaker Hans Lippershey. This discovery has paved the way for multiple notable telescopes including Hubble and James Webb Telescopes.

The James Webb Space Telescope on its own after separating from the Arianespace Ariane 5 rocket that launched it into space. The spacecraft separated from the rocket 27 minutes into the flight at an altitude of approximately 1,400 kilometers. (Image Credits: NASA)

Why space telescopes?

First suggested by Lyman Spitzer in 1946, a space telescope or space observatory is a telescope in outer space used to observe astronomical objects. These telescopes are pretty distinct from Earth imaging satellites (usually used for gathering information for weather analysis, espionage, etc.). Space telescopes are divided into two types:

1. satellites that map the entire sky, that is, an astronomical survey
2. satellites that focus on selected astronomical objects or parts of the sky and beyond.

The most recent being the James Webb Space Telescope (also called JWST or Webb) is the largest and most powerful space science telescope developed by NASA in collaboration with European Space Agency (ESA) and the Canadian Space Agency (CSA). It is a premier observatory with a large infrared telescope that has an approximately 6.5-meter primary mirror. It aims to build on the discoveries of its predecessor the Hubble Space Telescope, by studying every existing phase in the history of our universe, ranging from the first luminous glows after the big bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own solar system.

An artist’s concept of the Webb Space Telescope. (Image Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez)

A Brief History

The first operational space telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard Salyut 1 in 1971.

Launched on 23rd July 1999 by NASA Chandra X-ray observatory allows scientists to obtain X-ray images of exotic environments to help understand the structure and evolution of the universe.

The Spitzer Space Telescope, launched in 2003, was NASA’s Infrared Great Observatory. In its 16 years of operation, some of its accomplishments include discovering a giant ring of Saturn, revealing a system of seven Earth-size planets around a star 40 light years away, and studying the most distant known galaxies.

The Hubble Space Telescope launched on 25th April 1990 is one of NASA’s most successful and long-lasting science missions. An engineering marvel which showcases more than two decades of dedicated collaboration between scientists, engineers, contractors, and institutions from all over the world. The telescope is set to complete its mission in 2030, the success of this complex system relies on the integration of communication antennas, solar arrays, computers and automation, thermal protest, and pointing systems.

James Webb Space Telescope (JWST) is an Infrared Telescope launched on 25th December 2021. As the largest optical telescope in space, its high resolution and sensitivity allow it to view objects too old, distant, or faint for the Hubble Space Telescope.

Spitzer’s first light image of IC 1396 (Image Credits: NASA/JPL- Caltech)

A simplified version of the Hubble Space Telescope (Image credits: hubblesite.org)

Assembled JWST following environmental testing (Image credits: NASA Goddard Space Flight Center)

What lies ahead?

NASA has been working for several years on an infrared space telescope the Nancy Grace Roman Space Telescope (formerly known as the Wide-Field Infrared Survey Telescope or WFIRST) which consists of two instruments: the Wide Field Instrument and the Coronagraph Instrument. By demonstrating these tools in an integrated end-to-end system and enabling scientific observing operations, NASA will validate performance models and provide the pathway for potential flagship missions. Roman Space Telescope is scheduled to launch by May 2027.

Rendered model of the Roman Space Telescope in May 2020 (Image credit: NASA)

Over the years, these telescopes have taught many lessons that we were not anticipating. It helped us determine that the Universe was not just expanding, but that the expansion was accelerating. We discovered how galaxies grew and evolved over cosmic time, determined when star formation peaks, and produced images that are as spectacular as they are scientifically valuable. We were able to push the frontiers in ways that they had never been tested before, and that led to new observations, new data, new results, and in many cases new and surprising conclusions. We followed the evidence wherever it led us and the Universe revealed secrets we did not even fathom it could process.

References

Discoveries - Why a Space Telescope?

In-Depth | James Webb Space Telescope - NASA Solar System Exploration

The Nancy Grace Roman Space Telescope