Cosmic Exploration Hub

Sunday, October 13, 2019

The Hubble Telescope

October 13, 2019

By: Haris Ahmad[1]

The Hubble telescope was launched by NASA (National Aeronautics and Space Administration) and ESA (European Space Agency) on April 24, 1990. Space Shuttle Discovery launched it into orbit. The Hubble telescope orbits approximately 547km above Earth. It travels 5 miles per second and is solar-powered; hence, it gets energy from the Sun. Hubble takes clear and sharp images of the celestial bodies in space e.g. planets, stars, galaxies and nebulae. It can take images of celestial bodies, which are billions of light-years away from us such as the birth and death of stars.

Picture Credits: NASA

According to NASA, Hubble transmits about 140 gigabytes of science data every week back to Earth. That's equal to about 45 two-hour, HD-quality movies or about 30,000 mp3 songs. The digital signals are relayed to satellites, then to a ground station, then to NASA's Goddard Space Flight Center, and finally to the Space Telescope Science Institute. The STScI (Space Telescope Science Institute) translates the data into images and information we can understand.

This mission is a very successful one but many people don’t know a tragedy that happened to this telescope in 1990, when ‘Spherical aberration’ a flaw in the main mirror occurred and it meant that the telescope couldn't focus properly. Where Hubble's images should have been razor-sharp, astronomers instead struggled to make out the fine details of their observations due to the blurred images. A servicing mission later fixed this flaw in 1993. According to reports, Hubble is expected to last up to 5 more years.

One of the greatest images this telescope took was the Hubble deep field, which is an image of a small region in the Ursa Major constellation.

Hubble deep field picture of some galaxies in the universe by NASA

All the colorful spots you see are individual galaxies and this makes you wonder just how big this universe is and how small we are. These galaxies may seem a lot but they are just the ones from a tiny spot we can see in the sky. You can even find more Hubble deep field images on NASA and ESA websites. Just to see how zoomed-in this image is, please watch this video uploaded by NASA:

https://www.youtube.com/watch?v=99uWHUQ-dC0

[1] Haris Ahmad is currently studying in 9^th grade (O levels) in The City School Islamabad.

Sunday, October 6, 2019

Voyager 1 and 2 - A Relentless Journey into the Dark

October 6, 2019

By: Haris Ahmad[1]

Voyager 1 and 2 were twin space probes launched by NASA. Voyager 2 was launched on 20 August 1977, while voyager 1 was launched on 5 September 1977. Both were launched from Launch Complex 41 at the Cape Canaveral Air Force Station. Both were launched from the Titan IIIE launch vehicle. The primary mission of the voyagers was to take close up studies of Jupiter, Saturn, their moons and Saturn’s rings. These probes were designed to take advantage of a rare planetary alignment of the outer planets. Due to this planetary alignment voyagers were able to complete their missions with ease and without any propulsion systems. These probes used a method called ‘gravity assist’ to slingshot themselves to other planets. Both Voyager probes have a golden record placed in them, which is a phonograph record containing sounds and images to show the diversity of cultures and life on Earth. These records were made so that if any extra-terrestrial life finds it; then they can know about the biodiversity and cultures of the Earth and the existence of humans.

Image of Voyager. (Source - www.britannica.com)

These probes took historic images of the outer planets. These images helped us see the outer planets much clearer. Not only did these probes study the planets but also took pictures of their moons and studied them. Among all the images these probes took, the image it took 4 billion km away from the Earth was a historic image, which was a part of the solar system portrait, which is shown below.

A small part of the solar system portrait taken by Voyager. (Image Source, https://voyager.jpl.nasa.gov/galleries/images-voyager-took/solar-system-portrait/#gallery-2)

Carl Sagan quoted about this image, in a very inspiring way, by saying, “Look again at that dot. That's here. That's home, that's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out his or her life. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero, and coward, every creator, and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor, and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam”.

These probes are still traveling in the universe. The Voyager 1 is traveling at the speed of 17 km/s while Voyager 2 is traveling at the speed of 15.4 km/s. If you’re thinking that when will these probes encounter another celestial body then the answer is that they are not going to encounter anything soon, at least not in our lifetimes. Although they are traveling very fast but are still not even near the speed of light, which is the fastest speed and can take us to other celestial bodies very quick. It is impossible to travel in the speed of light; at least for humans, it is impossible.

These probes have contributed a lot to help humans in the research about the outer bodies in our solar system. It removed all the misunderstandings about the outer planets of the solar system and made everything clear. My interest in space started because of the story of the Voyager probes and the quote of Carl Sagan on the pale blue dot.

As a student of Space Science, I am curious to continue learning about the unfolding secrets of this endless universe.