Everything about Hubble

What is the Hubble space telescope?

The Hubble is one of the largest and most important telescopes in space. It was launched into orbit by the Space Shuttle Discovery on 24 April 1990 which was 33 years ago! It is 13.2 meters long (43.5 feet) and weighs about 12,246 kg (27,000 pounds) and to put this into scale, it’s as heavy as two elephants. It travels around 27,300 kilometers (17,500 miles) per hour as it orbits Earth. Hubble is an important tool to explore and take pictures of cosmic objects such as galaxies and planets that aids in our understanding of our universe. It has made more than 1 million observations since 1990, including the death of stars called supernovae, finding galaxies many light years away from us and the beginning of our universe. The Hubble is able to see very far, up to 13.4 billion light years away. Its farthest observation was the galaxy named GN-z11 in 2014.

Vocabubbleary: A light year is a measurement of distance which is how far light travels in one year which is equivalent to about 9.46 trillion kilometers!

Image from: forbes 

History of the Hubble

The Hubble was named after the astronomer Edwin Powell Hubble in 1983. He made an important discovery that the universe has been expanding since the Big Bang theory through the observation that galaxies are moving further away from us. What is the Big Bang theory you may ask? The Big Bang is a widely accepted theory of how the universe came into existence where it was compacted closely into an infinitely small point with a lot of energy. In a fraction of a second, this dense point exploded with strong force and the energy and matter began expanding till this day. After the Hubble was launched in 1990, it sent its first true color image of Jupiter in March 1991 as seen below. True color images are those that have been rendered in the RGB (red, green, blue) color model which we will talk about in detail later! However, there was soon an issue noticed by NASA in Hubble’s primary mirror called spherical aberration. The mirror’s curvature was not built accurately and was off by 1/50th the width of a human hair. Although this doesn’t sound significant, this resulted in Hubble’s images being slightly more blurry than they were supposed to be.

Vocabbubbleary: Spherical aberration is an optical issue when the parallel light rays converge at different points after passing through a spherical surface like Hubble’s mirror. As seen in the diagram, the light passing through nearer to the edge and the middle converge at different points, resulting in different focus points and images of poorer resolution.

Image from: photographylife 

This problem was solved when astronauts were sent up to Hubble by the space shuttle Endeavour. They installed new instruments that amended the light rays that traveled through Hubble’s mirrors.

How does Hubble work?

Now you may be wondering, how does this telescope capture images of beautiful cosmic objects? Well, since the Earth’s atmosphere blocks light from space, Hubble orbits beyond that to make clearer observations than what telescopes down here can see! The next part is shocking. Hubble doesn’t take the pictures that we’ve seen in color- it’s all black and white images. Its detectors only record the light that passes through the camera instead of directly capturing the light. The Hubble uses its RGB filters (red, green and blue) to capture the range of these wavelengths in each of the 3 images. The way this is done can be seen below.

Image from: wikipedia

After that, colors are assigned to the pictures of different exposures by scientists and image processes. The coloured versions of the images are then put together to obtain the final ones that we often see. Coloring these images are important for different reasons such as to accurately depict images as how they would look to the human eye or to highlight important details. Here’s a simple breakdown of how the RGB filters work with the Crab Nebula!

Image from: hubblesite

Hubble’s filters also make it capable of recording astronomical objects in different wavelengths, even those that aren’t visible to the naked eye like ultraviolet and infrared light. This allows scientists to even see details of these objects that we wouldn’t be able to see normally.

Important discoveries made by Hubble

Hubble has made some really important discoveries over the past 30 years that have contributed to our understanding of the universe. With its help, it was discovered that most galaxies have massive black holes, which we will explore in a later post, that have such a strong gravitational force that nothing can escape its boundary called the event horizon. Hubble was also useful to discover that dark energy exists and plays a huge role in the expansion of the universe which is causing galaxies to move away from each other. In 2006, it also found a planet called Xena beyond Pluto which caused scientists to reconsider Pluto as a dwarf planet. Here's an image of Xena!

Image from: NASA

Future of Hubble; Introduction of the James Webb Space Telescope

Some of you may have heard of the new James Webb Space Telescope and may be wondering if it’ll replace Hubble. Let’s first start with an introduction to the telescope. The Webb is NASA's observatory that uses infrared light to see the universe and was launched on 25 December 2021 which was not too long ago! 

Vocabubbleary: Infrared light is light with wavelengths longer than the red end of visible light and shorter than microwaves. As you can see in the electromagnetic spectrum, visible light to our eye is between infrared and ultraviolet radiation.

Image from: nasa.gov

It is 22 meters long (69.5 ft) which is almost double of Hubble and weighs approximately 6,500kg (14,300 lbs). Furthermore, instead of orbiting the Earth like Hubble, this telescope will orbit the Sun around 1.5 million kilometers away from the planet. This distance is also called the second Langrange point (or L2) which is also around 4x further than the distance between the Earth and the moon. Being at L2 is beneficial since it helps Webb make clearer observations of the larger universe.

Vocabubbleary: A lagrange is a position in space where gravitational forces balance when there are two massive bodies orbiting each other such as a planet and a star. Objects at such points remain in position and spacecraft are often placed there to move in orbit without consuming fuel.

Now, the real question is whether soon Hubble will be replaced by the James Webb telescope. NASA addressed this and clearly denied this! You see, both of these telescopes have different abilities and the main objective here is for them to work at the same time and make collaborative observations. Since Webb can see deeper into the universe with infrared light, it can add on to Hubble’s discoveries and give us more detail!

☕ Hubble Tea of the post! ☕

As mentioned in our first post, we will have a new recent observation made by Hubble in every post to keep you updated with the latest tea! This time, we will be talking about how it has provided us with a new view of the Tarantula Nebula! You may be wondering, what is it? Well, the Tarantula Nebula, also called 30 Doradus, is a huge H II region made of ionized hydrogen gas and it lies 161 000 light years away from Earth. A H II region is essentially a cloud of glowing plasma made from ionized hydrogen and electrons where star formation takes place. Here’s an image so look at just how beautiful this is!

Image from: nasa.gov

That wraps up everything about the Hubble you should know of as you hop on Hubble Tea’s adventure of exploring space! Please leave us a follow to never miss out on our articles and support us! As always, enjoy learning about our beautiful universe while sipping space tea! 🔭✨

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