How does Hubble photograph and send it to Earth?
ScienceLovers - If you see a remarkable image of the universe, that possibility comes from the Hubble Space Telescope. Launched in 1990, Hubble is a telescope that orbits above Earth's atmosphere. How does Hubble photograph and send it to Earth?
The Hubble Space Telescope is a joint mission between the US Space Agency (NASA) and the European Space Agency (ESA) that has helped mankind, especially astronomers, solve some of the greatest mysteries of the universe.
Hubble Technology
Hubble orbits the Earth at speeds of about 8 kilometers per second. Such speed is needed so that Hubble can maintain its momentum and orbit the Earth without fuel. That way, Hubble can circle the Earth once every 97 minutes. In its orbit, Hubble equipped with a giant mirror can collect light from the objects of the universe.
We often see photos of Hubble shots spaced up to millions of light-years away, how can he photograph the distance so far as it only orbits the Earth? In fact, Hubble does not need to approach an object to be seen. In contrast, Hubble (like a telescope in general) collects light from objects of the universe far more than the human eye can do.
On a telescope, the bigger the mirror, the better in the light collection. The Hubble Space Telescope mirror has a diameter of 2.4 meters, smaller than the mirror diameter of most ground-based telescopes. However, because Hubble is placed in Earth orbit, the shots are much more amazing.
The Hubble telescope's primary mirror weighs 826 kilograms. This mirror is made of silica glass lined with a thin layer of pure aluminum to reflect light. In addition to the aluminum layer, the lens also has a magnesium fluoride coating that is useful to prevent oxidation and ultraviolet (UV) from the Sun so that the lens is not easily damaged.
For you who are a photographer, you may understand that your camera must be stable to take sharp images, especially when taking pictures of distant objects. The same concept applies to Hubble, the difference is Hubble does not have a tripod for balance.
However, Hubble Space Telescope technology can lock into a target or object to be observed without deviating more than 7/1000 arc seconds, around the width of a human hair visible from a distance of one kilometer away.
Power Source
As described above, Hubble does not require fuel to orbit because it is taking advantage of momentum. However, the sun's rays remain the main source of power for operating the Hubble instrument.
The space telescope is equipped with two solar panels of 7.6 meters each that can convert sunlight into electricity. But how when Hubble does not receive sunlight? Fortunately, Hubble can store that electrical energy in a special battery.
The Hubble Space Telescope instrument has been updated for many years. But the most powerful is the Wide Field Camera 3 (WFC3) instrument, which allows Hubble to get images with greater resolution than other devices. WFC3 can even study dark energy, dark matter and star formation.
The WFC3 instrument has two channels: one for ultraviolet light and visible waves, and another for infrared waves. Hubble photographed every object of the universe through these two different channels, allowing it to create many beautiful images.
You can see the difference in these two images which are the Carina Nebula. The first image is photographed in visible light:
Carina nebula in visible light. Credit: Hubble, NASA / ESA
This second image is from the same area in the Carina Nebula, but photographed using an infrared wave channel:
Carina nebula in infrared waves. Credit: Hubble, NASA / ESA
The Hubble Space Telescope has collected more than a million amazing images from the universe, and collected about 120 gigabytes of scientific data each week. But, how can we get all the data and scientific information collected by Hubble?
Hubble is operated by Goddard Space Flight Center in Maryland, USA with the use of a giant radio antenna that can download all data from Hubble. First of all, Hubble captures the image. Once received by the telescope, the image will be converted into digital code and radiated to Earth using an antenna that has the ability to transmit 1 million bits per second.
Once the digital code is received by the data receiving station on Earth, the code will be converted into images and spectrographs (an instrument used to record the astronomical spectrum).
While Hubble's very famous telescope worldwide is still very active, Hubble's mission is about to end. After Hubble retired, his successor is James Webb Space Telescope, which will be launched in 2018 to find the first galaxies formed in the early universe.
