Have you ever imagined yourself leaving the Earth, travelling into outer space, visiting other planets, and eventually leaving the solar system to view the universe in all its glory? Well, Voyagers did just that! Come, let’s take a journey into interstellar space with Voyager.
Voyager the Journey and Beyond
In the early 1970s, NASA had a stellar plan to study outer planets of the solar system and gain a deeper knowledge of them. They were wondering how to build a space probe that could hover through space. With the information gathered from the Pioneer 10 spacecraft, scientists at NASA’s Jet Propulsion Laboratory were able to design the probe such that it could take immense radiation from Jupiter with enhanced radiation shielding. On July 1st 1972, the project to launch Voyager 1 and Voyager 2 for the purpose of deep space exploration began.
Equipped with 16 hydrazine thrusters referencing instruments and gyroscopes, the two Voyagers had instruments to study objects in space and bring to light the best pictures of the cosmos through its cameras.
Take off… the beginning of an awesome journey
On September 5th 1977, Voyager 1 took off from NASA’s Kennedy Space Centre in Florida. Although Voyager 2 probe was launched a month before, Voyager 1 would be the first to reach Jupiter and Saturn due to its trajectory. Scientists at the Kennedy Space Centre and employees of NASA’s jet propulsion laboratory watched the rocket break through the stratosphere and reach outer space. Voyager 1 sent the first picture of the Earth and the Moon on September 6th 1977, a trickle of tear rolled down the eyes of scientists and engineers as they saw the image.
Flyby of planets in the solar system
Travelling at the speed of 17 kilometres per second, Voyager 1 reached Jupiter on March 5th 1979. It was a sight to behold; it captured images that helped scientists decipher the giant red spot and conclude that it is the eye of a huge storm. It also uncovered other strange phenomena that inflated Jupiter’s magnetic field due to ions stripping from the planet’s surface and creating a torus around it. This acts as an electric generator in Jupiter’s magnetic field.
Voyager encountered Saturn, the ringed planet, on November 9th 1980 and captured its rings in the most magnificent picture. It also flew by Titan, one of Saturn’s moons, and discovered the possibility of seas of liquid methane and ethane on its surface. Voyager 2, on the other hand, reached Saturn nearly a year later in August 1981 and made it to Uranus in January 1986. It made a phenomenal discovery of 11 new moons orbiting Uranus and took pictures of them.
In August 1987, NASA’s deep space network completed expanding the three big dishes that enabled engineers and scientists at the laboratory to better communicate with the two Voyagers. Voyager 2 made yet another startling discovery of six new moons when it encountered Neptune in August 1989. In the meantime, Voyager 1 was on its way towards the end of the solar system. You may ask, why didn’t the Voyagers encounter Pluto? That’s because the primary objective of the Voyager mission was focused on exploring Jupiter and Saturn for Voyager 1 and Uranus and Neptune for Voyager 2.
Are we just a speck? The Pale Blue Dot
On valentine’s day 1990, NASA’s engineers turned the camera of Voyager 1 towards Earth just before disabling the camera to conserve energy. The camera captured the image of a pale blue dot with its size hardly a fragment of a pixel. This image shook the whole of humankind as it was a clear depiction that the human race is just a speck of merely irrelevant species in this vast humongous universe that spans to a diameter of 93 billion lightyears (observable). (nine thousand three hundred crore lightyears).
First man-made object to enter interstellar space
On February 17th 1998, Voyager 1 became the farthest ever human-made object from the Earth, beating the Pioneer 10. The termination shock is a boundary that separates the solar wind and the Heleosheath; it is the outermost region of the solar system. At this point, the solar wind slows down and heats up abruptly. Scientists and engineers at NASA could not communicate with Voyager 1 as ground antennas were not scheduled to capture the data that the spacecraft was listening to. However, after a while, NASA’s experts were able to connect back to the Voyager as it entered the Heleosheath. They were able to measure the analyze the measurements and nature of the spacecraft only when Voyager 2 crossed the termination shock three years later.
The Heliosphere is the region outside the solar system that resembles a bubble that is inflated by plasma emitted by the Sun. This region ends at a point known as the Heliopause, which is exposed to the particles and ions of deep interstellar space. Picture this, you are visiting another country and are going through two different checkpoints, the security checkpoint and the immigration and customs checkpoint. This concept is somewhat similar and also applies to both Voyagers that left the solar system.
On August 25th 2012, the Voyager 1 becomes the first human-made object in the history of mankind to leave the solar system and enter interstellar space, followed by Voyager 2 on November 5th 2018. The Voyagers collect detect the intensity of the cosmic space and the interstellar magnetic field around the heliosheath and send data back for our scientists to rack their brains about. Scientists understand the nature of the coronal mass ejection thrown out by the Sun, causing the Voyagers to ring.
For the universe to see… The Golden Record
Where would the two Voyagers go? You may ask, well, their trajectory is not pointed to any nebula, specific star or a planet, but it travels aimlessly through interstellar space at the speed of 62,140 km/hour. Oh! You might think that is fast, but it is nothing compared to the speed of light, which is 300,000 kilometres per second. Since most starts in our neighbourhood are around 4-8 light-years away, it would take the Voyager a whopping 73,000 years to reach Proxima Centauri at its current speed of 17 km/second. That is if its trajectory is aimed towards Proxima Centauri.
The odds that one of the Voyagers would come in contact with intelligent life in this colossal universe is highly minuscule. Scientists at NASA, along with Carl Sagan, decided to add a Golden phonographic record for any intelligent life to decipher. This golden record contains a message from the human race that includes greetings in various languages, sounds, music, thoughts, and images of Earth and life. Jimmy Carter, the US president at that time, also shared a small message, “We are attempting to survive our time and may live into yours, having solved the problems we face, to join a community of galactic civilizations.”
Placing the Golden record on both the Voyagers was truly a remarkable idea. Experts at NASA have included some simple ways how the record can be played and accessed through pictorial representations. Also, the record is built in such a way that data could be extracted from it even after a billion years (100 crore years). The record also includes an hour-long brain wave of Carl Sagan’s wife.
A Tribute to Carl Sagan
Although he lived a relatively short life, Carl Sagan was one of the most influential and brilliant astrophysicists. He was also a cosmologist, astrobiologist, and science communicator. He has written several books that continue to influence students and young scientists to pursue their dreams in the field of Scientology. His inquisitiveness, scientific thinking, and advocacy has propelled several kinds of research and built a platform for young scientists to emulate.
Here is the link to the speech by Carl Sagan in Cornell lecture 1994 regarding the pale blue dot.
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